水中PFAS吸附去除技術(shù)研究進(jìn)展
2024-01-06 01:38:34包一翔鐘金魁李井峰曹志國(guó)
中國(guó)環(huán)境科學(xué) 2023年12期
王 菟,包一翔,鐘金魁,李井峰,曹志國(guó),吳 敏
水中PFAS吸附去除技術(shù)研究進(jìn)展
王 菟1,2,包一翔2*,鐘金魁1,李井峰2,曹志國(guó)2,吳 敏2
(1.蘭州交通大學(xué)環(huán)境與市政工程學(xué)院,甘肅 蘭州 730070；2.北京低碳清潔能源研究院,煤炭開(kāi)采水資源保護(hù)與利用全國(guó)重點(diǎn)實(shí)驗(yàn)室,北京 102209)
總結(jié)了不同吸附劑(活性炭,樹(shù)脂,礦物材料,分子印跡聚合物,生物基材料等)對(duì)PFAS吸附性能,機(jī)理,影響因素,優(yōu)勢(shì)及潛在問(wèn)題.孔徑與PFAS分子尺寸相近,表面帶相反電荷的吸附劑對(duì)PFAS具有更高的吸附性能.低pH值和高溫度的水質(zhì)條件對(duì)PFAS吸附更有利,共存有機(jī)物會(huì)與PFAS發(fā)生競(jìng)爭(zhēng)吸附.吸附劑對(duì)PFAS的吸附性能與其鏈長(zhǎng)呈正相關(guān),在相同鏈長(zhǎng)的情況下,吸附劑對(duì)磺酸類PFAS的吸附容量普遍高于羧酸類PFAS.主要的吸附機(jī)理包括靜電吸引,疏水相互作用,離子交換,配體交換等.吸附劑的合理再生和處置是實(shí)際工程應(yīng)用中重要挑戰(zhàn),如化學(xué)再生法和生物再生法再生效果差,熱再生法能耗高,溶劑再生,填埋處置易造成二次污染等.通過(guò)對(duì)水中PFAS吸附去除材料及技術(shù)的研究進(jìn)展進(jìn)行綜述,系統(tǒng)闡述了不同技術(shù)的優(yōu)劣勢(shì),并展望了吸附去除技術(shù)的發(fā)展方向,可為水中PFAS污染控制提供參考.
PFAS；吸附；機(jī)理；工程應(yīng)用；再生；新污染物
全氟或多氟烷基化合物(PFAS)是指有機(jī)化合物分子中與碳連接的氫原子全部或部分被氟原子取代而生成的化合物[1-2].PFAS結(jié)構(gòu)中含有親水性官能團(tuán)(如磺酸基團(tuán)和羧基)和疏水疏油性C-F鏈[2-4],PFAS具有良好的化學(xué)穩(wěn)定性,因此被廣泛應(yīng)用于消防,鍍鉻,農(nóng)藥,醫(yī)藥,服裝,食品等領(lǐng)域[2-3,5-8].目前所發(fā)現(xiàn)的PFAS種類有9000多種[9],一些典型PFAS的相關(guān)物理和化學(xué)性質(zhì)見(jiàn)表1.全氟辛酸(PFOA)和全氟辛烷磺酸(PFOS)是使用歷史最長(zhǎng),檢出頻率最高的兩類PFAS,在人體內(nèi)的半衰期長(zhǎng)達(dá)2.3～5.4a[2,10].PFAS對(duì)生物體的毒性包括生殖毒性,肝臟毒性,心臟毒性,免疫毒性和神經(jīng)毒性等[11-14].考慮到PFAS對(duì)生態(tài)環(huán)境和人體健康的危害,PFAS的全球監(jiān)管力度正在逐年加強(qiáng).PFOS及其鹽類和全氟辛基磺酰氟(PFOSF),PFOA及其鹽類和相關(guān)化合物,全氟己基磺酸(PFHxS)及其鹽類和相關(guān)化合物分別于2009,2019和2022年被納入《關(guān)于持久性有機(jī)污染物斯德哥爾摩公約》進(jìn)行管控[2,6].2022年,美國(guó)環(huán)境保護(hù)署發(fā)布了飲用水中PFOA,PFOS,全氟(2-甲基-3-氧雜己酸)銨(GenX),全氟丁烷磺酸(PFBS)4種PFAS的健康建議值,分別為0.004,0.02,10和2000ng/L.我國(guó)也將PFOA和PFOS加入《生活飲用水衛(wèi)生標(biāo)準(zhǔn)》(GB 5749-2022)[15],PFOS和PFOA的限值分別為40和80ng/L.但由于短期內(nèi)缺乏合適的替代品,部分PFAS仍被允許使用.在我國(guó)公布的《重點(diǎn)管控新污染物清單》(2023年版)中, PFOS和PFOSF被允許用于生產(chǎn)滅火泡沫藥劑,PFOA被允許用于半導(dǎo)體光刻和蝕刻,膠卷涂料,高壓電線電纜等領(lǐng)域.水環(huán)境是PFAS的主要環(huán)境歸宿,如何控制和去除水體中PFAS已經(jīng)成為全球研究熱點(diǎn),亟需經(jīng)濟(jì)可行的PFAS處理技術(shù).
現(xiàn)有的PFAS處理技術(shù)有微生物法,吸附法,電化學(xué)法,熱化學(xué),光化學(xué)法,膜技術(shù)等[16-17].其中生物氧化或生物降解對(duì)PFAS幾乎沒(méi)有降解效果[18],電化學(xué)降解PFAS可用的電極材料較少且制備成本較高[17].由于PFAS氟代結(jié)構(gòu),其更易接受電子,且碳氟鍵鍵能較高,臭氧和羥基自由基很難徹底氧化PFAS而形成短鏈PFAS產(chǎn)物[19].超聲,微波(熱化學(xué)),光化學(xué)等降解技術(shù)獲得了一定的研究進(jìn)展,但這些技術(shù)存在能耗高,操作復(fù)雜,反應(yīng)條件苛刻,易產(chǎn)生二次污染等弊端,不利于大規(guī)模去除水體中PFAS[17,20-21].
吸附是一種成熟的污染物去除技術(shù)[22-24],由于其操作簡(jiǎn)單,成本低,效率高,被廣泛應(yīng)用于水中PFAS的去除[17,25].常見(jiàn)的PFAS吸附劑有活性炭,樹(shù)脂,沸石,碳納米管,針鐵礦,殼聚糖和生物炭等[26-27].本文系統(tǒng)歸納了不同吸附劑對(duì)PFAS的吸附性能,吸附機(jī)理和優(yōu)缺點(diǎn)等.討論了影響PFAS吸附去除的關(guān)鍵因素以及吸附劑的再生,處置方法,展望了PFAS吸附去除所面臨的挑戰(zhàn)和未來(lái)重要的研究方向,可為水中PFAS污染控制提供理論參考.
表1 典型PFAS的物化性質(zhì)[10]
注: Logow為正辛醇/水分配系數(shù)對(duì)數(shù)值,pa為解離常數(shù).
1 吸附技術(shù)及優(yōu)缺點(diǎn)
1.1 活性炭吸附
活性炭是水處理中最常用的吸附劑之一,因其比表面積大,孔隙結(jié)構(gòu)發(fā)達(dá),成本低,吸附效果好,制備簡(jiǎn)單,材料來(lái)源廣泛而被應(yīng)用于多種污染物的去除[28],通過(guò)適當(dāng)?shù)母男钥梢赃M(jìn)一步提高對(duì)PFAS的吸附性能,但活性炭也存在再生性能較差的缺點(diǎn)[29].
1.1.1 未改性活性炭 活性炭對(duì)PFAS具有較高的吸附容量,不同粒度,制備原料的活性炭對(duì)PFAS的吸附性能有差異.Du等[30]研究了竹源活性炭(BAC)對(duì)實(shí)際廢水中PFAS(0.10mmol/L全氟己酸(PFHxA), 0.11mmol/L全氟庚酸(PFHpA),0.29mmol/LPFOA)的去除,BAC投加量為1.9g/L,pH=4,吸附平衡時(shí)間為48h,PFHxA,PFHpA,PFOA的飽和吸附量分別為15.2, 20.23,61.04mg/g.Ochoa-Herrera等[31]研究了煤質(zhì)顆粒活性炭(GAC)吸附去除水中PFAS(PFOS, PFOA, PFBS)的效果,PFOS,PFOA和PFBS的飽和吸附量分別為182,57和48mg/g.顯然不同原料制備的活性炭對(duì)PFAS的吸附性能具有差異性,可能是由于活性炭性質(zhì)和結(jié)構(gòu)的不同所導(dǎo)致.Yu等[32]對(duì)比了粉末活性炭(PAC)和GAC對(duì)PFOA與PFOS的吸附性能,發(fā)現(xiàn)PAC對(duì)PFOA和PFOS的飽和吸附量分別為277.3,518.96mg/g,吸附平衡時(shí)間在4h左右,GAC對(duì)PFOA和PFOS的飽和吸附量分別為161.46, 184.63mg/g,吸附平衡時(shí)間為168h,由于小粒徑的PAC比GAC具有更大的比表面積,可以提供更多的吸附點(diǎn)位[33],因此對(duì)PFAS的吸附性能更高.
PFAS結(jié)構(gòu)對(duì)吸附去除效果影響較大.Rostvall等[34]評(píng)估了GAC對(duì)不同PFAS的吸附性能,去除率隨PFAS碳氟鏈長(zhǎng)度的增加而增加且全氟磺酸的去除效率要高于相同鏈長(zhǎng)的全氟羧酸.Westreich等[35]研究了GAC去除地下水中一系列長(zhǎng)鏈和短鏈PFAS(全氟丁酸(PFBA),PFHxA,PFBS,PFOA,PFHxS, PFOS)的效果,長(zhǎng)鏈和短鏈PFAS都能被GAC吸附,吸附能力順序?yàn)镻FBA 1.1.2 改性活性炭 傳統(tǒng)活性炭對(duì)部分PFAS不能有效去除[37],因此通過(guò)改性活性炭以提高對(duì)PFAS的去除效果和選擇性具有重要意義[38].目前已廣泛應(yīng)用化學(xué)和物理改性工藝來(lái)改變活性炭的表面特征[39],如熱處理,微波,超聲化學(xué)改性氧化還原改性,酸堿改性,負(fù)載改性,等離子體改性和電化學(xué)改性等[40]. 負(fù)載金屬改性是較為常用的活性炭改性方法,具有操作簡(jiǎn)單,成本較低等優(yōu)點(diǎn)[40].童錫臻等[38]分別用FeCl3及中功率微波對(duì)椰殼活性炭進(jìn)行改性.改性椰殼活性炭與原炭吸附PFOS達(dá)到吸附平衡的時(shí)間基本相同,均為6h左右.椰殼活性炭經(jīng)FeCl3及中功率微波改性后對(duì)PFOS的吸附量明顯提高,原因是椰殼活性炭經(jīng)微波及FeCl3改性后,BET,中孔比表面積及總孔容,平均孔徑顯著增大,且酸性含氧官能團(tuán)減少,堿性含氧官能團(tuán)增加,有利于PFAS的吸附. 惰性氣體,氫氣或氨氣中高溫處理活性炭是一類有效的改性方法[41-43].Saeidi等[44]在900℃的H2中進(jìn)行熱處理以及用乙二胺改性活性炭,得到氨基官能化活性炭和脫官能化活性炭?jī)煞N改性活性炭,對(duì)PFOA,PFOS和PFBA進(jìn)行吸附實(shí)驗(yàn).三種吸附劑的吸附能力順序?yàn)槊摴倌芑钚蕴?氨基官能化活性炭>未改性活性炭,未改性活性炭的等電點(diǎn)為5.9,氨基官能化活性炭為7.3,脫官能化活性炭為9.3.脫官能化活性炭具有足夠密度的正電荷來(lái)吸附PFAS,其吸附容量提高了40倍.而氨基官能化活性炭表面正電荷的增加并未等效轉(zhuǎn)化為PFAS吸附量的增加,只提升了2倍.這是因?yàn)榘被倌芑钚蕴勘砻娴呢?fù)電荷密度依舊較高,對(duì)PFAS具有一定的靜電排斥作用. 浸漬法改性是使一些化合物或金屬顆粒分布在活性炭的孔結(jié)構(gòu)中的改性方法[40],苑晨等[45]以椰殼活性炭和木質(zhì)活性炭?jī)煞N炭材料作為改性活性炭的母體,3-氯-2-羥基丙基三甲氯化銨(QUAB188)和3-氯-2-羥基丙基烷基二甲基氯化銨(QUAB360)兩種季銨鹽化合物(QAE)為改性劑制備季銨鹽改性活性炭(QAE-AC),通過(guò)快速小型柱實(shí)驗(yàn)考察QAE- AC對(duì)PFOA的吸附性能.1.5g木質(zhì)活性炭經(jīng)過(guò)4mol/L HNO3浸泡后,投加15.8g QUAB188,在溫度50℃,溶液pH值為12.5的條件下,反應(yīng)48h,得到的QAE-AC對(duì)PFOA的吸附效果可達(dá)到未改性活性炭的4倍.PFOA主要通過(guò)靜電和疏水作用吸附在活性炭較小的介孔中,當(dāng)QAE的分子數(shù)量增加,分子間會(huì)形成一個(gè)網(wǎng)狀結(jié)構(gòu),該結(jié)構(gòu)與活性炭形成一個(gè)帶正電荷的特殊空間,增強(qiáng)對(duì)PFOA的吸附能力. 1.1.3 吸附機(jī)理 活性炭吸附PFAS的作用機(jī)理包括靜電作用,疏水作用,配體交換,氫鍵,范德華力等[28],其中靜電作用和疏水作用占主導(dǎo)地位.疏水作用是PFAS向非極性疏水表面運(yùn)動(dòng)而排斥水分子的現(xiàn)象[10].活性炭的疏水性越強(qiáng),對(duì)PFAS的吸附效果越好. 靜電作用包括靜電引力和靜電斥力,PFAS在水溶液中通常以陰離子形式存在,活性炭表面帶正電可通過(guò)靜電引力吸附水中PFAS.因此,活性炭表面所帶正電荷的數(shù)量是決定PFAS吸附容量的關(guān)鍵因素之一.pH值是影響活性炭表面電荷的主要因素,當(dāng)水體pH值低于活性炭等電點(diǎn),活性炭表面發(fā)生質(zhì)子化作用帶正電,有利于PFAS吸附,pH值高于等電點(diǎn)則由于去質(zhì)子化作用而帶負(fù)電,發(fā)生靜電排斥作用,不利于PFAS去除.此外,PFAS的離子端基團(tuán)可通過(guò)交換反應(yīng)吸附到活性炭上,如金屬改性活性炭和季銨鹽改性活性炭[38,45]. 活性炭的孔徑,比表面積和粒度等物理性質(zhì)會(huì)影響其吸附性能.當(dāng)活性炭孔徑與PFAS的尺寸相似時(shí),吸附是有利的[46].Cantoni等[46]研究了8種PFAS(PFOA, PFOS, PFBA, PFBS,全氟戊酸(PFPeA), PFHxA, PFHpA)在4種活性炭(原始椰子基活性炭,再活化椰子基活性炭,原始瀝青活性炭,再活化瀝青活性炭)上的吸附行為,靜電作用是主要吸附機(jī)制,在帶正電荷活性炭中,孔徑分布和微孔表面積對(duì)PFAS吸附的影響大于PFAS的疏水性,活性炭中存在大量的中孔(2～50nm)對(duì)強(qiáng)疏水性PFAS吸附更有利[46],因?yàn)橹锌字腥芙庑杂袡C(jī)物(DOM)的孔堵塞較少. Park等[47]研究了4種煙煤基活性炭對(duì)9種PFAS (PFOA, PFOS,PFBA,PFBS,全氟癸酸(PFDA), PFPeA, PFHxA,全氟十二酸(PFDoDA),PFHpA)的吸附效果,介孔碳(2～50nm)對(duì)長(zhǎng)鏈PFAS的吸附效果比微孔碳(<2nm)好,因?yàn)槲⒖讜?huì)被長(zhǎng)鏈PFAS形成的膠束或半膠束堵塞,微孔占比較高的活性炭對(duì)短鏈PFAS具有更高的吸附容量[47-48]. 增加活性炭的比表面積以及表面所帶正電荷的數(shù)量和改變孔隙結(jié)構(gòu)分布是提高PFAS吸附容量的有效方式.活性炭孔隙結(jié)構(gòu)的改變方法有活化過(guò)程控制法,熱處理法,化學(xué)氣相沉積法和添加劑法等[49-50],通過(guò)調(diào)節(jié)活性炭孔隙結(jié)構(gòu),與PFAS分子尺寸相匹配,從而提高活性炭吸附性能.改變表面電荷種類及數(shù)量的方式有金屬負(fù)載和堿處理等[40],如季銨鹽改性活性炭,季銨鹽通過(guò)與活性炭表面的羥基反應(yīng)負(fù)載在活性炭的邊緣位點(diǎn),增加了活性炭表面的正電荷,PFAS與形成含氧官能團(tuán)的季銨鹽結(jié)合而被吸附[45].一些通過(guò)金屬改性的活性炭,金屬首先被吸附在活性炭表面的負(fù)電荷位點(diǎn),然后通過(guò)金屬與PFAS之間的絡(luò)合力吸附PFAS[51],從而提高PFAS吸附量. 活性炭的經(jīng)濟(jì)可行性和較高的吸附性能使其成為去除PFAS的首選吸附劑之一,但吸附PFAS后的活性炭可再生性差.一些研究對(duì)吸附PFOS,PFOA后的PAC和GAC使用甲醇,乙醇進(jìn)行再生,PAC和GAC的再生率分別為75.4%和40%[52-53].而醇溶液對(duì)活性炭進(jìn)行再生可能會(huì)產(chǎn)生二次污染等問(wèn)題[29],不能應(yīng)用于飲用水處理中吸附劑的再生.此外,活性炭的可重復(fù)使用性較差,經(jīng)過(guò)幾次再生后,吸附劑的吸附能力會(huì)下降[7],對(duì)于活性炭的后續(xù)處理是值得研究和關(guān)注的問(wèn)題. 樹(shù)脂包括離子交換樹(shù)脂和非離子交換樹(shù)脂,具有吸附效果好,化學(xué)穩(wěn)定性好,交換能力強(qiáng),可再生能力強(qiáng),操作簡(jiǎn)便等優(yōu)點(diǎn)[28],就吸附性能和原位再生能力而言,陰離子交換樹(shù)脂被認(rèn)為是去除PFAS最有效的吸附劑[54]. 1.2.1 未改性樹(shù)脂 離子交換樹(shù)脂由樹(shù)脂基體骨架和骨架上的活性離子基團(tuán)構(gòu)成[28],陰離子交換樹(shù)脂表面具有永久正電荷交換位點(diǎn),因此對(duì)PFAS吸附性能較高[33].非離子交換樹(shù)脂主要通過(guò)疏水相互作用和范德華力吸附PFAS,相較于陰離子交換樹(shù)脂,它們更容易再生[55],但吸附性能遠(yuǎn)低于陰離子交換樹(shù)脂,因此陰離子交換樹(shù)脂在實(shí)際應(yīng)用中更廣泛[2].與其他吸附劑相比,陰離子交換樹(shù)脂對(duì)PFAS有更高的吸附性能[56](表2),Carter等[56]發(fā)現(xiàn)樹(shù)脂對(duì)PFOS的吸附平衡時(shí)間(10h)遠(yuǎn)小于傳統(tǒng)GAC(50h),且4h后PFOS飽和吸附量達(dá)到17.46mg/g,而GAC需要15h才能達(dá)到17.46mg/g. 離子交換樹(shù)脂上交換位點(diǎn)的可用性是影響PFAS吸附的關(guān)鍵因素[7].用于去除水中PFAS的陰離子交換樹(shù)脂分為兩類,分別是強(qiáng)堿和弱堿型陰離子交換樹(shù)脂[3].具有季銨官能團(tuán)的被稱為強(qiáng)堿型陰離子交換樹(shù)脂,根據(jù)化學(xué)結(jié)構(gòu)分為I型(三甲基銨基)和II型(二甲基乙醇銨基)[3],強(qiáng)堿型陰離子交換樹(shù)脂具有優(yōu)異的物理和化學(xué)穩(wěn)定性,能夠在較寬的pH值范圍內(nèi)交換不同的陰離子.弱堿型陰離子交換樹(shù)脂以伯胺,仲胺,叔胺或混合胺作為官能團(tuán),具有優(yōu)異的再生能力[3].不同樹(shù)脂去除PFAS的能力具有差異[57]. Zaggia等[36]考察了A532E(三甲基季胺聚合物,高疏水性),A520E(三乙基季胺聚合物,一般疏水性)和A600E(雙功能季胺聚合物,非疏水性)三種陰離子交換樹(shù)脂對(duì)飲用水中PFOS與PFOA的吸附性能, A532E對(duì)PFOS和PFOA的飽和吸附量分別為142.1和260.5mg/g, A520E為134.7和210.4mg/g, A600E為125.2和186.2mg/g.樹(shù)脂的官能團(tuán)及基體的疏水性在PFAS去除方面起主導(dǎo)作用[33],A532E的疏水性最強(qiáng),因此對(duì)PFAS的吸附性能越高. 樹(shù)脂對(duì)不同PFAS的吸附性能也有差異,Gao等[6]研究了F-53B和PFOS在弱堿型陰離子交換樹(shù)脂IRA67上的吸附,F-53B和PFOS在IRA67上的吸附容量分別為2396.81和2744.5mg/g.Du等[30]也對(duì)陰離子交換樹(shù)脂IRA67去除PFAS(PFOA,PFHxA, PFHpA)做了研究,去除效果為PFOA>PFHpA> PFHxA.這是由于PFAS結(jié)構(gòu)的不同(官能團(tuán),鏈長(zhǎng)等)所導(dǎo)致,全氟化碳鏈越短,疏水性越弱,吸附容量越低. 注:0為污染物初始濃度,平衡為吸附平衡時(shí)間,m為吸附劑飽和吸附量. 1.2.2 改性樹(shù)脂 傳統(tǒng)樹(shù)脂存在機(jī)械強(qiáng)度低,選擇性差等缺點(diǎn)[58],一些共存有機(jī)物和不同PFAS在樹(shù)脂上會(huì)產(chǎn)生競(jìng)爭(zhēng)吸附,為改善其吸附性能和吸附選擇性,需要對(duì)其進(jìn)行改性.常用的改性方法有氫鍵改性,接枝改性,磁改性,氟化改性等[58-59]. 氫鍵改性是先將樹(shù)脂氯甲基化,然后引入極性基團(tuán)從而制得氫鍵型樹(shù)脂,通過(guò)極性基團(tuán)與吸附質(zhì)之間形成氫鍵實(shí)現(xiàn)樹(shù)脂吸附量增加的方法[58].常用的極性基團(tuán)有酚羥基,胺基,羧基,酰胺基等[60].接枝改性是使一定的單體聚合,在主干聚合物上將分支聚合物通過(guò)化學(xué)鍵結(jié)合上一種分枝的反應(yīng)[61],常采用的接枝方法有鏈轉(zhuǎn)移接枝,化學(xué)接枝和輻射接枝等[58].磁性樹(shù)脂是指將磁性粒子嵌入到樹(shù)脂中,使其能夠沉淀分離,具有吸附效率快,易分離,操作簡(jiǎn)單等優(yōu)點(diǎn)[62].Park等[63]研究了磁性離子交換樹(shù)脂(MIEX)對(duì)地下水中的6種羧基和3種磺酸基PFAS(PFBA, PFPeA,PFHxA,PFHpA,PFOA,PFDA,PFOS,PFBS,PFOS支鏈異構(gòu)體)的吸附性能.MIEX投加量為15g/L,9種PFAS的飽和吸附量均高于16ng/g,靜電作用是主要吸附機(jī)制,MIEX易于與水分離,通過(guò)10%NaCl溶液再生30min后,幾乎完全恢復(fù)了MIEX的PFAS吸附量.含氟聚合物具有高耐化學(xué)性,耐氧化性和耐熱性等優(yōu)點(diǎn)[64],Dinesh等[65]開(kāi)發(fā)了兩種含氟杯芳烴基多孔聚合物(FCX 4-P和FCX 4-BP),研究了對(duì)水中PFOA的吸附性能.FCX 4-P具有較快的吸附速率(3.80g/mg?h)和較高的飽和吸附量(188.7mg/g).含氟結(jié)構(gòu)的引入增強(qiáng)了吸附劑與PFOA之間的疏水相互作用,提高了PFOA的吸附速率和吸附容量.此外,該材料再生效果較好,PFOA可以通過(guò)甲醇洗滌而解吸且吸附劑沒(méi)有顯著性能損失. 為了提高樹(shù)脂對(duì)PFAS的選擇性,一些PFAS專用樹(shù)脂開(kāi)始生產(chǎn),如A592E(大孔樹(shù)脂)和PFA694E(凝膠樹(shù)脂)[66]可有效地靶向陰離子PFAS,包括一些短鏈PFAS[67-68].但這些PFAS專用樹(shù)脂制備成本較高且再生效果較差,如何降低經(jīng)濟(jì)成本,以及安全有效再生樹(shù)脂和處理再生液是值得關(guān)注的問(wèn)題. 1.2.3 吸附機(jī)理 離子交換是樹(shù)脂吸附PFAS的主要機(jī)理[2],此外還包括靜電作用,疏水作用,團(tuán)聚和膠束等[33](圖1). 在陰離子PFAS和帶正電的樹(shù)脂之間可以形成靜電吸引作用[61].PFAS的離子端可通過(guò)離子交換吸附在陰離子交換樹(shù)脂上.離子交換點(diǎn)位由樹(shù)脂上的正電基團(tuán)提供,如強(qiáng)堿性基團(tuán)季胺基(-NR3OH,R為碳?xì)浠鶊F(tuán))和弱堿性基團(tuán)伯胺基(-NH2),均可在水中解離出OH-,正電基團(tuán)與PFAS吸附結(jié)合,從而發(fā)生離子交換作用. 圖1 離子交換樹(shù)脂吸附PFAS機(jī)理[69] Senevirathna等[53]研究了低濃度PFOS(100～ 1000ng/L)在離子及非離子交換聚合物,GAC上的吸附效果,GAC可在4h達(dá)到吸附平衡,遠(yuǎn)遠(yuǎn)快于非離子交換聚合物,但GAC對(duì)于PFOS的吸附量卻遠(yuǎn)低于聚合物吸附劑,原因是離子交換聚合物與PFOS之間通過(guò)離子交換形成的化學(xué)鍵要強(qiáng)于GAC與PFOS之間的靜電吸引作用. 在離子濃度較高的情況下,疏水作用在PFAS吸附中占主導(dǎo)地位[70], PFAS可以克服靜電斥力通過(guò)疏水作用吸附到帶負(fù)電的吸附劑表面[71-73].膠束和半膠束的形成也會(huì)影響PFAS的吸附,PFAS濃度達(dá)到一定程度時(shí)可在溶液中形成半膠束,當(dāng)PFAS聚集到吸附劑表面時(shí),較擁擠的空間使得表面比溶液中PFAS的濃度更高從而形成膠束[2,32,74].Du等[2]提到膠束和半膠束的形成可增強(qiáng)PFAS在帶正電表面上的吸附,但是可能會(huì)阻礙PFAS擴(kuò)散到吸附劑的微孔中,導(dǎo)致吸附容量降低.此外,樹(shù)脂表面的官能團(tuán)可以與PFAS的離子端基團(tuán)形成內(nèi)球絡(luò)合物,進(jìn)而去除PFAS[69].PFAS也可通過(guò)官能團(tuán)中所含的氧原子與樹(shù)脂官能團(tuán)中的氫原子鍵合形成氫鍵被去除[69]. 礦物材料如活性氧化鋁,二氧化硅,沸石和蒙脫石等[2]也被用于去除PFAS,它們具有高表面積,可調(diào)的中孔,可變的層狀結(jié)構(gòu),高吸附能力和較好的可重復(fù)使用性[75].但也存在穩(wěn)定性和選擇性較差等缺點(diǎn)[76]. 1.3.1 未改性礦物材料 用于去除PFAS的礦物材料分為層狀黏土礦物(高嶺石,蒙脫石等)和非結(jié)晶黏土礦物(針鐵礦,磁鐵礦,赤鐵礦等)[76].不同礦物材料對(duì)PFAS的吸附性能具有差異.Ochoa-Herrera等[31]研究并比較了三種具有不同Si/Al比的八面沸石,即13X沸石(Si/Al=2.8),NaY(Si/Al=5.5)和NaY80(Si/ Al=80)對(duì)于PFOS的吸附性能.Si/Al比較高的NaY80型沸石對(duì)PFOS具有更強(qiáng)的吸附作用,原因是疏水作用在沸石吸附PFOS過(guò)程中占主導(dǎo)地位,而二氧化硅含量是決定沸石疏水性的關(guān)鍵參數(shù)[31],因此高硅沸石NaY80對(duì)PFOS的吸附能力最高.Johnson等[77]研究了高嶺石,渥太華砂,合成的針鐵礦,高鐵沙對(duì)PFOS的吸附性能.材料中的硅,鋁和氧化鐵對(duì)PFAS吸附的貢獻(xiàn)較少.各材料對(duì)PFOS的吸附能力如下:針鐵礦<高嶺石<高鐵沙<渥太華砂.當(dāng)pH值升高,PFAS飽和吸附量隨著高鐵沙表面負(fù)電荷的增加而增加,而隨著針鐵礦和高嶺石表面負(fù)電荷的增加而下降.靜電作用的主導(dǎo)地位在不同材料上PFAS的吸附中是相反的.此現(xiàn)象的解釋需要研究其他機(jī)制.一項(xiàng)研究[78]中公布了PFOS在污水處理廠污泥中的固液分配系數(shù)(Kd),該值(120)比Johnson等[77]研究材料的固液分配系數(shù)值(2.81～35.3)大一個(gè)數(shù)量級(jí).PFOS更傾向于吸附在有機(jī)碳含量較高(53%)的污泥上.Jeon等[79]也發(fā)現(xiàn)了此現(xiàn)象,PFAS的飽和吸附量隨黏土礦物表面有機(jī)碳含量的增加而增加,原因是當(dāng)有機(jī)碳濃度較高時(shí),疏水作用是PFAS吸附的主要驅(qū)動(dòng)力.而當(dāng)有機(jī)碳不存在時(shí),靜電吸引可能占主導(dǎo)地位. 氧化黏土礦物如金屬氧化物(Al,Fe,Si氧化物)和勃姆石也被用于去除水中PFAS.Tang等[27]研究了不同溶液組分下PFOS在針鐵礦和SiO2上的吸附行為,PFOS在針鐵礦上的吸附量隨H+和Ca2+增加而增加,原因是PFAS與帶正電針鐵礦表面之間的靜電引力增強(qiáng),且與針鐵礦表面離子形成配體絡(luò)合物.而PFOS在SiO2上的吸附幾乎不受溶液pH值和Ca2+離子強(qiáng)度的影響,原因是該吸附過(guò)程中一些非靜電作用力占主導(dǎo)地位.Gao等[80]研究了納米級(jí)赤鐵礦(Fe2O3)對(duì)PFOS和PFOA的吸附,在低pH值下(pH=3),Fe2O3對(duì)PFOS和PFOA具有較好的去除效果,除靜電相互作用外,PFOA通過(guò)配體交換形成了內(nèi)層羧酸鐵絡(luò)合物,而PFOS與礦物表面形成氫鍵,最后形成了外層絡(luò)合物.勃姆石以水合氧化鋁的形式存在于土壤中,由于其比表面積高,具有可變的表面電荷,也被用于PFAS去除.靜電作用是其去除PFAS的主要機(jī)制,因此去除效果較為依賴pH值[81]. 1.3.2 改性礦物材料 天然礦物材料穩(wěn)定性和選擇性較差,為了提高其選擇性,穩(wěn)定性,吸附效果和表面功能性[76,81-83],需通過(guò)物理化學(xué)手段對(duì)礦物吸附劑進(jìn)行改性,礦物材料常用的改性方法有酸堿活化,熱處理,多羥基陽(yáng)離子柱化,聚合物和表面活性劑改性等[76]. 通過(guò)物理吸附,化學(xué)接枝,離子交換等方式向礦物材料的層間空間添加聚合物可以改善礦物材料的吸附性能[76].常用的聚合物有聚氯乙烯,聚酯,環(huán)氧樹(shù)脂,聚氨酯,聚丙烯,殼聚糖和聚苯乙烯[84].Bhattarai等[85]使用二氧化硅與β-環(huán)糊精聚合物交聯(lián),通過(guò)氫鍵的形成增強(qiáng)對(duì)PFAS的吸附能力,PFOA去除隨著β-環(huán)糊精聚合物負(fù)載量的增加而增加,飽和吸附量為33.3μg/g.此外,一些表面活性劑也被用來(lái)改性礦物材料,周琴等[21]研究發(fā)現(xiàn),負(fù)載在蒙脫石上的陽(yáng)離子表面活性劑(蒙脫石負(fù)載陽(yáng)離子表面活性劑會(huì)進(jìn)入結(jié)構(gòu)內(nèi)層,增加層間空間,從而增強(qiáng)對(duì)PFOS的吸附能力.Du等[82]采用陽(yáng)離子型含氟表面活性劑交換法制備了新型含氟蒙脫石(F-MT),研究了對(duì)水中PFOS和PFOA的吸附性能,由于氟的電負(fù)性大以及原子半徑小,其極性很低,主鏈中氟原子由于相鄰氟原子的相互排斥沿碳鏈作螺旋分布包裹住了碳鏈,使其他原子難以嵌入[86].此外,原子間共用電子對(duì)偏向于氟原子,形成一層負(fù)電荷保護(hù),因此C-F鏈不僅疏水疏油而且對(duì)其他化合物具有一定排斥性[87].基于相似相溶原理, F-MT對(duì)低濃度(<10μg/L)的PFOS和PFOA具有較高的吸附性能和選擇性(在苯酚,菲,十二烷基苯磺酸鈉的存在下,PFOS和PFOA的吸附基本不受影響). 納米金屬氧化物是較為典型的礦物吸附材料,其表面官能團(tuán)會(huì)在PFAS與金屬陽(yáng)離子之間發(fā)生橋接效應(yīng)[76].金屬氧化物的穩(wěn)定性較差,Gong等[88]發(fā)現(xiàn)磁鐵礦(Fe3O4)納米粒子可以被淀粉穩(wěn)定以防止團(tuán)聚并保持高表面積,淀粉穩(wěn)定的磁鐵礦納米顆粒的BET表面積(8.21m2/g)遠(yuǎn)高于未穩(wěn)定的磁鐵礦(3.98m2/g),使PFOA吸附量提高了2.4倍. Mancinelli[89]采用間歇吸附和同步輻射X射線粉末衍射(XRPD)相結(jié)合的方法研究了不同硅鋁比的Y型分子篩(FAU型)對(duì)PFOA和PFOS的吸附性能.Y390對(duì)PFOA和PFOS的飽和吸附量分別為43和17mg/g,AgY390為62和32mg/g,吸附性能高于單一沸石材料,原因是Y390和AgY390與沸石骨架中的氧原子強(qiáng)烈相互作用形成氫鍵,增強(qiáng)了對(duì)PFAS的吸附.此外,在沸石上引入Ag+可以將防污和吸附相結(jié)合,協(xié)同去除PFAS. 復(fù)合材料是PFAS吸附去除技術(shù)的重要研究方向.碳質(zhì)吸附劑被廣泛應(yīng)用于水中PFAS去除,但是其解吸率較高[90],Supriya等[91]考察了氧化石墨烯(GO),氧化鐵改性還原GO復(fù)合材料(FeG)和活性炭/粘土/氧化鋁基吸附劑(RemB)對(duì)PFOA的吸附性能.RemB對(duì)PFOA的吸附性能比GO高1.5倍(pH= 7.9),原因是RemB去除PFOA的主要作用機(jī)制為疏水相互作用和配體交換作用,受到pH值影響較小,而GO去除PFOA的機(jī)理主要是靜電作用,在研究的pH值范圍(3～9)內(nèi),GO表面帶大量負(fù)電荷,不利于PFOA吸附. 1.3.3 吸附機(jī)理 靜電相互作用,疏水相互作用和配體交換是礦物材料吸附PFAS的主要吸附機(jī)制[81].PFAS的吸附機(jī)理由天然或改性礦物材料的物化特性決定,且受水質(zhì)條件影響,如pH值和離子強(qiáng)度,此外,天然有機(jī)物和溫度等因素也會(huì)影響PFAS的去除[81]. pH值是從水中去除PFAS的關(guān)鍵影響因素,溶液pH值可以通過(guò)改變PFAS的形態(tài)和礦物材料的表面電荷而影響PFAS的吸附.如天然高嶺石和蒙脫石的等電點(diǎn)分別為3.2和2.0[92],pH值高于其零電點(diǎn)時(shí),礦物表面所帶負(fù)電荷增加,而PFAS在水溶液中的陰離子形態(tài),導(dǎo)致天然高嶺石和蒙脫石對(duì)PFAS的吸附性能較低[81]. PFAS與疏水性表面活性劑改性的礦物材料之間會(huì)產(chǎn)生疏水作用[82].此外,一些疏水性有機(jī)物會(huì)與PFAS競(jìng)爭(zhēng)吸附位點(diǎn),造成PFAS的吸附量降低[93]. 以生物質(zhì)為原料通過(guò)一系列的物化改性制備的生物基吸附材料具有來(lái)源廣泛,易得,成本低廉等優(yōu)勢(shì)[102].常用的生物基材料有生物炭,殼聚糖以及一些基于生物提取,合成的材料. 1.4.1 未改性生物基材料 生物炭和殼聚糖是去除PFAS應(yīng)用較多的生物基材料.生物炭與活性炭對(duì)PFAS具有相近的吸附性能,由于生物炭更具有環(huán)保性,近年來(lái)生物炭逐漸成為活性炭的可持續(xù)替代品[30].Wei等[103]將底泥和玉米秸稈生物炭(0%,2%和5%)混合,考察了生物炭含量對(duì)底泥吸附PFOS和17α-乙炔雌二醇(EE2)的影響,有機(jī)碳濃度是影響吸附過(guò)程的主要因素,EE2和PFOS在底泥上的吸附速率和吸附容量在添加生物炭后提高了1.7～3.5倍.原因可能是生物炭的添加降低了PFOS和EE2的遷移率,底泥中的腐殖酸通過(guò)電荷轉(zhuǎn)移與PFOS中的供電荷基團(tuán)形成了絡(luò)合物.Palau等[104]研究了6種生物炭(樹(shù)皮,桉樹(shù),甘蔗渣,蓖麻粗粉,椰殼和水葫蘆)對(duì)7種PFAS(PFHxA,PFOA,全氟壬酸(PFNA),全氟十二烷酸(PFDoA),PFHxS,PFBS,PFOS)的吸附,12～24h內(nèi)達(dá)到吸附平衡,由于初始溶液固液比較高(40g/L)且PFAS濃度較低(400 μg/L),因此等溫吸附過(guò)程呈線性,PFAS的吸附機(jī)制主要為疏水相互作用,受水質(zhì)條件(pH值,二價(jià)陽(yáng)離子等)影響較小. 殼聚糖含有大量的氨基,乙酰氨基,伯羥基和仲羥基,使其成為PFAS的優(yōu)良螯合位點(diǎn),在PFAS污染水修復(fù)領(lǐng)域具有巨大的潛力[98].殼聚糖小球的成本介于活性炭和樹(shù)脂之間,吸附PFAS的過(guò)程受pH值影響較大,交聯(lián)的殼聚糖小球在pH=3下對(duì)PFOS具有很大的吸附量,甚至高于陰離子交換樹(shù)脂[105],當(dāng)pH=9.5時(shí),殼聚糖小球?qū)FOS的飽和吸附量?jī)H有359.28mg/g[106].Zhang等[107]以交聯(lián)殼聚糖微球?yàn)槲絼?研究了其對(duì)水溶液中PFOS的吸附性能,PFOS的飽和吸附量達(dá)到2744.5mg/g,吸附對(duì)pH值環(huán)境具有高度依懶性,在pH=3時(shí)吸附效果最佳,靜電作用,疏水作用,膠束和半膠束的形成是殼聚糖吸附PFAS的主要吸附機(jī)制.其他生物基材料也被廣泛用于去除水中PFAS,Militao等[108]研究了集成辣木(MO)種子粉的海藻酸鈣珠對(duì)PFAS的吸附.在30min內(nèi)達(dá)到平衡,其對(duì)PFOS具有較高的飽和吸附量(941.7 μg/g).吸附機(jī)制主要是疏水作用和氫鍵作用.Katinka等[109]利用污泥生物炭從水中去除PFAS,并比較了兩種污泥生物炭(脫水污泥和厭氧消化污泥)和木質(zhì)生物炭對(duì)PFAS的吸附性能,脫水污泥對(duì)PFAS的去除率與木質(zhì)生物炭相近,厭氧消化污泥對(duì)PFAS的吸附性能低于木質(zhì)生物炭.原因是脫水污泥的C/H比(0.04)和C/N比(26)較低. 新型生物基材料被開(kāi)發(fā)用于PFAS吸附去除,Xin等[110]合成了一種新的吲哚衍生物—雙吲哚十六烷基銨(DIHA),它能形成穩(wěn)定的納米球,優(yōu)先選擇性吸附水中的PFAS.還表現(xiàn)出極快的吸附速率和高飽和吸附量(764～857mg/g).這歸因于納米球超細(xì)粒度(亞納米級(jí)),提供了大量比表面積,縮短了PFAS的擴(kuò)散距離.植物蛋白可以提供疏水位點(diǎn)和氫鍵位(在氨基酸和谷氨酸的側(cè)鏈)去除PFAS,Turner等[111]研究了6種不同的蛋白質(zhì)(蛋白粉,大豆分離蛋白,羽扇豆和豌豆分離蛋白,雞蛋,乳清)從污染的地下水中去除PFAS的能力,在不到1h內(nèi),PFOS和PFHxS的飽和吸附量為91.69和30.25 μg/g.PFAS與蛋白質(zhì)疏水位點(diǎn)的結(jié)合以及與氨基酸之間形成氫鍵是主要的吸附機(jī)制. 1.4.2 改性生物基材料 傳統(tǒng)生物基材料穩(wěn)定性差,難以從水中回收,因此需要通過(guò)改性提升其吸附性能,常用的改性方法有金屬摻雜,材料包覆和表面基團(tuán)改性等[98].Elanchezhiya等[98]使用還原氧化石墨烯改性鐵酸鋅固定化殼聚糖珠(rGO-ZF@CB)從水中吸附PFOA和PFOS.PFOA和PFOS的飽和吸附量分別為16.07和21.64mg/g.靜電吸引和疏水作用是主要吸附機(jī)制,rGO-ZF@CB可以通過(guò)外加磁源進(jìn)行回收.Rodrigo等[112]研究了9種PFAS(PFOS, PFOA, PFBA,全氟辛烷磺酰胺(PFOSA), GenX, PFHxS, PFPeA, PFHxA和PFHpA)在商業(yè)花旗松生物炭(BC)及Fe3O4改性BC(Fe3O4-BC)上的吸附, Fe3O4-BC對(duì)PFOA和PFOS的吸附速率和吸附容量最高,在天然水的pH值范圍(6～8)下,20～45min達(dá)到吸附平衡,PFOS和PFOA的飽和吸附量分別為14.6和652mg/g,疏水和靜電作用以及與Fe3+或Fe2+形成絡(luò)合物是主要的PFAS去除機(jī)制.Hassan等[113]制備了赤泥改性木屑生物炭和未改性木屑生物炭,考察了對(duì)水中PFOS的吸附性能,在赤泥改性木屑中發(fā)現(xiàn)了不同的金屬氧化物,如磁鐵礦,鐵水化物和脫硅產(chǎn)物.在pH=3下,改性生物炭和未改性生物炭對(duì)PFOS的飽和吸附量分別為194.6和178.6mg/g.改性木屑生物炭表面具有豐富的質(zhì)子化金屬官能團(tuán),通過(guò)靜電作用和離子交換作用增強(qiáng)了對(duì)PFOS的吸附. 使用新型包覆材料改性生物基材料成為研究熱點(diǎn),Verma等[114]通過(guò)戊二醛交聯(lián)殼聚糖和β-環(huán)糊精制備了一種聚合物吸附劑(Chi-Glu-β-CD),并考察了對(duì)水中PFBS的吸附性能.飽和吸附量為135.7mg/g,主要吸附機(jī)制為質(zhì)子化的胺與陰離子PFBS間的靜電吸引作用,此外,PFBS通過(guò)與β-CD空腔形成包合物被去除.Chi-Glu-β-CD可用甲醇進(jìn)行再生,經(jīng)4次循環(huán)再生后,吸附性能無(wú)顯著變化.基于β-CD吸附劑,Wang等[115]研究了一種新的β-CD聚合物平臺(tái),將苯乙烯基團(tuán)共價(jià)連接到β-CD上,形成易于自由基聚合的獨(dú)立單體,得到具有高比表面積和高分離產(chǎn)率(>93%)的β-CD聚合物.對(duì)水中初始濃度為1 μg/L的8種PFAS的去除率接近100%. 1.4.3 吸附機(jī)理 靜電作用和疏水作用是生物基材料吸附PFAS的主要機(jī)制,由于PFAS的低pKa,在水溶液中一般為陰離子形態(tài),吸附劑表面的一些官能團(tuán)在一定pH值下質(zhì)子化會(huì)吸引陰離子PFAS.此外,一些極性官能團(tuán)如-NH和-OH會(huì)對(duì)PFAS產(chǎn)生離子-偶極作用[94].當(dāng)疏水作用力為主導(dǎo)吸附機(jī)制時(shí),PFAS可以克服靜電排斥力,通過(guò)疏水作用力吸附到帶負(fù)電荷的吸附劑表面[71-73,116]. 經(jīng)過(guò)改性的生物基材料,例如金屬氧化物改性材料,作用機(jī)制還包括配體交換,氫鍵等.PFAS具有疏水性,因此難以與吸附劑官能團(tuán)中的氫原子結(jié)合形成氫鍵[117],但是PFAS的官能團(tuán)中所含的氧原子可以成為吸附劑官能團(tuán)形成氫鍵的受體[80,118-119]. PFAS可以通過(guò)電荷輔助氫鍵與吸附劑表面的含氧官能團(tuán)相互作用[120],若吸附劑中含氧或含氮基團(tuán)的pa值與PFAS的pa相近,則電荷輔助氫鍵會(huì)比正常氫鍵強(qiáng)得多[120-122]. 分子印跡技術(shù)是一種制造分子鎖以匹配分子鑰匙,創(chuàng)建分子印跡聚合物(MIP)的技術(shù)(圖2),其具有與模板分子形狀互補(bǔ)的定制結(jié)合位點(diǎn),大小和功能組.MIP由于其獨(dú)特的結(jié)構(gòu),可預(yù)測(cè)性,識(shí)別特異性和應(yīng)用普適性等特點(diǎn),在各個(gè)領(lǐng)域得到了廣泛的應(yīng)用.廢水中含有大量的化合物和膠體,且這些共存物質(zhì)濃度普遍比PFAS高,易與PFAS發(fā)生競(jìng)爭(zhēng)吸附,導(dǎo)致去除率下降.因此,吸附的選擇性對(duì)于去除水中PFAS很重要[123]. 圖2 分子印跡技術(shù)原理圖[125] 為了提高對(duì)PFAS的選擇性吸附,一些研究通過(guò)分子印跡技術(shù)制備了對(duì) PFAS 具有高選擇性的MIP.Deng等[97]使用環(huán)氧氯丙烷交聯(lián)的殼聚糖和乙二醇二甲基丙烯酸酯交聯(lián)的 4-乙烯基吡啶制備了兩種新型 MIP吸附劑,考察了MIP吸附劑對(duì)PFOS的吸附選擇性,以2,4-D為競(jìng)爭(zhēng)陰離子對(duì)PFOS進(jìn)行吸附.2,4-D濃度為2.26mmol/L,MIP吸附劑對(duì)PFOS的吸附量下降不大.與非印跡聚合物(NIP)相比,MIP吸附劑對(duì)PFOS的吸附量在平衡濃度低于0.25mmol/L時(shí)增加了1倍以上.原因是MIP吸附劑對(duì)PFOS的選擇性較強(qiáng),而NIP吸附劑由于競(jìng)爭(zhēng)吸附導(dǎo)致吸附量下降.林森等[124]以Fe3O4為內(nèi)核,水作溶劑,利用多巴胺作為交聯(lián)劑.多巴胺中的氨基和羥基作為雙功能單體,通過(guò)一步聚合制備超順磁性核殼型的Fe3O4@MIPDA微球.考察Fe3O4@MIPDA對(duì)PFOS的吸附性能,飽和吸附量為71.421mg/g.在PFHSK和F-53B共存下,PFOS吸附量顯著下降,原因是PFHSK和F-53B與PFOS結(jié)構(gòu)相似,對(duì)Fe3O4@MIPDA選擇性影響較大. Yu等[12]以油茶籽殼為碳源,PFOS為模板,間苯三酚為助劑,采用一鍋水熱法合成了印跡碳微球(MIC).研究了PFOS在PFOS-MIC和相應(yīng)的非印跡碳微球(NIC)上的吸附特性,NIC和PFOS-MIC在20°C時(shí)的飽和吸附量分別為2.93和5.38mg/g. PFOS-MIC對(duì)PFOS具有良好的吸附選擇性(PFOS-MIC對(duì)PFOS的相對(duì)選擇性系數(shù)大于1).MIP吸附劑用于PFAS去除的研究仍然較少,且具有PFAS相似分子大小,結(jié)構(gòu)和官能團(tuán)的競(jìng)爭(zhēng)性化合物仍然會(huì)降低MIP的選擇性[2,126]. MIP的合理設(shè)計(jì)需要將PFAS分子的結(jié)構(gòu)和特性與相應(yīng)的材料相匹配,基于PFAS分子特性的更精細(xì)設(shè)計(jì)將會(huì)是未來(lái)的研究方向. 其他常見(jiàn)吸附劑主要有金屬有機(jī)框架(MOF),共價(jià)有機(jī)框架(COF),人工合成物等.COF是一種新興的結(jié)晶多孔材料,通過(guò)堅(jiān)固的共價(jià)鍵將有機(jī)分子結(jié)構(gòu)單元連接在周期性網(wǎng)絡(luò)中[127], MOF是一類通過(guò)金屬離子或團(tuán)簇單元與有機(jī)配體的配位組裝而成的具有三維周期無(wú)限網(wǎng)狀結(jié)構(gòu)的配位聚合物[128].與傳統(tǒng)吸附劑相比,它們具有顯著增加的表面積,結(jié)構(gòu)可調(diào)性和更多的的改進(jìn)選擇性[7]. MOF和COF作為新一代吸附劑,近年來(lái)被用于去除水中的PFAS[39].Yang等[103]研究了PFOA在鐵基MOF(MIL-100-Fe和MIL-101-Fe)上的吸附,吸附機(jī)理包括π-CF相互作用,Lewis酸/堿(LAB)絡(luò)合,氫鍵和陰離子-π相互作用.當(dāng)PFOA濃度>1000mg/L時(shí),MIL-101-Fe的飽和吸附量(370mg/g)高于MIL-100-Fe(349mg/g),原因可能是MIL- 101-Fe(三角形孔結(jié)構(gòu))較于MIL-100-Fe(六邊形孔結(jié)構(gòu))有更多的吸附位點(diǎn),因此對(duì)PFOA的吸附容量更高.Chang等[129]制備了一種新型金屬有機(jī)骨架材料MOF-808,并研究了MOF-808對(duì)水中PFOS的吸附性能. MOF-808具有高比表面積(1610m2/g),在不同pH值水介質(zhì)中,其結(jié)構(gòu)可以穩(wěn)定7d.MOF-808對(duì)PFOS的吸附在30min內(nèi)達(dá)到平衡,在pH值為4.1～5.4時(shí),飽和吸附量為939mg/g,吸附機(jī)制主要為靜電相互作用,當(dāng)pH>7時(shí),吸附量逐漸降低.Hu等[130]制備了DUT-5-2等6種金屬有機(jī)骨架材料,測(cè)定了它們對(duì)PFOS和PFOA的吸附性能.DUT- 5-2對(duì)PFOS的飽和吸附量為145.4mg/g,原因可能是采用微波輔助法提高了DUT-5-2的比表面積(1840m2/g).Ji等[131]將不同密度的胺官能團(tuán)結(jié)合到亞胺連接的COF的孔隙中,同時(shí)保持高表面積(31000m2/g),研究其對(duì)GenX的吸附性能.胺功能化的COF對(duì)GenX具有較高的吸附速率和親和力.在胺功能化亞胺COF中,20%[NH2]-COF在高濃度GenX下具有最大吸附量,28%[NH2]-COF對(duì)GenX吸附表現(xiàn)出最快吸附速率.吸附機(jī)制主要是極性基團(tuán)和疏水表面的協(xié)同作用.MOF和COF的應(yīng)用仍然存在局限性,例如在極端條件下穩(wěn)定性低,工藝復(fù)雜以及合成成本較高等[7]. 2.1.1 粒徑的影響 吸附劑粒徑會(huì)影響PFAS的擴(kuò)散速率,一般來(lái)說(shuō),粒徑越小,PFAS的擴(kuò)散速率就越快[29],對(duì)于大顆粒吸附劑而言,堵塞和位阻作用更為明顯[2],因此去除速率要低于粒徑小的吸附劑.Yu等[32]通過(guò)偽二級(jí)吸附動(dòng)力學(xué)模型擬合發(fā)現(xiàn),PAC吸附水中PFOS和PFOA的性能高于GAC,吸附平衡時(shí)間短,飽和吸附量更高.比表面積相同條件下,PAC (<0.1mm)對(duì)PFOS和PFOA的吸附能力幾乎是GAC(0.9～1mm)的兩倍[2,29].孫博等[132]發(fā)現(xiàn),研磨前后PAC(11μm)與超微粉末活性炭(S-PAC)的比表面積變化不大,但在相同的投加量(15mg/L)下,粒徑更小的S-PAC(1.2μm)對(duì)0.5μg/L的PFHxA的吸附速度比PAC更快,飽和吸附量沒(méi)有明顯差異.Wu等[133]采用3種不同的活性炭材料和2種不同的β-環(huán)糊精聚合物對(duì)20種PFAS進(jìn)行了吸附實(shí)驗(yàn),粒徑與PFAS去除速率之間為負(fù)相關(guān),同種吸附材料,粒徑小的吸附速率更快.而速率與粒徑之間的關(guān)系建立在同種類型的吸附劑上,不同類型吸附劑的粒徑與PFAS擴(kuò)散速率相關(guān)性并不強(qiáng)[33]. 2.1.2 孔徑的影響 吸附劑的孔徑會(huì)影響PFAS的擴(kuò)散速率,對(duì)不同分子大小PFAS的吸附具有差異性.樹(shù)脂按孔徑可分為普通樹(shù)脂(4～6nm),凝膠型脂(<3nm)和大孔型樹(shù)脂(10nm左右).活性炭的孔隙結(jié)構(gòu)可以大致分為小于2nm的微孔,2～50nm的中孔和大于50nm的大孔[29].Chen等[48]制備了具有微介孔結(jié)構(gòu)的聚丙烯腈纖維衍生活性炭,通過(guò)不同PFAS的吸附實(shí)驗(yàn)表明,分子量較大的PFAS更難擴(kuò)散到吸附劑的微孔和中孔中.在Park等[47]的研究中得出了相似的結(jié)論,在帶正電荷的活性炭中,微孔(<2nm)占比較高(80%)的活性炭對(duì)分子量較小的PFAS(PFBA, PFBS,PFPeA)吸附能力較高,而介孔(2～50nm)占比較高(58%)的活性炭對(duì)分子量較大的PFAS(PFOA, PFOS,PFDA)吸附能力比微孔炭強(qiáng).在Cantoni等[46]的研究中解釋了此現(xiàn)象,分子量較大,鏈長(zhǎng)較長(zhǎng)的PFAS堵塞微孔的程度較高,當(dāng)活性炭孔徑和PFAS大小相似時(shí),吸附是較為有利的.Deng等[26]研究了6種陰離子交換樹(shù)脂對(duì)PFOS吸附的影響,大孔樹(shù)脂(聚丙烯酸樹(shù)脂>10nm)比凝膠型樹(shù)脂(聚苯乙烯樹(shù)脂 <3nm)具有較高的吸附速率,原因是凝膠型樹(shù)脂形成的微孔(<2nm)較多,不利于PFOS的吸附.Deng等[134]采用KOH活化法制備具有更大孔徑的竹基GAC,KOH/C質(zhì)量比為2時(shí)制得的GAC主要孔徑分布小于2nm,KOH/C比值為6時(shí)制備的活性炭孔徑增大到約4nm.對(duì)PFOS和PFOA的飽和吸附量也有所增加,這說(shuō)明孔徑的增加有利于PFOS和PFOA的吸附.Pauletto[135]研究了商用活性炭(BAX),炭黑(BP2000)和以鋅為基礎(chǔ)的金屬有機(jī)骨架(UiO-66)對(duì)PFOS的吸附性能.它們的孔徑分布不同,UiO-66主要為微孔(<2nm),BAX主要為微孔(<2nm)和介孔(>2nm),BP2000中以介孔(>2nm)為主.BP2000,BAX和UiO-66的PFOS飽和吸附量分別為0.81,0.55和0.38mg/g.比表面積增加的順序?yàn)閁iOe66 2.1.3 表面官能團(tuán)的影響 PFAS的吸附受到吸附劑表面化學(xué)性質(zhì)影響,如表面電荷,表面官能團(tuán)種類,雜原子等[29].靜電作用是去除水中PFAS的主要作用之一,吸附劑表面所帶電荷是影響靜電作用的關(guān)鍵因素之一.PFAS的pKa較低(表1),在水中通常以陰離子形態(tài)存在,表面帶正電的吸附劑對(duì)PFAS的吸附性能更高. 含有不同官能團(tuán)的同種吸附劑,對(duì)PFAS的吸附能力存在明顯的差異[2].Punyapalakul等[95]發(fā)現(xiàn)具有不同表面官能團(tuán)的同種二氧化硅之間存在明顯的區(qū)別.一般情況下,吸附劑所含有的堿性基團(tuán)越多,對(duì)PFAS的吸附能力就越強(qiáng)[26],這是由于堿性基團(tuán)更容易被質(zhì)子化帶正電,從而有利于對(duì)陰離子PFAS的吸附[99],可以通過(guò)調(diào)節(jié)吸附劑表面堿性基團(tuán)的含量來(lái)提高吸附性能.PFAS在交聯(lián)殼聚糖珠,季銨化棉,胺化稻殼和坡縷石等胺改性材料上的高吸附量也與吸附劑的表面化學(xué)性質(zhì)密切相關(guān),羥基,羰基和含金屬基團(tuán)有助于PFAS的吸附[32,100,136-137].此外,親水性或極性官能團(tuán)有利于PFAS擴(kuò)散到多孔材料中,從而提高PFAS吸附量[26,138]. 吸附劑表面的某些有機(jī)官能團(tuán)或有機(jī)物通過(guò)疏水作用在一定程度上增強(qiáng)了PFAS的吸附[29,139],這一原理已被用于改性吸附劑提高對(duì)PFAS的吸附性能.Jeon等[139]用河水中的天然有機(jī)物單寧酸(TA)以及腐殖酸(HA)涂覆礦物材料,研究了礦物和沉積物在PFAS吸附方面的差異以及有機(jī)物的作用,礦物材料對(duì)PFAS的吸附與其有機(jī)碳含量密切相關(guān),由于污泥不僅含有原始的有機(jī)和礦物質(zhì)成分,而且含有生成的生物質(zhì)和蛋白質(zhì),其有機(jī)成分對(duì)吸附過(guò)程也有顯著影響[73,140].此外,吸附劑表面存在的雜原子和化合物也可以與PFAS形成較強(qiáng)的結(jié)合力,從而提高吸附劑的吸附性能[141]. 2.2.1 pH值 溶液pH值會(huì)對(duì)吸附劑帶電種類, PFAS存在形態(tài)等溶液環(huán)境造成影響.溶液pH值低于吸附劑的等電點(diǎn)時(shí),吸附劑的表面帶正電荷,吸附劑和PFAS之間的靜電吸引作用會(huì)增強(qiáng)[142].Yu[125]的研究表明,相對(duì)于中性環(huán)境,活性炭在pH值為3的酸性條件下對(duì)PFOS和PFOA的吸附量更大.原因是活性炭的等電點(diǎn)在7以下,酸性條件下活性炭表面基團(tuán)質(zhì)子化,正電荷數(shù)量增加.Du等[30]利用自制的竹基活性炭在pH值為2.0～9.0的條件下對(duì)PFOSF洗滌廢水中的PFHpA和PFOA進(jìn)行去除,當(dāng)pH值從2.0增加到4.0時(shí),竹基活性炭對(duì)PFHpA和PFOA的去除率迅速下降,但在pH值高于5.0后趨于穩(wěn)定,原因是PFHpA和PFOA與活性炭之間的靜電引力減弱,疏水相互作用在吸附過(guò)程中逐漸起主導(dǎo)作用. 當(dāng)溶液中存在一定量的陽(yáng)離子例如Ca2+或Mg2+時(shí),當(dāng)pH值增加時(shí),吸附劑表面形成更多的堿性位點(diǎn)以結(jié)合陽(yáng)離子,這時(shí)陽(yáng)離子可以通過(guò)橋接效應(yīng)增加對(duì)PFAS的吸附(圖3)[116,140,143].Buckley等[144]在0～100mmol/L的鈉離子濃度范圍內(nèi)進(jìn)行了PFAS吸附實(shí)驗(yàn),與不含任何陽(yáng)離子的測(cè)試相比,在NaCl存在下,特別是在10mmol/L和更高濃度下,PFAS的去除速率更快且PFAS的去除率隨著鹽濃度增加而增加.原因是Na離子的加入降低了穩(wěn)定氣泡形成的最小表面張力,且抑制了表面活性劑頭基之間的靜電雙層排斥作用. 圖3 二價(jià)陽(yáng)離子和有機(jī)物影響PFAS吸附的機(jī)制[69] pH值會(huì)顯著影響吸附劑的吸附性能[145],可在寬pH值范圍內(nèi)工作的吸附劑是研究熱點(diǎn).一些相對(duì)不依賴于pH值(例如pH值為4～9)的吸附劑已被報(bào)道[2].Chang等[146]在pH值為9～11下共沉淀制備煅燒水滑石(CHT)并研究了對(duì)PFOA的去除.CHT對(duì)PFOA的飽和吸附量高達(dá)1587mg/g,由于CHT具有穩(wěn)定的帶正電的表面,使得PFOA吸附具有較高的去除速率且不依賴于pH值(pH值為4～12的影響較小).盡管目前pH值對(duì)吸附PFAS的影響研究較為豐富,但實(shí)驗(yàn)室中主要模擬的低pH值環(huán)境與實(shí)際水體差異較大,對(duì)實(shí)際水處理應(yīng)用還待研究. 2.2.2 溫度 溫度對(duì)PFAS吸附具有顯著的影響,包括PFAS吸附反應(yīng)的吸放熱和溶液中分子的擴(kuò)散速率.PFAS的吸附自由能?G在多數(shù)情況下為負(fù),表明PFAS吸附過(guò)程多數(shù)是自發(fā)進(jìn)行的.孫建強(qiáng)[147]等利用微波改性膨潤(rùn)土吸附PFOS,發(fā)現(xiàn)吸附過(guò)程是吸熱反應(yīng),升溫有利于吸附,?S為正值也表明PFOS的吸附過(guò)程是由熵驅(qū)動(dòng)而不是焓驅(qū)動(dòng)[146,148].許晨敏[149]研究了溫度對(duì)鹽態(tài)聚苯胺納米管(PASNTs)和基態(tài)聚苯胺納米管(PABNTs)吸附PFOA和PFOS的影響,PFOS和PFOA的吸附量隨溫度的升高而上升. 溫度也會(huì)影響PFAS在吸附劑中的擴(kuò)散速率.溫度越高,PFAS的擴(kuò)散速率越快,導(dǎo)致吸附速率加快.溫度對(duì)PFAS的影響也存在一定界限,Qu等[150]研究發(fā)現(xiàn),活性炭對(duì)PFOA的吸附量存在最適溫度,當(dāng)溫度從303K升高到313K時(shí),PFOA的吸附量隨著溫度的升高而逐漸增加,當(dāng)繼續(xù)升溫至323K時(shí), PFOA的吸附量下降.可能是由于溫度升高,PFAS在水中的溶解度升高,導(dǎo)致疏水相互作用變?nèi)?此外,也可能是PFAS在較高的溫度下發(fā)生解吸,導(dǎo)致吸附量下降. 2.2.3 共存有機(jī)物 不同濃度,分子量大小和電荷類型的有機(jī)物對(duì)PFAS吸附有不同影響[147]. 與PFAS具有相似特征的有機(jī)物(表面帶負(fù)電荷和200～1000Da的分子量)會(huì)發(fā)生競(jìng)爭(zhēng)吸附(通過(guò)靜電和疏水相互作用,配體交換和氫鍵)和孔阻塞效應(yīng)[67].Deng等[152]研究了腐殖酸,1-萘酚,苯酚和苯甲酸存在下,PFOS,PFOA,PFBS和PFHxS在未修飾多壁碳納米管(MWCNTs-Pri),羧基修飾多壁碳納米管(MWCTNs-COOH)和羥基修飾多壁碳納米管(MWCNTs-OH)上的吸附行為,這些有機(jī)物的存在降低了PFAS的初始吸附速率和吸附量,PFAS的飽和吸附量隨著共存有機(jī)物濃度的增加而降低,當(dāng)共存有機(jī)物濃度為2.5mg/L時(shí),PFOS的飽和吸附量降低了0.828～1.691mg/g.原因是不同的共存有機(jī)物與PFAS發(fā)生競(jìng)爭(zhēng)吸附.當(dāng)體系中存在多種PFAS時(shí),單一PFAS的吸附也會(huì)受到影響,Kimura等[153]研究了PAC對(duì)混合體系中8種PFAS的吸附效果,發(fā)現(xiàn)各種PFAS的去除率都低于單溶質(zhì)溶液.不同大小的有機(jī)物對(duì)PFAS吸附的影響程度也不同,Yu等[154]研究了在不同分子尺寸有機(jī)物存在下,活性炭從廢水中去除PFAS的效果.結(jié)果表明分子量<1kDa的小分子有機(jī)物的競(jìng)爭(zhēng)作用遠(yuǎn)大于分子量>30kDa的大分子物質(zhì),特別是與PFAS分子量相當(dāng)?shù)挠袡C(jī)物質(zhì)會(huì)產(chǎn)生更強(qiáng)的競(jìng)爭(zhēng)吸附,顯著減少PFAS吸附量.原因是分子量或結(jié)構(gòu)與PFAS相似的有機(jī)物競(jìng)爭(zhēng)吸附能力更強(qiáng). 可溶性有機(jī)物如腐殖酸具有配體交換位點(diǎn),會(huì)與溶液中的PFAS發(fā)生絡(luò)合,從而降低PFAS在吸附劑上的飽和吸附容量[88].Gong等[88]用水溶性淀粉制備Fe3O4納米顆粒,并測(cè)試了腐殖酸對(duì)PFOA去除的影響,12mg/L的腐殖酸使PFOA的飽和吸附量減少了24mg/g.同樣在Wang等[145]的研究中,由于腐殖酸的競(jìng)爭(zhēng)吸附,PFOS和PFBS勃姆石上幾乎沒(méi)有被勃姆石吸附.實(shí)際廢水中存在的有機(jī)物更為復(fù)雜,要提高PFAS的吸附性能,必須避免或減少有機(jī)物的影響,目前已經(jīng)對(duì)一些可以減少有機(jī)物影響的吸附劑進(jìn)行了研究.Wang等[155]開(kāi)發(fā)了一種基于熒光石墨烯(MNP@FG)的磁性納米顆粒吸附劑,該吸附劑對(duì)PFOA和PFOS具有高親和力,在天然有機(jī)物存在下, PFOA和PFOS的飽和吸附量依舊很高(12.82和13.095mg/g).Wang等[156]開(kāi)發(fā)了共價(jià)三嗪基骨架(CTF)吸附劑,CTF均勻的納米級(jí)孔(1.2nm)阻礙了大尺寸腐殖酸的吸附,最小化了對(duì)PFAS吸附的影響.Xiao等[157]開(kāi)發(fā)了一種基于β-環(huán)糊精的聚合物,與PAC相比,它對(duì)PFOA 具有更高的親和力,同時(shí)具有較高的吸附容量和速率.β-環(huán)糊精聚合物可將PFOA濃度從1μg/L降至10ng/L,且不受腐殖酸的影響. 除了吸附劑性質(zhì)以及外界環(huán)境,PFAS本身的結(jié)構(gòu)(如鏈長(zhǎng),官能團(tuán),雜原子等)對(duì)吸附性能影響也較為顯著. 隨著PFAS碳鏈長(zhǎng)度的增加,疏水性增強(qiáng)[22],疏水性強(qiáng)的吸附劑對(duì)其吸附效果更好.Qiu等[158]研究了不同鏈長(zhǎng)PFAS在活性炭上的吸附行為,長(zhǎng)鏈PFAS在活性炭上的吸附速度更快,活性炭對(duì)碳鏈較長(zhǎng)的PFAS具有較高的吸附容量[139,149,155].Cantoni等[46]研究了4種顆?；钚蕴繉?duì)8種PFAS的吸附效果,PFAS的碳鏈越長(zhǎng),疏水性越強(qiáng),去除效果越好.Inyang等[96]研究了硬木(HWC)和松木(PWC)生物炭對(duì)PFAS的去除,也得到了同樣的結(jié)論,其中長(zhǎng)鏈PFAS(PFOA, PFOS)的吸附量是短鏈PFAS(PFBA, PFHxA)的3～4倍. 當(dāng)PFAS碳鏈長(zhǎng)度相同官能團(tuán)不同時(shí),同時(shí)去除可能會(huì)發(fā)生競(jìng)爭(zhēng)吸附,吸附效果也有差異[160].根據(jù)軟硬酸堿理論,磺酸基是硬堿,羧酸基是軟堿,比如常見(jiàn)的一些黏土礦物吸附劑都是硬酸,硬酸硬堿更易反應(yīng),因而PFOS比PFOA更易吸附在黏土吸附劑的表面[92,161-162].Ochoa-Herrera等[31]測(cè)定了活性炭對(duì)PFOA,PFOS和PFBS的吸附性能,PFOS更容易被吸附,原因是磺酸基團(tuán)產(chǎn)生的靜電作用要強(qiáng)于羧酸基團(tuán).此外,PFAS同分異構(gòu)體的吸附能力也不同,比如直鏈的PFOS比其同分異構(gòu)體吸附容量更高,可能是由于帶支鏈的PFOS直徑較大在反應(yīng)時(shí)影響了擴(kuò)散[163-164]. 在實(shí)際工程應(yīng)用中,PFAS的處理要考慮到技術(shù)可行和經(jīng)濟(jì)合理.與其他技術(shù)相比,吸附由于其操作,維護(hù)簡(jiǎn)單,處理效果好,在PFAS處理中應(yīng)用更為廣泛[28,160].Rahman等[165]對(duì)多個(gè)水處理廠使用不同技術(shù)(吸附,膜過(guò)濾,氧化,生物降解,混凝和浮選)進(jìn)行PFAS去除,其中混凝,浮選,生物降解,氧化,紫外線照射和低壓膜,都不能有效去除PFAS,只有活性炭吸附,離子交換樹(shù)脂吸附和高壓膜過(guò)濾可以有效去除PFAS.PFAS吸附劑的選擇需要考慮到許多因素,包括易獲取,高效率,低成本,可再生性以及環(huán)保性等.由于活性炭和離子交換樹(shù)脂的經(jīng)濟(jì)性和吸附性能較高,它們?nèi)匀皇钱?dāng)前去除PFAS更好的選擇[166]. 水中PFAS的大規(guī)模去除是當(dāng)前研究的熱點(diǎn),由于PFAS污染較為復(fù)雜,分析技術(shù)難度大,且不同研究水體差異大,導(dǎo)致研究結(jié)果有時(shí)差別較大[167].目前關(guān)于水中PFAS大規(guī)模去除的研究有限,可能是由于成本較高且分析較為困難而造成[167]. Shivakoti等[168]研究了兩個(gè)水廠中活性炭濾池進(jìn)出水中PFAS的含量,兩個(gè)水廠的活性炭池運(yùn)行參數(shù)相似,炭池厚度為2.1m,接觸時(shí)間為8.5min,濾池對(duì)部分長(zhǎng)鏈PFAS有一定程度的去除作用,而短鏈PFAS能夠輕易穿過(guò)GAC濾池.目前短鏈PFAS和PFAS支鏈異構(gòu)體的可用信息非常有限,而這些PFAS被越來(lái)越多地使用,對(duì)當(dāng)前的PFAS處理技術(shù)提出了巨大的挑戰(zhàn). 目前對(duì)于受PFAS污染場(chǎng)地(特別是受水成膜泡沫滅火劑(AFFF)高度污染的地點(diǎn))和實(shí)驗(yàn)室中PFAS的去除具有差異[169].有研究表明,在AFFF周圍的環(huán)境介質(zhì)中檢測(cè)到大量PFAS,其濃度達(dá)到了幾個(gè)mg/L水平[169].PFAS在此環(huán)境下的吸附行為較為復(fù)雜,PFAS可能會(huì)優(yōu)先吸附到熱解碳質(zhì)材料(PCM)上,如生物炭和煤煙等,而不是土壤有機(jī)質(zhì)(SOM),導(dǎo)致PFAS生物轉(zhuǎn)化更加困難[170].此外,PCM的吸附位點(diǎn)可能被SOM和其他有機(jī)化合物占據(jù),導(dǎo)致PFAS解吸到環(huán)境中,使其遷移和轉(zhuǎn)化變得更加復(fù)雜,修復(fù)工作極具挑戰(zhàn)性[69].意大利韋內(nèi)托的氟化物生產(chǎn)導(dǎo)致附近地下水源受到嚴(yán)重的PFAS污染,Conte等[36]開(kāi)展了一項(xiàng)研究,使用4種不同的樹(shù)脂(A600E, PAD500,PAD428和MN102)從水源中去除PFBA, PFBS,PFOA和PFOS.4種樹(shù)脂對(duì)PFOA和PFOS的去除效率都很高,但PAD500,PAD428和MN102對(duì)PFBA和PFBS的吸附容量較低.原因是PFBA和PFBS的鏈長(zhǎng)較短,疏水性較弱,需要通過(guò)高度疏水的官能團(tuán)改性加強(qiáng)吸附. 吸附劑上PFAS的逐漸累積會(huì)導(dǎo)致材料的吸附能力逐漸降低[171].吸附劑再生是在不破壞原有結(jié)構(gòu)的前提下,用物理或化學(xué)方法,使PFAS脫離或分解,恢復(fù)吸附劑吸附性能[172].通過(guò)再生可以實(shí)現(xiàn)吸附劑的循環(huán)使用,降低PFAS處理成本.目前較常用的再生方法有熱再生法,化學(xué)再生法以及溶劑再生法等[172-173]. 熱再生法是當(dāng)前應(yīng)用最廣泛,技術(shù)最成熟的再生方法[173-174].它是指通過(guò)外部加熱,升高溫度來(lái)提高PFAS分子振動(dòng),使吸附平衡關(guān)系發(fā)生改變,將PFAS從吸附劑中脫附的方法,具有再生率高,再生時(shí)間短等優(yōu)點(diǎn)[172-173].但熱再生法也存在處理后吸附劑表面積減小,吸附劑損失大等缺點(diǎn)[175],Castilla等[176]利用熱再生法對(duì)吸附酚類飽和的活性炭進(jìn)行再生研究,熱再生溫度為1100K,He作為保護(hù)氣,經(jīng)過(guò)4次循環(huán)吸附再生后,吸附劑的吸附容量下降了50%.這是由于熱再生后的活性炭比表面積減少.微波輻照再生法是用微波產(chǎn)生高溫使吸附劑上的PFAS炭化,恢復(fù)吸附劑吸附能力的方法[172].微波可產(chǎn)生介質(zhì)損耗熱,傳導(dǎo)損耗熱和磁性損耗熱3種形式的熱,具有再生時(shí)間短,再生效率高,耗能低等優(yōu)點(diǎn)[173].微波輻射法是目前研究較多的新型再生方法,具有較大的發(fā)展?jié)摿? 溶劑再生法是指利用化學(xué)藥劑與PFAS之間的化學(xué)反應(yīng)使吸附質(zhì)解析至溶劑相中的再生方法,溶劑分為無(wú)機(jī)溶劑和有機(jī)溶劑[172].無(wú)機(jī)溶劑一般以HCl,NaOH等為主,使吸附劑上的污染物轉(zhuǎn)化成易溶于水的物質(zhì),釋放吸附位點(diǎn)而達(dá)到再生的效果.有機(jī)溶劑再生法是指用苯,丙酮,甲醇,二氯甲烷及乙酸乙酯等有機(jī)溶劑萃取吸附劑上的污染物[172].而鈉鹽溶液無(wú)法有效再生PFAS吸附飽和的吸附劑[10],鈉鹽和有機(jī)溶劑(如CH3OH,C2H5OH和C3H6O)的混合物已被廣泛應(yīng)用于PFAS吸附劑的再生,鈉鹽對(duì)PFAS頭基進(jìn)行解吸,而醇溶液主要解吸PFAS的尾部[10,134]. Deng等[134]研究了不同溫度的去離子水作為再生溶液對(duì)PFOS解吸的影響.較高溫度的去離子水(約80 ℃)可增強(qiáng)PFOS的解吸,再生率為53%. 化學(xué)再生法在實(shí)際應(yīng)用中較為廣泛的有濕式氧化再生法,電化學(xué)氧化再生法,Fenton氧化再生法,臭氧氧化再生法等[172,174].濕式氧化再生法是利用空氣中的氧在高溫和高壓條件下使吸附質(zhì)氧化的過(guò)程,適用于粉狀吸附劑的再生[172].這種工藝操作條件比較嚴(yán)格(在完全封閉的系統(tǒng)中進(jìn)行),吸附劑的再生率和損失率與再生溫度和再生壓力有關(guān)[172].電化學(xué)氧化法是指將吸附飽和的吸附劑作為陽(yáng)極,使吸附質(zhì)氧化分解,以達(dá)到恢復(fù)吸附劑吸附容量的方法[174].但可用于電化學(xué)降解PFAS的電極材料稀少且昂貴[17],且PFAS本身難以被氧化,因此通過(guò)氧化降解PFAS達(dá)到再生效果較為困難[17]. 生物再生法是指利用經(jīng)過(guò)馴化培養(yǎng)的微生物降解吸附劑表面的污染物,從而恢復(fù)吸附劑的吸附容量,達(dá)到重復(fù)使用目的的方法[173-174].而微生物再生法僅適用于易被生物分解,具有吸附可逆性,容易脫附的污染物[172].由微生物解析下來(lái)的有機(jī)物必須可以一步分解成CO2和H2O.而PFAS基本不能被生物氧化或還原[18],其礦化是非常困難的,因此利用生物再生法再生PFAS吸附飽和的吸附劑難以實(shí)現(xiàn). 再生后脫附的PFAS易造成二次污染,需要結(jié)合降解技術(shù),才能達(dá)到PFAS無(wú)害化處理目的.PFAS降解技術(shù)包括化學(xué)氧化法和化學(xué)還原法等.化學(xué)氧化技術(shù)主要利用?OH和SO4?-等具有強(qiáng)氧化的活性物質(zhì)降解PFAS,主要的降解體系包括Fenton體系,類Fenton體系,SO4?-降解體系,超聲降解體系,光催化降解體系和電化學(xué)降解體系等[28, 177].但PFAS中所含的碳氟鍵鍵能較高,且分子表面的電子云密度較高,因此化學(xué)氧化技術(shù)很難徹底降解PFAS[178].氟原子具有很高的電負(fù)性,可以吸收電子發(fā)生還原降解,故化學(xué)還原技術(shù)可實(shí)現(xiàn)對(duì)PFAS的高效降解[176].目前應(yīng)用于PFAS降解的還原體系主要包括水合電子體系,納米零價(jià)鐵體系和超氧陰離子體系等[28]. 焚燒技術(shù)因其在減量化和能量回收方面的優(yōu)勢(shì)逐漸成為處理PFAS吸附劑的主流技術(shù)[179].焚燒可以有效減少吸附劑的體積和質(zhì)量,此外,一些碳質(zhì)吸附劑中含有大量的聚合物,例如纖維素,半纖維素和木質(zhì)素等[179],還可以從其燃燒中回收能量. 碳氟鍵的化學(xué)穩(wěn)定性是焚燒處理PFAS的一大挑戰(zhàn),PFOA,PFOS已被證明可以通過(guò)焚燒有效分解[180].但是焚燒需要相當(dāng)高的溫度(>700℃)和較長(zhǎng)的時(shí)間將PFAS轉(zhuǎn)化為HF和非氟化產(chǎn)品,全氟化程度較高的PFAS則需要更長(zhǎng)的時(shí)間和更高的溫度[102,180].部分PFAS可以在較低溫度(例如400℃)下催化氧化,然而由于效率較低尚未大規(guī)模應(yīng)用[181]. PFAS在焚燒過(guò)程中的遷移和轉(zhuǎn)化是亟需解決的問(wèn)題[182].目前對(duì)于PFAS焚燒期間可能形成的全部潛在副產(chǎn)物目前并沒(méi)有探究清楚,一些報(bào)告提出PFAS焚燒可能會(huì)釋放氯氟烴,氟化溫室氣體(如四氟甲烷,六氟乙烷和氟代二噁英),氟化芳香族化合物等[183-184],還會(huì)釋放出大量未識(shí)別和報(bào)道的分解產(chǎn)物[185].Watanabe等[186]研究了吸附有PFOS,PFOA和PFHxA的GAC在焚燒過(guò)程中PFAS的去向,在700℃下,很大一部分PFAS轉(zhuǎn)化為無(wú)法進(jìn)行最終分析的揮發(fā)性物質(zhì).因此,在焚燒產(chǎn)生的廢氣中捕獲或銷毀PFAS是研究的熱點(diǎn). 吸附劑的焚燒或熱再生均是通過(guò)高溫處理污染物,但它們的目的和應(yīng)用場(chǎng)景不同[174].熱再生是一種恢復(fù)吸附劑性能的方法,它通過(guò)升高溫度,使吸附物脫附,從而恢復(fù)吸附劑的吸附能力,達(dá)到循環(huán)利用目的,適用范圍廣[173].而焚燒是一種以減量化和資源化為目標(biāo),處理危險(xiǎn)廢物的方法[179].焚燒旨在減少?gòu)U物量并將其轉(zhuǎn)化為更安全的形式,而熱再生則旨在恢復(fù)吸附劑性能并保持吸附劑原有結(jié)構(gòu). 盡管焚燒可破壞部分PFAS,但仍需要從焚燒設(shè)施中獲取詳細(xì)數(shù)據(jù),評(píng)估PFAS焚燒對(duì)人類和環(huán)境健康的影響[182-183].此外,一些PFAS不完全燃燒而產(chǎn)生的分解物質(zhì),需要結(jié)合其他方法(如填埋)進(jìn)一步處理. 填埋處置具有操作簡(jiǎn)便,設(shè)備簡(jiǎn)單,成本效益良好等優(yōu)點(diǎn)[187].但會(huì)占用大量土地資源,且會(huì)造成二次污染,并不利于廢物資源化利用[187]. 填埋過(guò)程中,吸附劑中的PFAS會(huì)通過(guò)物理,化學(xué)和生物作用逐漸釋放到滲濾液中[188].Lang等[189]測(cè)定了美國(guó)18個(gè)垃圾填埋場(chǎng)滲濾液中的PFAS,70種 PFAS的濃度達(dá)到66μg/L.Wang等[190]的調(diào)查結(jié)果顯示,城市固體廢物填埋場(chǎng)和轉(zhuǎn)運(yùn)站滲濾液中也含有多種PFAS,濃度為22～46μg/L.如果對(duì)這些PFAS未能有效捕獲和處理,它們甚至可能穿透防滲層,使填埋場(chǎng)成為PFAS進(jìn)入水環(huán)境的二次源頭[188]. 目前對(duì)滲濾液中PFAS的研究較少,主要集中在一些發(fā)達(dá)國(guó)家[191-193].我國(guó)針對(duì)垃圾滲濾液中PFAS的調(diào)查研究尚處于起步階段,僅有的少量研究主要集中在北京,上海等經(jīng)濟(jì)發(fā)達(dá)地區(qū),而其他地區(qū)有關(guān)滲濾液中PFAS的調(diào)查鮮有報(bào)道[194-195].Yan等[195]收集了中國(guó)5個(gè)城市原始和處理過(guò)的垃圾填埋場(chǎng)樣本,原始樣本中多種PFAS的濃度從7280～292000ng/L不等,處理后滲濾液中的PFAS濃度為98.4～282000ng/L,其中PFOS和PFBS占比最高(分別為28.8%和26.1%). 不同類型的填埋場(chǎng),滲濾液中所含PFAS的濃度也有差異.在Gallen等[192]的調(diào)查中,含有建筑和拆除碎片的填埋場(chǎng),滲濾液中的PFAS平均濃度較高.在Gabriele等[188]的研究也發(fā)現(xiàn)了同樣的結(jié)果,建筑垃圾填埋場(chǎng)和拆除垃圾填埋場(chǎng)滲濾液中PFAS含量較高.建筑材料中的密封劑和防水劑等含有PFAS,這可能是造成垃圾填埋場(chǎng)滲濾液中PFAS含量較高的原因之一.相比之下,灰燼填埋場(chǎng)滲濾液中的PFAS含量較低.這可能是由于PFAS在焚燒過(guò)程中被分解或揮發(fā)到大氣中. 垃圾滲濾液收集系統(tǒng)的設(shè)計(jì)初衷是為了防止地下水和土壤受到污染.然而,目前在垃圾填埋場(chǎng)中,PFAS的徑流和滲漏仍然是一個(gè)重要問(wèn)題[188].據(jù)明尼蘇達(dá)州污染控制機(jī)構(gòu)報(bào)道[196],該州垃圾填埋場(chǎng)附近的地下水已受到PFAS污染.雖然通過(guò)填埋處理PFAS吸附劑可以臨時(shí)封存這些物質(zhì),但由于大多數(shù)PFAS不會(huì)自然降解成非氟物質(zhì),填埋場(chǎng)最終可能成為新的PFAS污染源[187]. 吸附技術(shù)是水處理廠應(yīng)對(duì)PFAS污染的最佳可行技術(shù)之一,相比復(fù)雜的降解技術(shù)體系,活性炭和樹(shù)脂等吸附技術(shù)建造和運(yùn)行成本更低,相比膜分離技術(shù),操作的簡(jiǎn)便性是顯著優(yōu)勢(shì).依據(jù)水質(zhì)和PFAS污染類型的不同,吸附劑的科學(xué)選型或者復(fù)合吸附填料的應(yīng)用將決定技術(shù)的實(shí)際工程應(yīng)用效果.針對(duì)水中PFAS的污染控制,吸附技術(shù)未來(lái)在以下幾個(gè)方向可加強(qiáng)研究: (1)針對(duì)PFAS污染的復(fù)雜特征,制定具有普遍適用性的吸附策略,比如對(duì)多類型水體中不同碳鏈長(zhǎng)度,離子端基團(tuán),電荷類型的PFAS都有高去除效率的吸附材料,技術(shù),工藝及裝備. (2)開(kāi)發(fā)高效的吸附劑再生/處置技術(shù),解決目前方法能耗高,效率低,易產(chǎn)生二次污染物等問(wèn)題,使PFAS吸附技術(shù)形成閉環(huán). (3)開(kāi)發(fā)具有吸附協(xié)同降解功能的先進(jìn)材料,實(shí)現(xiàn)PFAS的同步富集和礦化,延長(zhǎng)吸附劑使用壽命,降低技術(shù)能耗,提高PFAS去除效率. [1] 袁雅靜.全氟或多氟烷基物質(zhì)水處理技術(shù)研究進(jìn)展 [J]. 化工進(jìn)展, 2021,40(S1):397-403. Yuan J Y. Progress in water treatment technology for perfluorinated or polyfluorinated alkyl substances [J]. Chemical Industry and Engineering Progress, 2021,40(S1):397-403. [2] Du Z W, Deng S B, Bei Y, et al. Adsorption behavior and mechanism of perfluorinated compounds on various adsorbents—A review [J]. Journal of Hazardous Materials, 2014,274:443-454. [3] Dixit F, Dutta R, Barbeau B, et al. PFAS removal by ion exchange resins: A review [J]. Chemosphere, 2021,272:129777. [4] Zenobio J E, Salawu O A, Han Z W, et al. Adsorption of per- and polyfluoroalkyl substances (PFAS) to containers [J]. Journal of Hazardous Materials Advances, 2022,7:100130. [5] Boyer T H, Fang Y D, Ellis A, et al. Anion exchange resin removal of per- and polyfluoroalkyl substances (PFAS) from impacted water: A critical review [J]. Water Research, 2021,200:117244. [6] Gao Y X, Deng S B, Du Z W, et al. Adsorptive removal of emerging polyfluoroalky substances F-53B and PFOS by anion-exchange resin: A comparative study [J]. Journal of Hazardous Materials, 2017,323 (Pt.A):550-557. [7] Elika K, Medha K, Sweta M, et al. A juxtaposed review on adsorptive removal of PFAS by metal-organic frameworks (MOFs) with carbon-based materials, ion exchange resins, and polymer adsorbents [J]. Chemosphere, 2023,311(Part 1):136933. [8] Pelch K E, Reade A, Wolffe T A M, et al. PFAS health effects database: protocol for a systematic evidence map [J]. Environment International, 2019,130:104851. [9] Baker E S, Knappe D R U. Per- and polyfluoroalkyl substances (PFAS)—contaminants of emerging concern [J]. Analytical and Bioanalytical Chemistry, 2022,414(3):1187-1188. [10] Gagliano E, Sgroi M, Falciglia P P, et al. Removal of poly- and perfluoroalkyl substances (PFAS) from water by adsorption: role of PFAS chain length, effect of organic matter and challenges in adsorbent regeneration [J]. Water Research, 2020,171:115381. [11] 溫 馨,呂 佳,王園媛,等.常規(guī)處理工藝對(duì)飲用水中全氟化合物的去除效果研究 [J]. 環(huán)境衛(wèi)生學(xué)雜志, 2022,12(7):526-532. Wen X, Lyu Jia, Wang Y Y, et al. Removal efficiency of perfluorinated compounds in drinking water by conventional treatment process [J]. Journal of Environmental Hygiene, 2022,12(7):526-532. [12] Yu H, Chen Y F, Guo H Q, et al. Preparation of molecularly imprinted carbon microspheres by one-pot hydrothermal method and their adsorption properties to perfluorooctane sulfonate [J]. Chinese Journal of Analytical Chemistry, 2019,47(11):1776-1784. [13] Dickman R A, Aga D S. A review of recent studies on toxicity, sequestration, and degradation of per- and polyfluoroalkyl substances (PFAS) [J]. Journal of Hazardous Materials, 2022,436:129120. [14] 杜玲玲.全氟辛烷磺酸分子印跡納米材料的制備與性能研究 [D]. 重慶:西南大學(xué), 2018. Du L L. Study on the preparation and properties of perfluorooctane sulfonate molecularly imprinted nanomaterials [D]. Chongqing: Southwest University, 2018. [15] GB 5749-2022 生活飲用水衛(wèi)生標(biāo)準(zhǔn)[S].GB 5749-2022 Standards for drinking water quality [S]. [16] Leung S C E, Shukla P, Chen D C, et al. Emerging technologies for PFOS/PFOA degradation and removal: a review [J]. Science of the Total Environment, 2022,827:153669. [17] Kazwini T, Yadav S, Ibrar I, et al. Updated review on emerging technologies for PFAS contaminated water treatment [J]. Chemical Engineering Research and Design, 2022,182:667-700. [18] Zhang Z M, Sarkar D, Biswas J K, et al. Biodegradation of per- and polyfluoroalkyl substances (PFAS): a review [J]. Bioresource Technology, 2022,344(Part B):126223. [19] Nzeribe B N, Crimi M, Mededovic Thagard S, et al. Physico-chemical processes for the treatment of per- and polyfluoroalkyl substances (PFAS): a review [J]. Critical Reviews in Environmental Science and Technology, 2019,49(10):866-915. [20] 張春暉,劉 育,唐佳偉,等.典型工業(yè)廢水中全氟化合物處理技術(shù)研究進(jìn)展 [J]. 中國(guó)環(huán)境科學(xué), 2021,41(3):1109-1118. Zhang C H, Liu Y, Tang J W, et al. Progress of research on treatment technology of perfluorinated compounds in typical industrial wastewater [J]. Chinese Environmental Sciences, 2021,41(3):1109- 1118. [21] 周 琴,欒 萱,潘 綱.水中典型全氟化合物的吸附行為 [J]. 科學(xué)通報(bào), 2012,57(17):1526-1532. Zhou Q, Luan X, Pan G. Sorption of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) from water [J]. Chinese Science Bulletin, 2012,57(17):1526-1532. [22] Arvaniti O S, Stasinakis A S. Review on the occurrence, fate and removal of perfluorinated compounds during wastewater treatment [J]. Science of the Total Environment, 2015,524-525:81-92. [23] Eschauzier C, Beerendonk E, Scholte-Veenendaal P, et al. Impact of treatment processes on the removal of perfluoroalkyl acids from the drinking water production chain [J]. Environmental Science, 2012,46 (3):1708-1715. [24] Qui?ones O, Snyder S A. Occurrence of perfluoroalkyl carboxylates and sulfonates in drinking water utilities and related waters from the united states [J]. Environmental Science, 2009,43(24):9089-9095. [25] 郭 睿,張超杰,周 琪.水環(huán)境中全氟化合物的去除技術(shù)研究綜述 [J]. 凈水技術(shù), 2016,35(6):18-24. Guo R, Zhang C J, Zhou Q. Research overview of technology of perfluorinated compounds removal in water environment [J]. Water Purification Technology, 2016,35(6):18-24. [26] Deng S B, Yu Q, Huang J, et al. Removal of perfluorooctane sulfonate from wastewater by anion exchange resins: Effects of resin properties and solution chemistry [J]. Water Research, 2010,44(18):5188-5195. [27] Tang C Y, Fu Q S, Gao D, et al. Effect of solution chemistry on the adsorption of perfluorooctane sulfonate onto mineral surfaces [J]. Water Research, 2010,44(8):2654-2662. [28] 滕 影,王雯冉,黃柳青,等.全氟烷基化合物的去除技術(shù)研究進(jìn)展 [J]. 環(huán)境化學(xué), 2023,42(7):2210-2227. Teng Y, Wang W R, Huang L Q, et al. Research progress on the removal of perfluorinated allkyl substances: A review [J]. Environmental Chemistry, 2023,42(7):2210-2227. [29] 朱鵬宇,劉建廣,辛?xí)詵|.活性炭吸附水中全氟化合物的研究進(jìn)展 [J]. 凈水技術(shù), 2022,41(10):17-22,147. Zhu P Y, Liu J G, Xin X D. Research progress of activated carbon for adsorption of perfluorinated compounds in water [J]. Water Purification Technology, 2022,41(10):17-22,147. [30] Du Z W, Deng S B, Chen Y G, et al. Removal of perfluorinated carboxylates from washing wastewater of perfluorooctanesulfonyl fluoride using activated carbons and resins [J]. Journal of Hazardous Materials, 2015,286:136-143. [31] Ochoa-Herrera V, Sierra-Alvarez R. Removal of perfluorinated surfactants by sorption onto granular activated carbon, zeolite and sludge [J]. Chemosphere, 2008,72(10):1588-1593. [32] Yu Q, Zhang R Q, Deng S B, et al. Sorption of perfluorooctane sulfonate and perfluorooctanoate on activated carbons and resin: Kinetic and isotherm study [J]. Water Research, 2009,43(4):1150- 1158. [33] Yu H, Chen H, Fang B, et al. Sorptive removal of per- and polyfluoroalkyl substances from aqueous solution: Enhanced sorption, challenges and perspectives [J]. Science of The Total Environment, 2023,861:160647. [34] Rostvall A, Zhang W, Dürig W, et al. Removal of pharmaceuticals, perfluoroalkyl substances and other micropollutants from wastewater using lignite, xylit, sand, granular activated carbon (GAC) and GAC+polonite? in column tests – role of physicochemical properties [J]. Water Research, 2018,137:97-106. [35] Westreich P, Mimna R, Brewer J, et al. The removal of short‐chain and long‐chain perfluoroalkyl acids and sulfonates via granular activated carbons: A comparative column study [J]. Remediation Journal, 2018,29(1):19-26. [36] Zaggia A, Conte L, Falletti L, et al. Use of strong anion exchange resins for the removal of perfluoroalkylated substances from contaminated drinking water in batch and continuous pilot plants [J]. Water Research, 2016,91:137-146. [37] Westerhoff P, Yoon Y, Snyder S, et al. Fate of endocrine-disruptor, pharmaceutical, and personal care product chemicals during simulated drinking water treatment processes [J]. Environmental Science, 2005,39(17):6649-6663. [38] 童錫臻,石寶友,解 岳,等.改性活性炭對(duì)水中PFOS的吸附去除研究 [J]. 環(huán)境科學(xué), 2012,33(9):3132-3138. Tong X Z, Shi B Y, Xie Y, et al. Adsorption of perfluorooctanesulfonate (PFOS) onto modified activated carbons [J]. Environmental Science, 2012,33(9):3132-3138. [39] Pauletto P S, Bandosz T J. Activated carbon versus metal-organic frameworks: A review of their PFAS adsorption performance [J]. Journal of Hazardous Materials, 2022,425:127810. [40] Bhatnagar A, Hogland W, Marques M, et al. An overview of the modification methods of activated carbon for its water treatment applications [J]. Chemical Engineering Journal, 2013,219(3):499–511. [41] Menéndez J A, phillips J, Xia B, et al. On the modification and characterization of chemical surface properties of activated carbon: In the search of carbons with stable basic properties [J]. Langmuir, 1996, 12(18):4404-4410. [42] Faria P C C, Orfao J J M, Pereira M F R. Adsorption of anionic and cationic dyes on activated carbons with different surface chemistries [J]. Water Research, 2004,38(8):2043-2052. [43] Shaarani F W, Hameed B H. Ammonia-modified activated carbon for the adsorption of 2,4-dichlorophenol [J]. Chemical Engineering Journal, 2011,169(1-3):180-185. [44] Saeidi N, Kopinke F D, Georgi A. What is specific in adsorption of perfluoroalkyl acids on carbon materials? [J]. Chemosphere, 2020,273: 128520. [45] 苑 晨.季銨鹽改性活性炭吸附地下水中PFOA的效能及其機(jī)理研究 [D]. 重慶:重慶大學(xué), 2019. Yuan C. Adsorption of PFOA in groundwater by quaternary ammonium epoxide compounds modified activated carbon and its mechanism analysis [D]. Chongqing: Chongqing University, 2019. [46] Cantoni B, Turolla A, Wellmitz J, et al. Perfluoroalkyl substances (PFAS) adsorption in drinking water by granular activated carbon: Influence of activated carbon and PFAS characteristics [J]. Science of The Total Environment, 2021,795:148821. [47] Park M, Wu S M, Lopez I J, et al. Adsorption of perfluoroalkyl substances (PFAS) in groundwater by granular activated carbons: Roles of hydrophobicity of PFAS and carbon characteristics [J]. Water Research, 2019,170:115364. [48] Chen W, Zhang X P, Mamadiev M, et al. Sorption of perfluorooctane sulfonate and perfluorooctanoate on polyacrylonitrile fiber-derived activated carbon fibers: in comparison with activated carbon [J]. RSC advances, 2017,7(2):927-938. [49] 趙麗媛,呂劍明,李慶利,等.活性炭制備及應(yīng)用研究進(jìn)展 [J]. 科學(xué)技術(shù)與工程, 2008,8(11):6. Zhao L Y, Lü J M, Li Q L, et al. Present situation and progress in preparation of activated carbon [J]. Science Technology and Engineering, 2008,8(11):6. [50] Dastgheib S A, Karanfil T. Adsorption of oxygen by heat-treated granular and fibrous activated carbons [J]. Journal of Colloid and Interface Science, 2004,274(1):1-8. [51] 周 平,黃汝常,李永輝,等.去除廢水中重金屬離子的新工藝研究 [J]. 中國(guó)給水排水, 1998,14(4):17-20. Zhou P, Huang R C, Li Y H, et al. Study of a novel process for removal of heavy metals from industrial wastewater [J]. China Water & Wastewater, 1998,14(4):17-20. [52] Punyapalakul P, Soonglerdsongpha S, Kanlayaprasit C, et al. Effects of crystalline structures and surface functional groups on the adsorption of haloacetic acids by inorganic materials [J]. Journal of Hazardous Materials, 2009,171(1-3):491-499. [53] Senevirathna S, Tanaka S, Fujii S, et al. A comparative study of adsorption of perfluorooctane sulfonate (PFOS) onto granular activated carbon, ion-exchange polymers and non-ion-exchange polymers [J]. Chemosphere, 2010,80(6):647-651. [54] Zhang D Q, Zhang W L, Liang Y N. Adsorption of perfluoroalkyl and polyfluoroalkyl substances (PFASs) from aqueous solution - A review [J]. Science of the Total Environment, 2019,694:133606. [55] Ross I, McDonough J, Miles J, et al. A review of emerging technologies for remediation of PFASs [J]. Remediation Journal, 2018,28(2):101-126. [56] 許 羅,林秋風(fēng),李 聰,等.典型全氟化合物污染現(xiàn)狀及其處理技術(shù)研究進(jìn)展 [J]. 中國(guó)給水排水, 2022,38(10):56-62. Xu L, Lin Q F, Li C, et al. Current situation of typical perfluorinated compounds pollution and its treatment technology progress [J]. China Water & Wastewater, 2022,38(10):56-62. [57] Maimaiti A, Deng S B, Meng P P, et al. Competitive adsorption of perfluoroalkyl substances on anion exchange resins in simulated AFFF-impacted groundwater [J]. Chemical Engineering Journal, 2018, 348:494-502. [58] 馬蘊(yùn)杰,陳 程,張 偉.吸附樹(shù)脂改性的研究進(jìn)展 [J]. 遼寧化工, 2019,48(8):796-799. Ma Y J, Chen C, Zhang W. Research progress in the modification of adsorbent resin [J]. Liaoning Chemical Industry, 2019,48(8):796-799. [59] Xie R C, Zhou L, Smith A E, et al. A dual grafted fluorinated hydrocarbon amine weak anion exchange resin polymer for adsorption of perfluorooctanoic acid from water [J]. Journal of Hazardous Materials, 2022,431:128521. [60] 蘇 球.含酚羥基超高交聯(lián)分子印跡吸附樹(shù)脂的制備及吸附性能研究 [D]. 鎮(zhèn)江:江蘇大學(xué), 2016. Su Q. Preparation and adsorptive property of phenol hydroxyl hypercrosslinked and molecularly imprinted adsorption resin [D]. Zhenjiang: Jiangsu University, 2016. [61] Ateia M, Alsbaiee A, Karanfil T, et al. Efficient PFAS removal by amine-functionalized sorbents: critical review of the current literature [J]. Environmental Science & Technology, 2019,6(12):688-695. [62] 王夢(mèng)喬.新型磁性胺基修飾超高交聯(lián)樹(shù)脂的合成及其應(yīng)用研究 [D]. 南京:南京大學(xué), 2014. Wang M Q. Synthesis and application of novel magnetic hypercrosslinked resin modified with amino group [D]. Nanjiang: Nanjing University, 2014. [63] Park M, Daniels K D, Wu S M, et al. Magnetic ion-exchange (MIEX) resin for perfluorinated alkylsubstance (PFAS) removal in groundwater: Roles of atomic charges for adsorption [J]. Water Research, 2020,181:115897. [64] Améduri Bruno. The promising future of fluoropolymers [J]. Macromolecular Chemistry and physics, 2019,221(8):1900573. [65] Shetty D, Jahovic? I, Skorjanc T, et al. Rapid and efficient removal of perfluorooctanoic acid from water with fluorine-rich calixarene-based porous polymers [J]. ACS applied materials & interfaces, 2020, 12(38):43160-43166. [66] Dixit F, Barbeau B, Mostafavi S G, et al. PFAS and DOM removal using an organic scavenger and PFAS-specific resin: Trade-off between regeneration and faster kinetics [J]. Science of The Total Environment, 2020,754:142107. [67] Kothawala D N, K?hler S J, ?stlund A, et al. Influence of dissolved organic matter concentration and composition on the removal efficiency of perfluoroalkyl substances (PFASs) during drinking water treatment [J]. Water Research, 2017,121:320-328. [68] McCleaf P, Englund S, ?stlund A, et al. Removal efficiency of multiple poly- and perfluoroalkyl substances (PFASs) in drinking water using granular activated carbon (GAC) and anion exchange (AE) column tests [J]. Water Research, 2017,120:77-87. [69] Vu C T, Wu T T. Recent progress in adsorptive removal of per- and poly-fluoroalkyl substances (PFAS) from water/wastewater [J]. Critical Reviews in Environmental Science and Technology, 2022, 52(1):90-129. [70] Levchuk I, Màrquez J J R, Sillanp?? M. Removal of natural organic matter (NOM) from water by ion exchange - A review [J]. Chemosphere, 2018,192:90-104. [71] Deng S B, Zhang Q Y, Nie Y, et al. Sorption mechanisms of perfluorinated compounds on carbon nanotubes [J]. Environmental Pollution, 2012,168:138-144. [72] Wang F, Shih K. Adsorption of perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) on alumina: Influence of solution pH and cations [J]. Water Research, 2011,45(9):2925-2930. [73] Zhou Q, Deng S B, Zhang Q Y, et al. Sorption of perfluorooctane sulfonate and perfluorooctanoate on activated sludge [J]. Chemosphere, 2010,81(4):453-458. [74] He G Z, Zhang M Y, Zhou Q, et al. Molecular dynamics simulations of structural transformation of perfluorooctane sulfonate (PFOS) at water/rutile interfaces [J]. Chemosphere, 2015,134:272-278. [75] Feng Y, Zhou Y, Lee P H, et al. Mineralization of perfluorooctanesulfonate (PFOS) and perfluorodecanoate (PFDA) from aqueous solution by porous hexagonal boron nitride: adsorption followed by simultaneous thermal decomposition and regeneration [J]. RSC advances, 2016,6(114):113773-113780. [76] Barakan S, Aghazadeh V. The advantages of clay mineral modification methods for enhancing adsorption efficiency in wastewater treatment: a review [J]. Environmental Science and Pollution Research, 2021, 28(3):2572-2599. [77] Johnson R L, Anschutz A J, Smolen J M, et al. The adsorption of perfluorooctane sulfonate onto sand, clay, and iron oxide surfaces [J]. Journal of Chemical & Engineering Data, 2007,52(4):1165-1170. [78] Ellefson M. Soil adsorption/desorption study of potassium perfluorooctane sulfonate(PFOS). EPA Docket AR226-1030a030, 3M Company, Maplewood, MN, 2001. [79] Junho Jeon, Kurunthachalam Kannan, Byung J Lim, et al. Effects of salinity and organic matter on the partitioning of perfluoroalkyl acid (PFAs) to clay particles [J]. Journal of Environmental Monitoring, 2011,13(6):1803-1810. [80] Gao X, Chorover J. Adsorption of perfluorooctanoic acid and perfluorooctanesulfonic acid to iron oxide surfaces as studied by flow-through ATR-FTIR spectroscopy [J]. Environmental Chemistry, 2012,9(2):148-157. [81] Mukhopadhyay R, Sarkar B, Palansooriya K N, et al. Natural and engineered clays and clay minerals for the removal of poly- and perfluoroalkyl substances from water: State-of-the-art and future perspectives [J]. Advances in Colloid and Interface Science, 2021, 297:102537. [82] Du Z W, Deng S B, Zhang S Y, et al. Selective and high Sorption of perfluorooctane sulfonate and perfluorooctanoate by fluorinated alkyl chain modified montmorillonite [J]. The Journal of Physical Chemistry C, 2016,120(30):16782-16790. [83] El Mouzdahir Y, Elmchaouri A, Mahboub R, et al. Equilibrium modeling for the adsorption of methylene blue from aqueous solutions on activated clay minerals [J]. Desalination, 2010,250(1):335-338. [84] Mukhopadhyay R, Bhaduri D, Sarkar B, et al. Clay-polymer nanocomposites: Progress and challenges for use in sustainable water treatment [J]. Journal of Hazardous Materials, 2020,383:121125. [85] Bhattarai B, Muruganandham M, Suri R P S. Development of high efficiency silica coated β-cyclodextrin polymeric adsorbent for the removal of emerging contaminants of concern from water [J]. Journal of Hazardous Materials, 2014,273:146-154. [86] Smart B E. Characteristics of C-F Systems [M]. Organofluorine Chemistry: Principles and Commercial Applications. Boston, MA: Springer US, 1994,57-88. [87] Riess J G. Understanding the fundamentals of perfluorocarbons and perfluorocarbon emulsions relevant to in vivo oxygen delivery [J]. Artificial Cells, Blood Substitutes, and Biotechnology, 2005,33(1):47- 63. [88] Gong Y Y, Wang L, Liu J C, et al. Removal of aqueous perfluorooctanoic acid (PFOA) using starch-stabilized magnetite nanoparticles [J]. Science of the Total Environment, 2016,562:191- 200. [89] Mancinelli M, Stevanin C, Ardit M, et al. PFAS as emerging pollutants in the environment: A challenge with FAU type and silver-FAU exchanged zeolites for their removal from water [J]. Journal of Environmental Chemical Engineering, 2022,10(4):108026. [90] Wei Z S, Xu T Y, Zhao D Y. Treatment of per- and polyfluoroalkyl substances in landfill leachate: status, chemistry and prospects [J]. Environmental Science: Water Research & Technology, 2019,5(11): 1814-1835. [91] Lath S, Navarro D A, Losic D, et al. Sorptive remediation of perfluorooctanoic acid (PFOA) using mixed mineral and graphene/ carbon-based materials [J]. Environmental Chemistry, 2018,15(8): 472-480. [92] Zhang R M, Yan W, Jing C Y. Mechanistic study of PFOS adsorption on kaolinite and montmorillonite [J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2014,462:252-258. [93] Pereira H C, Ullberg M, Kleja D B, et al. Sorption of perfluoroalkyl substances (PFASs) to an organic soil horizon – Effect of cation composition and pH [J]. Chemosphere, 2018,207:183-191. [94] Karoyo A H, Wilson L D. Tunable macromolecular-based materials for the adsorption of perfluorooctanoic and octanoic acid anions [J]. Journal of Colloid and Interface Science, 2013,402:196-203. [95] Meng P P, Fang X L, Maimaiti A, et al. Efficient removal of perfluorinated compounds from water using a regenerable magnetic activated carbon [J]. Chemosphere, 2019,224:187-194. [96] Inyang M, Dickenson E R V. The use of carbon adsorbents for the removal of perfluoroalkyl acids from potable reuse systems [J]. Chemosphere, 2017,184:168-175. [97] Yu Q, Deng S B, Yu G. Selective removal of perfluorooctane sulfonate from aqueous solution using chitosan-based molecularly imprinted polymer adsorbents [J]. Water Research, 2008,42(12):3089-3097. [98] Elanchezhiyan S S D, Preethi J, Rathinam K, et al. Synthesis of magnetic chitosan biopolymeric spheres and their adsorption performances for PFOA and PFOS from aqueous environment [J]. Carbohydrate Polymers, 2021,267:118165. [99] Punyapalakul P, Suksomboon K, Prarat P, et al. Effects of surface functional groups and porous structures on adsorption and recovery of perfluorinated compounds by inorganic porous silicas [J]. Separation Science and Technology, 2013,48(5):775-788. [100]Guo W, Huo S L, Feng J L, et al. Adsorption of perfluorooctane sulfonate (PFOS) on corn straw-derived biochar prepared at different pyrolytic temperatures [J]. Journal of the Taiwan Institute of Chemical Engineers, 2017,78:265-271. [101]Zhou Q, Deng S B, Yu Q, et al. Sorption of perfluorooctane sulfonate on organo-montmorillonites [J]. Chemosphere, 2010,78(6):688-694. [102]Rayne S, Forest K. Perfluoroalkyl sulfonic and carboxylic acids: a critical review of physicochemical properties, levels and patterns in waters and wastewaters, and treatment methods [J]. Journal of Environmental Science and Health Part A, 2009,44(12):1145-1199. [103]Guo W, Lu S Y, Shi J H, et al. Effect of corn straw biochar application to sediments on the adsorption of 17α-ethinyl estradiol and perfluorooctane sulfonate at sediment-water interface [J]. Ecotoxicology and Environmental Safety, 2019,174:363-369. [104]Fabregat-Palau J, Vidal M, Rigol A. Examining sorption of perfluoroalkyl substances (PFAS) in biochars and other carbon-rich materials [J]. Chemosphere, 2022,302:134733. [105]杜子文.吸附去除廢水中全氟化合物及高選擇性氟化吸附劑的研究 [D]. 北京:清華大學(xué), 2017. Du Z W. Adsorptive removal of perfluorinated compounds from industrial wastewater and preparation of highly selective fluorinated adsorbents [D]. Beijing: Tsinghua University, 2017. [106]靳曉雨.污水中全氟化合物的去除方法 [J]. 化工管理, 2022,(20): 144-146. Jin X Y. Removal methods of perfluorinated compounds from sewage [J]. Chemical Enterprise Management, 2022,(20):144-146. [107]Zhang Q Y, Deng S B, Yu G, et al. Removal of perfluorooctane sulfonate from aqueous solution by crosslinked chitosan beads: Sorption kinetics and uptake mechanism [J]. Bioresource Technology, 2011,102(3):2265-2271. [108]Militao I M, Roddick F, Bergamasco R, et al. Rapid adsorption of PFAS: application of moringa oleifera seed powder encapsulated in alginate beads [J]. Environmental Technology & Innovation, 2022,28: 102761. [109]Krahn K M, Cornelissen G, Castro G, et al. Sewage sludge biochars as effective PFAS-sorbents [J]. Journal of Hazardous Materials, 2022, 445:130449. [110]Jin X, Wang Z, Hong R, et al. Supramolecular assemblies of a newly developed indole derivative for selective adsorption and photo- destruction of perfluoroalkyl substances [J]. Water Research, 2022, 225:119147. [111]Turner B D, Sloan S W, Currell G R. Novel remediation of per- and polyfluoroalkyl substances (PFASs) from contaminated groundwater using Cannabis Sativa L. (hemp) protein powder [J]. Chemosphere, 2019,229:22-31. [112]Rodrigo P M, Navarathna C, pham M T H, et al. Batch and fixed bed sorption of low to moderate concentrations of aqueous per- and poly-fluoroalkyl substances (PFAS) on Douglas fir biochar and its Fe3O4hybrids [J]. Chemosphere, 2022,308:136155. [113]Hassan M, Liu Y J, Naidu R, et al. Adsorption of perfluorooctane sulfonate (PFOS) onto metal oxides modified biochar [J]. Environmental Technology & Innovation, 2020,19:100816. [114]Verma M, Lee I, Kumar V, et al. Chitosan cross-linked β–cyclodextrin polymeric adsorbent for the removal of perfluorobutanesulfonate from aqueous solution: adsorption kinetics, isotherm, and mechanism [J]. Environmental Science and Pollution Research, 2022,30:19259– 19268. [115]Wang R, Lin Z W, Klemes M J, et al. A tunable porous β-cyclodextrin polymer platform to understand and improve anionic PFAS removal [J]. ACS Central Science, 2022,8(5):663-669. [116]Zhang C J, Yan H, Li F, et al. Sorption of short- and long-chain perfluoroalkyl surfactants on sewage sludges [J]. Journal of Hazardous Materials, 2013,260(18):689-699. [117]He G Z, Pan G, Zhang M Y. Assembling structures and dynamics properties of perfluorooctane sulfonate (PFOS) at water–titanium oxide interfaces [J]. Journal of Colloid and Interface Science, 2013, 405:189-194. [118]Takayose M, Nishimoto K, Matsui J. A fluorous synthetic receptor that recognizes perfluorooctanoic acid (PFOA) via fluorous interaction obtained by molecular imprinting [J]. Analyst, 2012,137(12):2762- 2765. [119]Xiao F, Davidsavor K J, Park S, et al. Batch and column study: Sorption of perfluorinated surfactants from water and cosolvent systems by Amberlite XAD resins [J]. Journal of Colloid and Interface Science, 2012,368(1):505-511. [120]Li X, Pignatello J J, Wang Y, et al. New insight into adsorption mechanism of ionizable compounds on carbon nanotubes [J]. Environmental science & technology, 2013,47(15):8334-8341. [121]Gilli P, Bertolasi V, Ferretti V, et al. Covalent nature of the strong homonuclear hydrogen bond. Study of the O-H-O system by crystal [J]. Journal of the American Chemical Society, 1994,116(3):909-915. [122]Ward M D. Design of crystalline molecular networks with charge- assisted hydrogen bonds [J]. Chemical communications, 2005,(47): 5838-5842. [123]Deng S B, Shuai D M, Yu Q, et al. Selective sorption of perfluorooctane sulfonate on molecularly imprinted polymer adsorbents [J]. Frontiers of Environmental Science & Engineering in China, 2009,3(2):171-177. [124]林 森.聚多巴胺表面功能化及其對(duì)水中PFOS分離富集性能研究 [D]. 南昌:南昌航空大學(xué), 2019. Lin S. Surface functionalization of polydopamine and their separation and enrichment performance of PFOS in water [D]. Nanchang: Nanchang Hangkong University, 2019. [125]余 強(qiáng).水中典型全氟化合物的吸附去除研究 [D]. 北京:清華大學(xué), 2009. Yu Q. Removal of Representative Perfluorinated Compounds from Water by Sorption Process [D]. Beijing: Tsinghua University, 2009. [126]郭會(huì)琴,劉 宇,馬文天,等.基于生物質(zhì)碳微球的表面全氟辛磺酸鹽(PFOS)分子印跡聚合物的制備及吸附特性[C]. 第21屆全國(guó)色譜學(xué)術(shù)報(bào)告會(huì)及儀器展覽會(huì)會(huì)議論文集, 2017. Guo H Q, Liu Y, Ma W T, et al. Preparation and adsorption properties of biomass carbon microsphere-based molecularly imprinted polymers with perfluorooctane sulfonate (PFOS) on the surface [C]. Proceedings of the 21 st National Chromatography Symposium and Instrument Exhibition, 2017. [127]Li H Y, Bre?das J L. Large Out-of-Plane Deformations of two- dimensional covalent organic framework (COF) sheets [J]. The Journal of physical Chemistry Letters, 2018,9(15):4215-4220. [128]Fenlon E E. Double, double trefoil and trouble [J]. Nature Synthesis, 2022,1(8):586-587. [129]Chang P H, Chen C Y, Mukhopadhyay R, et al. Novel MOF- 808metal–organic framework as highly efficient adsorbent of perfluorooctane sulfonate in water [J]. Journal of Colloid and Interface Science, 2022,623:627-636. [130]Hu Y, Guo M M, Zhang S L, et al. Microwave synthesis of metal- organic frameworks absorbents (DUT-5-2) for the removal of PFOS and PFOA from aqueous solutions [J]. Microporous and Mesoporous Materials, 2022,333:111740. [131]Ji W J, Xiao L L, Ling Y H, et al. Removal of GenX and perfluorinated alkyl substances from water by amine-functionalized covalent organic frameworks [J]. Journal of the American Chemical Society, 2018,140(40):12677-12681. [132]孫 博,馬 軍.水中全氟化合物的活性炭吸附特性研究 [J]. 給水排水, 2017,53(2):14-18. Sun B, Ma J. Study on adsorption characteristic of perfluorinated compounds on activated carbon [J]. Water & Wastewater Engineering, 2017,53(2):14-18. [133]Wu C Y, Klemes M J, Trang B, et al. Exploring the factors that influence the adsorption of anionic PFAS on conventional and emerging adsorbents in aquatic matrices [J]. Water Research, 2020,182:115950. [134]Deng S B, Nie Y, Du Z W, et al. Enhanced adsorption of perfluorooctane sulfonate and perfluorooctanoate by bamboo-derived granular activated carbon [J]. Journal of Hazardous Materials, 2015, 282:150-157. [135]Pauletto P S, Florent M, Bandosz T J. Insight into the mechanism of perfluorooctanesulfonic acid adsorption on highly porous media: Sizes of hydrophobic pores and the extent of multilayer formation [J]. Carbon, 2022,191:535-545. [136]S?reng?rd M, ?stblom E, K?hler S, et al. Adsorption behavior of per- and polyfluoralkyl substances (PFASs) to 44inorganic and organic sorbents and use of dyes as proxies for PFAS sorption [J]. Journal of Environmental Chemical Engineering, 2020,8(3):103744. [137]Furtado R X S, Sabatini C A, Zaiat M, et al. Perfluorooctane sulfonic acid (PFOS) degradation by optimized heterogeneous photocatalysis (TiO2/UV) using the response surface methodology (RSM) [J]. Journal of Water Process Engineering, 2021,41:101986. [138]Park S, Zenobio J E, Lee L S. Perfluorooctane sulfonate (PFOS) removal with Pd0/nFe0nanoparticles: Adsorption or aqueous Fe- complexation, not transformation? [J]. Journal of Hazardous Materials, 2018,342:20-28. [139]Jeon J, Kannan K, Lim B J, et al. Effects of salinity and organic matter on the partitioning of perfluoroalkyl acid (PFAs) to clay particles [J]. Journal of Environmental Monitoring, 2011,13(6):1803-1810. [140]Fagbayigbo B O, Opeolu B O, Fatoki O S, et al. Sorption and partitioning of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) onto sediments of Diep and Plankenburg river systems Western Cape, South Africa [J]. Environmental Technology & Innovation, 2022,25:102110. [141]王 鵬,張海祿.表面化學(xué)改性吸附用活性炭的研究進(jìn)展 [J]. 炭素技術(shù), 2003,(3):23-28. Wang P, Zhang H L. Progress in surface chemical modification of activated carbon for absorption [J]. Carbon Techniques, 2003,(3):23- 28. [142]Ahmadi A, Yang W W, Jones S, et al. Separation-free Al-Mg/ graphene oxide composites for enhancement of urban stormwater runoff quality [J]. Advanced Composites and Hybrid Materials, 2018, 1:591-601. [143]Hansen M C, B?rresen M H, Schlabach M, et al. Sorption of perfluorinated compounds from contaminated water to activated carbon [J]. Journal of Soils and Sediments, 2010,10:179-185. [144]Buckley T, Karanam K, Xu X Y, et al. Effect of mono- and di-valent cations on PFAS removal from water using foam fractionation-A modelling and experimental study [J]. Separation and Purification Technology, 2022,286:120508. [145]Wang F, Shih K, Leckie J O. Effect of humic acid on the sorption of perfluorooctane sulfonate (PFOS) and perfluorobutane sulfonate (PFBS) on boehmite [J]. Chemosphere, 2015,118:213-218. [146]Chang P H, Jiang W T, Li Z. Removal of perfluorooctanoic acid from water using calcined hydrotalcite – A mechanistic study [J]. Journal of Hazardous Materials, 2019,368:487-495. [147]孫建強(qiáng),洪 雷,賈旭日.微波改性膨潤(rùn)土對(duì)水中PFOS的吸附熱力學(xué)和動(dòng)力學(xué)研究 [J]. 離子交換與吸附, 2017,33(2):10. Sun J Q, Hong L, Jia X R. adsorption thermodynamics and kinetics of PFOS on microwave modified bentonite form aqueous solution [J]. Ion Exchange and Adsorption, 2017,33(2):10. [148]Qian J, Shen M M, Wang P F, et al. Perfluorooctane sulfonate adsorption on powder activated carbon: Effect of phosphate (P) competition, pH, and temperature [J]. Chemosphere, 2017,182:215- 222. [149]許晨敏.水中典型全氟化合物(PFCs)的吸附及光催化降解研究 [D]. 南京:南京理工大學(xué), 2018. Xu C M. Removal of typical perfluorinated compounds(PFCs) by adsorption and photocatalysis [D]. Nanjing:Nanjing University of Science and Technology, 2018. [150]Qu Y, Zhang C J, Li F, et al. Equilibrium and kinetics study on the adsorption of perfluorooctanoic acid from aqueous solution onto powdered activated carbon [J]. Journal of Hazardous Materials, 2009, 169(1-3):146-152. [151]Siriwardena D P, Crimi M, Holsen T M, et al. Influence of groundwater conditions and co‐contaminants on sorption of perfluoroalkyl compounds on granular activated carbon [J]. Remediation Journal, 2019,29(3):5-15. [152]Deng S B, Bei Y, Lu X Y, et al. Effect of co-existing organic compounds on adsorption of perfluorinated compounds onto carbon nanotubes [J]. Frontiers of Environmental Science & Engineering, 2015,9:784–792. [153]Kimura K, Fujii S, Tanaka S, et al. A study on removal characteristics and effect factors of removal of persistent perfluorinated compounds by powdered activated carbon [J]. Eenvironmental Eengineering Rresearch, 2011,45:301-308. [154]Yu J, Lv L, Lan P, et al. Effect of effluent organic matter on the adsorption of perfluorinated compounds onto activated carbon [J]. Journal of Hazardous Materials, 2012,225-226:99-106. [155]Wang W J, Xu Z L, Zhang X X, et al. Rapid and efficient removal of organic micropollutants from environmental water using a magnetic nanoparticles-attached fluorographene-based sorbent [J]. Chemical Engineering Journal, 2018,343:61-68. [156]Wang B Y, Lee L S, Wei C H, et al. Covalent triazine-based framework: A promising adsorbent for removal of perfluoroalkyl acids from aqueous solution [J]. Environmental Pollution, 2016,216:884- 892. [157]Xiao L L, Ling Y H, Alsbaiee A, et al. β-Cyclodextrin polymer network sequesters perfluorooctanoic acid at environmentally relevant concentrations [J]. Journal of the American Chemical Society, 2017,139(23):7689-7692. [158]Qiu Y, Fujii S, Tanaka S. Removal of perfluorochemicals from wastewater by granular activated carbon adsorption [J]. Environmental Engineering Research, 2007,44:185-193. [159]Bao Y P, Niu J F, Xu Z S, et al. Removal of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) from water by coagulation: Mechanisms and influencing factors [J]. Journal of colloid and interface science, 2014,434:59-64. [160]洪 雷,丁倩云,亓祥坤,等.吸附法去除水中全氟化合物的研究進(jìn)展 [J]. 環(huán)境化學(xué), 2021,40(7):2193-2203. Hong L, Ding Q Y, Qi X K, et al. The research progress of removing perfluoroalkyl substances by adsorption in water [J]. Environmental Chemistry, 2021,40(7):2193-2203. [161]Chrysikopoulos C V, Syngouna V I. Attachment of bacteriophages MS2 and ΦX174 onto kaolinite and montmorillonite: Extended- DLVO interactions [J]. Colloids and Surfaces B: Biointerfaces, 2012,92(none):74-83. [162]Steenland K, Tinker S, Shankar A. Association of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) with uric acid among adults with elevated community exposure to PFOA [J]. Environmental Health Perspectives, 2010,118(2):229-233. [163]Uwayezu J N, Yeung L W Y, B?ckstr?m M. Sorption of PFOS isomers on goethite as a function of pH, dissolved organic matter (humic and fulvic acid) and sulfate [J]. Chemosphere, 2019,233:896-904. [164]Schuricht F, Borovinskaya E S, Reschetilowski W. Removal of perfluorinated surfactants from wastewater by adsorption and ion exchange--Influence of material properties,sorption mechanism and modeling [J]. Journal of Environmental Sciences, 2017,54:160-170. [165]Rahman M F, Peldszus S, Anderson W B. Behaviour and fate of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in drinking water treatment: A review [J]. Water Research, 2014,50:318-340. [166]Franke V, McCleaf P, Lindegren K, et al. Efficient removal of per- and polyfluoroalkyl substances (PFASs) in drinking water treatment: nanofiltration combined with active carbon or anion exchange [J]. Environmental Science: Water Research & Technology, 2019,5(11): 1836-1843. [167]Kucharzyk K H, Darlington R, Benotti M, et al. Novel treatment technologies for PFAS compounds: A critical review [J]. Journal of Environmental Management, 2017,204(Part 2):757-764. [168]Shivakoti B R, Fujii S, Nozoe M, et al. Perfluorinated chemicals (PFCs) in water purification plants (WPPs) with advanced treatment processes [J]. Water Science and Technology: Water Supply, 2010, 10(1):87-95. [169]DeWitt J C. Toxicological effects of perfluoroalkyl and polyfluoroalkyl substances [R]. Springer, 2015. [170]Zhi Y, Liu J X. Sorption and desorption of anionic, cationic and zwitterionic polyfluoroalkyl substances by soil organic matter and pyrogenic carbonaceous materials [J]. Chemical Engineering Journal, 2018,346:682-691. [171]Salvador F, Martin-Sanchez N, Sanchez-Hernandez R, et al. Regeneration of carbonaceous adsorbents. Part I: Thermal Regeneration [J]. Microporous and Mesoporous Materials, 2015,202: 259-276. [172]白玉潔,張愛(ài)麗,周集體.吸附劑再生技術(shù)的研究進(jìn)展 [J]. 遼寧化工, 2012,41(1):21-24. Bai Y J, Zhang A L, Zhou J T. Research process in regeneration technologies of sorbents [J]. Liaoning Chemical Industry, 2012,41(1):21-24. [173]孫政釗.關(guān)于吸附劑再生技術(shù)的研究 [J]. 化工管理, 2014,(32):103. Sun Z Z. Research on adsorbent regeneration technology [J]. Chemical Enterprise Management, 2014,(32):103. [174]鄧 勤,馬少健,周顯文.水處理吸附劑的再生技術(shù)研究進(jìn)展 [C]. 第十三屆全國(guó)粉體工程及礦產(chǎn)資源高效開(kāi)發(fā)利用研討會(huì)論文專輯, 2007. Deng L, Ma S J, Zhou X W. Progress in water treatment adsorbents regeneration [C]. The Thirteenth National Symposium on Powder Engineering and Efficient Development and Utilization of Mineral Resources Paper Series, 2007. [175]Zhu R L, Zhu J X, Ge F, et al. Regeneration of spent organoclays after the sorption of organic pollutants: A review [J]. Journal of Environmental Management, 2009,90(11):3212-3216. [176]Moreno-Castilla C, Rivera-Utrilla J, Joly J P, et al. Thermal regeneration of an activated carbon exhausted with different substituted phenols [J]. Carbon, 1995,33(10):1417-1423. [177]Alalm M G, Boffito D C. Mechanisms and pathways of PFAS degradation by advanced oxidation and reduction processes: A critical review [J]. Chemical Engineering Journal, 2022,450:138352. [178]Bao Y X, Deng S S, Jiang X S, et al. Degradation of PFOA substitute: GenX (HFPO-DA ammonium Salt): oxidation with UV/persulfate or reduction with UV/sulfite? [J]. Environmental Science & Technology, 2018,52(20):11728-11734. [179]Kumar M, Xiong X N, Sun Y Q, et al. Critical review on biochar- supported catalysts for pollutant degradation and sustainable biorefinery [J]. Advanced Sustainable Systems, 2020,4(10):1900149. [180]Khan M Y, Sui S, Gabriel da Silva. Decomposition kinetics of perfluorinated sulfonic acids [J]. Chemosphere, 2020,238:124615. [181]Riedel T P, Wallace M A G, Shields E P, et al. Low temperature thermal treatment of gas-phase fluorotelomer alcohols by calcium oxide [J]. Chemosphere, 2021,272:129859. [182]Margallo M, Taddei M B M, Hernández-Pellón A, et al. Environmental sustainability assessment of the management of municipal solid waste incineration residues: a review of the current situation [J]. Clean Technologies and Environmental Policy, 2015,17 (5):1333-1353. [183]Merino N, Qu Y, Deeb R A, et al. Degradation and removal methods for perfluoroalkyl and polyfluoroalkyl substances in water [J]. Environmental Engineering Science, 2016,33(9):615-649. [184]Feng M B, Qu R J, Zhong B W, et al. Characterization of the thermolysis products of Nafion membrane: A potential source of perfluorinated compounds in the environment [J]. Scientific Reports, 2015,5(1):9859. [185]Ellis D A, Martin J W, Muir D C G, et al. The use of 19F NMR and mass spectrometry for the elucidation of novel fluorinated acids and atmospheric fluoroacid precursors evolved in the thermolysis of fluoropolymers [J]. Analyst, 2003,128(6):756-764. [186]Watanabe N, Takata M, Takemine S, et al. Thermal mineralization behavior of PFOA, PFHxA, and PFOS during reactivation of granular activated carbon (GAC) in nitrogen atmosphere [J]. Environmental Science and Pollution Research, 2018,25(8):7200-7205. [187]Dhillon G S, Rosine G M L, Kaur S, et al. Novel biomaterials from citric acid fermentation as biosorbents for removal of metals from waste chromated copper arsenate wood leachates [J]. International Biodeterioration & Biodegradation, 2017,119:147-154. [188]Solo-Gabriele H M, Jones A S, Lindstrom A B, et al. Waste type, incineration, and aeration are associated with per- and polyfluoroalkyl levels in landfill leachates [J]. Waste Management, 2020,107:191-200. [189]Lang J R, Allred B M K, Field J A, et al. National estimate of per- and polyfluoroalkyl substance (PFAS) release to U.S. municipal landfill leachate [J]. Environmental Science & Technology, 2017,51(4):2197-2205. [190]Wang B, Yao Y M, Chen H, et al. Per- and polyfluoroalkyl substances and the contribution of unknown precursors and short-chain (C2-C3) perfluoroalkyl carboxylic acids at solid waste disposal facilities [J]. The Science of the Total Environment, 2020,705:135832. [191]Kallenborn R, Berger U, Jarnberg U, et al. Perfluorinated alkylated substances (PFAS) in the nordic environment [M]. Copenhagen: Nordic Council of Ministers, 2004. [192]Gallen C, Drage D, Eaglesham G, et al. Australia-wide assessment of perfluoroalkyl substances (PFASs) in landfill leachates [J]. Journal of Hazardous Materials, 2017,331:132-141. [193]Huset C A, Barlaz M A, Barofsky D F, et al. Quantitative determination of fluorochemicals in municipal landfill leachates [J]. Chemosphere, 2011,82(10):1380-1386. [194]Zhang C H, Peng Y, Ning K, et al. Remediation of perfluoroalkyl substances in landfill leachates by electrocoagulation [J]. CLEAN– Soil, Air, Water, 2014,42(12):1740-1743. [195]Yan H, Cousins I T, Zhang C J, et al. Perfluoroalkyl acids in municipal landfill leachates from China: occurrence, fate during leachate treatment and potential impact on groundwater [J]. Science of the Total Environment, 2015,524-525:23-31. [196]Stoiber T, Evans S, Naidenko O V. Disposal of products and materials containing per- and polyfluoroalkyl substances (PFAS): A cyclical problem [J]. Chemosphere, 2020,260:127659. Research progress on adsorption technologies for PFAS removal from water. WANG Tu1,2, BAO Yi-xiang2*, ZHONG Jin-kui1, LI Jing-feng2, CAO Zhi-guo2, WU Min2 (1.School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China；2.State Key Laboratory of Water Resource Protection and Utilization in Coal Mining, National Institute of Clean and Low Carbon Energy, Beijing 102209, China)., 2023,43(12)：6413～6434 In this paper, the adsorption properties, mechanisms, influencing factors, advantages and potential problems of different adsorbents (activated carbon, resin, mineral materials, molecularly imprinted polymers, bio-based materials, etc.) for PFAS removal were summarized. Adsorbents with similar pore size to PFAS molecules, and with opposite surface charge had higher adsorption capacity to PFAS. Lower pH and higher temperature are more favorable for PFAS adsorption, and coexisting organic matter will compete with PFAS on adsorption. The adsorption performance of the adsorbent to PFAS was positively correlated with its chain length, and the adsorption capacity of the adsorbent to PFAS containing sulfonic group was higher than that of PFAS with carboxylic group at the same chain length. The main adsorption mechanisms include electrostatic attraction, hydrophobic interaction, ion exchange, ligand exchange, etc. The reasonable regeneration and disposal of adsorbents was a common problem in practical engineering applications, such as poor regeneration effect of chemical regeneration and biological regeneration, high energy consumption of thermal regeneration, easy to cause secondary pollution by solvent regeneration or landfill treatment. By reviewing the research progress of adsorption removal materials and technologies for PFAS from water, the advantages and disadvantages of different technologies are systematically expounded, and the research direction of adsorption removal technology is prospected, which could provide reference for PFAS pollution control in water. PFAS；adsorption；mechanism；engineering applications；regeneration；emerging pollutants X703.1 A 1000-6923(2023)12-6413-22 王 菟,包一翔,鐘金魁,等.水中PFAS吸附去除技術(shù)研究進(jìn)展 [J]. 中國(guó)環(huán)境科學(xué), 2023,43(12):6413-6434. Wang T, Bao Y X, Zhong J K, et al. Research progress on adsorption technologies for PFAS removal from water [J]. China Environmental Science, 2023,43(12):6413-6434. 2023-04-21 國(guó)家自然科學(xué)基金青年基金資助項(xiàng)目(52100070);國(guó)家能源集團(tuán)科技創(chuàng)新項(xiàng)目(SZY93002219N) * 責(zé)任作者, 高級(jí)工程師, baoja2008@163.com 王 菟(1999-),男,甘肅張掖人,蘭州交通大學(xué)碩士研究生,主要研究方向?yàn)樗廴究刂?17718654733@163.com.1.2 樹(shù)脂吸附
1.3 礦物材料吸附
1.4 生物基材料吸附
1.5 分子印跡聚合物吸附
1.6 其他吸附材料
2 影響PFAS吸附效果的關(guān)鍵因素
2.1 吸附劑結(jié)構(gòu)的影響
2.2 水質(zhì)條件的影響
2.3 PFAS分子結(jié)構(gòu)的影響
3 工程應(yīng)用
4 吸附劑的處置
4.1 吸附劑再生處置
4.2 吸附劑焚燒處置
4.3 吸附劑填埋處置
5 結(jié)論與展望
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