秸稈生物炭對(duì)雙氯芬酸鈉的吸附性能研究

夏文君,徐 劼,劉 鋒,2,黃天寅,王忠明,陳家斌*

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秸稈生物炭對(duì)雙氯芬酸鈉的吸附性能研究

夏文君1,徐 劼1,劉 鋒1,2,黃天寅1,王忠明3,陳家斌1*

(1.蘇州科技大學(xué)環(huán)境科學(xué)與工程學(xué)院,江蘇 蘇州 215009；2.城市生活污水資源化利用技術(shù)國(guó)家地方聯(lián)合工程實(shí)驗(yàn)室,江蘇 蘇州 215009；3.常州市市政工程設(shè)計(jì)研究院有限公司,江蘇 常州 213003)

利用廉價(jià)的農(nóng)業(yè)廢棄物稻草秸稈,通過(guò)磷酸氫二銨((NH4)2HPO4)活化制備得到秸稈生物炭(SBC),通過(guò)掃描電子顯微鏡(SEM)、比表面積分析(BET)、紅外光譜(FTIR)等手段對(duì)其進(jìn)行表征.研究了SBC對(duì)雙氯芬酸鈉(DCF)的吸附去除,并探討了吸附時(shí)間、SBC投加量、pH值、陰離子濃度對(duì)吸附過(guò)程的影響.結(jié)果表明,當(dāng)SBC投加量為0.3g/L時(shí),DCF濃度為0.05mmol/L,60min后吸附量達(dá)到平衡;pH值范圍在5.00~9.00時(shí),SBC對(duì)DCF的吸附量去除率隨著pH值的增加而減少;Cl-、SO42-和HCO3-對(duì)吸附過(guò)程的影響不大.擬合結(jié)果表明,SBC對(duì)DCF的吸附過(guò)程更符合準(zhǔn)二級(jí)動(dòng)力學(xué)模型和Freundlich吸附等溫線.經(jīng)Langmuir等溫線模型計(jì)算理論最大吸附量為277.78mg/g(pH=7.00,=20℃).熱力學(xué)參數(shù)表明SBC對(duì)DCF的吸附是自發(fā)吸熱過(guò)程.同活性炭和碳納米管相比,SBC對(duì)DCF的吸附效果更好.

吸附；秸稈生物炭；雙氯芬酸鈉；動(dòng)力學(xué)；熱力學(xué)

近年來(lái),藥物與個(gè)人護(hù)理用品(PPCPs)的產(chǎn)量和用量日趨增大,其對(duì)生態(tài)環(huán)境的潛在影響包括耐藥性以及對(duì)水生生物的毒性等[1-3].雙氯芬酸鈉是一種常用的非甾體抗炎藥,在風(fēng)濕病臨床用藥中占有很重要的地位[4],每年的全球消耗量在1443t左右[5].由于雙氯芬酸鈉的大量使用,導(dǎo)致其在污水處理廠、河水和地表水中被頻繁的檢測(cè)出來(lái)[6-8],并且已有關(guān)于雙氯芬酸鈉對(duì)水體中不同生物體產(chǎn)生了不良影響的報(bào)道[9-12].

據(jù)文獻(xiàn)報(bào)道,傳統(tǒng)的水處理技術(shù)和生物方法對(duì)雙氯芬酸鈉的去除率很低[13-14].目前常用的去除雙氯芬酸鈉的方法主要有高級(jí)氧化法(光降解、臭氧氧化和芬頓等)和吸附法[15-17].雖然高級(jí)氧化法對(duì)雙氯芬酸鈉的去除有良好的效果,但同時(shí)它也存在著成本高和產(chǎn)生有毒副產(chǎn)物的問(wèn)題[18].吸附法則具有簡(jiǎn)單可靠,成本低,無(wú)副產(chǎn)物生成等優(yōu)勢(shì)[14].Nam等[19]用氧化石墨烯吸附雙氯芬酸鈉,去除率可達(dá)到75%.但吸附劑的經(jīng)濟(jì)環(huán)保性能是影響其廣泛實(shí)際應(yīng)用的關(guān)鍵因素.因此利用價(jià)廉易得的廢棄生物質(zhì)材料來(lái)制備生物炭吸附材料成為近年來(lái)研究的熱點(diǎn).

我國(guó)是傳統(tǒng)的農(nóng)業(yè)大國(guó),農(nóng)作物秸稈的年產(chǎn)量可達(dá)7億多t.隨著秸稈還田、秸稈造紙、秸稈堆肥等技術(shù)的逐漸應(yīng)用,秸稈得到了一定程度的資源化利用,但仍未使得秸稈被充分消耗,仍然有大量秸稈被堆置,甚至直接焚燒,這不僅造成了大量生物質(zhì)能源浪費(fèi),同時(shí)也產(chǎn)生了煙霧、灰塵等污染物,導(dǎo)致大氣中二氧化硫、二氧化氮和可吸入顆粒物污染指數(shù)明顯升高,造成大氣污染和農(nóng)田土壤結(jié)構(gòu)破壞.利用農(nóng)業(yè)廢棄物制備生物炭,不僅能使農(nóng)業(yè)廢棄物資源化利用,也解決了秸稈焚燒污染問(wèn)題.Bashir等[20]利用氫氧化鉀改性稻草秸稈制備的生物炭可吸附99%以上的Cd2+;Tan等[21]把氧化錳負(fù)載在稻草秸稈生物炭上吸附Pb2+,最大吸附量為1.4732mmol/g. Feng等[22]分別用堿改性的稻草、木材和竹子制備生物炭,對(duì)多環(huán)芳烴的去除有很好的效果.本研究以稻草秸稈為原材料,通過(guò)磷酸氫二銨活化制備出秸稈生物炭(SBC),研究了SBC對(duì)雙氯芬酸鈉的吸附性能,利用吸附動(dòng)力學(xué)模型和吸附等溫線模型對(duì)實(shí)驗(yàn)數(shù)據(jù)進(jìn)行擬合,探討吸附機(jī)制,并為其在實(shí)際應(yīng)用中提供基礎(chǔ)依據(jù).

1 材料與方法

1.1 材料與試劑

秸稈收集于蘇州地區(qū)農(nóng)田;甲醇(CH3OH)、磷酸(H3PO4)、雙氯芬酸鈉(C14H10Cl2NNaO2,DCF)均購(gòu)于Sigma-Aldrich,DCF化學(xué)結(jié)構(gòu)式如圖1所示;硫酸(H2SO4)、氫氧化鈉(NaOH)、磷酸氫二銨((NH4)2HPO4)均為分析純,實(shí)驗(yàn)用水為超純水.

圖1 雙氯芬酸鈉的化學(xué)結(jié)構(gòu)式 Fig.1 Chemical structure of diclofenac sodium

1.2 制備方法

挑選干燥的優(yōu)質(zhì)秸稈剪切成5cm左右,在濃度為2%(Wt)的NaOH溶液中浸泡48h后用超純水洗至中性并在105℃條件下烘干以備用.稱量20g干燥好的秸稈置于300mL濃度為30%(Wt)的(NH4)2HPO4溶液中浸泡24h,然后在105℃條件下烘干,再置于恒溫鼓風(fēng)烘箱中200℃下預(yù)氧化2h,最后于箱式氣氛爐中700℃條件下活化1h.冷卻至室溫后將其取出并研磨,篩選取100目粒徑,記為SBC.

1.3 實(shí)驗(yàn)方法

室溫下,準(zhǔn)確稱取0.03g的SBC加入到100mL初始濃度為0.05mmol/L的雙氯芬酸鈉溶液中,用稀H2SO4和NaOH調(diào)節(jié)pH值,在置于磁力攪拌器攪拌上反應(yīng),并在預(yù)定時(shí)間內(nèi)取樣,用0.22μm水相針式濾頭過(guò)濾后通過(guò)高效液相色譜儀(HPLC)測(cè)定DCF濃度.

重復(fù)利用實(shí)驗(yàn)中準(zhǔn)確稱取0.03g吸附后的SBC放入到100mL甲醇溶液中解吸24h,之后用超純水清洗并烘干,再次進(jìn)行吸附實(shí)驗(yàn),重復(fù)4次測(cè)定吸附量.實(shí)際水樣來(lái)自污水廠出水和地表水,過(guò)0.45μm水相濾膜,4℃保存?zhèn)溆?數(shù)據(jù)均取自2組平行實(shí)驗(yàn)數(shù)據(jù)的平均值.

1.4 分析方法

采用WTW inLab pH7110pH計(jì)測(cè)定pH值;利用Agilent 1260高效液相色譜儀測(cè)定DCF濃度,操作條件為:分離柱是C18柱(4.6mm×250mm,5μm),流動(dòng)相為甲醇和6‰磷酸,配比為83/17,流動(dòng)相流速1mL/ min,檢測(cè)波長(zhǎng)280nm.

采用美國(guó)FEI Quanta 250掃描電子顯微鏡(SEM)、美國(guó)Micromeritics ASAP2020全自動(dòng)比表面積測(cè)定儀(BET)和美國(guó)Nicolet 6700型傅里葉變換紅外光譜儀(FTIR)對(duì)材料進(jìn)行表征.

1.5 計(jì)算方法

單位吸附劑對(duì)雙氯芬酸鈉的吸附量e通過(guò)式(1)計(jì)算,去除率通過(guò)式(2)計(jì)算:

式中:0和e分別為溶液中DCF的初始濃度和平衡濃度,mg/L,e為SBC的平衡吸附量,mg/g,為溶液體積,L,為SBC的投加量,g.

準(zhǔn)一級(jí)動(dòng)力學(xué)、準(zhǔn)二級(jí)動(dòng)力學(xué)模型及顆粒內(nèi)擴(kuò)散模型表達(dá)式分別為(3)~(5).

式中:e和t分別為平衡時(shí)和時(shí)刻的吸附量,mg/g,1為準(zhǔn)一級(jí)動(dòng)力學(xué)方程的吸附速率常數(shù),min-1.2為準(zhǔn)二級(jí)動(dòng)力學(xué)的吸附速率常數(shù), g/(mg×min).3為內(nèi)擴(kuò)散速率常數(shù), mg/(g×min1/2).

Langmuir和Freundlich吸附等溫模型數(shù)學(xué)表達(dá)式分別為(6)~(7).

式中:e是DCF吸附達(dá)到平衡時(shí)的濃度,mg/L,e為平衡吸附量,mg/g,m是最大吸附量, mg/g;L,L/mg和F,mg/g分別為L(zhǎng)angmuir和Freundlich吸附速率常數(shù).

標(biāo)準(zhǔn)自由能(Δθ)、標(biāo)準(zhǔn)焓變量(Δθ)、標(biāo)準(zhǔn)熵變量(Δθ)有關(guān)方程式分別為(8)~(9).

式中:d為平衡吸附常數(shù),L/g,T為反應(yīng)溫度,K,R為理想氣體常數(shù),8.314J/(mol×K).

2 結(jié)果與討論

2.1 SBC的表征

2.1.1 SEM分析 圖2(A)、(B)是不同放大倍數(shù)下SBC的掃描電鏡圖.由圖可看出,其表面粗糙凹凸不平,存在較多孔隙,而且孔隙分布比較密集.通過(guò)BET分析可以得出SBC孔徑主要以微孔為主,平均孔徑為2.19nm,具體結(jié)構(gòu)參數(shù)如表1所示.

圖2 SBC的SEM Fig.2 SEM images of SBC

表1 SBC結(jié)構(gòu)參數(shù) Table 1 Texrural parameters of SBC

2.1.2 FTIR分析 圖3為吸附前后SBC的FTIR圖譜.可以看出它們的吸收峰位置基本相同,在1095, 1385,1637,2922和3443cm-1處均存在吸收峰.1095, 1385,1637和2922cm-1處可歸于C—O對(duì)稱伸縮振動(dòng)峰、—COOH官能團(tuán)的對(duì)稱與反對(duì)稱伸縮特征峰、羧基的C=O特征伸縮振動(dòng)峰和—CH3或—CH2的對(duì)稱與反對(duì)稱伸縮特征峰;3443cm-1處對(duì)應(yīng)于O—H伸縮振動(dòng)吸收峰.因此可以得出SBC主要有含氧官能團(tuán)為—OH、C=O、—COOH等.

圖3 吸附前后SBC的FTIR圖譜 Fig.3 FTIR spectra of of SBC before and after adsorption

2.2 吸附時(shí)間對(duì)吸附的影響

圖4顯示了吸附時(shí)間對(duì)吸附性能的影響.可以看出,當(dāng)吸附時(shí)間為0~60min時(shí),隨著時(shí)間的增加,對(duì)DCF的去除率不斷增加,在60min時(shí),去除率達(dá)到91.89%,吸附量為49.84mg/g.當(dāng)吸附時(shí)間增加到240min時(shí),去除率和吸附量均無(wú)變化,說(shuō)明此時(shí)吸附已經(jīng)基本達(dá)到平衡.原因可能是,隨著吸附時(shí)間的不斷增加,吸附在孔隙內(nèi)的DCF占據(jù)了活性位點(diǎn),使其不斷減少?gòu)亩璧K了吸附的繼續(xù)進(jìn)行,使得吸附容量趨于平衡.

圖4 吸附時(shí)間對(duì)去除雙氯芬酸鈉的影響 Fig. 4 Effect of contact time on the removal of DCFc(DCF)=0.05mmol/L, m(SBC)=0.3g/L, pH=7.00, T=20℃

2.3 SBC投加量對(duì)吸附的影響

由圖5可見(jiàn),隨著SBC投加量的增加,對(duì)DCF的去除率不斷增加,同時(shí)對(duì)DCF的單位吸附量卻在逐漸降低.當(dāng)(SBC)=0.4g/L時(shí),平均去除率為98.65%,當(dāng)投加量繼續(xù)增加到(SBC)=0.5g/L時(shí),DCF已經(jīng)被全部去除.在吸附過(guò)程中,隨著SBC投加量的增加,可吸附的活性位點(diǎn)增多,使得被吸附的DCF總量增多;但是隨著SBC投加量的增加,溶液中DCF與SBC的質(zhì)量比逐漸降低,導(dǎo)致單位質(zhì)量SBC的利用率降低,從而使SBC的單位吸附容量下降.

圖5 SBC投加量對(duì)去除雙氯芬酸鈉的影響 Fig. 5 Effect of adsorbent dosage on the removal of DCFc(DCF)=0.05mmol/L, pH=7.00, T=20℃

2.4 pH值的影響

pH值是吸附過(guò)程的重要影響因素.由圖6可以看出,DCF的去除率隨著pH值不斷升高而降低.這可能與SBC的表面零電荷點(diǎn)(pHpzc = 2.40,如圖7所示)有關(guān).當(dāng)溶液pH > pHpzc時(shí),SBC表面帶負(fù)電荷.而DCF的pKa = 4.1[23],當(dāng)pH值大于4.1時(shí),DCF帶負(fù)電.所以當(dāng)pH = 5.00~9.00時(shí),隨著pH值的升高,靜電排斥力逐漸增強(qiáng),SBC對(duì)DCF的去除率不斷降低.利用碳納米管負(fù)載氧化鋁和功能化二氧化硅多孔材料等材料吸附DCF的時(shí)候也有同樣的發(fā)現(xiàn)[24-25].

圖6 pH對(duì)去除雙氯芬酸鈉的影響 Fig. 6 Effect of pH on the removal of DCFc(DCF)=0.05mmol/L, m(SBC)=0.3g/L, T=20℃

圖7 SBC的pHpzc測(cè)定 Fig. 7 pHpzc measured of SBC

2.5 陰離子的影響

在實(shí)際應(yīng)用時(shí),天然水體中存在的陰離子(Cl-、SO42-和HCO3-)可能會(huì)影響材料的吸附性能.不同陰離子濃度對(duì)雙氯芬酸鈉吸附過(guò)程的影響見(jiàn)圖8.隨著Cl-濃度的增加,對(duì)DCF的去除率逐漸增加.對(duì)SO42-和HCO3-來(lái)說(shuō),當(dāng)濃度小于10mmol/L時(shí),去除率隨著濃度的增加而減少;當(dāng)濃度大于10mmol/L時(shí),去除率隨著濃度的增加而有所增加.但就整體而言,對(duì)DCF去除率的變化不超過(guò)5%,說(shuō)明各共存陰離子對(duì)吸附過(guò)程的影響較小.

圖8 共存陰離子對(duì)去除雙氯芬酸鈉的影響 Fig. 8 Effect of coexistence anionic on the removal of DCFc(DCF)=0.05mmol/L, m(SBC)=0.3g/L, pH=7.00, T=20℃

2.6 動(dòng)力學(xué)分析

為了更好地分析SBC對(duì)DCF的吸附行為,采用準(zhǔn)一級(jí)、準(zhǔn)二級(jí)動(dòng)力學(xué)模型和顆粒內(nèi)擴(kuò)散動(dòng)力學(xué)方程對(duì)吸附過(guò)程進(jìn)行模擬,結(jié)果如圖9所示.由圖9可見(jiàn),與準(zhǔn)一級(jí)動(dòng)力學(xué)模型相比,準(zhǔn)二級(jí)動(dòng)力學(xué)模型對(duì)實(shí)驗(yàn)數(shù)據(jù)的擬合相關(guān)性系數(shù)較高(2>0.98),而且準(zhǔn)二級(jí)動(dòng)力學(xué)方程中的e測(cè)定值與計(jì)算值更接近.說(shuō)明準(zhǔn)二級(jí)動(dòng)力學(xué)模型能更好地描述SBC對(duì)DCF的吸附過(guò)程.顆粒內(nèi)擴(kuò)散模型擬合結(jié)果見(jiàn)圖9(C),可以看出吸附過(guò)程分為2個(gè)階段:急劇上升階段和平緩階段.急劇上升階段對(duì)應(yīng)分子內(nèi)擴(kuò)散過(guò)程,平緩階段對(duì)應(yīng)最終的平衡階段.由擬合參數(shù)可知,顆粒內(nèi)擴(kuò)散模型不通過(guò)原點(diǎn),說(shuō)明吸附過(guò)程受其他吸附階段的共同控制.

表2 SBC對(duì)DCF的吸附動(dòng)力學(xué)擬合參數(shù) Table 2 Kinetics parameters for adsorption of DCF by SBC

2.7 吸附等溫線和熱力學(xué)研究

吸附等溫線可反映被吸附的分子在平衡時(shí)液相和固相間的分布情況,是評(píng)價(jià)吸附劑吸附性能的重要指標(biāo),擬合參數(shù)見(jiàn)表3.從中可看出,雖然Langmuir等溫線方程與實(shí)驗(yàn)數(shù)據(jù)有很好的相關(guān)性(2>0.96),但是Freundlish等溫線方程的相關(guān)性系數(shù)更高(2>0.98),能夠更好地解釋實(shí)驗(yàn)中發(fā)生的現(xiàn)象.Freundlish模型描述了吸附分子在非均勻表面相互作用產(chǎn)生的多層吸附.模型參數(shù)>1[26],說(shuō)明SBC對(duì)DCF的吸附屬于優(yōu)惠吸附.活性炭、碳凝膠等材料對(duì)雙氯芬酸鈉的吸附過(guò)程也可以更好地通過(guò)Freundlish模型來(lái)解釋[27-29].

為了更深入地了解吸附過(guò)程,通過(guò)不同溫度下的吸附實(shí)驗(yàn),計(jì)算吸附過(guò)程的標(biāo)準(zhǔn)吉布斯自由能變(Δθ)、焓變(Δθ)和熵變(Δθ)等相關(guān)的吸附熱力學(xué)參數(shù),具體結(jié)果見(jiàn)表4.在不同溫度條件下經(jīng)計(jì)算得出的Δθ為負(fù)值,表明吸附過(guò)程是自發(fā)進(jìn)行的.而且Δθ隨著溫度的升高呈減少趨勢(shì),同時(shí)Δθ的值為正,進(jìn)一步說(shuō)明該吸附過(guò)程屬于吸熱反應(yīng),提高溫度有利于對(duì)DCF的吸附.而正的Δθ值則反映出在吸附過(guò)程中固液界面上混亂度的增加.

表3 SBC對(duì)DCF的吸附等溫線擬合參數(shù) Table 3 Isotherms parameters for adsorption of DCF by SBC

表4 SBC吸附DCF的熱力學(xué)參數(shù) Table 4 Thermodynamic parameters for adsorption of DCF by SBC

2.8 與其他碳質(zhì)材料對(duì)比

實(shí)驗(yàn)對(duì)比了活性炭(AC)、碳納米管(CNT)與SBC對(duì)DCF的吸附性能.與活性炭和碳納米管相比,SBC表現(xiàn)出更好的吸附性能.活性炭和碳納米管對(duì)DCF的吸附量分別為18.03和36.05mg/g,而SBC的吸附量則得到顯著提高,為48.78mg/g,對(duì)DCF有較好的吸附去除效果,其在環(huán)境微污染水處理領(lǐng)域具有應(yīng)用前景

2.9 重復(fù)利用性

吸附劑的重復(fù)利用性是其經(jīng)濟(jì)性的關(guān)鍵因素[30].采用甲醇作為脫附劑,考察SBC的穩(wěn)定性和再生性.如圖10所示,隨著循環(huán)使用次數(shù)的增加,SBC對(duì)DCF的吸附量在逐漸下降,與第1次的吸附量相比,使用5次后的吸附量下降了12%左右,但是吸附量仍能達(dá)到44mg/g,而且吸附量保持相對(duì)穩(wěn)定.因此SBC具備可重復(fù)利用性,有實(shí)際應(yīng)用的潛力.

圖10 SBC重復(fù)使用對(duì)吸附DCF的影響 Fig.10 Effect of the regeneration of SBC on the removal of DCFc(DCF)=0.02mmol/L, m(SBC)=0.3g/L, pH=7.00, T=20℃

2.10 實(shí)際水樣影響

為了進(jìn)一步檢驗(yàn)SBC的實(shí)際應(yīng)用性,分別選取了污水廠出水和地表水,探究在不同水體中SBC對(duì)DCF的吸附性能.超純水體系中SBC對(duì)DCF的吸附量最大,為49.31mg/g,而在實(shí)際水樣中均體現(xiàn)出抑制作用,吸附量分別為37.65mg/g和44.54mg/g.兩種實(shí)際水樣的常規(guī)檢測(cè)指標(biāo)結(jié)果見(jiàn)表5.由表5可知,原因可能是實(shí)際水樣中存在的天然有機(jī)物會(huì)與DCF競(jìng)爭(zhēng)吸附劑上的活性位點(diǎn),從而抑制對(duì)DCF的吸附.

表5 兩種實(shí)際水樣的常規(guī)檢測(cè)指標(biāo)結(jié)果 Table 5 Indicators for different water matrix samples

3 結(jié)論

3.1 利用磷酸氫二銨活化制備得到秸稈生物炭,對(duì)DCF有較好的去除效果,經(jīng)Langmuir等溫線模型計(jì)算理論最大吸附量為277.78mg/g;當(dāng)pH=5.00時(shí),去除效果最好;共存陰離子對(duì)吸附過(guò)程影響較小.

3.2 SBC對(duì)DCF的吸附過(guò)程更符合準(zhǔn)二級(jí)動(dòng)力學(xué)模型和Freundlish等溫吸附線模型.

3.3 與活性炭和碳納米管相比,SBC對(duì)DCF的吸附效果更好,而且循環(huán)使用5次后,依然保持了良好的吸附去除效率,具有實(shí)際應(yīng)用前景.

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Adsorption of diclofenac on straw-biochar.

XIA Wen-jun1, XU Jie1, LIU Feng1,2, HUANG Tian-yin1, WANG Zhong-mimg3, CHEN Jia-bin1*

(1.School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China；2.National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Suzhou 215009, China；3.Changzhou Municipal Enginerring Design Research College Co., Ltd, Changzhou 213003, China)., 2019,39(3)：1054~1060

Straw-biochar (SBC) was prepared by rice straw, a cheap agricultural waste, through activation with ammonium hydrogen phosphate ((NH4)2HPO4). SBC was characterized by scanning electron microscopy (SEM), surface area measurements (BET) and Fourier transform infrared spectroscopy (FTIR). The effect of contact time, SBC dosage, initial pH and concentration of anions were investigated. The results indicated that adsorption capacity of SBC reached an equilibrium within 60min with 0.3g/L of SBC and 0.05mmol/L DCF. The removal rate of DCF decreased with pH increasing from 5.00 to 9.00. The addition of Cl-、SO42-and HCO3-had a negligible impact on the adsorption of DCF. The adsorption of diclofenac on SBC could be well fitted by the pseudo-second-order kinetics and Freundlich isotherm model. The maximum adsorption capacity of SBC for DCF was calculated to be 277.78mg/g based on Langmuir isotherm model. Thermodynamic parameters illustrated that the adsorption process was spontaneous and endothermic. Compared with activated carbon (AC) and carbon nanotube (CNT), SAC achieved a better performance on the removal of DCF.

adsorption；straw-biochar；diclofenac；kinetics；thermodynamics

X522

A

1000-6923(2019)03-1054-07

夏文君(1994-),女,江蘇南通人,蘇州科技大學(xué)碩士研究生,主要研究方向?yàn)槲鬯幚砼c回用技術(shù).發(fā)表論文2篇.

2018-08-07

江蘇省研究生實(shí)踐創(chuàng)新計(jì)劃項(xiàng)目(SJCX17_0676);蘇州市科技計(jì)劃項(xiàng)目(SS201722);國(guó)家自然科學(xué)基金資助項(xiàng)目(51778391)

* 責(zé)任作者, 副教授, chenjiabincn@163.com