宿程遠(yuǎn),盧宇翔,覃菁菁,黃梅,鄭鵬,林香鳳,黃智
(1廣西師范大學(xué)環(huán)境與資源學(xué)院,廣西 桂林 541004;2珍稀瀕危動(dòng)植物生態(tài)與環(huán)境保護(hù)教育部重點(diǎn)實(shí)驗(yàn)室,廣西 桂林 541004)
不同氨氮含量對(duì)厭氧顆粒污泥理化特性的影響
宿程遠(yuǎn)1,2,盧宇翔1,覃菁菁1,黃梅1,鄭鵬1,林香鳳1,黃智1
(1廣西師范大學(xué)環(huán)境與資源學(xué)院,廣西 桂林 541004;2珍稀瀕危動(dòng)植物生態(tài)與環(huán)境保護(hù)教育部重點(diǎn)實(shí)驗(yàn)室,廣西 桂林 541004)
通過(guò)序批式試驗(yàn),研究了氨氮含量變化對(duì)厭氧顆粒污泥去除有機(jī)物及氨氮效能的影響,并通過(guò)紫外可見(jiàn)光譜(UV-Vis)、三維熒光光譜(EEM)、傅里葉紅外光譜(FTIR)對(duì)厭氧顆粒污泥的溶解性微生物產(chǎn)物(SMP)、疏松胞外聚合物(LB-EPS)及緊密胞外聚合物(TB-EPS)進(jìn)行了分析。結(jié)果表明,當(dāng)進(jìn)水氨氮濃度增加到1000 mg·L-1時(shí),厭氧顆粒污泥對(duì)COD去除率由對(duì)照組的94.19%下降至93.33%,其對(duì)COD去除影響不明顯;但NH+4-N去除率由40.6%降至7.9%,去除效率明顯降低。UV-Vis譜圖分析表明,LB-EPS與TB-EPS在205~210 nm處出現(xiàn)了吸收峰,表明其中均含有苯環(huán)與雙鍵結(jié)構(gòu),且隨著氨氮濃度的增大,吸收帶出現(xiàn)了紅移。EEM譜圖分析表明,隨著氨氮濃度的增大,SMP中芳香蛋白吸收峰強(qiáng)度降低,而在EX/EM為370~390/420~450 nm處的類胡敏酸吸附峰增強(qiáng);對(duì)于LB-EPS而言,輔酶F420吸收峰消失,表明高氨氮濃度對(duì)產(chǎn)甲烷菌的活性產(chǎn)生了抑制作用;同時(shí)TB-EPS類蛋白熒光峰發(fā)生了紅移。而由LB-EPS的FTIR譜圖可知,氨氮濃度為1000 mg·L-1時(shí),LB-EPS中存在較多的羧酸。通過(guò)利用UV-Vis、FTIR、EEM譜圖可對(duì)厭氧顆粒污泥的SMP、LB-EPS、TB-EPS進(jìn)行較為全面的分析,從而為指導(dǎo)厭氧反應(yīng)器的運(yùn)行提供科學(xué)借鑒。
厭氧;氨氮;穩(wěn)定性;胞外聚合物;廢水
厭氧生物處理技術(shù)具有能耗低、污泥產(chǎn)量少、抗沖擊負(fù)荷能力強(qiáng),并可產(chǎn)生能源等優(yōu)點(diǎn)[1-3],其將環(huán)境保護(hù)與產(chǎn)能有機(jī)地結(jié)合在一起,具有良好的環(huán)境與社會(huì)經(jīng)濟(jì)效益,因此升流式厭氧污泥床(UASB)、厭氧膨脹顆粒污泥床(EGSB)、厭氧折流板反應(yīng)器(ABR)等厭氧反應(yīng)器在高濃度有機(jī)工業(yè)廢水的處理中得到了廣泛應(yīng)用[1-3]。近年來(lái),在厭氧生物處理過(guò)程中,毒性物質(zhì)對(duì)其處理效能的抑制,特別是關(guān)于高濃度氨氮對(duì)厭氧微生物的抑制研究成為人們關(guān)注的焦點(diǎn)[4-5]。如以高蛋白含量的餐廚垃圾為底物進(jìn)行厭氧消化時(shí),氨氮的積累被認(rèn)為是影響其厭氧處理過(guò)程穩(wěn)定性的重要原因[6-7]。蛋白質(zhì)在水解過(guò)程中會(huì)釋放氨氮,低濃度的氨氮是微生物生長(zhǎng)的營(yíng)養(yǎng)物,當(dāng)濃度過(guò)高時(shí)會(huì)使細(xì)胞活性或生長(zhǎng)速率降低,導(dǎo)致反應(yīng)器產(chǎn)氣量下降,揮發(fā)性脂肪酸(VFA)積累甚至造成反應(yīng)體系運(yùn)行失敗[8]。當(dāng)前對(duì)于高濃度氨氮的抑制多針對(duì)厭氧反應(yīng)器處理效能,或者微生態(tài)學(xué)進(jìn)行研究,對(duì)厭氧顆粒污泥理化特性的影響研究較少,而活性良好的厭氧顆粒污泥是厭氧反應(yīng)器高效運(yùn)行的重要保障之一[9-10]。
鑒于此,本文研究了不同氨氮濃度對(duì)厭氧顆粒污泥去除污染物效能的影響,并借助紫外可見(jiàn)(UV-Vis)、三維熒光(EEM)、傅里葉紅外(FTIR)光譜系統(tǒng)分析了厭氧顆粒污泥溶解性微生物產(chǎn)物(SMP)、疏松胞外聚合物(LB-EPS)、緊密胞外聚合物(TB-EPS)的變化情況,旨在通過(guò)光譜分析揭示氨氮濃度對(duì)厭氧顆粒污泥理化特性的影響,在為厭氧顆粒污泥理化特性的研究提供有效分析手段的同時(shí),為厭氧反應(yīng)器的運(yùn)行提供一定的指導(dǎo)。
試驗(yàn)采用史氏發(fā)酵法,將進(jìn)水氨氮濃度分別控制為 0、200、400、600、800、1000 mg·L-1左右,對(duì)應(yīng)的編號(hào)為0#~5#,取COD濃度為2000 mg·L-1的營(yíng)養(yǎng)液(含葡萄糖、NH4Cl、KH2PO4、NaHCO3、微量元素)100 ml,15 ml厭氧顆粒污泥一同加入250 ml錐形瓶中,污泥濃度為10 g VSS·L-1。厭氧顆粒污泥來(lái)自實(shí)驗(yàn)室正常運(yùn)行處理餐廚垃圾的可控內(nèi)循環(huán)厭氧反應(yīng)器,蓋上連有史氏發(fā)酵管的橡膠塞,置于35℃恒溫水浴中,持續(xù)培養(yǎng)10 d[11]。試驗(yàn)結(jié)束后分析 0#~5#錐形瓶進(jìn)出水 COD、氨氮的去除情況,并對(duì)0#~5#錐形瓶?jī)?nèi)污泥特性進(jìn)行分析。
本試驗(yàn)中 COD的測(cè)定采用快速消解法,氨氮含量采用納氏試劑分光光度法[12]。
污泥特性分析[13]:首先,取泥水混合液至離心管中,4000 r·min-1離心10 min,然后取一部分上清液,分別編號(hào)為SMP 0#~5#;將另一部分上清液加入稱量皿,同樣分別編號(hào)SMP 0#~5#。然后在離心管內(nèi)加入0.05%的NaCl溶液,在20 kHz、800 W的條件下超聲2 min,然后在150 r·min-1的條件下振蕩10 min,最后通過(guò)8000 r·min-1離心10 min,取一部分上清液,分別編號(hào)為L(zhǎng)B-EPS 0#~5#;將另一部分上清液加入稱量皿中。繼而在離心管中加入0.9%的NaCl溶液,在80℃條件下水浴30 min后拿出,冷卻至常溫,同樣離心后,一部分上清液倒入離心管,對(duì)應(yīng)編號(hào)TB-EPS 0#~5#;將另一部分上清液加入稱量皿中。樣品一部分上清液用于紫外-可見(jiàn)吸收光譜與三維熒光光譜分析,并將稱量皿內(nèi)的上清液在45℃條件下烘干,用于進(jìn)行傅里葉變換紅外光譜的分析。
本試驗(yàn)首先分析了不同氨氮濃度對(duì)于厭氧顆粒污泥對(duì)COD去除情況的影響,結(jié)果如圖1所示。
圖1 不同氨氮濃度對(duì)COD去除率的影響Fig.1 Effect of different ammonia concentration on COD removal rate
由圖 1可知,0#~5#反應(yīng)器出水 COD濃度為114~156 mg·L-1,厭氧顆粒污泥對(duì)COD的去除率分別為94.19%、94.01%、92.18%、93.93%、93.69%與 93.33%,COD去除率變化不大,這說(shuō)明在一定的氨氮濃度范圍內(nèi)下,氨氮對(duì) COD的去除影響并不明顯,一方面在于,本試驗(yàn)過(guò)程中,COD濃度為2000 mg·L-1左右,有機(jī)負(fù)荷不高,只要保障一定的厭氧顆粒污泥濃度與良好的活性,可實(shí)現(xiàn)對(duì)廢水COD的高效去除;另一方面厭氧生物處理的一個(gè)優(yōu)勢(shì)即在于對(duì)有機(jī)物的良好去除效能,如采用升流式厭氧污泥床反應(yīng)器、厭氧折流板反應(yīng)器等處理高濃度工業(yè)廢水時(shí),即使進(jìn)水COD高達(dá)10000 mg·L-1,這些厭氧反應(yīng)器依然可以保持高效的運(yùn)行。
本試驗(yàn)分析了在不同氨氮濃度條件下,厭氧顆粒污泥對(duì)氨氮的去除效果,結(jié)果如圖2所示。
從圖2可知,在厭氧生物處理過(guò)程中,隨著進(jìn)水氨氮濃度的增加,的去除效果由40.6%降至7.9%,去除率降低。主要原因在于,一方面由于進(jìn)水氨氮濃度的增加,增大了氨氮的負(fù)荷,從而造成其去除效率降低;另一方面說(shuō)明厭氧顆粒污泥對(duì)表現(xiàn)得較為敏感,對(duì)于厭氧微生物而言,其營(yíng)養(yǎng)需求為 C:N:P=200~300:5:1,因此對(duì)氮的需求相對(duì)較低,而氨氮濃度過(guò)高時(shí)便容易對(duì)厭氧微生物的活性造成影響,這也是當(dāng)前采用傳統(tǒng)厭氧反應(yīng)器處理高氨氮工業(yè)廢水時(shí)所遇到的關(guān)鍵問(wèn)題之一?,F(xiàn)有處理工藝多針對(duì)有機(jī)物去除,經(jīng)過(guò)處理后廢水中COD雖有大幅減少,但出水中氨氮含量仍較高,而對(duì)氨氮的高效去除尚存在一定的技術(shù)經(jīng)濟(jì)難度,進(jìn)而成為該類工業(yè)廢水達(dá)標(biāo)排放的主要限制因素。
圖2 不同氨氮濃度對(duì)去除率的影響Fig.2 Effect of different ammonia concentration on removal rate
本試驗(yàn)利用紫外-可見(jiàn)分光光度計(jì)對(duì)污泥的SMP、LB-EPS、TB-EPS進(jìn)行了分析,結(jié)果如圖 3所示。
從圖3可知,0#~5#厭氧顆粒污泥SMP的吸收峰在205 nm左右,說(shuō)明SMP中含有苯環(huán)物質(zhì)[14-15]。而由LB-EPS的UV-Vis譜圖可知,LB-EPS在205~220 nm處出現(xiàn)強(qiáng)的吸收帶,表明存在雙鍵結(jié)構(gòu)且處于共軛狀態(tài)[14];隨著氨氮濃度的不斷增加,其吸收峰逐漸增強(qiáng)且發(fā)生紅移,且在氨氮濃度為 1000 mg·L-1時(shí)紅移更為明顯,這說(shuō)明在厭氧生物處理過(guò)程中,存在物質(zhì)發(fā)生相互作用,改變了厭氧反應(yīng)器內(nèi)的微環(huán)境,從而改變了物質(zhì)的最大吸收波長(zhǎng)與結(jié)構(gòu)[14];同時(shí)在237~250 nm范圍內(nèi)有中等強(qiáng)度的吸收,說(shuō)明LB-EPS中含有苯環(huán)結(jié)構(gòu)[16]。而由TB-EPS的UV-Vis譜圖可知,TB-EPS同樣含有苯環(huán)與雙鍵結(jié)構(gòu),約在210 nm處出現(xiàn)較高強(qiáng)度的吸收帶,且隨著氨氮濃度的增加,吸收峰強(qiáng)度逐漸增強(qiáng),同樣出現(xiàn)了明顯的紅移[17-18]。
厭氧生物處理過(guò)程中,所產(chǎn)生的類腐殖質(zhì)和類蛋白物質(zhì)可在特定波長(zhǎng)光的激發(fā)下發(fā)射出不同波長(zhǎng)的熒光,具有熒光效應(yīng),因此為了更好地評(píng)價(jià)氨氮對(duì)厭氧顆粒污泥性能的影響,本文采用 EEM 光譜分析了各厭氧裝置中污泥的 SMP、LB-EPS及TB-EPS中的組分情況,結(jié)果如圖4~圖6所示。
圖3 0#~5# SMP與EPS紫外-可見(jiàn)光譜分析Fig.3 UV-Vis spectra of SMP and EPS of 0# to 5#
由圖4可知,在序批式試驗(yàn)中,0#~5#SMP的EEM光譜較為相似,出現(xiàn)了兩個(gè)主要的熒光峰,其中熒光峰 A的中心位置EX/EM在 220~240/330~350 nm處,為簡(jiǎn)單芳香蛋白產(chǎn)生的熒光峰,隨著氨氮底物濃度的增加,SMP中的簡(jiǎn)單芳香蛋白質(zhì)含量降低,其熒光強(qiáng)度分別為 1013、959、756、680、671及654 au,表明隨氨氮濃度升高,對(duì)合成芳香蛋白質(zhì)有一定的抑制作用。熒光峰 B的中心位置EX/EM為270~280/330~360 nm,主要是類色氨酸物質(zhì)的熒光所貢獻(xiàn),為類蛋白質(zhì)物質(zhì),熒光強(qiáng)度較強(qiáng)[19-21]。隨著氨氮濃度的增加,3#SMP中在EX/EM=320~350/420~450 nm 處出現(xiàn)了類腐殖酸的熒光峰C;4#與5#SMP中出現(xiàn)了熒光峰D,其中心位置在EX/EM=370~390/420~450 nm處,主要是類胡敏酸的熒光貢獻(xiàn);同時(shí)5#SMP中出現(xiàn)了類富里酸熒光峰E,其中心位置在EX/EM=260~280/440~470 nm處,說(shuō)明在氨氮底物濃度較高時(shí),厭氧顆粒污泥出現(xiàn)了一定程度的腐化,厭氧顆粒污泥的穩(wěn)定性將受到一定的影響,不適宜再繼續(xù)增大進(jìn)水氨氮負(fù)荷。
通過(guò)分析比較圖 5可知,0#~5#的 LB-EPS有兩個(gè)明顯的熒光峰,即簡(jiǎn)單芳香蛋白質(zhì)熒光峰和類色氨酸熒光峰,兩種蛋白質(zhì)物質(zhì)有利于形成與提高厭氧顆粒污泥的穩(wěn)定性,從而提高厭氧顆粒污泥對(duì)廢水中污染物的去除率,這與前人研究LB-EPS的結(jié)果相符[22-23];同時(shí)在EX為320~340 nm,EM為430~450 nm處存在一個(gè)輔酶NADH熒光峰。在0#LB-EPS和1#LB-EPS中,氨氮底物濃度較低,在EX為260~270 nm,EM為450~460 nm處出現(xiàn)熒光峰,主要是富里酸物質(zhì)的熒光貢獻(xiàn);增加氨氮底物濃度,富里酸物質(zhì)含量降低。在0#的LB-EPS中,熒光峰中心位置EX/EM為420/470 nm處,其為輔酶F420物質(zhì)產(chǎn)生的熒光峰,說(shuō)明此時(shí)厭氧裝置中的污泥活性良好;隨著氨氮濃度增大,輔酶F420消失,表明高氨氮濃度對(duì)厭氧生物處理過(guò)程具有一定的抑制作用。
圖6可知,TB-EPS的熒光峰強(qiáng)度較大,在EX/EM為 240~250/400~410 nm 處出現(xiàn)了紫外區(qū)類富里酸熒光峰;在EX/EM約為380/430 nm處出現(xiàn)熒光峰,主要是類腐殖酸熒光物質(zhì)所貢獻(xiàn)。與LB-EPS相比,TB-EPS類蛋白熒光峰發(fā)生了約20 nm發(fā)射波長(zhǎng)的紅移,發(fā)生紅移多與羰基、氨基等官能團(tuán)有關(guān)[24]。同時(shí)在氨氮含量為 600、800、1000 mg·L-1的厭氧裝置中,EX/EM在320/400 nm處存在著可見(jiàn)區(qū)類富里酸熒光峰,對(duì)比LB-EPS可見(jiàn)區(qū)類富里酸熒光峰發(fā)生了藍(lán)移,藍(lán)移多是由于大分子破裂成小分子物質(zhì)所導(dǎo)致的[25]。在TB-EPS中熒光吸收峰紅移和藍(lán)移與微生物降解的物質(zhì)密切相關(guān),這將影響污泥的活性與穩(wěn)定性[26]。
圖4 0#~5# SMP三維熒光分析Fig.4 EEM spectra of SMP of 0# to 5#
通過(guò)對(duì)各裝置中厭氧顆粒污泥的 SMP、LB-EPS、TB-EPS進(jìn)行的 EEM 光譜分析可知,在污泥的SMP與EPS中一直存在著簡(jiǎn)單芳香蛋白和類色氨酸這兩大類物質(zhì),蛋白類物質(zhì)在以氨氮含量為基質(zhì)的厭氧生物處理過(guò)程中發(fā)揮重要作用,在一定范圍內(nèi)蛋白類物質(zhì)含量越高,越有利于厭氧顆粒污泥形成與提高顆粒污泥的穩(wěn)定性,從而為污染物的有效去除提供保障。
FTIR光譜非常靈敏,且掃描速度迅速,為了從微觀層面更為深入地了解不同氨氮濃度對(duì)厭氧顆粒污泥性能的影響,本試驗(yàn)對(duì)各裝置中厭氧顆粒污泥SMP、LB-EPS、TB-EPS中官能團(tuán)的變化情況進(jìn)行了FTIR分析,結(jié)果如圖7~圖9所示。
圖5 0#~5# LB-EPS三維熒光分析Fig.5 EEM spectra of LB-EPS of 0# to 5#
由圖 7可知,不同氨氮濃度下,0#~5#厭氧顆粒污泥SMP的FTIR圖譜基本一致,圖中出現(xiàn)較明顯吸收峰的波數(shù)為3470 cm-1,可推斷出各裝置SMP中主要含有氨基;在1460和1700 cm-1均出現(xiàn)明顯吸收峰,表明其含有羧基;且在850 cm-1處出現(xiàn)波峰,表明其含有苯環(huán)的C—H面外彎曲振動(dòng)[27]。
由圖8可知,LB-EPS中主要含氨基、羧基,在 1100 cm-1處出現(xiàn)較小的吸收峰,說(shuō)明其還含有苯環(huán)的C—H面內(nèi)彎曲振動(dòng);在850 cm-1處出現(xiàn)較小的吸收峰,說(shuō)明其含有苯環(huán)的C—H面外彎曲振動(dòng);在1450與1560 cm-1處出現(xiàn)較小的吸收峰,所代表的官能團(tuán)為酰胺Ⅱ(蛋白質(zhì)肽鍵);在 1675 cm-1處出現(xiàn)較小的吸收峰,該振動(dòng)類型為伸縮振動(dòng),官能團(tuán)為酰胺Ⅰ(蛋白質(zhì)肽鍵)[28]。對(duì)比圖8中0#~5#曲線可知,當(dāng)氨氮濃度為1000 mg·L-1時(shí),在 1400 cm-1處出現(xiàn)了較大的吸收峰,表明氨氮濃度越大,LB-EPS中存在的羧酸較多;同時(shí)3460~3100 cm-1的吸收峰以及1560~1670 cm-1處出現(xiàn)了非常明顯的雙峰,表明此時(shí)LB-EPS中的蛋白結(jié)構(gòu)發(fā)生了改變,可見(jiàn)LB-EPS中蛋白的種類會(huì)影響厭氧顆粒污泥的特性,進(jìn)而對(duì)其除污的效能造成影響[29-30]。
圖6 0#~5# TB-EPS三維熒光分析Fig.6 EEM spectra of TB-EPS of 0# to 5#
圖7 0#~5# SMP傅里葉紅外分析Fig.7 FTIR spectra of SMP of 0# to 5#
圖8 0#~5# LB-EPS傅里葉紅外分析Fig.8 FTIR spectra of LB-EPS of 0# to 5#
由圖9可知,TB-EPS的FTIR譜圖在波數(shù)為3500 cm-1出現(xiàn)明顯的吸收峰,說(shuō)明反應(yīng)器TB-EPS中含有較多的氨基;在譜圖1400 cm-1出現(xiàn)吸收峰,表明 TB-EPS中同時(shí)存在羧基;同時(shí)在 1100 cm-1處出現(xiàn)較小的吸收峰,表明其還含有苯環(huán)的 C—H面內(nèi)彎曲振動(dòng)[14]。通過(guò)對(duì)比圖9可知,在5#TB-EPS中,在848 cm-1處代表苯環(huán)物質(zhì)的吸收峰增強(qiáng),同時(shí)1400~1470 cm-1處代表羧酸物質(zhì)的吸收峰變?yōu)榱穗p峰,表明高濃度氨氮對(duì)TB-EPS中的官能團(tuán)造成了一定的影響。由此可見(jiàn),在厭氧反應(yīng)器的運(yùn)行過(guò)程中,可利用 FTIR對(duì)其中的厭氧顆粒污泥LB-EPS與TB-EPS的組分進(jìn)行定期分析,從而掌握污泥的狀態(tài),繼而為保障厭氧反應(yīng)器的良好運(yùn)行提供一定的依據(jù)。
圖9 0#~5# TB-EPS傅里葉紅外分析Fig.9 FTIR spectra of TB-EPS of 0# to 5#
(1)在序批式試驗(yàn)中,隨著進(jìn)水氨氮負(fù)荷的增大,厭氧顆粒污泥對(duì)氨氮去除率明顯降低,對(duì)COD去除率影響不大。
(2)隨著進(jìn)水氨氮濃度的增加,LB-EPS與TB-EPS的 UV-Vis譜圖中的吸收峰發(fā)生紅移;在FTIR譜圖中,TB-EPS的羧酸物質(zhì)及LB-EPS的氨基吸收峰變?yōu)殡p峰;LB-EPS的 EEM 譜圖中輔酶F420吸收峰消失,厭氧顆粒污泥EPS的含量與組分的變化影響了其對(duì)廢水中污染物的去除效能。
(3)厭氧顆粒污泥的理化特性直接影響其對(duì)污染物的去除效能,通過(guò)UV-Vis、FTIR、EEM譜圖可對(duì)厭氧顆粒污泥的SMP、EPS進(jìn)行分析,從而對(duì)厭氧顆粒污泥的理化特性進(jìn)行較為全面的了解。
[1]閆立龍,王曉輝,梁海晶,等.UASB去除豬場(chǎng)廢水有機(jī)物影響因素研究[J].安全與環(huán)境學(xué)報(bào),2013,13(3):61-65.YAN L L,WANG X H,LIANG H J,et al.On the factors influencing COD removal in pigsty sewage by UASB[J].Journal of Safety &Environment,2013,13(3):61-65.
[2]邢波,章燕,王志榮,等.水力剪切條件對(duì) IC工藝處理豬場(chǎng)廢水的影響[J].中國(guó)沼氣,2012,30(5):19-25.XING B,ZHANG Y,WANG Z R,et al.Effect of hydraulic shear on the IC process for piggery wastewater treatment[J].China Biogas,2012,30(5):19-25.
[3]GULHANE M,PANDIT P,KHARDENAVIS A,et al.Study of microbial community plasticity for anaerobic digestion of vegetable waste in anaerobic baffled reactor [J].Renewable Energy,2017,101:59-66.
[4]陳亞坤,陳繁榮,李翔宇.部分硝化-厭氧氨氧化反應(yīng)器處理養(yǎng)豬場(chǎng)廢水的模擬試驗(yàn)研究[J].水處理技術(shù),2013,39(9):104-108.CHEN Y K,CHEN F R,LI X Y.The research on the simulator of the partial nitrification-anammox reactor for treatment of piggery wastewater[J].Technology of Water Treatment,2013,39(9):104-108.
[5]YENIGUN O,DEMIREL B.Ammonia inhibition in anaerobic digestion:a review[J].Process Biochemistry,2013,48:901-911.
[6]DRENNAN M F,DISTEFANO T D.High solids co-digestion of food and landscape waste and the potential for ammonia toxicity[J].Waste Management,2014,34:1289-1298.
[7]CHEN X,YAN W,SHENG K,et al.Comparison of high-solids to liquid anaerobic co-digestion of food waste and green waste[J].Bioresource Technology,2014,154:215-221.
[8]NIELSEN H B,ANGELIDAKI I.Strategies for optimizing recovery of the biogas process following ammonia inhibition[J].Bioresource Technology,2008,99:7995-8001.
[9]HAO L P,BIZE A,CONTEAU D,et al.New insights into the key microbial phylotypes of anaerobic sludge digesters under different operational conditions[J].Water Research,2016,102:158-169.
[10]RICO C,MONTES J A,RICO J L.Evaluation of different types of anaerobic seed sludge for the high rate anaerobic digestion of pig slurry in UASB reactors[J].Bioresource Technology,2017,238:147-156.
[11]MA J Y,QUAN X C,SI X R,et al.Responses of anaerobic granule and fl occulent sludge to ceria nanoparticles and toxic mechanisms[J].Bioresource Technology,2013,149:346-352.
[12]趙博瑋,李建政,鄧凱文,等.木質(zhì)框架土壤滲濾系統(tǒng)處理養(yǎng)豬廢水厭氧消化液的效能[J].化工學(xué)報(bào),2015,66(6):2248-2255.ZHAO B W,LI J Z,DENG K W,et al.Efficiency of wood-chip-framework soil infiltration system in treating anaerobically digested swine wastewater [J].CIESC Journal,2015,66(6):2248-2255.
[13]ZHANG W J,CAO B D,WANG D H,et al.Influence of wastewater sludge treatment using combined peroxyacetic acid oxidation and inorganic coagulants re-flocculation on characteristics of extracellular polymeric substances (EPS)[J].Water Research,2016,88:728-739.
[14]RAJAGOPAL R,MASSE D I,SINGH G.A critical review on inhibition of anaerobic digestion process by excess ammonia[J].Bioresource Technology,2013,143:632-641.
[15]高軍,陳瑩瑩,李建.氨氮濃度對(duì)剩余污泥高溫固態(tài)厭氧消化的影響[J].現(xiàn)代農(nóng)業(yè)科技,2013,3:252-253.GAO J,CHEN Y Y,LI J.Ammonia nitrogen concentration on the influence of high temperature solid anaerobic digestion sludge [J].Modern Agricultural Science and Technology,2013,3:252-253.
[16]LENZ S,BOHM K,OTTNER R,et al.Determination of leachate compounds relevant for landfill aftercare using FT-IR spectroscopy[J].Waste Management,2016,55:321-329.
[17]吳江,陳波水,方建華,等.氧化前后生物柴油的紅外和紫外光譜分析[J].石油學(xué)報(bào),2014,30(2):262-265.WU J,CHEN B S,FANG J H,et al.FT-IR and UV spectral analysis of biodiesel before and after oxidation[J].Acta Petrolei Sinica,2014,30(2):262-265.
[18]王一兵,吳衛(wèi)紅,陳植成,等.傅里葉變換紅外光譜法和紫外-可見(jiàn)譜線組法分析廣西特產(chǎn)羅漢果[J].光譜實(shí)驗(yàn)室,2009,26(4):907-911.WANG Y B,WU W H,CHEN Z C,et al.Qualitative analysis of dry-fruit of Siraitia Grosvenorii by FTIR and UV-Vis spectrometry[J].Chinese Journal of Spectroscopy Laboratory,2009,26(4):907-911.
[19]楊曉明,張朝暉,王亮,等.MIEX和 PAC對(duì)微污染水源水的水質(zhì)凈化效果比較[J].化工學(xué)報(bào),2016,67(4):1505-1511.YANG X M,ZHANG C H,WANG L,et al.Comparison of purification of micropolluted source water by MIEX and PAC[J].CIESC Journal,2016,67(4):1505-1511.
[20]ZHANG Z S,GUO L,WANG Y,et al.Degradation and transformation of extracellular polymeric substances (EPS) and dissolved organic matters (DOM) during two-stage anaerobic digestion with waste sludge[J].International Journal of Hydrogen Energy,2017,42:9619-9629.
[21]SHI Y H,HUANG J H,ZENG G M,et al.Exploiting extracellular polymeric substances (EPS) controlling strategies for performance enhancement of biological wastewater treatments:an overview[J].Chemosphere,2017,180:396-411.
[22]TU X,SU B S,LI X M.Characteristics of extracellular fluorescent substances of aerobic granular sludge in pilot-scale sequencing batch reactor[J].Journal of Central South University,2010,17:522-528.
[23]ZHU L,QI H,LV M,et al.Component analysis of extracellular polymeric substances (EPS) during aerobic sludge granulation using FTIR and 3D-EEM technologies[J].Bioresource Technology,2012,124:455-459.
[24]CHEN J,GU B,LEBOEUF E J,et al.Spectroscopic characterization of the structural and functional properties of natural organic matter fractions[J].Chemosphere,2002,48:59-68.
[25]ZHU L,ZHOU J,LV M,et al.Specific component comparison of extracellular polymeric substances (EPS) in flocs and granular sludge using EEM and SDS-PAGE[J].Chemosphere,2015,121:26-32.
[26]BADIREDDY A R,CHELLAM S,GASSMAN P L,et al.Role of extracellular polymeric substances in bioflocculation of activated sludge microorganisms under glucose-controlled conditions[J].Water Research,2010,44:4505-4516.
[27]MULLER T,WALTER B,WIRTZ A,et al.Ammonium toxicity in bacteria[J].Current Microbiology,2006,52:400-406.
[28]劉芳,張萬(wàn)欽,吳樹(shù)彪,等.厭氧發(fā)酵中揮發(fā)酸含量與碳酸氫鹽堿度的滴定法修正[J].農(nóng)業(yè)機(jī)械學(xué)報(bào),2013,44(9):91-96.LIU F,ZHANG W Q,WU S B,et al.Titration method for total inorganic carbon and volatile fatty acids determination in anaerobic digestion[J].Journal of Agricultural Machinery,2013,44(9):91-96.
[29]陳芳妮,孫曉君,魏金枝,等.磁性三乙烯四胺氧化石墨烯對(duì)Cu2+的吸附行為[J].化工學(xué)報(bào),2016,67(5):1949-1956.CHEN F N,SUN X J,WEI J Z,et al.Adsorption behavior of magnetic triethylene tetramine-graphene oxide nanocomposite for Cu2+[J].CIESC Journal,2016,67(5):1949-1956.
[30]MIAO L Z,WANG C,HOU J,et al.Response of wastewater bio fi lm to CuO nanoparticle exposure in terms of extracellular polymeric substances and microbial community structure[J].Science of the Total Environment,2017,579:588-597.
date:2017-05-10.
SU Chengyuan,suchengyuan2008@126.com
supported by the National Natural Science Foundation of China (51641803,51768009) and the Natural Science Foundation of Guangxi (2015GXNSFAA139267).
Effects of ammonia concentration on physico-chemical characteristics of anaerobic granular sludge
SU Chengyuan1,2,LU Yuxiang1,QIN Jingjing1,HUANG Mei1,ZHENG Peng1,LIN Xiangfeng1,HUANG Zhi1
(1School of Environment and Resources,Guangxi Normal University,Guilin541004,Guangxi,China;2Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection,Ministry of Education,Guilin541004,Guangxi,China)
The effects of variable ammonia concentration on the removal efficiency of organic matter and ammonia nitrogen were examined by conducting sequencing batch experiments.Meanwhile,the soluble microbial products (SMP),loosely bound extracellular polymers (LB-EPS),and tightly bound extracellular polymers(TB-EPS) of anaerobic granular sludge were analyzed by using ultraviolet-visible spectroscopy (UV-Vis),excitation emission matrix fluorescence spectroscopy (EEM),and Fourier transform infrared spectroscopy (FTIR).The results demonstrated that the removal rate of COD reduced from 94.19% to 93.33% by anaerobic granular sludge,when the influent concentration of ammonia nitrogen reached to 1000 mg·L-1,which indicated that anaerobic granular sludge had an insignificant impact on the removal efficiency of COD.However,at the same time,the removal rate of ammonia nitrogen substantially decreased from 40.6% to 7.9%,due to its influent concentration.UV-Vis spectra analysis showed that a strong absorption band appeared at 205—210 nm scope of the LB-EPS and TB-EPS,and it was demonstrated that the LB-EPS and TB-EPS contained benzene ring and double bond structure.EEM spectra analysis showed that with increase of concentration of ammonia nitrogen,the intensity of aromatic protein adsorption peak decreased in the SMP,and the humic acid adsorption peak atEX/EM=370—390/420—450 nm enhanced.For the LB-EPS,the coenzyme F420absorption peak disappeared.It was illustrated that high concentration of ammonia nitrogen had an adverse effect on the activity of methanogens.In addition,the protein-like fluorescence peak in the TB-EPS has occurred red shift.At the ammonia nitrogen concentration of 1000 mg·L-1,it was showed the existence of carboxyl in the LB-EPS.By using UV-Vis,FTIR and EEM spectra,the SMP,LB-EPS and TB-EPS of anaerobic granular sludge were analyzed comprehensively,which could provide scientific reference for the operation of anaerobic reactor.
anaerobic;ammonia;stability;extracellular polymeric substances;wastewater
X 703.1
A
0438—1157(2017)12—4784—09
10.11949/j.issn.0438-1157.20170588
2017-05-10收到初稿,2017-07-06收到修改稿。
聯(lián)系人及第一作者:宿程遠(yuǎn)(1981—),男,博士,副教授。
國(guó)家自然科學(xué)基金項(xiàng)目(51641803,51768009);廣西自然科學(xué)基金項(xiàng)目(2015GXNSFAA139267)。