本文關(guān)鍵詞：基于電勢(shì)調(diào)控的生物電極與厭氧工藝耦合系統(tǒng)強(qiáng)化氯代硝基苯還原轉(zhuǎn)化研究　出處：《浙江大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 2 4-二氯硝基苯 生物陰極 上流式厭氧生物反應(yīng)器 陰極電勢(shì) 還原脫氯

【摘要】：氯代硝基苯類化合物(ClNBs)是化工、醫(yī)藥、染料等行業(yè)重要基礎(chǔ)原料,具有三致效應(yīng)與遺傳毒性、化學(xué)性質(zhì)穩(wěn)定、生物降解性差等特點(diǎn),在生產(chǎn)與使用過(guò)程中因不合理處置導(dǎo)致大量進(jìn)入環(huán)境,威脅生態(tài)安全與人類健康。目前,含ClNBs廢水處理多以厭氧工藝為主,存在啟動(dòng)周期長(zhǎng)、電子供體不足、還原性能待提升等問(wèn)題。論文以2,4-二氯硝基苯(2,4-DClNB)為研究對(duì)象,構(gòu)建了耦合生物電化學(xué)(BES)的厭氧生物處理裝置,從陰極電勢(shì)、電子供體、電極位置等方面開(kāi)展生物電化學(xué)-厭氧污泥耦合工藝性能強(qiáng)化研究,通過(guò)目標(biāo)污染物降解途徑、污泥菌群結(jié)構(gòu)分析初步揭示基于電勢(shì)調(diào)控的生物電極與厭氧微生物耦合工藝的作用機(jī)制,取得如下研究成果:1、構(gòu)建了雙極室生物電化學(xué)裝置,在外加電壓0.6V、陰極室無(wú)電子供體,陽(yáng)極室含有500mg/LCOD,目標(biāo)污染物2,4-DClNB濃度為50mg/L的條件下,反應(yīng)24 h后,2,4-DClNB在陰極室完全還原轉(zhuǎn)化。而在開(kāi)路對(duì)照實(shí)驗(yàn)裝置中,2,4-DClNB還原轉(zhuǎn)化停滯,證實(shí)陰極微生物可利用陰極作為唯一電子供體還原轉(zhuǎn)化2,4-DClNB。構(gòu)建多組生物電極-厭氧污泥耦合的單極室生物電化學(xué)裝置研究生物電極與厭氧污泥協(xié)同還原轉(zhuǎn)化2,4-DClNB過(guò)程發(fā)現(xiàn),在初始COD濃度500mg/L,2,4-DClNB濃度50mg/L,污泥濃度3g/L的條件下,120h時(shí),單獨(dú)厭氧污泥反應(yīng)器中4-氯苯胺(4-ClAn)的降解速率為2.24mg/L·d,而陰極電勢(shì)為-450mV、-660mV、-870mV的耦合反應(yīng)器中,4-ClAn的降解速率分別為3.51 mg·L~(-1)·d~(-1)、4.61 mg·L~(-1)·d~(-1)和4.84mg·L~(-1)·d~(-1),明顯高于對(duì)照反應(yīng)器,表明生物電極-厭氧污泥耦合體系可明顯加快反應(yīng)限速步驟4-ClAn的脫氯過(guò)程,且較低的陰極電勢(shì)有更利于C-Cl鍵斷裂,促進(jìn)4-ClAn的還原脫氯。2、構(gòu)建了MEC-UASB耦合反應(yīng)器,研究陰極電勢(shì)對(duì)耦合工藝處理2,4-DClNBs的影響。結(jié)果表明,在進(jìn)水COD和2,4-DClNB負(fù)荷分別500 g·m~(-3)·d~(-1)和50g·m~(-3)·d~(-1)、水力停留時(shí)間24 h條件下,陰極電勢(shì)為-660mV的耦合反應(yīng)器中,4-ClAn的去除速率與苯胺(An)的生成速率分別為19.56±0.84mg·L~(-1)·d~(-1)和4.12±1.33mg·L~(-1)·d~(-1),高于陰極電勢(shì)-450mV的耦合反應(yīng)器的17.38±0.97mg·L~(-1)·d~(-1)和2.97±1.21mg·L~(-1)·d~(-1)。分析認(rèn)為,陰極電勢(shì)是驅(qū)動(dòng)陰極生物化學(xué)反應(yīng)的本征電化學(xué)參數(shù),較低的陰極電勢(shì)能夠?yàn)槊撀任⑸锾峁└嗟哪芰坑糜诿撀确磻?yīng),并通過(guò)析氫反應(yīng)產(chǎn)生有效電子供體H2,強(qiáng)化氯代硝基苯還原脫氯。對(duì)反應(yīng)器內(nèi)電極空間布設(shè)影響研究發(fā)現(xiàn),將電極位置由反應(yīng)器底部抬升10cm至反應(yīng)器中部,限速反應(yīng)步驟4-ClAn的去除速率增至20.92±0.82mg·L~(-1)·d~(-1)。推測(cè)抬升電極位置可強(qiáng)化目標(biāo)污染物中間產(chǎn)物在升流式反應(yīng)器中上部進(jìn)一步還原脫氯。此外,進(jìn)水有機(jī)負(fù)荷由500gCOD·m~(-3)·d~(-1)降至200gCOD·m~(-3)·d~(-1)時(shí),2,4-DClNB進(jìn)水負(fù)荷仍保持50g·m~(-3)·d~(-1)時(shí),耦合反應(yīng)器的脫氯率為56.41±3.51%,高于傳統(tǒng)UASB的43.25±2.88%,表明耦合工藝能夠?qū)⒂邢薜碾娮痈咝У赜糜?,4-DClNB還原轉(zhuǎn)化。3、對(duì)耦合工藝生物陰極顯微觀察發(fā)現(xiàn),生物陰極表面附著具有鞭毛狀結(jié)構(gòu)的球菌、桿菌、絲狀菌等微生物;生物陰極生物膜熒光染色技術(shù)分析活細(xì)胞主要存在于陰極生物膜表層與中間層,而內(nèi)層多為死細(xì)胞,推測(cè)可能存在類似納米導(dǎo)線的長(zhǎng)距離電子傳遞機(jī)制。應(yīng)用Illumina高通量測(cè)序技術(shù)分析顆粒污泥菌群結(jié)構(gòu)發(fā)現(xiàn),耦合工藝運(yùn)行過(guò)程污泥微生物菌群結(jié)構(gòu)演替顯著,在屬水平上,耦合工藝中的Methanoregula、Methanolinea、Pseudomonas、Desulfovibrio、Longilinea、Dehalococcoides、Dehalobacter和Anaeromyxobacter的相對(duì)豐度顯著增加,表明耦合系統(tǒng)中產(chǎn)甲烷微生物、厭氧發(fā)酵菌、脫氯微生物得到明顯富集。進(jìn)一步分析生物陰極表面生物膜微生物菌群結(jié)構(gòu)發(fā)現(xiàn),生物陰極作為催化還原反應(yīng)的活性界面,定向富集了Dehalobacter、Dehalococcoides和Anaeromyxobacter等多種脫氯菌屬,是耦合工藝強(qiáng)化還原脫氯的內(nèi)在原因。相比,陰極電勢(shì)為-660mV的生物陰極上,脫氯功能菌Dehalococcoides(5.2%)、Anaeromyxobacter(2.9%)和Dehalobacter(3.0%)占比較高,推測(cè)這些功能菌在電勢(shì)較低的陰極上能夠獲得更多的能量用于還原脫氯與自身生長(zhǎng)。
[Abstract]:Chloronitrobenzenes compound (ClNBs) is a chemical, pharmaceutical industry, dyes and other important raw materials, with three induced effects and genetic toxicity, stable chemical properties, poor biodegradation characteristics in the production and use of the process because of the unreasonable disposition lead into environment, threatening the ecological safety and human health. At present, including ClNBs wastewater treatment by anaerobic process, starting a long cycle, the electron donor shortage reduction performance to be improved and so on. This paper use 2,4- two 4-chloronitrobenzene (2,4-DClNB) as the research object, construct a coupled biological electrochemical (BES) anaerobic biological treatment device, from the cathode potential, electron donor, electrode position etc. study on strengthening the technological performance of anaerobic sludge bio electrochemical coupling, through the target pollutant degradation pathway, preliminary analysis reveals the biological regulation of the electrode potential and anaerobic microorganisms based on sludge microflora The mechanism coupling process, the main achievements were as follows: 1, construct the double chamber bioelectrochemical device with voltage 0.6V, the cathode chamber of electron donor, the anode chamber containing 500mg/LCOD, 2,4-DClNB concentration of the target pollutants under the condition of 50mg/L, after 24 h reaction, 2,4-DClNB reductive transformation completely in the cathode chamber. In open circuit control the experimental setup, the 2,4-DClNB reduction can be used as the cathode microbial stagnation, confirmed only electron donor reduction chamber bioelectrochemical transformation construction of 2,4-DClNB. monopole multi biological electrode coupling device of anaerobic sludge and anaerobic sludge bio electrode process by 2,4-DClNB synergistic reductive transformation of cathode at the initial COD concentration 500mg/L, 2,4-DClNB concentration 50mg/L, sludge concentration 3g/L under the condition of 120h, 4- chloro aniline single anaerobic sludge reactor (4-ClAn) degradation rate of 2.24mg/ L D, while the cathode potential is -4 50mV,-660mV,-870mV鐨勮，

本文編號(hào)：1424200