微生物燃料电池共代谢降解氰化物及产电性能研究

发布时间：2018-04-05 11:12

本文选题：微生物燃料电池　切入点：氰化物　出处：《北京科技大学》2015年博士论文

【摘要】：废水中低浓度氰化物的物化处理存在成本高,出水不达标,易造成二次污染等问题,微生物共代谢降解低浓度氰化物是目前研究的主要方向。微生物燃料电池(Microbial fuel cell, MFC)是一种新兴的废水处理同步能源回收技术,具有清洁高效,可实现能源回收以及污泥少等优点。本研究利用微生物燃料电池来对废水中的氰化物进行共代谢降解并产电,针对氰化物的毒性抑制生物降解和产电,从产电菌的驯化富集以及阳极材料的优化两个方面来提高MFC的降氰产电性能,并研究了运行参数对MFC降氰产电性能的影响。采用梯度驯化和稀释分离法获得了具有降氰功能的产电菌液,该菌液可降解浓度为50mg/L的氰化物,电阻为510Ω2时,MFC的最高输出电压为438mV,5.37W/m3,库伦效率为36.8%,氰化物的去除率可达99.82%。对该菌液中的菌进行了筛选分离,筛选出了10株具有降氰产电功能的菌株,这些菌株与富集的产电菌液相比,二者的降氰性能相当,但单菌株的产电效果较差。为了能够达到更好的产电效果和降氰效果,将电子介体固定在电极上,制备了一种PCF/PPY/CNTs/AQDS复合电极。复合电极作为MFC的阳极,MFC的启动时间(196h),缩短1/3；功率密度(9.27W/m3)提高近1倍。复合电极能够强化电子的传递效率,增强废水中氰化物的降解速率和电极表面的生物多样性。阳极电极表面的微生物多样性要远高于阳极悬浮液,氰化物驯化后阳极生物多样性减少,而复合阳极可提高阳极生物膜的群落多样性,其中变形菌纲占据着阳极生物膜的主要生态位。阳极液pH为8.2,醋酸钠浓度为1.0g/L,氰化物的浓度为80mg/L,外阻为510Ω时,MFC的功率密度可达10.86W/m3,氰化物的去除率在35h内可达99.98%以上。微生物燃料电池中氰化物的降解遵循表观一级反应动力学。建立了Andrews抑制动力学模型,得到氰化物的最大比降解速率(Vm)为4.21h-1,饱和系数(KS)为42.02mg/L,抑制系数(Ki)为114.42mg/L。上述结果表明利用微生物燃料电池共代谢降解低浓度的氰化物同时产电可行的,经处理后的氰化物达到了污水一级排放标准,为将来微生物燃料电池技术用于实际含氰废水的处理提供了理论基础。
[Abstract]:The physicochemical treatment of low concentration cyanide in wastewater has many problems such as high cost, substandard effluent, easy to cause secondary pollution and so on. The main research direction is to decompose low concentration cyanide by microorganism co-metabolism.Microbial fuel cell (MFCs) is a new synchronous energy recovery technology for wastewater treatment. It has the advantages of clean and high efficiency, energy recovery and less sludge.In this study, microbial fuel cells were used to degrade cyanide in wastewater and produce electricity. The toxicity of cyanide inhibited biodegradation and electricity production.The cyanide-reducing electrical properties of MFC were improved from the aspects of acclimation and enrichment of electrogen-producing bacteria and optimization of anode materials. The effects of operation parameters on the electrical properties of MFC were studied.By gradient acclimation and dilution separation, the electrogen-producing liquid with the function of reducing cyanide was obtained. The cyanide with degradable concentration of 50mg/L was obtained. The maximum output voltage of the solution was 438mV ~ (5.37) W / m ~ (3), the efficiency of Coulomb was 36.8%, and the removal rate of cyanide could reach 99.82%.By screening and isolating the bacteria in the liquid, 10 strains with the function of reducing cyanide and producing electricity were screened out. Compared with the enriched electrogen-producing liquid, the two strains had the same performance of reducing cyanide, but the effect of single strain was worse than that of the single strain.In order to achieve better electricity generation and cyanide reduction effect, an PCF/PPY/CNTs/AQDS composite electrode was prepared by immobilization of electronic medium on the electrode.The starting time of the composite electrode used as the anode of MFC was reduced by 1 / 3, and the power density was increased by nearly twice as much as 9.27 W / m ~ (3).The composite electrode can enhance the efficiency of electron transfer, enhance the degradation rate of cyanide in wastewater and the biodiversity of electrode surface.The microbial diversity on the anode electrode surface was much higher than that on the anode suspension. After acclimation of cyanide, the biological diversity of the anode was decreased, while the community diversity of the anode biofilm was improved by composite anode.Proteus occupies the main niche of anode biofilm.When the pH value of anode solution is 8.2, sodium acetate concentration is 1.0 g / L, cyanide concentration is 80 mg / L, the power density of MFC is 10.86 W / m ~ 3 and the removal rate of cyanide is over 99.98% within 35 hours when the external resistance is 510 惟.The degradation of cyanide in microbial fuel cells follows the first order reaction kinetics.The kinetic model of Andrews inhibition was established. The maximum specific degradation rate of cyanide was 4.21h-1, the saturation coefficient was 42.02 mg / L, and the inhibition coefficient was 114.42 mg / L.The results show that it is feasible to decompose low concentration of cyanide by co-metabolism of microbial fuel cell and produce electricity simultaneously, and the treated cyanide can reach the first class discharge standard of sewage.It provides a theoretical basis for the application of microbial fuel cell technology to the treatment of cyanide-containing wastewater in the future.
【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：X703.1;TM911.45

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