基于电场微生物群体刺激效应降解典型PPCPs类有机物的试验研究

发布时间：2018-03-22 15:11

本文选题：电场微生物　切入点：微生物群体刺激效应　出处：《济南大学》2017年硕士论文　论文类型：学位论文

【摘要】：目前,新型微量污染物药品及个人护理用品(PPCPs)在水环境中已普遍存在,这些有机物具有持久性、富集性和难生物降解等特点,不仅造成了水环境污染,而且对人类的健康有一定的影响,因此寻求一种经济有效的城市污水深度处理技术是去除有毒难降解PPCPs类有机物的关键。本文针对常规污水处理工艺对于城市污水中难降解PPCPs类有机物的降解效能较弱、结构复杂、活化能高等问题,基于电场对微生物群体的刺激效应,自主设计构建电生物耦合体系,考察电场和微生物生长代谢之间的关系,研究电生物耦合系统去除城市污水中典型PPCPs类有机物的效能及作用机理,采用高通量测序技术进行微生物群落结构多样性分析,进一步揭示电场对微生物群体的刺激效应。主要研究结论如下:研究结果表明,普通曝气生物滤池在适当的直流电场刺激下,其COD_(Cr)、TOC和氨氮的去除率可以得到相应的提高,若超过最佳的电流密度时,去除率则受到影响。同时,当电流密度低于最佳电流密度时,微生物群落丰富度和多样性与去除效率之间没有显著的相关性,而当电流密度高于最优电流密度时,微生物群落丰富度和多样性逐渐与污染物去除趋势保持一致。在最佳电流密度14.25A/m~2时微生物群落的优势种群主要包括噬氢菌属Hydrogenophaga(18.80%)、未分类的腐螺旋菌属Saprospiraceae_uncultured(12.15%)、代尔夫特菌属Delftia(6.84%)、假单胞菌属Pseudomonas(5.22%)、假黄色单胞菌属Pseudoxanthomonas(4.33%)和硝化螺旋菌属Nitrosospira(3.63%)等。根据三维粒子电极对三种PPCPs有机物的静态吸附和动态降解效能,选择活性炭作为电生物耦合系统的三维粒子电极,其对布洛芬、苯扎贝特、卡马西平的静态吸附率分别为21.26%、17.22%、11.89%,动态降解率分别为54.55%、37.23%、30.11%。在电生物耦合系统稳定运行阶段,分别研究了不同电流密度、不同有机物浓度对污染物去除效能的影响。研究发现当电流密度为14A/m~2时,电生物耦合曝气滤池对COD_(Cr)、TOC和氨氮的平均去除率分别为91.12%、98.17%、91.64%,明显高于普通曝气生物滤池。由于PPCPs有机物为难生物降解有机物,因此随着有机物浓度的增加,污水的可生化性在逐渐降低,进而导致两组滤池对污染物的去除率降低。但面对有机物负荷的冲击,电生物耦合曝气滤池拥有更好的抗冲击和缓冲能力。同时对两组稳定运行的滤池沿程出水可生化性的探究表明,电生物耦合曝气滤池出水的可生化性由原水的0.51提高到0.8以上,而普通曝气生物滤池出水的可生化性则无提高,甚至降低,原因是电生物耦合曝气滤池在加电部分的电催化氧化作用可以将难降解有机物即PPCPs氧化为易生物降解的小分子有机物,进而提高了电生物耦合曝气滤池中污水的可生化性。根据三种PPCPs类有机物的中间产物推所测的降解路径显示,在电生物耦合系统中,PPCPs类有机物的降解均是先通过生物和羟基自由基的氧化作用,氧化成分子量稍小的中间产物,然后再在一系列的氧化还原(包括电催化的氧化还原和微生物的氧化还原)作用下,裂解为小分子有机物或易降解的苯胺类化合物,最后进一步氧化、矿化为CO_2和H_2O。
[Abstract]:At present, the new micro pollutants of pharmaceuticals and personal care products (PPCPs) has been widespread in the water environment, the organic matter is durable, enrichment and hard biodegradable, not only caused the water pollution of the environment, but also has a certain influence on human health, therefore seek a kind of economic and effective city sewage advanced treatment technology is the key to the removal of toxic and refractory organic compounds PPCPs. The conventional sewage treatment process for the weak, the degradation efficiency of refractory organic wastewater in PPCPs city complex structure, higher activation energy, the electric field on the stimulating effect of the microbial community based on the independent design of building electrical biological coupling system, study the relationship between the the electric field and the growth and metabolism of microorganisms, the removal efficiency and mechanism of city sewage in typical PPCPs organic matter of electro biological coupling system using high throughput sequencing technology. Operation analysis of microbial community structure diversity, further reveal the stimulating effect of electric field on the microbial community. The main conclusions are as follows: the results showed that the common biological aerated filter in DC electric field stimulation, the COD_ (Cr), TOC and ammonia nitrogen removal rate can be improved, if more than the best current density when the removal rate is affected. At the same time, when the current density is lower than the optimal current density, no significant correlation between microbial community richness and diversity and removal efficiency, when the current density is higher than the optimal current density, microbial community richness and diversity gradually and the removal trend is consistent. The optimal current density 14.25A/m~2 dominant species of microbial communities including Hydrogenophaga phage bacteria hydrogen (18.80%), not rot spirochete classification of the genus Saprospiraceae_uncultured (12 .15%), Delftia Delft (6.84%), Pseudomonas genus Pseudomonas (5.22%), Pseudoxanthomonas sham Flavimonas genera (4.33%) Nitrosospira and nitrospirae genera (3.63%). According to the static adsorption of three PPCPs organic three-dimensional particle electrode and dynamic degradation efficiency, selection of activated carbon as dc-3d biological coupling system, the Bloven, Bate C Masi Bing, benzalkonii, static adsorption rates were 21.26%, 17.22%, 11.89%, the dynamic degradation rate were 54.55%, 37.23%, 30.11%. in the electric biological coupling system stable operation stage, the different current density were studied, different concentrations of organic matter removal efficiency effect of pollutants. It was found that when the current density is 14A/m~2, biological aerated filter for electric coupling COD_ (Cr) TOC, and the average removal rate of ammonia were 91.12%, 98.17%, 91.64%, significantly higher than that of ordinary biological aerated filter Due to the PPCPs pool. Organic biodegradable organic matter, so with the increase of organic matter concentration, the biodegradability of the wastewater decreased gradually, resulting in two groups of filter on the removal efficiency of pollutants decreased. But in the face of the impact of organic loading, biological aerated filter electric coupling has better impact and buffer capacity. At the same time of the two groups along the stable operation of the filter effluent can explore the biochemical of biological aerated filter show that the electrical coupling of the biodegradability of the effluent water from 0.51 increased to more than 0.8, and the biodegradability of the effluent is ordinary biological aerated filter without increase, or even lower, because the electric power in the biological aerated filter coupling electrocatalytic oxidation can be part of the refractory organics is for PPCPs oxidation of small organic molecules readily biodegradable, thus improving the electrical coupling in the sewage biological aerated filter biodegradability. According to the three The intermediate product of PPCPs showed degradation pathways of organic compounds measured in the push, the electric biological coupling system, the degradation of PPCPs compounds were first through oxidation of biological and hydroxyl radical, oxidation of intermediate molecular weight smaller, and then in a series of oxidation reduction oxidation (including electricity catalytic reduction and microbial redox) under the action of aniline compounds decomposed into small organic molecules or easy degradation, finally further oxidation of CO_2 and H_2O. mineralization

【学位授予单位】：济南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X799.3;X172

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