【作者】 张剑杰；

【导师】 张秀霞；

【作者基本信息】 中国石油大学 ， 环境科学与工程， 2010， 硕士

【摘要】 本文以环氧氯丙烷废水为研究对象,通过活性污泥驯化,研究氯离子浓度变化对污泥浓度、微生物群落、耗氧速率和COD去除率的影响;同时采用固定化微生物技术研究固定化耐盐细菌对环氧氯丙烷的降解性能。活性污泥驯化的实验结果表明:污泥浓度随氯离子浓度的增加而下降,最后趋于平稳。活性污泥由灰褐色变为黄褐色,驯化后污泥具有良好的絮凝性能,停止曝气后,能迅速形成较大的絮状物,而沉淀后出水中悬浮物很少。污泥驯化过程中,随氯离子浓度的升高,系统内微生物的组成也发生变化。在低氯离子浓度时,镜检发现微生物种类丰富,伴有钟虫。在高氯离子浓度时,微生物的种类和数量都变少。通过对驯化和未驯化两组污泥微生物提取DNA进行分析,发现经过耐盐驯化后的活性污泥中微生物的优势菌群较未驯化活性污泥的优势菌群发生了变化。污泥驯化过程中,随污泥系统氯离子浓度的增加,出水COD的去除率由96%下降至75%左右。利用好氧活性污泥对环氧氯丙烷废水进行生物降解实验研究,根据Grau实验模型,氯离子浓度为2g/L和12g/L的动力学模型。通过对A/O+MBBR的工艺研究,可以确定工艺参数如下:水力停留时间:厌氧为24h,好氧为12h,MBBR为12h,共48h;好氧段pH维持在7-8,可使系统对COD的去除率稳定在80%以上。固定化微生物处理环氧氯丙烷废水的实验,考察了固定化方法、载体材料、环境条件对处理环氧氯丙烷废水的影响。实验结果表明:聚乙烯醇-海藻酸包埋法优于吸附法,凝胶剂配比为聚乙烯醇:海藻酸为10∶1.5,交联剂配比H3BO3:CaCl2为6∶1,当废水pH调节到7,微球接种量为20%,活化时间为稳定期16h,环境温度为30℃时,固定化微生物对环氧氯丙烷的降解率可以达到80%以上。更多还原

【Abstract】 This paper takes the epichlorohydrin wastewater as an object，in which the influence ofchloride ion concentration’s change on sludge concentration, microbial community, oxygenconsumption rate and the COD removal rate was studied by activated sludge acclimationexperiment. At the same time, the immobilized microorganisms technology was used to studythe degradation performance of immobilized halotolerant bacteria to epichlorohydrin.The experimental results of activated sludge acclimation showed that the sludgeconcentration decreased with the increase of chloride ion concentration, and finally stabilized.The activated sludge changed yellow-brown from gray-brown and had a good flocculationperformance after acclimation, which could form larger floc rapidly after cessation of aerationand the suspended solid of effluent was rare after precipitation.In the process of sludge domestication, the composition of microbes in system changedwith the increase of chloride ion concentration. At low chloride ion concentration, themicroscopic examination showed abundant microbial species associated with campanula. Athigh chloride ion concentration, the types and quantities of microorganisms were both gettingfewer. It could be found that the dominant microorganisms in activated sludge acclimated bysalt-resistent changed comparing to non-acclimated sludge through the analysis to the DNAextracted from microbial groups in acclimated and non-acclimated sludge.In the process of sludge acclimation, the COD removal rate of effluent decreased from96% to about 75% with the increase of chloride ion concentration in sludge system. The aerobicactivated sludge was used in this paper to carry out the biodegradation of epichlorohydrinwastewater. According to Grau experimental model, when chloride ion concentration was 2%and 12%.Through the study to A/O+MBBR, the parameters could be determined by experiment asfollows:the total hydraulic retention time(HRT)is 48h (anaerobic acidification unit is 24h,anoxic unit is 12h,aerobic unit is 12h), the pH in the aerobic unit should be maintained the level of 7.8-8.0. Under above conditions, the removel rate of COD was over 80%.The influence of immobilized method, carrier material and environmental conditions onthe treatment of epichlorohydrin wastewater was examined in the experiment of immobilizedmicroorganism treating epichlorohydrin wastewater.The results showed that polyvinyl alcoholalginateembedding method is superior to physical adsorption, the jellies ration of polyvinylalcohol:alginate was 10:1.5, the crosslinker H3BO3:CaCl2 was 6:1. When the wastewater’s pHvalue, inoculums size, activation time, temperature were 7, 20%, 16h, 30℃,respectively, thedegradation rate of immobilized microbe to the epichlorohydrin could reach 80%.更多还原