摘要
为了给减缓膜生物反应器(MBR)膜污染提供新思路,对MBR中EPS各组分对污泥聚集性能的影响及其膜污染特性进行研究。通过分析MBR中污泥的聚集性,发现原始污泥的聚集速率常数为0.0151,提取EPS后污泥的聚集速率常数为0.00181,由此可以看出EPS在污泥聚集的过程中起重要作用。为了进一步明确EPS各组分对MBR中污泥聚集性能的影响,利用扩展的DLVO理论研究MBR中EPS及其各组分对污泥聚集性能的影响,发现MBR中EPS里粘液的二级能量最小值大约为-0.94 KT,松散型EPS(LB-EPS)为-2.98 KT,紧密型EPS(TB-EPS)为-3.87 KT,说明TB-EPS在污泥聚集的过程中起重要作用。进一步通过三维荧光光谱及EPS浓度分析,发现EPS各组分浓度及结构的不同导致EPS各组分对污泥聚集性起不同的作用。通过吸附实验、原子力显微镜观察发现EPS各组分的膜污染速率为:上清液<粘液<LB-EPS<TB-EPS,由此,可以推测出减少粘液和LB-EPS含量可有效降低膜污染,同时对污泥絮体结构影响较小。
In order to research extracellular polymeric substances(EPS) to the formation of sludge flocs in membrane bioreactor and its membrane fouling characteristics,providing new methods for controling of MBR membrane fouling.Through analyzing sludge aggregation in MBR,it can be founded that the aggregation rate constant of original sludge was 0.0151,after extracting EPS the aggregation rate constant of sludge was 0.00181.Thus it can be seen that EPS played an important role in sludge gathered.In order to further clarify the influence of each component of EPS on sludge aggregation in MBR,using extended DLVO theory to research extracellular polymeric substances(EPS) to the formation of sludge flocs in membrane bioreactor.The result showed that secondary energy minimum values of slime in MBR was approximately-0.94 KT.The secondary energy minimum values of loosely bound EPS(LB-EPS) was-2.98 KT.Secondary energy minimum values of tightly bound EPS(TB-EPS) was-3.87 KT.It proved that TB-EPS played an important role in sludge aggregation.Through further analysis of three dimensional fluorescence spectra and the concentration of EPS,finding that the differences of structrure and concentration of each component in EPS on sludge aggregation play different roles.Through adsorption experiment and atomic force microscopy revealed membrane fouling rate of each component in EPS:supernatant < slime < LB-EPS < TB-EPS.It can be speculated that decreased the content of slime and LB-EPS can reduce membrane fouling effectively.At the same time,it has little effect on sludge floc structure.
出处
《环境工程学报》
CAS
CSCD
北大核心
2015年第2期645-652,共8页
Chinese Journal of Environmental Engineering
基金
国家"水体污染控制与治理"科技重大专项(2013ZX07201007)
高等学校博士学科点专项科研基金资助项目(20112302110060)
国家创新研究群体科学基金资助项目(51121062)
中央高校基本科研业务费专项基金(HIT.NSRIF.2015096)
关键词
膜生物反应器
EPS
膜污染
污泥絮体
扩展的DLVO理论
membrane bioreactor(MBR)
extracellular polymeric substances
membrane fouling
sludge flocs
extended DLVO theory
