一种测定活性污泥中高等微生物活性的方法

采用机械破碎方式灭活活性污泥中高等微生物,并通过测定破碎前后泥样耗氧速率(OUR)之差别间接计算高等微生物的活性作用.实验结果表明,以分散机破碎活性污泥,高等微生物均可被有效地破碎灭活,且再培养138h后不再恢复.与此同时,对酵母菌破碎实验显示,机械破碎并未对其数量、形态以及活性产生太大影响,这表明机械破碎亦不会对个体尺寸比酵母菌更小的细菌构成任何影响.为使破碎前后活性污泥絮凝体形态基本一致,将破碎后的泥样经离心处理,以尽可能使絮凝体恢复如初(以SVI衡量).通过比较破碎前后泥样的OUR并计算可知,高等微生物活性相对于活性污泥总活性约占12%～14%.     

活性炭滤池中微生物特征及其对溶解性有机碳的去除作用

采用异养菌总数计数（HPC）法检测了北京地区J水厂活性炭滤池中微生物量,并分析了活性炭滤池进出水中有机物的组成、活性炭的吸附作用及微生物作用对溶解性有机碳(DOC)去除的贡献率.结果表明,不同炭龄、不同运行周期活性炭滤池中的微生物量有显著的差异.由于溶解性可生物降解有机碳（BDOC）占溶解性有机碳（DOC）的比例较小,且受微生物数量、活性等因素的影响,微生物对DOC的去除效果极为有限,在1.5年和5年炭龄活性炭滤池中对DOC的去除率仅占总去除率的18.8%和26.4%.此外,微生物对较为敏感的嗅味物质2-MIB和geosmin去除作用也不显著,去除率在15%以下（初始浓度为100ng·L-1）;在使用5年活性炭滤池中,微生物对2-MIB和geosmin去除率为12%和14%,分别占总去除率的32%和29%.因此,北京地区地表水净水厂活性炭滤池中微生物对有机物控制的贡献率较低,对DOC的去除主要以活性炭的吸附为主.     

焦炭塔现场操作的危险原因分析和解决措施

根据具体的事故案例,对焦炭塔现场操作过程存在的各种危险进行了原因分析,提出要从完善仪表控制、加强操作工培训、改善操作条件、进行技术动改及不断完善操作规程和各类制度等方面入手,切实做好各类基础工作,才能消除危险,保障安全。     

铜藻基载铁活性炭的制备及其对亚甲基蓝的吸附特性研究

以一种大型海藻——铜藻为原料,Fe Cl3·6H2O为活化剂,采用超声浸渍-原位合成法制备了铜藻基载铁活性炭(Fe/SAC),并以活性炭得率和亚甲基蓝吸附值为指标,通过正交法考察了活化温度、活化时间和浸渍比的影响.同时,采用X射线衍射、扫描电镜和比表面积分析仪对最优结果进行表征,并考察了Fe/SAC吸附亚甲基蓝的热力学与动力学特性.结果表明,Fe/SAC的最优制备工艺条件为活化温度600℃、活化时间1 h、浸渍比1∶1,此时的活性炭得率为39.5%,亚甲基蓝吸附值为255.67 mg·g~(-1);最优工艺条件下制得的Fe/SAC比表面积为558.31 m2·g~(-1),其负载的铁组分主要为Fe3O4和Fe O;亚甲基蓝在Fe/SAC上的吸附过程符合准二级动力学模型,Langmuir等温吸附模型能够很好地描述吸附平衡过程,该吸附是熵增加的自发吸热(ΔS0、ΔG0、ΔH0)过程,升温有利于吸附.     

驯化活性污泥SBR工艺处理乳制品废水研究

乳制品废水直接采用生物法处理在现有研究中较少,为验证处理效果,将4阶段驯化后的活性污泥投加到SBR中,进行了低浓度乳制品废水的直接生物降解试验,主要考察了对COD、NH4-N的去除效果,结果显示:活性污泥驯化期间,COD、NH4-N平均去除率分别为93%、90%;驯化后的活性污泥处理效果稳定,当进水COD为1654 mg/L、NH4-N为115 mg/L时,出水COD、NH4-N分别为66 mg/L、2 mg/L,达到《污水综合排放标准》(GB 8978-1996)一级排放标准,证明了用驯化活性污泥直接处理低浓度乳制品废水是可行的.     

Occurrence, distribution, and potential influencing factors of sewage sludge components derived from nine full-scale wastewater treatment plants of Beijing, China

Millions of tons of waste activated sludge (WAS) produced from biological wastewater treatment processes cause severe adverse environmental consequences. A better understanding of WAS composition is thus very critical for sustainable sludge management. In this work, the occurrence and distribution of several fundamental sludge constituents were explored in WAS samples from nine full-scale wastewater treatment plants (WWTPs) of Beijing, China. Among all the components investigated, active heterotrophic biomass was dominant in the samples (up to 9478 mg/L), followed by endogenous residues (6736 mg/L), extracellular polymeric substances (2088 mg/L), and intracellular storage products (464 mg/L) among others. Moreover, significant differences (p < 0.05) were observed in composition profiles of sludge samples among the studied WWTPs. To identify the potential parameters affecting the variable fractions of sludge components, wastewater source as well as design and operational parameters of WWTPs were studied using statistical methods. The findings indicated that the component fraction of sewage sludge depends more on wastewater treatment alternatives than on wastewater characteristics among other parameters. A principal component analysis was conducted, which further indicated that there was a greater proportion of residual inert biomass in the sludge produced by the combined system of the conventional anaerobic/anoxic/oxic process and a membrane bioreactor. Additionally, a much longer solids retention time was also found to influence the sludge composition and induce an increase in both endogenous inert residues and extracellular polymeric substances in the sludge.     

A new process to improve short-chain fatty acids and bio-methane generation from waste activated sludge

As an important intermediate product, short-chain fatty acids(SCFAs) can be generated after hydrolysis and acidification from waste activated sludge, and then can be transformed to methane during anaerobic digestion process. In order to obtain more SCFA and methane,most studies in literatures were centered on enhancing the hydrolysis of sludge anaerobic digestion which was proved as un-efficient. Though the alkaline pretreatment in our previous study increased both the hydrolysis and acidification processes, it had a vast chemical cost which was considered uneconomical. In this paper, a low energy consumption pretreatment method, i.e. enhanced the whole three stages of the anaerobic fermentation processes at the same time, was reported, by which hydrolysis and acidification were both enhanced, and the SCFA and methane generation can be significantly improved with a small quantity of chemical input. Firstly, the effect of different pretreated temperatures and pretreatment time on sludge hydrolyzation was compared. It was found that sludge pretreated at 100°C for 60 min can achieve the maximal hydrolyzation. Further, effects of different initial p Hs on acidification of the thermal pretreated sludge were investigated and the highest SCFA was observed at initial p H 9.0with fermentation time of 6 d, the production of which was 348.63 mg COD/g VSS(6.8 times higher than the blank test) and the acetic acid was dominant acid. Then, the mechanisms for this new pretreatment significantly improving SCFA production were discussed. Finally,the effect of this low energy consumption pretreatment on methane generation was investigated.     

Efficient treatment of azo dye containing wastewater in a hybrid acidogenic bioreactor stimulated by biocatalyzed electrolysis

In this study, a novel scaled-up hybrid acidogenic bioreactor(HAB) was designed and adopted to evaluate the performance of azo dye(acid red G, ARG) containing wastewater treatment. Principally, HAB is an acidogenic bioreactor coupled with a biocatalyzed electrolysis module. The effects of hydraulic retention time(HRT) and ARG loading rate on the performance of HAB were investigated. In addition, the influent was switched from synthetic wastewater to domestic wastewater to examine the key parameters for the application of HAB. The results showed that the introduction of the biocatalyzed electrolysis module could enhance anoxic decolorization and COD(chemical oxygen demand) removal. The combined process of HAB-CASS presented superior performance compared to a control system without biocatalyzed electrolysis(AB-CASS). When the influent was switched to domestic wastewater, with an environment having more balanced nutrients and diverse organic matters, the ARG, COD and nitrogen removal efficiencies of HAB-CASS were further improved, reaching 73.3% ± 2.5%, 86.2% ± 3.8% and 93.5% ± 1.6% at HRT of 6 hr, respectively, which were much higher than those of AB-CASS(61.1% ± 4.7%,75.4% ± 5.0% and 82.1% ± 2.1%, respectively). Moreover, larger TCV/TV(total cathode volume/total volume) for HAB led to higher current and ARG removal. The ARG removal efficiency and current at TCV/TV of 0.15 were 39.2% ± 3.7% and 28.30 ± 1.48 m A,respectively. They were significantly increased to 62.1% ± 2.0% and 34.55 ± 0.83 m A at TCV/TV of 0.25. These results show that HAB system could be used to effectively treat real wastewater.     

The biological effect of metal ions on the granulation of aerobic granular activated sludge

As a special biofilm structure, microbial attachment is believed to play an important role in the granulation of aerobic granular activated sludge (AGAS). This experiment was to investigate the biological effect of Ca^2 +, Mg^2 +, Cu^2 +, Fe^2 +, Zn^2 +, and K⁺ which are the most common ions present in biological wastewater treatment systems, on the microbial attachment of AGAS and flocculent activated sludge (FAS), from which AGAS is always derived, in order to provide a new strategy for the rapid cultivation and stability control of AGAS. The result showed that attachment biomass of AGAS was about 300% higher than that of FAS without the addition of metal ions. Different metal ions had different effects on the process of microbial attachment. FAS and AGAS reacted differently to the metal ions as well, and in fact, AGAS was more sensitive to the metal ions. Specifically, Ca^2 +, Mg^2 +, and K⁺ could increase the microbial attachment ability of both AGAS and FAS under appropriate concentrations, Cu^2 +, Fe^2 +, and Zn^2 + were also beneficial to the microbial attachment of FAS at low concentrations, but Cu^2 +, Fe^2 +, and Zn^2 + greatly inhibited the attachment process of AGAS even at extremely low concentrations. In addition, the acylated homoserine lactone (AHL)-based quorum sensing system, the content of extracellular polymeric substances and the relative hydrophobicity of the sludges were greatly influenced by metal ions. As all these parameters had close relationships with the microbial attachment process, the microbial attachment may be affected by changes of these parameters.     

生物洗涤和化学吸收组合工艺处理污水厂臭气工程试验研究

目前臭气处理技术发展趋于组合工艺方向,兼顾技术和经济可行性。研究采用生物洗涤和化学吸收组合工艺,在城市污水处理厂开展除臭工程试验。试验分2个阶段进行:第一阶段,启动运行生物洗涤塔,考察生物洗涤塔对H_2S和NH_3的处理效果,并研究生物洗涤塔中活性污泥吸收液成分及性状;第二阶段,在继续运行生物洗涤塔的基础上,启动运行化学吸收塔,考察整个双塔系统对H_2S和NH_3的处理效果。在此基础上开展机理分析和应用验证评价。研究表明除臭系统运行稳定,对H_2S和NH_3去除效果良好,达到国家排放标准。