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71.
Bioaugmentation with genetically engineered microorganisms (GEMs) in a membrane bioreactor (MBR) for enhanced removal of recalcitrant
pollutants was explored. An atrazine-degrading genetically engineered microorganism (GEM) with green fluorescent protein was
inoculated into an MBR and the effects of such a bioaugmentation strategy on atrazine removal were investigated. The results
show that atrazine removal was improved greatly in the bioaugmented MBR compared with a control system. After a start-up period
of 6 days, average 94.7% of atrazine was removed in bioaugmented MBR when atrazine concentration of influent was 14.5 mg/L.
The volumetric removal rates increased linearly followed by atrazine loading increase and the maximum was 65.5 mg/(L·d). No
negative effects were found on COD removal although carbon oxidation activity of bioaugmented sludge was lower than that of
common sludge. After inoculation, adsorption to sludge flocs was favorable for GEM survival. The GEM population size initially
decreased shortly and then was kept constant at about 104–105 CFU/mL. Predation of micro-organisms played an important role in the decay of the GEM population. GEM leakage from MBR was
less than 102 CFU/mL initially and was then undetectable. In contrast, in a conventionally activated sludge bioreactor (CAS), sludge bulking
occurred possibly due to atrazine exposure, resulting in bioaugmentation failure and serious GEM leakage. So MBR was superior
to CAS in atrazine bioaugmentation treatment using GEM. 相似文献
72.
73.
UF膜与混凝粉末活性炭联用处理微污染原水 总被引:21,自引:3,他引:21
采用混凝、粉末活性炭和UF膜分离的联用技术对黄浦江原水进行试验 ,结果表明 ,混凝、粉末活性炭可有效地去除溶解性有机物 .混凝处理主要去除大分子量的有机物 ,粉末活性炭主要去除低分子量的有机物 .混凝、粉末活性炭还能有效地去除三氯甲烷生成潜能 (THMFP) ,对于低分子量的THMFP ,混凝去除效果很差 ,而粉末活性炭去除很好 .试验还表明 ,混凝、粉末活性炭还可大大降低膜的滤饼层阻力 ,当混凝剂投加量为 4mg/L时 ,膜的滤饼层阻力最小 . 相似文献
74.
活性炭-纳滤膜工艺去除饮用水中总有机碳和Ames致突变物 总被引:15,自引:2,他引:15
分别以地表水和地下水为水源的水厂出水为研究对象 ,探讨活性炭 纳滤膜工艺对饮用水中总有机碳和Ames致突变物的去除效果及机理 .结果表明 ,活性炭的吸附作用受其本身性质和有机物特性影响较大 ,去除能力有限 ,但它可作为纳滤的预处理 ,确保膜进水符合要求 ;纳滤则可将水中总有机碳和Ames致突变物大部分去除 ,使TA98及TA100菌株在各试验剂量下的MR值均小于 2 ,Ames试验结果均完全呈阴性 ,确保了饮用水的安全性 .两者的组合是获得优质饮用水的有效处理工艺 . 相似文献
75.
膜萃取处理水溶液中镉、锌离子的工艺 总被引:3,自引:0,他引:3
以P204+正庚烷为萃取剂,将中空纤维膜萃取技术用于处理水溶液中镉离子、锌离子.研究了两相流速、初始浓度及溶液pH等因素对传质系数和萃取率的影响,计算了膜萃取器的传质单元高度(HTU)w,同时还研究了萃取剂的再生问题.实验结果表明,在低浓度下(<500 mg/L),平衡分配系数较大,传质阻力主要是在水相;在初始浓度较高时(<2000mg/L),由于分配系数较小,三项传质阻力均不可忽略;在初始浓度很高时(>2000mg/L),传质由有机相和膜相阻力控制.实验还表明通过膜器串联可以实现萃取剂的再生.对于稀溶液(<200mg/L),中空纤维膜萃取可以使水溶液中金属离子浓度减小2个数量级,通过计算,中空纤维膜萃取器(HTU)w在15~30cm之间,大大低于传统的萃取塔. 相似文献
76.
77.
A membrane extraction-gas chromatography method was developed fordetermination of organophosphorus pesticides and related compounds including methamidophos, DDVP, dimethoate, methyl parathion, parathion, thiophosphoric acid trimethyl ester, and thiophosphoramidic acid dimethyl ester in water samples. In thismethod, surface-modified acetic cellulose membranes were used to extract the target analytes in water samples, the extracted analytes were back-extracted into a small amount of methanol, andgas chromatography with pulsed flame photometric detector (GC-PFPD) was used to determine the concentrations of targetanalytes in the extracts. The recoveries obtained for thetarget analytes spiked into the water samples ranged from 66to 94%. The method detection limit for each target analyte was 0.05 g L-1. The method developed in this study had shown the advantages of being cheap, simple, fast, and reliable. It had been used successfully to determine the concentrations of target analytes in river water samples. 相似文献
78.
79.
Removal of inorganic nitrogen (inorganic-N) from toilet wastewater, using a pilot-scale airlift external circulation membrane bioreactor (AEC-MBR) was studied. The results showed that the use of AEC-MBR with limited addition of alkaline reagents and volumetric loading rates of inorganic-N of 0.19-0.40 kg inorganic-N/(m3·d) helped achieve the desired nitrification and denitrification. Furthermore, the effects of pH and dissolved oxygen (DO) on inorganic-N removal were examined. Under the condition of MLSS at 1.56-2.35 g/L, BOD5/ammonia nitrogen (NH/-N) at 1.0, pH at 7.0-7.5, and DO at 1.0-2.0 mg/L, the removal efficiencies of NH4 -N and inorganic-N were 91.5% and 70.0%, respectively, in the AEC-MBR. The cost of addition of alkaline reagent was approximately 0.5-1.5 RMB yuan/m3, and the energy consumption was approximately 0.72 kWh/m3 at the flux of 8 L/(m2·h). 相似文献
80.