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911.
The effect and uptake of copper ion on SBR(sequence batch reactor)biological treatment system was studied.special nutrient and powder activated carbon(PAC)additive were tested as uptake stimulation technique.Results showed that copper ion had higher effect on unacclimated activated sludge system than on acelimated one.The special nutrient adding could enhance the uptake of copper significantly,while PAC adding could improve the sludge settling and decrease the turbidity of effluent.The variation of bacterial community analyzed by 16S rDNA method showed the acclimation of copper could increase copper resistance species,and excess accumulation could cause some species diminish.It was confirmed that acclimation could improve the resistance and uptake ability of microorganism to heavy metal.  相似文献   
912.
假单胞菌摄磷和释磷条件的研究   总被引:4,自引:0,他引:4  
考察了碳、硫等物质对废水生物脱磷优势菌假单胞菌磷代谢的影响.结果表明,缺磷环境导致假单胞菌产生过量摄磷现象;假单胞菌无论是经过无碳厌氧、无碳好氧还是无硫厌氧、无硫好氧培养后,转接到富磷培养基内好氧培养时,都产生过量摄磷现象.随着在富磷培养基内的好氧培养时间延长,细菌的摄磷量下降.  相似文献   
913.
以磷酸钙盐的形式从污水处理厂回收磷的研究   总被引:7,自引:0,他引:7  
磷是一种不可再生、难以替代的有限自然资源.磷的可持续利用问题越来越受到世界各国学者与政府的高度重视.近年来,从污水厂回收磷在世界各国逐渐兴起,而我国在这方面的研究还处于起步阶段,尤其是以磷酸钙盐的形式回收磷的相关研究还未见报道.以磷酸钙盐形式回收废水中的磷,优化磷回收过程相关工艺控制条件.结果表明,pH值和Ca2 浓度是磷酸钙盐回收的关键因素,最优值分别为10和6.68,磷回收率达到90%.  相似文献   
914.
通过对抚仙湖流域磷矿开采区内不同植被类型在同一降雨下水土流失的对比研究,筛选出磷矿开采区内水土保持能力较好的植被类型,研究表明:在所选8种植被类型中,竹林植物群落的水土保持能力最强,旱冬瓜林植物群落次之。  相似文献   
915.
大型磷酸-磷铵企业环境风险的防范   总被引:1,自引:2,他引:1  
运用工程分析,物料衡算,综合判断等方法对大型磷酸-磷铵企业的重点污染风险因子进行筛选只别,根据磷石膏库暴雨满溢时氟化物对地表水环境的污染影响,含氟废气(事故)排放对大气环境及农作物的污染影响,氨贮罐泄漏及燃爆对大气环境及健康影响的风险评价结果,重点研究了磷酸-磷铵企业环境风险的防范措施。针对广西鹿化肥公司及国内同类厂的一般情况,提出了保证库周排洪导流沟渠通畅,建设备用磷石膏库等防止暴雨满溢污染地染地表水,改造磷酸尾气洗涤吸收系统防止含氟废气(事故)排放,加强氨系统的安全管理以杜绝氨泄漏等防范措施。  相似文献   
916.
At 7·5 weeks gestation, two small chorionic villous biopsies were obtained from a woman at risk for Zellweger's cerebro-hepato-renal syndrome, and were separately established in culture. After 3 weeks, dihydroxyacetone phosphate acyltransferase (DHAP-AT) activity was measured in both cultures. The enzyme was markedly deficient in one cell strain and this was subsequently shown to have a male karyotype. However, the second culture had normal enzyme activity and a female karyotype. The pregnancy was terminated at 11·5 weeks gestation, and follow-up studies on fetal tissues confirmed a male fetus with markedly deficient DHAP-AT activity.  相似文献   
917.
研究了金鱼( Carassiusauratus L.) 在铅暴露实验中的铅吸收过程及鱼鳃分泌物的自身保护作用、水相Pb2+ 的鳃吸收机理以及分泌粘液对铅的络合作用.结果表明,金鱼因铅暴露导致粘液分泌量增加.结合到鳃上的铅与水相Pb2+ 活度关系可用Langmuir 吸附等温式表述.据此估算的最大结合量为0-9424 m mol/kg(干重) .非常接近1 的Hill 常数(1-012)说明金鱼鳃上仅有一种类型的Pb2+ 结合位点.平均每尾金鱼鳃上Pb2+ 的结合位点数达1-62 ×10- 5 m mol,结合的条件稳定常数(log KPb鳃) 为4-8 .血液铅含量与鳃铅含量间呈显著线性关系.金鱼吸收Pb2+ 的主要过程为:Pb2+ 结合到鳃上,其后被动扩散或载体转运穿过鳃上皮,进入血液循环.  相似文献   
918.
To achieve advanced nitrogen removal from actual municipal sewage, a novel multistage anoxic/aerobic process with sludge regeneration zone (R-MAO) was developed. The reactor was used to treat actual domestic sewage and the nitrogen removal capacity of the sludge regeneration zone (R zone) was investigated during the long-term operation. The best performance was obtained at the R zone's Oxidation-Reduction Potential (ORP) of -50±30 mV and hydraulic residence times (HRT) of 1.2 hr. The average effluent COD, TN, NH4+-N and NO3-N of the R-MAO process were 18.0±2.3, 7.5±0.6, 1.0±0.5 and 4.6±0.4 mg/L, respectively, with the corresponding removal efficiency of COD, TN and NH4+-N were 92.9%±1.0%, 84.1%±1.5% and 97.5%±1.1%. Compared to the sole MAO system, the TN removal efficiency of the R-MAO increased by 10.1%. Besides, under the optimal conditions, the contribution of the R zone in the R-MAO that removal COD, TN, NH4+-N and NO3-N were 0.36, 0.15, 0.032 and 0.82 g/day. High-throughput sequencing results showed that uncultured_bacterium_f_Burkholderiaceae (5.20%), OLB8 (1.04%) and Ottowia (1.03%) played an important role in denitrification in the R zone. This study provided effective guidance for the design and operation of the R-MAO process in domestic sewage treatment.  相似文献   
919.
研究了金鱼在铅暴露实验中的铅吸收过程及鱼鳃分泌物的自身保护作用,水相Pb^2+的鳃吸收机理以及分泌粘液对铅的络作用。结果表明,金鱼因铅暴露导致粘液分泌量增加。结合到鳃上的铅与水相Pb^2+活度关系可用Langmuir吸附等温式表述。  相似文献   
920.
This work aims to explore a procedure to improve biological wastewater treatment efficiency using low intensity ultrasound. The aerobic activated sludge from a municipal wastewater treatment plant was used as the experimental material. Oxygen uptake rate (OUR) of the activated sludge (AS) was determined to indicate the changes of AS activity stimulated by ultrasound at 35 kHz for 0–40 min with ultrasonic intensities of 0–1.2 W/cm2. The highest OUR was observed at the ultrasonic intensity of 0.3 W/cm2 and an irradiation period of 10 min; more than 15% increase was achieved immediately after sonication. More significantly, the AS activity stimulated by ultrasound could last 24 h after sonication, and the AS activity achieved its peak value within 8 h after sonication, or nearly 100% higher than the initial level after sonication. Therefore, to improve the wastewater treatment efficiency of bioreactors, ultrasound with an intensity of 0.3 W/cm2 could be employed to irradiate a part of the AS in the bioreactor for 10 min every 8 h. Translated from Environmental Science, 2005, 26(4): 124–128 [译自: 环境科学]  相似文献   
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