UniTank工艺流程氨氮浓度的动态特征

利用基于ASM2D的数学模型对上海石洞口污水厂UniTank工艺内氨氮浓度的动态特性进行了仿真研究,发现该流程反应器氨氮浓度具有非稳态特征.反应器内氨氮浓度的变化规律与曝气时间设定及进水时间设定有关.增加曝气强度,能降低边池及中池的氨氮浓度,相应增大边池及中池的硝态氮浓度.     

猪粪堆肥发酵菌种的分离筛选及特性研究

从多种样品材料中分离筛选出8株能以猪粪为基质生长的菌种,对其中4株菌(8B、8C、8E、2B)进行了初步分类鉴定,并对它们发酵猪粪培养基的特性作了研究.结果表明,这4株菌均属于芽孢杆菌属,其中8C、2B菌种生长最好,8B次之,而8E菌种则不适合作为发酵菌种;对培养基采取完全灭菌对菌种生长繁殖是有利的,间歇灭菌和不灭菌效果相对较差,甚至会对菌种产生不利影响;pH值的变化在一定程度上反映出微生物生长繁殖能力的强弱;较低的pH值不利于微生物菌种生长.     

土壤有机物污染控制标准制订的方法学研究

指出了中国现行土壤环境质量标准存在的问题.对日本和美国等发达国家的有机物污染土壤质量控制标准进行了分析.从土壤环境质量基准制订的方法学和污染控制标准的确定原则上,提出了制订中国土壤有机物污染控制标准的建议.     

涡凹气浮(CAF)/SBR法在高寒地区屠宰废水中的应用

采用涡凹气浮(CAF)和序批式活性污泥(SBR)法处理高寒地区屠宰废水,在冬季室温15℃以上培养的活性污泥完全适应该工艺的要求.经该工艺处理后,出水水质可达到国家《污水综合排放标准》(GB 8978-1996)一级标准,COD、BOD5、SS、氨氮和TN去除率分别达到95.3%、96.7%、87.1%、63.3%和60.9%.     

Use of chemical coagulants to control fouling potential for wastewater membrane bioreactor processes.

Chemical coagulation with ferric chloride, alum, and an organic polymer were used to control the fouling potential of mixed liquors for submerged membrane bioreactor (MBR) processes in treating municipal wastewater. Their filterability was evaluated using a submerged hollow fiber ultrafiltration apparatus operated in constant permeate flux mode. The collected transmembrane pressures over filtration time were used to calculate the membrane fouling rates. The results showed that coagulation pretreatment can reduce fouling rates when MBRs were operated above the critical flux. Even though coagulation with the organic polymer formed larger mixed liquor suspended solids particles and had shorter time-to-filtration than those with ferric chloride and alum, the filterability for membrane filtration were similar, indicating that the membrane fouling in MBR systems was mainly controlled by the concentration of smaller colloidal particles.     

Quantifying air pollution attenuation within urban parks: an experimental approach in Shanghai, China

Parks with various types of vegetations played an important role in ameliorating air quality in urban areas. However, the attenuation effect of urban vegetation on levels of air pollution was rarely been experimentally estimated. This study, using seasonal monitoring data of total suspended particles (TSP), sulfur dioxide (SO(2)) and nitrogen dioxide (NO(2)) from six parks in Pudong District, Shanghai, China, demonstrated vegetations in parks can remove large amount of airborne pollutants. In addition, crown volume coverage (CVC) was introduced to characterize vegetation conditions in parks and a mixed-effects model indicated that CVC and the pollution diffusion distance were key predictors influencing pollutants removal rate. Therefore, it could be estimated by regression analysis that in summer, urban vegetations in Pudong District could contribute to 9.1% of TSP removal, 5.3% of SO(2) and 2.6% of NO(2). The results could be considered for a better park planning and improving air quality.     

Biosorption of zinc and copper from aqueous solutions by two freshwater green microalgae Chlorella pyrenoidosa and Scenedesmus obliquus

Purpose

The objective of this study was to determine the removal of zinc and copper by two freshwater green microalgae Chlorella pyrenoidosa and Scenedesmus obliquus and to investigate changes of algal ultrastructure and photosynthetic pigment.

Methods

Algal cells were exposed for 8 days to different initial zinc or copper concentrations. Heavy metal concentrations were detected by an atomic absorption spectrophotometer. Algal growth, ultrastructure, and photosynthetic pigment were analyzed by a microplate reader, transmission electron microscope, and spectrophotometer, respectively.

Results

Low zinc and copper concentrations induced increase in algal growth, whereas application of high zinc and copper concentrations suppressed the growth of both algae. High metal concentrations also decreased the photosynthetic pigments and destroyed algal cell ultrastructure. The zinc removal efficiency by both algae increased rapidly during the first day and thereafter remained nearly constant throughout the experiment. The copper removal efficiency by both algae increased slowly during the whole experimental periods. In all cultures, the quantity of both metals removed intracellularly was much lower than the adsorbed quantity on the cell surface.

Conclusions

Both strains of the microalgae had proven effective in removing zinc and copper from aqueous solutions, with the highest removal efficiency being near 100%. In addition, C. pyrenoidosa appeared to be more efficient than S. obliquus for removing copper ions. On the contrary, S. obliquus appeared to be more efficient than C. pyrenoidosa for removing zinc ions.     

青霉菌HHE-P7利用酱油废水产生微生物絮凝剂的研究

研究了微生物絮凝剂产生菌HHE-P7在酱油废水中产生微生物絮凝剂的絮凝特性。实验表明，酱油废水由于碳源丰富，是一种良好的培养基。HHE-P7菌最佳培养条件为：COD20000mg／L，K2HP041．0g／L，培养3d。最佳絮凝条件为在1L高岭土水中投加10～15mL微生物絮凝剂（MBF7），pH调至9，则絮凝率为90％以上；微生物絮凝荆在水系中主要起吸附架桥的作用。     

玉米浸泡液制备苏云金杆菌生物杀虫剂的影响因素研究

以玉米淀粉生产过程中的浸泡液为培养基,摇瓶发酵培养苏云金杆菌生物杀虫剂,通过一系列单因子试验,考察了不同培养条件(种子液的种龄、接种量、浸泡液的含固率、初始pH值、摇床转速、发酵温度及发酵时间)对苏云金杆菌在玉米浸泡液中的生长(菌数增长与芽孢形成)以及发酵液的生物毒效的影响.研究表明,在最佳摇瓶培养条件(种子液种龄10 h,接种量2%,浸泡液含固量3%,初始pH值7.0～7.5,摇床转速200 r/min,发酵温度30℃)下发酵48 h,活菌数和活芽孢数分别可达到7.9×108 CFU/mL和5.5×108 CFU/mL,毒力效价为698.0 IU/μL.本试验可为生物农药的工业化生产提供实用参数.