Application of ultrafiltration hybrid membrane processes for reuse of secondary effluent

This study evaluates the factors affecting pretreatment conditions for hybrid UF membrane processes for reuse of secondary effluent from the sewage treatment plant. The experimental results obtained from the ultrafiltration (UF) membrane process showed that the particles of the size range between 0.2 and 1.2 μm caused a significant impact on membrane fouling in all cases even with or without the coagulation process. As pretreatment of UF membrane process, the coagulation significantly improved the permeate flux. Optimal flux improvement was seen at an alum dose of 50 mg/L. In addition, it was found that the permeate flux was least declined under the coagulation condition of charge neutralization (pH 5.0). Also, the powdered activated carbon (PAC) adsorption enhanced the permeate flux. Application of the direct filtration as a pretreatment of UF membrane process was also very effective in reducing the UF membrane fouling.     

New explicit algebraic stress and flux model for active scalar and simulation of shear stratified cylinder wake flow

On the numerical simulation of active scalar, a new explicit algebraic expression on active scalar flux was derived based on Wikstr?m, Wallin and Johansson model (a ^WWJ model). Reynolds stress algebraic expressions were added by a term to account for the buoyancy effect. The new explicit Reynolds stress and active scalar flux model was then established. Governing equations of this model were solved by finite volume method with unstructured grids. The thermal shear stratified cylinder wake flow was computed by this new model. The computational results are in good agreement with laboratorial measurements. This work is the development on modeling of explicit algebraic Reynolds stress and scalar flux, and is also a further modification of the a ^WWJ model for complex situations such as a shear stratified flow. Supported by the National Nature Science Foundation of China (Grant Nos. 50679019, 50009001), the National Basic Research Program of China (“973” Project) (Grant No. 2008CB418202), the Project of “Six Talent Peak” of Jiangsu Province (08-C), Social Technology Development Foundation of Jiangsu Province (Grant No. BS2006095) and the “908” Special Foundation of Jiangsu Province (Grant No. JS-908-02-06)     

化学法浸提污泥土地利用的适用性

以L-天冬氨酸、氨三乙酸、DL-苹果酸和丙二酸为浸提剂,研究了化学法浸提污泥对重金属(Cu、Zn、Pb、Cr)形态、营养元素流失、污泥农用后作物生长状况及重金属累积的影响,分析了化学法浸提污泥土地利用的适用性.结果表明:浸提剂对Cu、Zn、Pb、Cr最高去除率分别为89.1%、32.4%、52.7%、39.2%,化学浸提后,残留于污泥中的重金属不稳定态含量显著减少,提高了污泥土地利用的安全性;污泥经化学法浸提后总氮和总磷的流失率分别为9.0%~92.0%和56.4%~77.3%,但仍能保持较好的肥效,满足土地利用的需要.将污泥适量施于农田,小麦植株干重明显增加,但随着污泥施用量的增加,小麦根系和茎叶中重金属的累积量随之增加.从小麦生长状况与重金属残留综合考虑,污泥与土壤的配比为50%较为合适.     

分汊型河道水流运动特性和污染物输移规律研究进展

对分汊型河道的水流运动特性和污染物输移扩散规律的相关研究进行综述,分别从分汊型河道中分汊口、交汇口、整个分汊河道的水流特性及分汊型河道中的污染物输移特性等4个方面进行总结。介绍分汊口和交汇口处的水流从其能量损失、水位变化、水流分离等一维、二维过流特征到三维流动结构和紊动特性的研究过程;从野外现场试验、室内物理模型试验和数学模型模拟等角度出发阐述了整个分汊河道的水流特性;认为污染物在分汊河道中的输运规律研究主要集中在数值模拟上,并进行了回顾和分析;提出分汊河道水流水质输移特性研究中一些有待深入探究的问题,尤其亟待加强不同排放方式、不同污染物密度和不同分汊形态下污染物输移机制的试验研究。     

活性炭池中桡足类浮游动物滋生的影响因素

以水温、光照条件等环境因素对桡足类的摄食行为和作用关系进行研究.结果表明,10～30℃时,桡足类浮游动物的清滤率和滤食率均保持在较高的水平,宽广的摄食温度范围有利于其在活性炭池中滋生繁殖;在全黑暗和光照周期12 h、光照强度700 lx条件下,桡足类的摄食强度出现高峰,而光强升高则会抑制水蚤的摄食行为;活性炭池中炭附细菌对桡足类饵料的贡献率超过自由细菌5倍以上,水蚤的摄食主要集中在小于10μm的粒径范围,占饵料总量的90%以上.控制活性炭池的光照条件和改善进水水质降低炭层中的微生物水平,均有利于抑制水蚤类浮游动物的滋生.     

溢流雨污水就地消纳生态控污结构设计研究

介绍了一种溢流雨污水就地消纳生态控污结构的设计方法,在考虑受纳水体环境要求的条件下,通过数值模拟与经验公式综合确定处理规模以控制用地面积;采用竹炭材质的短管作为核心填料以保证净化效果,经试验验证,其对COD、SS的平均去除率分别可达到35%和50%以上;利用生态型透水砖作为构筑物立面结构,根据该地区平均无雨时间间隔确定透水系数,在延长停留时间、强化净化效果的同时保证再次降水时的安全容积。该设计方法可为国内同类溢流雨污水控制提供参考。     

Mini Review on the Structure and Properties (Photocatalysis), and Preparation Techniques of Graphitic Carbon Nitride Nano-Based Particle,and Its Applications

Graphite carbon nitride (g-C₃N₄) is well known as one of the most promising materials for photocatalytic activities, such as CO₂ reduction and water splitting, and environmental remediation through the removal of organic pollutants. On the other hand, carbon nitride also pose outstanding properties and extensive application forecasts in the aspect of field emission properties. In this mini review, the novel structure, synthesis and preparation techniques of full-bodied g-C₃N₄-based composite and films were revealed. This mini review discussed contemporary advancement in the structure, synthesis, and diverse methods used for preparing g-C₃N₄ nanostructured materials. The present study gives an account of full knowledge of the use of the exceptional structural and properties, and the preparation techniques of graphite carbon nitride (g-C₃N₄) and its applications.     

Z型Ag2CO3/BiOCl异质结光催化剂的制备及其可见光催化机理分析

通过溶剂热法制备BiOCl纳米片,共沉淀法制备Ag2 CO3和复合催化剂Ag2 CO3/BiOCl,研究各材料可见光催化降解罗丹明B的效果,确定Ag2 CO3与BiOCl的最佳配比,并通过表征分析复合材料的结构和异质结光催化降解机理.结果表明,当Ag2 CO3与BiOCl的质量比为50％时,Ag2 CO3/BiOCl异...     

代谢解偶联技术在污泥减量化中的应用研究进展

针对废水生物处理中产生的剩余污泥处置问题,提出了实现污泥减量化的解偶联技术,并介绍了投加解偶联剂、好氧-沉淀-厌氧（OSA）、高S0/X0这三种解偶联工艺的原理、应用及优缺点,最后对这三种工艺的未来发展前景进行了预测。