Comparison of CNT-PVA membrane and commercial polymeric membranes in treatment of emulsified oily wastewater

CNT-PVA membrane was fabricated and compared with polymeric membranes. The separation performance was evaluated by homemade and cutting fluid emulsions. The three membranes show similar oil retention rates. CNT-PVA membranes have higher permeation fluxes compared with polymeric membranes. CNT-PVA membrane shows higher fouling resistance. Membrane separation is an attractive technique for removal of emulsified oily wastewater. However, polymeric membranes which dominate the current market usually suffer from severe membrane fouling. Therefore, membranes with high fouling resistance are imperative to treat emulsified oily wastewater. In this study, carbon nanotube-polyvinyl alcohol (CNT-PVA) membrane was fabricated. And its separation performance for emulsified oily wastewater was compared with two commercial polymeric membranes (PVDF membrane and PES membrane) by filtration of two homemade emulsions and one cutting fluid emulsion. The results show that these membranes have similar oil retention efficiencies for the three emulsions. Whereas, the permeation flux of CNT-PVA membrane is 1.60 to 3.09 times of PVDF membrane and 1.41 to 11.4 times of PES membrane, respectively. Moreover, after five consecutive operation circles of filtration process and back flush, CNT-PVA membrane can recover 62.3% to 72.9% of its initial pure water flux. However, the pure water flux recovery rates are only 24.1% to 35.3% for PVDF membrane and 6.0% to 26.3% for PES membrane, respectively. Therefore, CNT-PVA membrane are more resistant to oil fouling compared with the two polymeric membranes, showing superior potential in treatment of emulsified oily wastewater.     

榆林市某园区兰炭企业存在问题及解决对策

兰炭是榆林市的重要产业之一,但由于兰炭"粗放"的生产方式,对区域环境产生一定影响。为推进兰炭绿色健康发展,本文针对榆林市某园区内兰炭企业进行调研,了解该企业存在的主要问题,并提出相关建议。     

金属负载活性炭催化氧化法处理ZPT生产废水

研究了金属负载活性炭催化剂在常温常压下催化氧化处理吡啶硫酮锌(ZPT)废水的技术，在探讨影响催化氧化效果诸因素的基础上，确定出中和预处理、后接两级催化氧化处理该废水的工艺流程，该流程的COD的去除率最高可达92％，处理出水达到国家污水综合排放标准二级指标。     

酿酒废水培养钝顶螺旋藻(S.platensis)与营养物质去除的研究

经前处理后的酿酒厂废水用清水稀释用来培养钝顶螺旋藻 ,可以获得高生物量的钝顶螺旋藻。同时 ,废水中的营养物质也可以被去除。在连续培养条件下 ,使用改进的开放式通道装置培养获得螺旋藻的蛋白质、水分、灰化成份分别为 6 2 .7%、6 .2 1 %和 5 .2 6 % ,重金属含量也符合标准 (GB 1 991 9-1 997)。T -N ,NH4 + -N ,T -P和PO4 3 --P的去除效率分别可达到 72 %、97.9%、4 1 .3%、4 3.1 %。     

紫外-Fenton试剂的作用机理及在废水处理中的应用

本文研究了紫外光、铁离子对过氧化氢的催化分解作用.证实了紫外光和铁离子对过氧化氢的催化分解存在协同效应,并通过研究三价铁离子与紫外光的相互作用,探讨了协同效应产生的机理.UV-Fenton试剂对硝基苯、十二烷基苯磺酸钠(DBS)模拟废水的处理结果表明:将紫外光引入Fenton试剂可大大提高Fen-ton试剂的氧化性能,对生物难降解或难化学氧化的有机污染物具有良好的处理效果.     

Heavy-metal fractionation and distribution in soil profiles short-term-irrigated with sewage wastewater

Six soil profiles irrigated and non-irrigated with sewage wastewater were investigated for soil pH, electrical conductivity (EC), organic matter (OM), and CaCO₃. The distributions and chemical fractions of Cu, Zn, Cd, and Pb, and their lability were also studied. The results indicated that pH, EC, OM, and CaCO₃, as well as metal fractionation in soil profiles were affected by wastewater irrigation, especially in the surface layer. The surface layer (0-15 cm) irrigated with wastewater exhibited a 0.6 unit decrease in soil pH, a 40.6% decrease in CaCO₃, and a 200% increase in EC as compared with that of the non-irrigated soil. The soil OM increased from 0.04% to 0.35% in the surface layer. The irrigation of soil with wastewater resulted in transformation of metals from the carbonate fraction (CARB) towards the exchangeable (EXCH), Fe-Mn oxide (ERO), and organic (OM) fraction for Zn, towards the EXCH, the OM, and residual fraction for Cu, and towards the exchangeable (EXCH) fraction for Cd. It was concluded that the use of sewage wastewater led to salt accumulation and an increase in the readily labile fraction of Zn, Cu, and Cd in the surface layer. Therefore, this reason may limit the use of wastewater under arid and semi-arid conditions.     

催化剂对甲醛废水湿式氧化的增效作用

在设定的湿式氧化条件下 ,从若干种金属盐中筛选了Cu(NO3) 2 作为氧化甲醛废水的催化剂 ,考察了Cu(NO3) 2 用量、废水的初始浓度及温度对有机物去除率的影响 ,结果表明 :Cu(NO3) 2 以 5mg·l- 1 Cu2 计量投加为宜 ,甲醛初始浓度在 480mg·l- 1 — 1 5 0 0mg·l- 1 范围内一直保持较高的去除率 ,反应的适宜温度为 1 40℃以上 ;根据反应过程数据建立了该催化氧化反应的分段一级动力学模型 ,求得甲醛氧化动力学模型快、慢步骤的表观活化能分别为7 2 9kJ·mol- 1 和 1 4 45kJ·mol- 1 ;而COD降解动力学模型快、慢步骤的表观活化能则分别为2 0 47kJ·mol- 1 和 2 9 5 2kJ·mol- 1 .     

GIS在城市给水排水中的应用

阐述了GIS在城市给水排水领域的应用和发展趋势，包括水资源管理与分析、给水排水管网设计与管理、城市污水处理厂设计与管理、管网应急预警系统分析、水质污染状况和趋势分析等，并以大庆市给水排水管网信息管理系统实例，证明GIS可以及时准确完整的提供所需信息，更好的为市政管理者辅助决策提供依据。     

味精废水中重金属及金属污染对处理利用的影响

本文应用等离子光谱（ＩＣＰ）测试三个厂家味精生产废水中２１种金属元素的水平，其中金属元素的总水平分别达１９１９２ｍｇ．ｌ＾－１，３１９０ｍｇ．ｌ＾－１和３１６１ｍｇ．ｌ＾－１，对照国内外有关的四项水质标准，三厂家味精生产废水中存在着Ｆｅ，Ｚｎ等多种重金属或其他金属元素严重超标现象，味精生产废水对青芋存在急性毒性，２４，４８，７２和９６ｈ的半致死味精废水浓度ＬＣ５０分别为６．９％，３．２％，２．５％     

工业废液纳滤膜分离模型研究

纳滤膜处理工业废液时，纳滤膜系统可以看做一个封闭体系。实验表明透过液通量Jw与压力差呈直线关系；透过液通量Jw与管过液溶质浓度CR都与浓缩时间呈较好的数学关系。但数学关系形式不同；透过液溶质浓度CR与进液溶质浓度Ci呈指数关系；透过液溶质浓度CR与膜压力差△p的关系为指数关系。