Using loose nanofiltration membrane for lake water treatment: A pilot study

• A pilot study was conducted for drinking water treatment using loose NF membranes. • The membranes had very high rejection of NOM and medium rejection of Ca²⁺/Mg²⁺. • Organic fouling was dominant and contribution of inorganic fouling was substantial. • Both organic and inorganic fouling had spatial non-uniformity on membrane surface. • Applying EDTA at basic conditions was effective in removing membrane fouling. Nanofiltration (NF) using loose membranes has a high application potential for advanced treatment of drinking water by selectively removing contaminants from the water, while membrane fouling remains one of the biggest problems of the process. This paper reported a seven-month pilot study of using a loose NF membrane to treat a sand filtration effluent which had a relatively high turbidity (~0.4 NTU) and high concentrations of organic matter (up to 5 mg/L as TOC), hardness and sulfate. Results showed that the membrane demonstrated a high rejection of TOC (by>90%) and a moderately high rejection of two pesticides (54%–82%) while a moderate rejection of both calcium and magnesium (~45%) and a low rejection of total dissolved solids (~27%). The membrane elements suffered from severe membrane fouling, with the membrane permeance decreased by 70% after 85 days operation. The membrane fouling was dominated by organic fouling, while biological fouling was moderate. Inorganic fouling was mainly caused by deposition of aluminum-bearing substances. Though inorganic foulants were minor contents on membrane, their contribution to overall membrane fouling was substantial. Membrane fouling was not uniform on membrane. While contents of organic and inorganic foulants were the highest at the inlet and outlet region, respectively, the severity of membrane fouling increased from the inlet to the outlet region of membrane element with a difference higher than 30%. While alkaline cleaning was not effective in removing the membrane foulants, the use of ethylenediamine tetraacetate (EDTA) at alkaline conditions could effectively restore the membrane permeance.     

水体中四环素类抗生素的去除技术研究进展

四环素类抗生素因其可以防治人类和动物由病菌引起的疾病,同时又能用作生长促进剂以加快动物生长,目前在国内外被大量使用。抗生素的使用甚至滥用对自然环境造成不容忽视的污染,并进一步对人类身体健康产生潜在危害。从常规处理、膜处理、化学氧化和吸附等角度讨论了国内外对四环素类抗生素去除技术的研究进展,为环境水体中四环素类抗生素污染的有效去除提供了方向。     

老港填埋场新鲜渗滤液性质研究

用系列滤膜对老港填埋场2003年3月份新鲜渗滤液进行了梯度分离．并研究了其CODcr、氨氮、TOC、IC、TC、TS、FS、电导率、pH、色度,浊度的变化趋势与不同孔径膜之间的关系。结果表明,随着膜孔径的减小,CODcr、氨氮、TOC、IC、TC、TS、FS、色度、浊度等都有不同程度的降低,但降低不大,说明可溶性部分物质对新鲜渗滤液的污染性贡献最大;电导率、pH则先增大后减小。     

膜电容去离子复合电极处理自来水

采用膜电容去离子技术,对镇江自来水进行处理。确定膜电容去离子装置所需的各种材料,设计并制作复合电极单元。将5个复合电极处理单元串联并进行实验,确定能适应市场需求的装置参数,包括内部结构参数和外部运行参数。实验结果表明,当装置的活性炭纤维比表面积为1 600 m2/g,电极间距为1.5 mm,电压为2.0 V时,处理效果较好。流量为350 mL/min时复合电极装置的处理效果比100 mL/min差,但是更符合市场需求。一定范围内的温度变化对该装置去除效果的影响很小。将复合电极单元数从5个增至40个后,离子去除率由12.73%增至62.32%。     

Membrane bioreactor technology: A novel approach to the treatment of compost leachate

Compost leachate forms during the composting process of organic material. It is rich in oxidizable organics, ammonia and metals, which pose a risk to the environment if released without proper treatment. An innovative method based on the membrane bioreactor (MBR) technology was developed to treat compost leachate over 39 days. Water quality parameters, such as pH, dissolved oxygen, ammonia, nitrate, nitrite and chemical oxygen demand (COD) were measured daily. Concentrations of caffeine and metals were measured over the course of the experiment using gas chromatography – mass spectrometry (GC/MS) and inductively coupled plasma – mass spectrometry (ICP–MS) respectively. A decrease of more than 99% was achieved for a COD of 116 g/L in the initial leachate. Ammonia was decreased from 2720 mg/L to 0.046 mg/L, while the nitrate concentration in the effluent rose to 710 mg/L. The bacteria in the MBR system adjusted to the presence of the leachate, and increased 4 orders of magnitude. Heavy metals were removed by at least 82.7% except copper. These successful results demonstrated the membrane bioreactor technology is feasible, efficient method for the treatment of compost leachate.     

膜技术在水处理中的应用前景

介绍了膜分离技术的定义,种类,膜技术的应用领域及国内发展动态。     

旋转接头在MBR反应器改良中的应用研究

随着MBR反应器在国内污水处理行业中的不断应用,其重要性进一步得到了业界的认可。但是,如何消减运行过程中的膜污染问题,成为制约MBR推广和应用的重要因素。文章通过实验,将旋转接头应用在MBR反应器的改良中,重点研究通过旋转接头实现膜组件的旋转运行模式对膜污染的抑制效果。     

污泥陶粒流离球填料的应用研究

填料是流离生化技术处理污水的关键材料。文中模拟试验污水处理过程,测试污泥流离球填料的挂膜情况和污染物去除能力。确定运行适应性参数DO水平为4～5mg/L,水力停留时间4h,反应温度22℃,反应pH值7～9时,实施处理配制污水试验的结果表明,净化后污水CODcr和NH3-N去除效果良好,污水净化后符合国家污水综合排放标准二级标准的要求,污泥陶粒流离球填料应用于污水处理可行。     

大气中VOCs的污染现状及治理技术研究进展

对近十年来大气中有机污染物(VOCs)的污染现状以及目前采用的主要治理技术的研究进展进行了总结。重点介绍了吸附法、膜分离法、液体吸收法、催化燃烧法以及光催化氧化处理技术等治理技术,并对其优缺点进行了述评。最后探讨了大气中VOCs治理技术的发展现状。     

膜分离稀土废水预处理中钙镁去除的研究进展

稀土废水成分复杂,硬度高,利用膜法处理时,进膜之前必须进行预处理.介绍了降低稀土废水硬度传统的和新型的方法.经过分析得出,根据具体水质情况,选择适当的互补处理方法,稀土废水完全可达到膜分离装置进水水质要求.