连续微滤应用于印染废水反渗透预处理的研究

采用连续微滤(CMF)作为反渗透(RO)的预处理工艺,对印染废水二级生化出水进行深度处理。结果表明:CMF处理系统运行稳定,对色度、膜污染指数值的去除率均达到RO系统进水的要求。RO系统对盐度的去除率达到98%以上,出水水质优于自来水,各项水质指标满足印染工艺回用的要求。     

面向染料清洁生产和染料废水处理的纳滤技术

综述了纳滤膜对含盐染料溶液的分离原理、纳滤膜的选择、纳滤脱盐浓缩工艺过程与应用研究、纳滤处理染料废水与资源化方面的应用研究、纳滤技术的经济性以及应用过程中膜污染的控制。指出利用纳滤技术改进染料生产工艺是可行的,能够实现染料清洁生产,具有明显的经济效益和环境效益;采用纳滤处理染料废水,浓缩液和透过液可以分开处理,易于资源化,并且有利于染料废水的后继处理,是高浓度高含盐染料废水的一种有效处理方法。     

集成膜技术工业废水深度处理回用试验研究

试验采用超滤+反渗透集成膜分离技术,目的是研究其集成工艺处理有色冶金工业废水的合理性和可行性。超滤试验主要测试了在不同水质情况下超滤膜的相关运行参数,主要测定指标有超滤系统的进水、产水和反冲洗水的水量,运行压力,出水浊度,SDI值等;反渗透试验主要测定指标有电导率,反渗透系统的进、出水量,运行压力等。试验研究表明:以预处理+超滤+反渗透组成的集成膜处理工艺,能够满足有色冶金工业废水处理回用的要求。     

循环移动载体膜生物反应器处理印染废水的研究

采用好氧循环移动载体膜反应器处理模拟印染废水。试验结果表明,该反应器对模拟印染废水有很好的处理效果,出水水质稳定。COD_(Cr)平均去除率达到96.3%,色度平均去除率达到85%,氨氮平均去除率达到91.8%。当进水COD_(Cr)<2500mg/L时,出水水质达到《污水综合排放标准》(GB 8978—1996)一级排放标准。并就膜污染和膜清洗问题进行了分析。     

抗污染超滤—反渗透膜在电厂中水回用中的应用

以某钢铁厂废水处理车间出水为回用水源,采用双介质过滤器、超滤和反渗透工艺进行深度处理,其中的膜系统采用抗污染膜元件,对运行中膜污染情况和产水压力过高问题进行了分析。通过系统的长时间运行效果可以看出,超滤出水浊度小于0.1NTU,反渗透脱盐率大于98.5%,回收率维持在72%~75%,系统出水电导率维持在11μS/cm左右,COD、总铁、油均未检出,出水水质可达到回用要求,超滤、反渗透均未发生膜污染情况,系统每年可回用1 360万m3中水,节约厂区淡水资源。     

热电厂水系统的循环利用研究

针对电厂不同废水的水质,总结了电厂废水处理资源化的最新技术和工艺。分析了处理系统的运行成本以及电厂废水处理回用的技术经济可行性。     

研究生论文摘要

大豆乳清废水的膜处理研究研究生 :罗　敏　导师 :王占生(清华大学环境科学与工程系　 10 0 0 84 )本文立足于利用膜分离技术实现大豆乳清废水的资源化处理 ,通过理论分析与小试得出以下结论 :(1)首次提出以超滤 纳滤膜为主体的组合工艺进行大豆乳清废水中具有生物活性的乳清蛋白和低聚糖的提取 ,以实现大豆乳清的废水资源化 ,并在小试水平上完成了大豆乳清废水中大豆乳清蛋白和大豆低聚糖的提取。(2 )首次对致密超滤膜的性能进行了系统的研究。对于致密超滤膜 ,其截留特性介于超滤膜和纳滤膜之间 ,水通量采用渗透压 -吸附模型描述 ,膜污染…     

冷轧综合废水的再生与回用

采取微滤、超滤、反渗透为主体的集成膜工艺处理冷轧综合废水,工艺中融合磁过滤技术和生化处理技术,强化膜前的预处理工艺,对膜污染进行了有效的防治.利用生活污水以废制废,出水水质达到<城市污水再生利用工业用水水质>(GB/T 19923-2005)标准.整个工艺形成了废水的排放、处理、回用的资源循环链,体现了废水处理与生态治污相结合的理念.     

上海新风色织厂污水处理工程的设计

上海新风色织厂总污水量５００ｍ３／ｄ，废水中染料含量较高，不易处理。在污水处理工程设计中通过浓淡水分流、曝气、气浮、超滤等，将部分染料回收、回用，使出水水质大大低于国家排放标准，取得较好的社会和经济效益。     

膜组合工艺浓缩净化电厂湿法脱硫废水研究

对膜组合工艺中试设备处理燃煤电厂湿法脱硫废水的回用水、浓缩水水质进行了长期监测,并对各系统的性能和膜污染情况连续观察。结果表明,膜组合工艺能够有效截留水中的溶解性污染物,TDS的去除率大于99.3%,使产水水质达到回用水要求。纳滤膜和反渗透联用能够有效分离水中的二价盐和单价盐,使蒸发系统的处理量降低一半,得到纯度稳定高于99%的NaCl结晶盐。研究还发现,预处理过程中过量投加的絮凝剂会造成超滤膜通量的快速下降,超滤膜能够有效截留水中的各种颗粒性污染物,缓解纳滤膜和反渗透的污染过程。     

Technical and economical evaluation of water recycling in the carwash industry with membrane processes.

In the carwash industry, water recycling is necessary to be in accordance with present and upcoming environmental laws. As this is not possible with traditional techniques, membrane processes (like ultrafiltration (UF) and nanofiltration (NF)) are technically and economically evaluated in this study. Concerning the technical part, there needs to be a compromise between a high permeate permeability on the one hand and a high permeate purity on the other hand. Depending on the use of the purified wastewater, ultrafiltration (to recycle wastewater in the main wash cycle) or nanofiltration (to recycle wastewater in the rinsing step) would be the optimal choice. Concerning the financial part, the implementation of membrane processes in the wastewater purification installation is economically feasible, especially when expensive tap water is used as pure water. These positive evaluations imply that membrane processes can be useful to recycle wastewater in the carwash industry, on condition that the right membrane type (with the least membrane fouling) and the right process format (e.g., hybrid process of UF and/or NF with a biological treatment) is selected.     

Treatment of dairy wastewater by two-stage membrane operation with ultrafiltration and nanofiltration

Treatment of dairy wastewater by a two-stage membrane process with ultrafiltration (UF) and nanofiltration (NF) was investigated. The results showed that the flux of UF was higher at pH = 4.6 than that at pH = 8 because the resistance of the fouling membrane was lower at the isoelectric point of protein (pH = 4.6) in UF operation. Protein rejection exceeded 99% by UF + NF operation. Lactose rejections were 98.5 and 54% for UF + NF90 and UF + NF270 respectively. Experiments on membrane cleaning showed that the fouling layer of UF and NF was mainly protein and casein which could be removed by aqueous NaOH with pH = 10. The result of long-term experiments showed that the chemical oxygen demand (COD) of NF90 permeates was below 70 mg/L consistently and the wastewater could be concentrated to 24% by a two-stage membrane process.     

几种膜组件在管道直饮水处理系统中应用对比

膜处理是管道直饮水处理工艺的核心,介绍了微滤膜(MF)、超滤膜(UF)、纳滤膜(NF)、反渗透膜(RO)四种膜在管道直饮水处理系统中应用的对比,内容包括基本性能、去除杂质能力、工作压力以及出水电阻率等。结果显示,相比于其他三种膜,纳滤膜(NF)在直饮水处理工艺应用更具优势。     

Production integrated treatment of textile wastewater by closing raw material cycles.

A method for the in-house treatment of partial wastewater flows and the recycling of treated process water into the textile finishing process was developed in order to recycle effluents from textile finishing industry and feed them back into the production process. The method is based on a two-stage biological anaerobic-aerobic process to split colouring wastewater agents and to degrade organic substances contained in the water as well as a chemical stage to remove the remaining color of the water with the help of ozone. In the framework of a research and development project a demonstration plant for a treatment capacity of 1440 m3 per working day was installed and started in a textile finishing company. At the plant, a wastewater flow and a recycling flow are treated separately in two different treatment lanes. Approximately 40% of the total wastewater flows, i.e. 576 m3/d are treated in the wastewater lane, and a maximum of 60% of total wastewater, i.e. 864 m3/d are treated in the recycling lane. Thanks to the preliminary treatment of wastewater flows, which are discharged into the municipal sewage works, a reduction of average COD levels in the sewage works effluents could be achieved.     

Phosphorus removal using nanofiltration membranes

A high concentration of phosphorus in wastewater may lead to excessive algae growth and deoxygenation of the water. In this work, nanofiltration (NF) of phosphorus-rich solutions is studied in order to investigate its potential in removing and recycling phosphorus. Wastewater samples from a pulp and paper plant were first analyzed. Commercial membranes (DK5, MPF34, NF90, NF270, NF200) were characterized and tested in permeability and phosphorus removal experiments. NF90 membranes offer the highest rejection of phosphorus; a rejection of more than 70% phosphorus was achieved for a feed containing 2.5 g/L of phosphorus at a pH <2. Additionally, NF90, NF200 and NF270 membranes show higher permeability than DK5 and MPF34 membranes. The separation performance of NF90 is slightly affected by phosphorus concentration and pressure, which may be due to concentration polarization and fouling. By adjusting the pH to 2 or adding sulfuric acid, the separation performance of NF90 was improved in removing phosphorus. However, the presence of acetic acid significantly impairs the rejection of phosphorus.     

Membrane filtration and sonication for industrial wastewater reuse

This paper presents an experimental study aimed at estimating the efficiency of the innovative process of ultrafiltration (UF) combined with sonication (Son.) for the refinement of treated effluent to be reused in wet textile processes. Such a novel approach, which has not yet been employed on a full industrial scale, has been experienced at pilot scale on the secondary effluent of the Baciacavallo wastewater treatment plant (WWTP), which treats part of the effluent from one of the largest textile industry districts in Italy. The combined treatment efficiency was assessed both on ozonated and non-ozonated Baciacavallo secondary effluent. The membrane filtration process was optimized in terms of running time, backwash, chemical addition and cleaning procedures. The sonication treatment was optimized on laboratory-scale with synthetic solutions (demineralized water added with dyestuffs) in terms of hydroxyl radicals formation rate, frequency, acoustic power, hydrogen peroxide addition, contact time and pH. The optimal conditions have been applied on the pilot-scale sonicator which was used in combination with the UF treatment. According to the experimental results, the best configuration within the Baciacavallo WWTP was the sonication of non-ozonated wastewater followed by the UF. The combined treatment guaranteed the compliance with the target values for wastewater reuse in wet textile industries. This study is part of the Research Project PURIFAST (Purification of industrial and mixed wastewater by combined membrane filtration and sonochemical technologies) LIFE + ENV/IT/000439.     

Comparing the effluent organic matter removal of direct NF and powdered activated carbon/NF as high quality pretreatment options for artificial groundwater recharge.

Direct nanofiltration and nanofiltration combined with powdered activated carbon known as the PAC/NF process were tested regarding the removal of effluent organic matter for reclamation of tertiary effluent from a municipal wastewater treatment plant. They can be regarded as a promising treatment alternative for high quality water reuse applications, especially for direct injection. The total removal for DOC was above 90% with permeate concentrations below 0.5 mg/l. Size exclusion chromatography and fluorescence EEM proved to trace origin of the organic matter even in low concentration ranges. The type and dosage of adsorbent influences the process performance significantly and allows process optimization.     

The role of endocrine disrupters in water recycling: risk or mania?

The widespread occurrence of endocrine disrupting chemicals (EDCs), such as steroid hormones, in secondary wastewater effluents has become a major concern in the water recycling practice. This paper investigates the risk of steroid hormone breakthrough during nanofiltration membrane filtration in water recycling applications. The results indicate a dynamic equilibrium between adsorption and desorption of steroid hormone with regard to the membrane. This equilibrium can be pH dependent and there is a possibility for release of steroid hormones at high pH during membrane cleaning procedures or erratic pH variations. Increase in water recovery can severely increase the hormone breakthrough concentration. The results also indicate a possibility of accumulation of steroid hormones in the NF membrane, followed by subsequent release.