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.     

化工厂二级出水深度处理与回用

采用生物接触氧化—臭氧氧化—锰砂过滤组合工艺对化工厂二级出水进行深度处理,出水回用于循环冷却水。运行结果表明,处理出水能够满足《城市污水再生利用工业用水水质》(GB/T 19923—2005)中敞开式循环冷却水系统补充水标准要求。该工程运行后,节约了大量新鲜水,减少了COD排放,带来可观的经济效益和环境效益。     

Tertiary treatment of a secondary effluent by the coupling of coagulation-adsorption-ultrafiltration for reuse

We considered the treatment of secondary effluent by coagulation-adsorption coupled with ultrafiltration. Tests were performed on the secondary effluent of the wastewater treatment plant at Staoueli (Algeria) where the average chemical oxygen demand (COD) was 46 (mg O₂/L) and turbidity, 16 NTU. The ultrafiltration tests were made with mineral tubular CARBOSEP membranes — M5 (10 kg/ mol), M2 (15 kg/mol) — in the dynamic mode with a transmembrane pressure ΔP = 1 bar and cross flow velocity = 3 m/s. The reagents were calcium chloride (as coagulant agent) and powder activated carbon. Coagulation improved the ultrafiltration performances significantly. In the first step, the optimal conditions for coagulation were determined considering the best elimination of turbidity as well as organic matter. In the second step, the efficiency of different processes (coagulation, adsorption, ultrafiltration) was compared when used alone or in combination. The coagulation test showed a COD elimination equal to 12 mg/L at pH = 6.5 for a concentration of CaCl₂ = 50 mg/L and a turbidity equal to 3 NTU.     

城市污水厂二级出水的深度处理及其回用

邯郸热电厂的生产用水，一直以流经邯郸市的滏阳河水为水源，由于近几年滏阳河水污染日益严重．河水含盐量、COD、BOD及氨氮等主要水质指标大幅升高，使循环冷却水pH值下降，造成系统内碳钢、水泥构件的严重腐蚀，同时带来除盐成本升高、树脂污染及锅炉水pH值下降等一系列问题，给系统的安全经济运行带来严重威胁。为了从根本上解决安全生产中存在的这些隐患，对邯郸市东污水处理厂的二级出水进行回用试验．经适当深度处理后，分别用作邯郸热电厂的锅炉补充水和循环冷却水，为二级出水的回用提供了有益的尝试。     

Advanced treatment of secondary sewage effluent by membrane process

The experimental results on advanced treatment of secondary sewage effluent by ultrafiltration (UF) and reverse osmosis (RO) are presented in this paper, particularly focused on pretreatment system, operating condition, membrane cleaning system, and product water quality.     

城市污水厂二级出水脱氮除磷回用于景观水体的试验研究

采用纤维生物膜滤池-强化微絮凝纤维过滤的方法,对城市污水厂二级出水进行深度处理．回用于人工景观水体。试验结果表明：出水中总磷一般可达到0．2mg/L以下,氨氮一般可以达到1．5mg／L以下;本试验系统在对氮磷去除的同时,对CODcr、BOD5、SS、浊度等也有进一步的去除作用。试验出水水质可以达到GB 3838—2002《表水环境质量标准》中Ⅲ类水体标准,可满足人工景观用水等高级回用的要求。     

The nanofiltration and reuse of effluent from the caustic extraction stage of wood pulping

One of the bleach stages in the treatment of wood for the manufacture of pulp is the extraction of lignin with sodium hydroxide. The resulting wash water is highly coloured at a pH of 7 to 10 and a conductivity of 4 to 7 mS/cm.The high colour precludes its reuse in the bleaching section of the pulping process. The use of nanofiltration for the removal of colour bodies from the effluent while allowing most of the inorganic salts to pass through the membrane is described. In particular, aspects such as pretreatment and membrane cleaning will be addressed.     

膜技术在钢铁废水处理及回用中的应用

对膜技术在钢铁废水深度处理与回用应用进行分析,探讨了膜技术在处理钢铁企业废水处理中的优缺点和发展趋势,提出对膜技术在钢铁废水处理中回用应用的一些建议和展望。     

不同超滤膜处理二级出水的膜污染机制研究

为探究截留分子量与材质对污染物的去除效果,并分析二者对抗污染性能的影响,使用不同材料(PES、PVDF)和不同截留分子量(50,100 kDa)的超滤膜处理二级出水。结果表明,对于溶解性有机物(DOC)的去除效果,相同材料,截留分子量为50 kDa超滤膜优于100 kDa;100 kDa的超滤膜,PES材料优于PVDF。材料相同,100 kDa超滤膜膜通量下降程度小,反冲洗后,膜通量恢复程度越好,可逆污染占比较大;孔径相同,PES超滤膜的膜通量下降较慢,反冲洗效果更好,不可逆污染更轻。膜污染模型分析中,材料相同,100 kDa膜片对4种污染模型的拟合系数均高于50 kDa,4种污染模型造成的污染更加显著,膜污染过程更加复杂。     

Membrane processes for water reuse from the effluent of industrial park wastewater treatment plant: a study on flux and fouling of membrane

Both the relationship between the flux and the fouling mechanism of ultrafiltration (UF) membrane and the effects of pretreatment before reverse osmosis (RO) process on the treatment of the effluent of industrial park wastewater treatment plant (IPWTP) were investigated to examine the application of membrane processes on the water reuse treatment. For the former, the flux data was first fitted to the Hermia model to give the implication of the fouling mechanism. Then, the fouling mechanism was further identified with the aid of the SEM morphology of membrane surfaces. For the latter, the changes of both water characteristics (turbidity, TOC, conductivity, particle size distribution, and organic solute molecular weight) and membrane properties (surface zeta potential and surface morphology) before and after the treatment of membrane processes were measured. It was found that the major blocking mechanisms of UF membrane process at initial and final stage were standard blocking of pore (causing from colloid materials) and cake blocking of pore (causing from suspended particles), respectively. On the other hand, it was concluded that the permeate from 1 μm/UF/RO process was suitable for the reuse of cooling water and low pressure boiler water.     

化学生物絮凝工艺出水深度处理回用试验研究

采用悬浮填料床、流砂微絮凝过滤、复合二氧化氯消毒工艺对化学生物絮凝一级强化出水进行深度处理、回用.中试试验结果表明,当进水平均COD为65.39 mg/L、氨氮13.04mg/L、总磷(TP)0.89 mg/L、浊度19.8 NTU时,出水COD下降到31.51 mg/L,氨氮为5.11mg/L,TP和浊度分别下降到0.33 mg/L和1.7 NTU,出水指标均优于回用水水质标准,经复合二氧化氯消毒,出水总大肠菌群≤3L-1.出水可用于企业的办公和生活杂用、绿化、景观等领域.     

臭氧-陶瓷膜生物反应器处理市政污水二级出水

以某大学生活污水二级处理出水为原水,考察了臭氧氧化耦合陶瓷膜生物反应器的污染物去除效果。结果表明,在陶瓷膜孔径为200 nm,跨膜压差为0.1 MPa,臭氧投加量为5 mg/L的工艺条件下,组合工艺对浊度、氨氮、亚硝态氮、CODMn和UV254的平均去除率分别为98.7%、97.3%、96.0%、41.2%和34.1%,对应的出水指标分别为0.08 NTU、0.07 mg/L、0.01 mg/L、2.50 mg/L和0.037 cm-1。相同运行周期内,直接使用陶瓷膜生物反应器过滤市政二级出水,膜通量下降26.7%;而臭氧-陶瓷膜组合工艺膜通量只减少了14.3%,说明臭氧-陶瓷膜生物反应器组合工艺可有效减轻膜污染,提高陶瓷膜使用效率。     

超滤膜在工业循环冷却排污水回用中的应用

在循环冷却排污水的现场中试试验之中，采用超滤（UF）系统作为整个中水回用系统的预处理方法，经过近180h的试验，取得此种超滤膜在运行过程中的水质水量衰减状况曲线以及反冲周期。由试验结果可以看出，用超滤系统作为循环冷却排污水的预处理系统，其产水的水质指标已经达到反渗透系统的进水水质指标，产水水量符合标定水量，建议超滤产水进入反渗透系统，进行反渗透系统的运行安全性试验，并通过试验进一步寻找反渗透系统的化学清洗周期。     

A novel hydrogel based on agricultural waste for removal of hazardous dyes from aqueous solution and reuse process in a secondary adsorption

A novel hydrogel based on the orange peel (OP) and N-vinyl-2-pyrrolidone was prepared by free-radical polymerization using gamma irradiation. The effect of radiation dose and hydrogel composition on gel content was studied. The formed hydrogel was characterized by FT-IR, TGA, and SEM. The swelling behavior was determined as a function of swelling time, pH, and OP content. The hydrogel swelling was found to be pH dependent, and the diffusion mechanism of water into the hydrogel was found Fickian. The developed hydrogel was used for the removal of Congo red (CR) and methyl orange (MO) dyes from wastewater. The effects of various operating parameters, such as initial pH, contact time, initial dye concentration, and temperature on the removal of dyes, have been investigated. The Langmuir and the Freundlich adsorption models were applied to study the adsorption isotherm. The pseudo-first-order model was proved compatible for CR adsorption and the pseudo-second-order model well described the adsorption of MO. The adsorption of dyes increased with increasing temperature indicating that the endothermic nature of the adsorption process and the thermodynamic parameters was evaluated. Second, the adsorption cycle of dyes was also examined and discussed utilizing the loaded hydrogel with the other dye and cobalt metal ions.     

Roles of sponge sizes and membrane types in a single stage sponge-submerged membrane bioreactor for improving nutrient removal from wastewater for reuse

Sponge not only can reduce membrane fouling by means of mechanical cleaning and maintain a balance of suspended-attached microorganisms in submerged membrane bioreactor (SMBR), but also can enhance dissolved organic matter and nutrient removal. This study investigated the performance of three different sizes of sponge (S_28-30/45R, S_28-30/60R and S_28-30/90R) associated with continuous aerated SMBR. A laboratory-scale single stage sponge-SMBR (SSMBR) showed high performance for removing dissolved organic matter (>96%) and PO₄-P (>98.8), while coarse sponges such as S_28-30/45R, S_28-30/60R could achieve more than 99% removal of NH₄-N. When three-size sponges (S_28-30/45R, S_28-30/60R and S_28-30/90R) were mixed at a ratio of 1:1:1 and in conjunction with two kinds of membranes (0.1 µm hollow fiber and 2 µm nonwoven), the SSMBR system has proved its generic merits of superior treated effluent quality and less membrane fouling. The NH₄-N and PO₄-P removal were found excellent, which were more than 99.8% and over 99% respectively. Molecular weight distribution also indicated that major fractions of organic matter could be successfully removed by SSMBR.     

Potential for reuse of high cellulose containing wastewater after membrane bioreactor treatment

It is difficult to adequately treat wastewater with a high cellulose content with the traditional anaerobic and aerobic activated sludge processes. In this study we used microfiltration (MF) and reverse osmosis (RO) membranes combined with an anaerobic or aerobic activated sludge process to treat high cellulose containing wastewater for different hydraulic retention times (HRTs). The potential target applications for reuse of the treated wastewater are also compared. Six bioreactors, which were configured as anaerobic sequencing batch reactor (ANSBR), aerobic sequencing batch reactor (ASBR), aerobic membrane bioreactor (AMBR), AMBR plus RO (AMBR/RO), anaerobic activated sludge plus aerobic MBR (AOMBR), and AOMBR plus RO (AOMBR/RO), was operated in this study. The experiment results showed that, as expected, no effluents from the ASBR or the ANSBR could meet the Taiwan EPA criteria for effluent and wastewater reuse, no matter what the HRT was. However when the HRT was 12 h or more, the effluent from the AMBR and AOMBR processes did meet the criteria for effluent, but still did not meet the treated wastewater reuse criteria , primarily due to the color, total alkalinity, and total dissolved solid parameters. Finally, the effluents from the AMBR/RO and AOMBR/RO processes did meet the Taiwan criteria for both effluent and treated wastewater reuse when the HRT for the AOMBR/RO and AMBR/RO processes was equal to or longer than 12 h and 8 h, respectively. For the HRT of 4 h for both the AOMBR/RO and AMBR/RO process, and an HRT of 8 h for the AOMBR/RO process, neither the effluent criteria nor the treated wastewater reuse criteria were met.     

离子膜法烧碱生产中废水的再利用

介绍了中泰化学米东工业园自然循环离子膜电解制碱装置,在二次盐水工序树脂塔再生及32％碱浓缩成片碱过程中．废水综合利用措施。     

生活污水处理回用于生产的技术开发

随着济钢产能的不断扩大和水资源的日益紧缺,开源节流、节水降耗成为济钢节能的工作重点.通过技术开发,济钢将生活污水处理成中水回用,作为非常规水资源回用于生产,取得了很好的经济效益和社会效益.     

Sustainability and membrane processing of wastewater for reuse

Sustainability has various meanings in the context of water reclamation and reuse. In one sense it acknowledges that to sustain our water supplies we must develop technologies that can efficiently reclaim wastewater to augment natural supplies. Membrane technology is playing a vital role in this application. However a largely unasked question is how well do the membrane technologies we use and the way we operate them stand up to scrutiny based on ‘sustainable development’ criteria? Finally at the technical and operational level we have the age-old problem of fouling and its impact on ‘sustainable’ long-term operation. This paper addresses the three levels of sustainability in the context of membrane technology and water reclamation.     

精对苯二甲酸生产废水处理及回用技术探讨

针对精对苯二甲酸(PTA)生产过程产生的废水有机物成分复杂、化学需氧量高的特点,探讨了目前PTA生产废水处理技术的研究与应用情况。介绍了国内PTA废水处理的预处理技术、生化处理技术以及废水处理组合工艺技术,分析了各种处理技术的优点与缺点,指出PTA废水处理技术应朝着高效、无害、资源化利用的方向发展。