电镀废水处理及回用工程实例

采用混凝沉淀+水解酸化+膜生物反应器(MBR)+过滤+反渗透(RO)组合工艺,对某电镀企业生产废水进行深度处理和回用。首先通过混凝沉淀、生化和过滤去除重金属、有机物和悬浮物,然后利用RO系统去除剩余的有机物和盐分。实际运行结果表明,RO淡水水质可满足企业生产工艺用水水质要求,RO浓水水质达到了《电镀污染物排放标准》(GB 21900—2008)表2中的新建企业水污染物排放限值。     

膜工艺在饮用水处理中的应用

更严格的饮用水标准的实施,促使人们对应用膜工艺产生兴趣,如反渗透（RO）,超滤（UF）,微过滤（MF）和毫微过滤（NF）。在市政给水处理中,膜已应用在除盐,去除溶解有机物和软化等领域。本文将讨论膜在饮用水处理中的发展趋势,并确定改进膜过程效率研究的长期目标。     

纳滤/反渗透技术去除水中含氮消毒副产物的研究进展

以卤乙腈(HANs)、卤代硝基甲烷(HNMs)、亚硝胺(NAs)、卤乙酰胺(HAcAms)为典型代表的含氮消毒副产物(N-DBPs)具有强烈的细胞毒性和遗传毒性.纳滤(NF)膜和反渗透(RO)膜在空间位阻和静电排斥等机理的作用下,对水中微量有机污染物去除效果较好.阐述了NF膜和RO膜的去除机理及影响因素,探讨了其对水中...     

UASB—MBR—NF/RO工艺处理焚烧发电厂垃圾渗滤液

针对某垃圾焚烧发电厂垃圾渗滤液的特点,采用上流式厌氧污泥床(UASB)—外置式膜生物反应器(MBR)—NF/RO组合工艺进行零排放处理,设计处理规模为300 m³/d。运行结果表明,UASB—MBR—NF/RO组合工艺对COD、NH₃-N和电导率的去除率分别为99.98%、99.97%、95.36%。出水水质COD≤13.9 mg/L、NH₃-N≤0.69 mg/L、Cl^-≤175.19 mg/L,均满足《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水标准要求。采用UASB—MBR—NF/RO工艺处理垃圾渗滤液时,UASB阶段的COD去除率为89.70%,MBR阶段的NH₃-N去除率为98.64%,NF/RO阶段的电导率去除率为92.69%。运行数据表明,该组合工艺中,COD主要在UASB中被去除,MBR主要去除NH₃-N,NF/RO系统主要对污水进行脱盐并进一步去除污水中的离子。该组合工艺运行稳定,污染物去除率...     

高含盐有机废水处理与回用技术应用研究

采用三效蒸发器、膜生物反应器(MBR)与反渗透(RO)组合工艺,对某企业高含盐有机废水进行深度处理,首先通过三效蒸发器去除大分子有机物和盐分,然后利用MBR进一步去除有机污染物,利用RO系统去除剩余的有机物和盐分。运行结果表明:出水水质可满足企业生产工艺用水水质要求,并达到零排放的目的。     

Ph对RO/NF膜传质影响的研究进展

pH会改变RO/NF膜表面的荷电性质和孔径大小,还会通过影响溶质的存在形式来影响溶质与RO/NF膜的相互作用,所以pH会对RO/NF膜的膜材料及其水通量和截留率产生重要影响.由于这些影响的机理比较复杂,所以这一课题一直是国际上的研究热点,国内外对此已有许多报道.本文综述了pH对RO/NF膜传质影响的研究进展,并展望了p...     

二硫化钼纳米片基水处理纳滤/反渗透膜研究进展

二硫化钼（MoS₂）纳米片的层内固有缺陷以及层间纳米限域通道的存在,有利于提高水处理纳滤/反渗透（NF/RO）膜的渗透选择性。本文首先介绍了MoS₂纳米片的“三明治”结构,其具有易功能化、高吸附容量和氧化还原去除能力、层间纳米限域通道的光滑性和稳定性及抗污染等特性;然后重点综述了MoS₂基纳米孔膜、层叠膜和混合基质膜的制备方法及膜性能的影响因素;最后总结了MoS₂纳米片基水处理NF/RO膜未来发展亟待解决的关键问题,主要包括研究大尺寸纳米片和均匀亚纳米孔的可控制备方法,开发超薄、高度有序的MoS₂分离层构建方法,探索层间纳米限域通道内分子和离子的传输行为和潜在的分离机理,开发增强与聚合物基质界面相容性的改性策略,对下一代高性能水处理NF/RO膜的研发具有启发意义。     

纤维素酯膜的有机物渗透性

本文研究了经丙酮水溶液改性处理后的醋酸纤维素（CA）反渗透（RO）膜的有机物渗透性，在丙酮改性处理过程，透过CA－RO膜的丙酮溶剂量，开始时迅速下降，然后逐渐趋于零，多孔膜变成了致密均相膜，非对称性的超滤（UF）膜，纳滤（NF）膜，RO膜，分别经丙酮改性处理后，甲苯透过膜的渗透速率依次减少。孔径越小，脱盐率越低的RO膜，经改性处理后，甲苯渗透速率越小，三醋酸纤维素（CTA）与醋酸丁酸纤维素（CAB）二组分混的CTACAB膜，或者与醋酸丙酸纤维素（CAP）三组分共混的CTACABCAP膜，随着实验时间的延长，甲苯的渗透速率，前者逐渐下降到接近零时趋于稳定，后者没有变化，改性的CA膜和CTACAB共混膜分离甲基叔丁基醚（MTBE）／甲醇（MeOH)混合物时，渗透能量分别为835和226（g/m^2.h)，渗透物中MeOH浓度都达到88wt％。     

预处理+厌氧+生化+膜深度处理垃圾焚烧厂渗滤液

以华北地区某一生活垃圾焚烧发电厂渗滤液项目为例，采用“预处理+厌氧+一级AO+UF+NF+RO”工艺处理，出水水质满足《城市污水再生利用工业用水水质》(GB/T 19923—2005)中敞开式循环冷却系统补充水标准后回用至冷却塔循环水。NF浓液采用物料膜减量化处理，RO浓液采用二级RO处理，最终浓液入炉回喷或至主厂区综合利用。经调试运行，本项目系统整体得率≥80%,COD、NH₃-N、TN去除率分别为99.97%、99.96%、99.90%，出水水质达标排放。     

印染废水处理与回用技术应用研究

采用气浮、膜生物反应器(MBR)与反渗透(RO)组合工艺,对某印染企业生产废水进行深度处理和回用。通过气浮、MBR去除有机污染物,利用RO系统去除剩余的有机物和盐分。实际运行结果表明,RO淡水水质可满足企业生产工艺用水要求,RO浓水水质达到了《污水综合排放标准》(GB 8978—1996)的三级标准。     

Fabrication of halloysite nanotubes embedded thin film nanocomposite membranes for dye removal

Environmental friendly Halloysite nanotubes (HNTs) are used to fabricate novel nanofiltration membranes by in situ interfacial polymerization of piperazine and trimesoyl chloride. The removal of excess amine solution from the porous support membrane surface is a critical step to obtain defect free active layer. Hereby, two main removal tools for the excess aqueous amine solution; a rubber roll or air knife are compared to fabricate a defect free thin film nanocomposite (TFN) nanofiltration (NF) membrane. Removal by the rubber roll is eventuated more favorable than air knife in terms of the reproducibility of NF membranes by comparing salt rejections. By determining the removal step of excess amines, various HNTs concentrations are used to fabricate NF membranes and, these membranes are tested with salt and dye solutions at various pH and temperature ranges. R2 membrane (containing 0.02% [w/v] HNTs) performs the best flux results beside higher rejections of MgSO₄ (93.0%) and dye (99.5%). To evaluate the extreme conditionals, further performance tests such as pH and temperature resistance are also performed for R2 membrane. Considering the performances of R2 membrane, HNTs can be demonstrated for tailoring the balance between flux and separation performance of NF membranes.     

纳滤用于一价/二价无机盐溶液分离研究进展

一价和二价无机盐混合物溶液的分离在众多工业领域需求巨大,纳滤（NF）是新兴的一价/二价无机盐溶液分离方法,在经济性和可操作性上具有潜在优势。本文首先介绍了NF膜中离子跨膜传递机理的主流观点,分析了水合离子尺寸、膜结构、水合离子-水-膜相互作用以及进料液组成对离子跨膜传递过程的影响。接着介绍了高通量NF膜和高选择性NF膜的制备方法。并且概述了NF过程分离一价/二价无机盐溶液在资源开采、氯碱盐水脱硝、含盐废水处理、水软化和重金属离子去除领域的应用。分析了已有工作中存在的问题,并对该领域的发展前景进行了展望。     

Ultrafiltration and nanofiltration membranes applied to the removal of the pharmaceuticals amoxicillin,naproxen, metoprolol and phenacetin from water

BACKGROUND: In the removal of pharmaceuticals present in aquatic systems by membrane processes, some important issues must be explored in order to obtain a better knowledge of the global process. Among these issues, a better understanding of the influences of the operating parameters on the membrane flux, an analysis of membrane resistances and fouling, and determination of the removal of specific substances, must be studied. RESULTS: Four selected pharmaceuticals (amoxicillin, naproxen, metoprolol and phenacetin) were subjected to ultrafiltration (UF) and nanofiltration (NF) processes for their removal from several water matrices. The determined permeate fluxes at the steady state were affected by the main operating conditions: molecular weight cut‐off (MWCO) of the membrane, transmembrane pressure TMP, cross‐flow velocity and temperature. The retention coefficients with the UF membranes followed the sequence naproxen > metoprolol > amoxicillin > phenacetin, and with the NF membranes, followed the trend: amoxicillin > naproxen > metoprolol > phenacetin, due to the role of other mechanisms such as size exclusion and electrostatic repulsion. In the case of the selected water matrices, the retention coefficient was referred to some quality parameters (total organic carbon, chemical oxygen demand and absorbance at 254 nm), leading to moderate (UF) or high (NF) removals of the organic matter content. CONCLUSIONS: The NF CK membrane achieved the highest retention of these pharmaceuticals (excepting phenacetin), and provided retentions for quality parameters around 80% in the four water systems tested. Copyright © 2011 Society of Chemical Industry     

截留分子质量和材质对浸没式超滤膜过滤性能的影响

针对截留分子质量和材质对浸没式超滤膜处理微污染地表水过滤性能的影响问题,研究了两者对膜去除水中颗粒物和有机污染物的特性及其对膜污染的影响。结果表明,随着膜截留分子质量的减小,超滤膜对浊度和各有机物指标的去除率逐渐升高,但超滤膜对溶解性有机物的去除率较低;不同材质的超滤膜对有机物的去除率存在差异。不同截留分子质量和材质的超滤膜过滤原水时的污染程度不同,截留分子质量较小的超滤膜污染程度较轻,但容易引起不可逆膜污染;聚砜(PS)膜抗污染的能力要强于聚偏氟乙烯(PVDF)和聚氯乙烯(PVC)膜,在实际应用中应根据不同水质特点合理选择超滤膜的截留分子质量和材质。     

Electrolyte removal by mixed matrix membranes based on polyurethane

The membrane processes play a significant role in the water and wastewater treatment to remove dissolved solids, especially electrolytes. In this study, the asymmetric mixed matrix membranes based on polyurethane and SAPO-5 zeolite were used on electrolyte (NaCl) removal from water. Using a low operating pressure, the membrane performances (i.e., pure water permeation, flux and salt rejection) were measured. All membranes were showing an increase in water flux when the pressure was increased. This situation shows that the produced membranes were stable in producing flux and were suitable to be used to proceed for membrane testing process. Based on the results obtained, rejection of salt water increased as the pressure given increased for each membrane. The mixed matrix membranes showed the high rejection for the salt water (NaCl 0.02 M). This shows the good performance in both flux and rejection, and even achieves 98% rejection for the NaCl 0.02 M. Based on the experimental results, it is believed that these mixed matrix membranes are suitable for the electrolytes removal applications.     

Nanofiltration and reverse osmosis thin film composite membrane module for the removal of dye and salts from the simulated mixtures

Nanofiltration (NF) and reverse osmosis (RO) thin film composite polyamide membrane modules were used to remove the color from the contaminated solution mixture. The feasibility of membrane processes for treating simulated mixture by varying the feed pressures (100-400 psi) and feed concentrations was studied to assess the separation performance of both NF and RO membranes. It was found that the efficiency of NF and RO membranes used in the treatment of colored water effluents was greatly affected by the presence of salts and dyes in the mixture. Color removal by NF with a high rejection of 99.80% and total dissolved solids (TDS) of 99.99% was achieved from RO by retaining significant flux rate compared to pure water flux, which suggested that membranes were not affected by fouling during the simulated wastewater process operation. The effect of varying concentrations of Na₂SO₄ salt and methyl orange (MO) dye on the performance of spiral wound membranes was determined. Increasing the dye concentration from 500 to 1000 mg/L resulted in a decrease of salt rejection at all operating pressures and for both concentrations of 5000 and 10,000 mg/L as the feed TDS. Increasing the salt concentration from 5000 to 10,000 mg/L resulted in a slight decrease in dye removal.     

纳滤处理水杨醛废水中操作压力的影响

本文研究纳滤法处理水杨醛废水时,操作压力对产水率、有机物去除率和脱盐率的影响,同时分析了操作压力对浓差极化的影响。     

Preparation and characterization of chloromethylated/quaternized poly(phthalazinone ether sulfone ketone) for positively charged nanofiltration membranes

Chloromethylated poly(phthalazinone ether sulfone ketone) (CMPPESK) as a novel membrane material was successfully prepared from poly(phthalazinone ether sulfone ketone), with concentrated sulfuric acid as the solvent and catalyst, and chloromethyl octyl ether with lower toxicity as the chloromethylated regent. The effects of the reaction conditions on the preparation of CMPPESKs with different degrees of chloromethylation were examined. The quantity of chloromethyl groups per repeated unit (DCM) of CMPPESK was determined by the method of analysis of the chlorine element, and structures were characterized by ¹H‐NMR spectroscopy. The introduction of chloromethyl groups into the polymer chains led to a decrease in the decomposition temperature. With increasing DCM, the initial degradation temperature declined. CMPPESK had good solubility and was soluble in N‐methyl‐2‐pyrrolidone (NMP), N,N‐dimethylacetamide (DMAc), and chloroform. However, quaternized poly(phthalazinone ether sulfone ketone) (QAPPESK) had excellent solvent resistance, was only partly soluble in sulfuric acid (98%), and was swollen in N,N‐dimethylformamide. QAPPESK nanofiltration (NF) membranes had about 90% rejection for MgCl₂, and the performance of the NF membrane prepared with DMAc as the solvent was superior to that of the NF membrane prepared with NMP as the solvent. In addition, the rejection to the different salt solutions followed the following sequence: MgCl₂ > MgSO₄ > NaCl > Na₂SO₄. Furthermore, the thermotolerance of the QAPPESK NF membrane was examined, and the results show that when the solution temperature rose from 11 to 90°C, the water flux increased more than threefold with stable salt rejection. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

纳滤和反渗透膜形貌结构与膜性能关系探索

纳滤和反渗透膜表面形貌结构、亲疏水性的性质与膜脱盐率、水通量等性能存在一定关系。对几款商用纳滤、反渗透膜进行表面形貌结构、表面粗糙度、亲水性表征。结果表明,纳滤膜表面平整粗糙度低、亲水性强、脱盐率较低,但水通量高。反渗透膜表面存在大量疏松的峰谷结构,比纳滤膜粗糙度更大、亲水性强。对比两款海水反渗透膜,推测调整反渗透膜"叶片"大小和数量可调节反渗透膜的脱盐率和水通量性能。     

Flux,antifouling and separation characteristics enhancement of nanocomposite polyethersulfone mixed-matrix membrane by embedding synthesized hydrophilic adipate ferroxane nanoparticles

Polyethersulfone (PES) nanofiltration (NF) membranes were prepared by blending of synthesized hydrophilic adipate ferroxane nanoparticles (AFNPs) as a novel multifunctional nanofiller via the phase inversion method. The water contact angle measurement indicated the higher hydrophilicity of the NF membranes. The water flux of the membranes improved significantly after the addition of AFNPs, from 10.4 to 32.2 kg/m²h. Antifouling characteristics of AFNPs/PES membranes were improved by increased hydrophilicity and decreased membrane surface roughness. The 0.6 wt% AFNPs/PES membrane exhibited the highest FRR (96%) and the lowest irreversible fouling resistance (6%). The nanofiltration performance of the prepared membranes was evaluated by dye removal and salt retention. The results proved the high dye removal capability of modified membranes (98% rejection) compared with the unfilled PES membrane (89% rejection). The salt retention sequence for membrane with 0.2 wt% of nanoparticles was Na₂SO₄ (70%)>MgSO₄ (60%)>NaCl (18%).