Ozone and membrane filtration based strategies for the treatment of cork processing wastewaters

The degradation of the pollutant organic matter present in the cork processing wastewater was studied by combining chemical treatments, which used ozone and some Advanced Oxidation Processes, and membrane filtration procedures. Two schemes were conducted: firstly, a single ozonation stage followed by an UF stage; and secondly, a membrane filtration stage, using different MF and UF membranes, followed by a chemical oxidation stage, where ozone, UV radiation, and the AOPs constituted by ozone plus UV radiation and ozone plus hydrogen peroxide, were used. The membrane filtration stages were carried out in tangential filtration laboratory equipment, and the membranes used were two MF membranes with pores sizes of 0.65 and 0.1microm, and three UF membranes with molecular weights cut-off of 300, 10, and 5kDa. The effectiveness of the different stages (conversions in the chemical procedures and rejection coefficients in the membrane processes) were evaluated in terms of several parameters which measure the global pollutant content of the wastewater: COD, absorbance at 254nm, tannins content, color, and ellagic acid. In the ozonation/UF combined process the following removals were achieved: 100% for ellagic acid and color, 90% for absorbance at 254nm, more than 80% for tannins, and 42-57% for COD reduction. In the filtration/chemical oxidation combined process, 100% elimination of ellagic acid, more than 90% elimination in color, absorbance at 254nm and tannins, and removal higher than 80% in COD were reached, which indicates a greater purification power of this combination.     

A membrane-based co-treatment strategy for the recovery of print- and beck-dyeing textile effluents

This paper describes the final part of a study on the recovery of print- and beck-dyeing wastewaters of the carpet manufacturing industry by membrane processes. These wastewaters had been previously treated separately where the print dyeing wastewaters were recovered by chemical precipitation followed by nanofiltration (NF) and beck-dyeing wastewaters were subjected to microfiltration (MF) and pH neutralization prior to NF. In this study, a co-treatment scheme after separate pre-treatment stages was adopted to simplify the overall process. The effect of mixing ratio on membrane fouling was also investigated. The co-treatment strategy was found advantageous since the number of NF units was minimized and the pH neutralization step in separate treatment of beck-dyeing wastewaters was eliminated, providing a reduction of chemical usage.     

用集成膜过程对含油废水进行资源化回收利用处理

采用电渗析与超滤、微滤相结合的集成膜过程对含油废水进行了资源化回收利用处理,并对该工艺中电渗析脱盐过程的各项运行参数与分离效果之间的关系进行了讨论.在此基础上,为进一步改善出水水质,还对不同材料的超滤、微滤膜去除废水CODCr的效果作了相应的实验比较.     

微滤膜与超滤膜:究竟有何不同?

介绍了微滤（MF）与超滤（UF）的主要应用情况,比较了微滤与超滤在病毒去除率、膜的耐久力,以及对下游反渗透保护的情况,重点强调了Pall微滤膜具有高的病毒去除率及非常低的断丝率。     

TiO_2动态改性膜应用于MBR的研究

采用二氧化钛(TiO_2)纳米粒子对聚偏氟乙烯中空纤维膜微滤膜(PVDF MF,0.1μm)和实验室自制聚砜中空纤维膜超滤膜(PSF UF,0.05μm)进行表面亲水改性,以期提高膜的抗污染能力.采用膜接触角、纯水通量、出水TOC、膜压差和扫描电子显微镜(SEM)进行表征了TiO_2动态膜的性能.将TiO_2纳米颗粒改性后的PVDF MF和PSF UF膜应用于膜生物反应器(MBR)处理模拟焦化废水(TOC=500 mg/L),考察了其对MBR过滤性能的影响.实验结果表明,改性后膜的水接触角明显减小,亲水性增强,TMP升高速率明显降低,模拟焦化废水,TOC的去除率平均可达95%,经返洗及次氯酸钠清洗后膜表面TiO_2层外观没有明显变化.改性后的膜组件较显著地增加了MBR的膜抗污染的优势,且具有一定的稳定性.因此,将TiO_2动态改性耐污染膜应用于MBR是可行的.     

Integrated Sono-Fenton ultrafiltration process for 4-chlorophenol removal from aqueous effluents: assessment of operational parameters (Part 1)

Advanced oxidation processes (AOPs) and membrane separation processes are successfully used in the final stages of wastewater treatment for recycling and reuse purposes. This research proposes a new two stage process including in the first step a homogeneous Sono-Fenton process (as an AOP), coupled with ultrafiltration (UF), as a cleaner and safer alternative for advanced wastewater treatment, designed specially to enhance the removal of priority organic pollutants which are difficult to eliminate by means of conventional treatments. The aim of this study is to analyze experimentally the performances of an integrated ultrasonication-UF process for the removal of 4-chlorophenol (4CP) (as a model-pollutant for priority organic compounds from wastewaters), both from the removal efficiency (expressed as phenolic concentration and chemical oxygen demand reduction) and the energy consumption point of view. The most important factors with influence on both stages of the proposed process, such as acoustic amplitude, power density, and operating mode for the Sono-Fenton process and pressure, time, operating mode, and cleaning operations for the UF stage, were assessed in this paper (Part 1). The experimental results indicate that the process can be applied for such aqueous effluents, in laboratory scale equipments and represent the basis for modeling the process steps and scale-up of different process arrangements (Cailean et al. (2014): “Integrated Sono-Fenton UF Process for 4CP Removal from Aqueous Effluents: Process Modeling and Simulation (Part 2)”), with the purpose to analyze and control such a process, under various conditions and to understand better its advantages and disadvantages.     

膜面孔特征的图像分析研究

利用图像分析方法对微滤膜和超滤膜的电镜照片进行了分析,定量确定了膜孔相关的形态结构参数,并将膜孔参数与膜通量相关联.结果表明,由于微滤膜的交错立体分层结构,使得膜通量在过滤过程中随膜层厚度急剧下降.截留分子量相同或相近的超滤膜,膜孔形态参数差别很大.     

国外膜技术进展及其在水处理中的应用

简单介绍国外膜材料、膜工艺进展;评述国外有关膜技术在水处理中应用的进展情况,包括饮用水生产、超纯水制备、沙滤池反冲水回用及工业水软化．当前膜组合工艺备受重视,因其将 Ｍ Ｆ、 Ｕ Ｆ 去除颗粒物和螺旋卷绕式组件不易污损的优点同 Ｎ Ｆ、 Ｒ Ｏ 去除 Ｄ Ｂ Ｐ 前体、病毒、合成有机化合物的优点结合起来,并把膜技术与活性炭过滤、臭氧氧化、生物处理等高级水处理技术相结合,对此作了论述     

Functionalized fibrous materials for the removal of dyes

Wastewater effluents from textile industry mainly contain dyes used in the dyeing or printing of textiles yarns or fabrics. A lot of technologies can be adopted for dye removal from wastewaters, including biological treatments based on activated sludge, adsorption on activated carbon, or membrane processes. Nevertheless, none of these methods is performing toward all classes of dyes; treatment plants of great dimensions and difficult handling can be required, while cost can be prohibitive. In the present study, dye adsorption was performed on low-cost fibrous cellulose materials, submitted to a cationization process using a quaternary ammonium reagent. These materials were characterized by FTIR–ATR spectroscopy, while the treatment efficiency was investigated through exhaustion and kinetic adsorption tests toward anionic dyes, such as acid, direct, reactive, and a cationic dye. Comparisons were carried out between treated and untreated samples, and with activated carbon. Best results were obtained with cationized cotton, both in linters or “tulle” fabric form, showing good performance toward all the investigated dyes. Tests in continuous flow confirmed the good behavior of these materials, but tulle fabric was better as filtration medium for a lower pressure drop. Finally, regeneration tests by bleaching were carried out finding that regenerated material maintained good adsorption power.     

Pre-ozonation coupled with UV/H2O2 process for the decolorization and mineralization of cotton dyeing effluent and synthesized C.I. Direct Black 22 wastewater

The decolorization and mineralization of cotton dyeing effluent containing C.I. Acid Black 22 as well as synthesized C.I. Acid Black 22 wastewater by means of advanced oxidation processes (AOPs), such as UV/H2O2, O3 and pre-ozonation coupled with UV/H2O2 processes, were evaluated in this study. It was observed that the UV/H2O2 process took longer retention time than ozonation for color removal of dye bath effluent. Reversely, the total organic carbon (TOC) removal showed different phenomena that ozonation and UV/H2O2 process obtained 33 and 90% of removal efficiency for 160 min of retention time, respectively. Additionally, laboratory synthesized dye wastewater was substantially more efficient in the decolorization process than dye bath effluent. Therefore, in this work, pre-ozonation coupled with UV/H2O2 process was employed to enhance the reduction of both color and TOC in dye bath effluent at the same time. At the same time, the retention time demand was reduced to less than 115 min for 90% removal of TOC and color by this combined process.     

Degradation of dyehouse effluent containing C.I. Direct Blue 199 by processes of ozonation, UV/H2O2 and in sequence of ozonation with UV/H2O2

The decolorization and mineralization of cotton dyeing effluent containing C.I. Direct Blue 199 (DB 199) by advanced oxidation processes (AOPs) such as ozonation, UV/H(2)O(2), and in sequence of ozonation with UV/H(2)O(2) processes were evaluated in this study. By ozonation alone, the color removal was almost 100% for DB 199 and greater than 80% for dye bath effluent rapidly within 5 and 15 min, respectively. Meanwhile, the reduction of total organic carbon (TOC) was about 60% for DB 199 and almost no change for dye bath effluent, respectively due to incomplete mineralization. On the other hand, by UV/H(2)O(2) alone, the color removing not only took longer time but obtained lower removal efficiencies for DB 199 and dye bath effluent about 80% and 95% in 30 and 120 min, respectively. Nevertheless, it was more effective than ozonation for TOC removal while about 75% and 80% in 30 and 120 min, respectively. As a result, this study conducted the combination with the above two processes in order to shorten time demand as well as the higher removal efficiencies of both color and TOC simultaneously. Thus, the sequence process was designed to begin with ozonation to rapidly remove color proficiently, following by UV/H(2)O(2) in order to promptly remove remaining TOC efficiently. The successful process design by sequence of ozonation with UV/H(2)O(2) has proved the significant improvement for the removal of both color and TOC in dye bath effluent shortly. Besides, the lab prepared dye solution was substantially much easier to be decolorized than field dye bath effluent so that the lab results were utilized to design the further applications of pilot or full scale.     

Antifouling ultrafiltration membranes via post-fabrication grafting of biocidal nanomaterials

Ultrafiltration (UF) membranes perform critical pre-treatment functions in advanced water treatment processes. In operational systems, however, biofouling decreases membrane performance and increases the frequency and cost of chemical cleaning. The present work demonstrates a novel technique for covalently or ionically tethering antimicrobial nanoparticles to the surface of UF membranes. Silver nanoparticles (AgNPs) encapsulated in positively charged polyethyleneimine (PEI) were reacted with an oxygen plasma modified polysulfone UF membrane with and without 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) present. The nucleophilic primary amines of the PEI react with the electrophilic carboxyl groups on the UF membrane surface to form electrostatic and covalent bonds. The irreversible modification process imparts significant antimicrobial activity to the membrane surface. Post-synthesis functionalization methods, such as the one presented here, maximize the density of nanomaterials at the membrane surface and may provide a more efficient route for fabricating diverse array of reactive nanocomposite membranes.     

A new submerged membrane photocatalysis reactor (SMPR) for fulvic acid removal using a nano-structured photocatalyst

The study focuses on the degradation of fulvic acid by nano-structured TiO2 in a submerged membrane photocatalysis reactor (SMPR). It has been demonstrated that the composite TiO2 photocatalyst could be automatically settled due to its gravity and then be easily separated by MF membrane. In addition, it was more efficient to maintain high flux of membranes than that of commercial TiO2 P25. The paper describes the effects of operational parameters on the photocatalytic degradation of fulvic acid in SMPR. It was found that the photocatalyst at 0.5 g/L and airflow at 0.06 m3/h were the optimal condition for the removal of fulvic acid (FA) and the FA degradation rate was higher at acidic condition than that at alkalinous media. In order to compare the effects of different filtration duration on permeate flux rate of MF, P25 powder and nano-structured TiO2 were employed. According to the experiments, the permeate flux rate of MF is improved and thus the membrane fouling phenomenon is reduced with the addition of nano-structured TiO2 catalyst. Therefore, the submerged membrane photocatalysis reactor can be potentially applied in photocatalytic oxidation process during drinking water treatment.     

Size-fractionation and characterization of refuse landfill leachate by sequential filtration using membranes with varied porosity

Fresh leachate and effluents samples were collected from the holding tank, anaerobic, anoxic, and aerobic lagoons at Shanghai Laogang Refuse Landfill, the largest landfill in China with a placement scale of 9000 t refuse per day. To characterize the difference in leachate along the treatment processes, especially the information about size distribution of colloids in those leachate, the organic matters were size-fractioned into suspended particles (SP, >1.2 microm), coarse colloids (CC, 1.2-0.45 microm), fine colloids (FC, 0.45 microm to 1 kDa MW, 1 Da=1/16 O atomic mass unit), and dissolved organic matters (DM, <1 kDa MW) using micro-filtration and ultra-filtration membranes in order. The parameters, such as COD (chemical oxygen demand), TOC (total organic carbon), TS (total solid), pH, TP (total phosphate), TN (total nitrogen), FS (fixed solid), NH4+, IC (inorganic carbon), TC (total carbon), color, turbidity and conductivity in the filtrates resulting from sequential filtration of leachate, were then determined, and quantitative relationships between these parameters and the membrane molecular sizes used were established. Typically, the total removal of COD, NH4+, conductivity and P were found to be 75%, 75%, 42% and 85%, respectively, after the biological treatment processes used at Laogang Refuse Landfill. Dissolved fractions were predominant in fresh leachate and in effluents from treatment processes in terms of TOC with a content of over 47%. The molecular weight (MW) percentage distribution in leachate varied as the leachate was treated in the biological treatment stages. The percentages of TOC of fine colloid fractions increased from 6% to 38% while those of dissolved fractions decreased from 78% to 47%. TN in leachate also predominated in the dissolved fraction, occupying over 58%, while those TP in leachate were combined with the SS and CC fractions. The ratios of ortho-phosphate/TP and NH4+/TN in leachate and effluents were over 50% and 80%, respectively.     

国外膜工业发展概况

主要介绍了近年来国外膜工业的发展概况,特别是美国、日本、西欧以及中东等国家和地区的膜技术产业的发展现状,主要生产厂家,膜器件和产品性能以及主要膜过程,微滤(ＭＦ)、超滤(ＵＦ)、纳滤(ＮＦ)、反渗透(ＲＯ)、电渗析(ＥＤ)和气体分离(ＧＳ)的市场状况和年增长速率．     

超滤膜净化水库水试验研究

用中空纤维超滤膜处理哈尔滨附近B水库水,以替代混凝、沉淀、砂滤的传统自来水生产方法,研究生产饮用水的新工艺.研究了原水温度、浊度、操作压力和混凝剂的加入量对膜通量的影响.研究发现超滤膜通量与膜进水浊度的对数成反比,跨膜压力增大、适当加入混凝剂,膜通量增加.超滤出水和传统工艺的出水进行了比较,超滤膜出水浊度小于0.2 NTU,明显好于传统工艺的出水浊度.对超滤处理后的出水水质进行了全分析,超滤对铁、铝、锰、色度、好氧量、总有机碳等均有较好的处理效果,完全满足饮用水水质的标准.     

超滤法处理宾馆洗浴废水及超滤装置化的研制开发

超过滤膜分离技术是一种新兴的物理分离方法，它可以有效地截留一定分子量大小的污染物，使小分子量的溶质和水透过，介绍了超过在水回用领域的应用，结果表明，出水水质优良，性能稳定。另外，该技术具有占地面积小，耗能少，运行费用低等优点。同时还对该技术作了简要的技术经济分析。     

理论研究方法在膜超(微)滤研究中的应用

在对超(微)滤的过滤性能及过程的研究中，实验研究作出了很多贡献，但实验研究存在着结论对具体实验体系有很大依赖性、研究费用较高等缺点．介绍几种较经典的扩散模型和流体动力学模型及其建模思路、适用范围和存在问题；提出借助理论分析和计算方法设计实验，再根据实验数据利用人工神经网络建立普用性模型的新方法、对于方程的求解，介绍了简化法、摄动法、数值计算与模拟等方法的特点及其在超(微)滤研究中的应用，认为用数值计算的方法研究超(微)滤机理及膜器优化设计必将成为今后超(微)滤研究的重要方向之一．     

Applicability of boron-doped diamond electrode to the degradation of chloride-mediated and chloride-free wastewaters

The electrochemical degradation of chloride-mediated and chloride-free dye wastewaters was investigated on a boron-doped diamond (BDD) electrode in comparison with that on a dimensionally stable anode (DSA), and the applicability of BDD electrode to the degradation of these two kinds of wastewaters was explored. In chloride-free wastewater, the electrochemical degradation efficiency of dye on BDD electrode was much higher than that on DSA, with a chemical oxygen demand (COD) removal of 100% and 26% for BDD and DSA, respectively. In chloride-mediated dye wastewater, COD removal was faster than that in chloride-free wastewater on both BDD and DSA electrodes with COD removal efficiencies higher than 95%, whereas the rate of COD removal on DSA was faster than that on BDD electrode. The investigation indicates that DSA is more suitable than BDD electrode in degradation of originally chloride contained dye wastewaters for the sake of energy and time saving. However, for chloride-free dye wastewaters, with the aim of environmental protection, BDD electrode is more appropriate to realize complete mineralization. At the same time, the secondary pollution can be avoided.     

集成膜过程污水深度处理工艺

介绍了集成膜过程及其在污水深度处理方面的应用．集成膜过程是将超遽／微遽与反渗透(或纳滤)相结合，形成能够满足各种回用目的的污水深度处理集成工艺．PVDF、PP、PE、PES等超滤／微滤膜，抗污染反渗透复合膜具有化学稳定性高、耐污染、装填密度高等特点，适宜于规模化污水处理．污水处理用超滤／微滤膜以中空纤维为主，系统技术采用了低压运行、频繁(气水、透过液)反冲、气水冲洗等抗污染工艺，能够维持稳定的通量、运行维护费用较低、产水质量稳定．二级出水的集成膜系统工艺已成熟并得以广泛推广，针对原废水的集成膜工艺(膜生物反应器 反渗透)还需要进一步的工程化研究．