微纳米气泡臭氧氧化处理印染废水产生的RO浓水

印染废水经反渗透（RO）膜处理后产生的高盐RO浓水可生化性差导致生化方法不适用,并且难以通过传统物化方法得到高效处理,臭氧氧化技术因其反应快、不产污泥等优点受到广泛关注,但印染废水RO浓水的臭氧氧化是传质控制反应,传统钛板曝气的低气液传质速率限制了臭氧氧化表观反应速率的提升。基于此,将微纳米气泡曝气技术与臭氧氧化工艺相结合来处理印染废水RO浓水。采用半连续流试验考察了废水初始pH、盐浓度、加压停留时间、臭氧浓度和投加H₂O₂对印染废水RO浓水处理效果的影响。结果表明,微纳米气泡臭氧氧化法对印染废水RO浓水的色度、UV₂₅₄、COD和TOC去除率比传统大气泡法均有明显提升。在废水初始pH为7、臭氧投加量为3.3 mg/（L·min）、H₂O₂投加量为15.6 mmol/L的最佳工艺条件下,采用微纳米气泡处理120 min以后,对色度、UV₂₅₄、COD和TOC的去除率分别为99.9%、79.1%、60.7%和56.2%,去除1 mg COD所需的臭氧量为1....     

改性活性炭/H_2O_2催化氧化法处理焦化废水RO浓水

以包头某焦化厂的焦化废水经生化、超滤、反渗透系统处理后产生的反渗透浓水为研究对象,分析了改性活性炭/H_2O_2催化氧化法对RO浓水的处理效果及影响因素。试验结果表明,在初始pH值为原水pH值、改性活性炭与H_2O_2的质量比为1. 0、H_2O_2投加量为120 mg/L、反应时间为1 h的条件下,RO浓水经改性活性炭/H_2O_2处理后,COD、色度、A_(254)分别由103 mg/L、103. 3倍、1. 021降至44 mg/L、39倍、0. 309,去除率分别为57. 3%、62. 2%、69. 74%,出水COD满足《炼焦化学工业污染物排放标准》(GB 16171—2012)中新建企业水污染物直接排放标准。     

O_3/BAF和BAF/O_3工艺处理石化二级出水的比较

采用O3/BAF和BAF/O3两种组合工艺对石化废水二级出水进行深度处理,探讨了在不同的臭氧投加量下,两种工艺对COD和NH3-N的去除效果,以及处理过程中废水中有机物分子质量分布的变化。结果表明,O3投加量为15 mg/L时,O3/BAF组合工艺对COD的去除率最高为32.8%,此时进、出水COD平均浓度分别为68.82、46.22 mg/L,但最高出水COD浓度50mg/L。而对于BAF/O3组合工艺而言,由于臭氧氧化后置,臭氧投加量越大,对COD的去除率越高,O3投加量20 mg/L时,BAF/O3工艺对COD的去除率要高于O3/BAF工艺,在O3投加量为25 mg/L时出水COD趋于稳定,且低于50 mg/L。SUVA和分子质量分布结果表明,在O3/BAF工艺中O3可以对废水起到预处理作用,使大分子物质转化为小分子物质,提高废水的可生化性,从而增强BAF单元对COD的去除效果。O3/BAF工艺的臭氧投加量为20 mg/L时,对NH3-N的去除效果最好,去除率为35.1%;而BAF/O3工艺对氨氮的去除与臭氧投加量的关系不大,试验过程中在12%左右。由于石化二级出水NH3-N平均在0.4~2.5 mg/L之间,可达到《污水综合排放标准》(GB 8978—1996)中一级标准的限值。从保障最终出水水质的要求来看,BAF/O3工艺更适用于石化二级出水的深度处理。     

微电解/Fenton法深度处理土霉素废水的研究

采用微电解/Fenton法对土霉素废水二级出水进行深度处理。正交和单因素试验结果表明,微电解法的最佳工艺条件:Fe投量为125 g/L、铁炭质量比为1.5∶1、初始pH值为4.0、反应时间为2 h,在进水COD为361～395 mg/L的条件下,处理后出水COD可降至198～207 mg/L,对COD的去除率可达44%以上;采用Fenton法进一步处理微电解出水,其最佳工艺条件:H2O2(浓度为30%)投加量为2 mL/L、初始pH值为3.0、反应时间为60 min,处理后出水COD<120 mg/L,组合工艺对COD的总去除率达到70%以上,满足《发酵类制药工业水污染物排放标准》(GB21903—2008)的要求。     

垃圾渗滤液反渗透浓水深度处理中试研究

采用混凝/Fenton/曝气生物滤池(BAF)组合工艺深度处理广东省某垃圾焚烧厂垃圾渗滤液反渗透(RO)浓水。连续两个多月的中试运行结果显示,在聚合硫酸铁投量为1 kg/m~3、双氧水(27.5%)投量为7.8 L/m~3、H_2O_2∶Fe~(2+)=2∶1(物质的量之比)、BAF的水力停留时间为12h的条件下,出水COD300 mg/L、色度64倍,优于《水污染物排放限值》(DB 44/26—2001)第二时段的三级标准和《污水排入城镇下水道水质标准》(CJ 343—2010)的B级标准,可回用于垃圾焚烧炉渣冷却。     

某城市污水处理厂改造工程的中试研究

采用厌氧塘/预曝气/絮凝沉淀/好氧生化工艺对工业废水所占比例较高的城市污水进行中试研究.结果表明,厌氧塘出水经30 min的预曝气后进行絮凝沉淀,当FeSO4投加量为150mg/L、聚合氯化铝(PAC)投加量为100 mg/L时,对COD的单元去除率能够达到52%,且BOD5/COD值由0.4提高到0.6;对好氧系统采用周期性改变反应池内溶解氧浓度和外加碳源的措施,能够提高生物脱氮效果;经该工艺处理后,出水水质能够达到GB 18918-2002标准的一级B标准;经核算,该工艺的直接运行成本为0.65元/m3(不合污泥处理费).     

复合潜流人工湿地强化处理低温地区生活污水

针对传统人工湿地处理低温地区生活污水出现的效能下降问题,提出以VBFW/HS-FW复合潜流人工湿地专利技术为核心,辅以化学除磷、接触氧化和污水内回流的工艺进行处理,并结合工程实例介绍了主要设计参数及特点。运行结果表明:在气温为0～5℃、不采取保温措施、PAC投加量为10mg/L、曝气量为0.6m3/min、回流比为100%的条件下,当进水COD、TP、NH3-N及TN分别为(143～205)、(1.2～2.6)、(14.3～30.1)及(35.3～56.5)mg/L时,出水COD、TP、NH3-N及TN平均值分别为27.5、0.4、6.2及14.2mg/L,达到了《城镇污水处理厂污染物排放标准》(GB18918—2002)的一级A标准。     

微米臭氧曝气深度处理工艺的最优曝气孔径研究

采用微米曝气对超滤膜出水通入臭氧进行深度处理,系统探讨了不同投加量(30、50、100、120 mg/L)及曝气孔径(5、10、20、30μm)对出水p H值以及COD、TOC、TN去除效果的影响。结果表明:在相同曝气孔径下,出水p H值随着臭氧投加量的增大而降低;当臭氧投加量为30mg/L时,出水p H值随着曝气孔径的增大而降低,而投加量≥50 mg/L时,出水p H值随曝气孔径的增大而升高。曝气孔径为30μm时对COD的去除效果相对最好,且该孔径下COD去除率随着臭氧投加量的增加而逐渐升高。臭氧对TOC的去除率小于对COD的去除率;曝气头孔径越小、臭氧投加量越大,对TOC的去除率越高。当臭氧投加量为120 mg/L时,对TOC的去除率为15.2%。臭氧对TN的去除率较其对COD和TOC的去除率低,TN去除率与臭氧投加量并没有明显的一致性规律。     

臭氧氧化工艺在城镇污水厂COD提标中的应用

开展间歇性试验(中试规模为24 m3/d)研究臭氧对某城镇污水处理厂二级生化出水的氧化特性,考察了臭氧对COD的去除效果。结果表明,当臭氧投加量为40 mg/L、氧化接触时间为1.0 h、系统进水COD和色度平均值分别为69 mg/L和115倍时,出水COD和色度平均值分别降至45 mg/L和12倍,达到GB 18918—2002的一级A标准。单独采用臭氧工艺的直接运行成本为0.34元/m3水。污水厂二级生化出水的有机物分子质量基本小于2 000 u,经臭氧氧化后,分子质量730 u的有机物比例由30%上升到54%。臭氧氧化对分子质量500 u的烷烃化合物具有较好的氧化作用,但对该分子质量范围内的含多种取代基的芳香族化合物的氧化性较差。     

同步培养驯化嗜盐菌处理纳滤浓水的试验研究

在序批式间歇反应器(SBR)中,通过逐步提高含盐量的方法同步驯化出嗜盐菌,驯化过程中含盐量从1 140 mg/L提高到1 880 mg/L,进水的葡萄糖投加量由200 mg/L降至零。同时考察了该嗜盐菌对纳滤浓水的处理效果。试验结果显示,对于COD为115～160 mg/L、TN为35～55 mg/L的纳滤浓水,在运行周期为8 h、曝气量为0.6 L/min、污泥浓度为4 500～5 500 mg/L、污泥龄为16 d的条件下,对COD的平均去除率为58%,对TN的平均去除率为67%;驯化出的嗜盐菌能够在含盐量为1 880 mg/L的条件下正常生长;改变进水有机负荷对出水COD的影响不大,该系统的耐有机负荷冲击能力较强。     

机械蒸汽再压缩技术处理反渗透浓水的中试研究

近年来,反渗透(RO)在污水厂二级出水深度处理中的应用越来越多.然而,RO浓水的含盐量较高、有机物难于降解,采用常规方法处理时出水水质难于达到排放标准.采用机械蒸汽再压缩技术(MVR)对某污水厂的反渗透浓水进行了6倍浓缩的中试,其出水COD≤50 mg/L、NH<,3>-N≤10 mg/L,可以达到<城市污水再生利用城市杂用水水质>(GB/T 18920-2002)的要求;COD、TDS、Mg<'2+>和色度等指标的浓缩倍数与体系的浓缩倍数基本一致,而浓缩水中的TP、SiO<,2>、TN、NH<,3>-N浓度却低于原水的,这主要是由于磷酸盐、硅酸盐的沉淀和氨气逸出所致.另外,钙盐等的沉淀作用还造成浓缩水中SS浓度的增加.由此可见,利用MVR处理反渗透浓水在技术上是可行的,但是需要增加沉淀物的预处理和排出气体的收集处理装置.     

Isolation of dissolved organic matter from the suwannee river using reverse osmosis

A portable reverse osmosis (RO) system was constructed and used to concentrate dissolved organic matter (DOM) from the Suwannee River in southeastern Georgia. Using this RO system, 150–180 1/h of river water could be processed with 90% recovery of DOM. After further cation exchange and lyophilization of the concentrated river water samples, large quantities of low-ash freeze-dried products were isolated. We highly recommend this RO method for concentration of DOM in fresh waters because (1) a very high percentage of DOM is recovered, which indicates minimal fractionation of the original sample; and (2) the process is quite rapid, which permits large quantities of DOM to be concentrated in a reasonable length of time.     

Development of antifouling reverse osmosis membranes for water treatment: A review

With the rapidly increasing demands on water resources, fresh water shortage has become an important issue affecting the economic and social development in many countries. As one of the main technologies for producing fresh water from saline water and other wastewater sources, reverse osmosis (RO) has been widely used so far. However, a major challenge facing widespread application of RO technology is membrane fouling, which results in reduced production capacity and increased operation costs. Therefore, many researches have been focused on enhancing the RO membrane resistance to fouling. This paper presents a review of developing antifouling RO membranes in recent years, including the selection of new starting monomers, improvement of interfacial polymerization process, surface modification of conventional RO membrane by physical and chemical methods as well as the hybrid organic/inorganic RO membrane. The review of research progress in this article may provide an insight for the development of antifouling RO membranes and extend the applications of RO technology in water treatment in the future.     

Coupling reverse osmosis with electrodialysis to isolate natural organic matter from fresh waters

Reverse osmosis (RO) has proven to be an effective method for the concentration of natural organic matter (NOM) from fresh waters, but an undesirable consequence of this process is the co-concentration of some inorganic solutes. Accordingly, current practice yields solutions of NOM that, upon desalting and freeze-drying, are converted into dry solids containing finely dispersed sulfuric acid and silicic acid (H(4)SiO(4)). These acids will contribute to the apparent carboxylic and phenolic contents of NOM, leading to an overestimation of both. NOM may also be chemically altered by sulfuric acid, which reacts strongly with many classes of organic compounds. The sulfur content and ash content of NOM will be elevated in the presence of sulfuric acid and H(4)SiO(4). The goal of this study is to develop and test a method in which the removal of water by RO is coupled with the removal of salts by electrodialysis (ED). Like RO, ED is a relatively mild treatment that enables the desalting of NOM solutions without subjecting those samples to conditions of extremely high or low pH. The end product of the coupled process is a desalted, concentrated liquid sample from which low-ash NOM can be obtained as a freeze-dried solid material. In this study, the efficacy of ED for desalting NOM is evaluated using concentrated synthetic river waters and actual concentrated (by RO) river waters. Under optimal operating conditions, both sulfate and silica can be largely removed from RO-concentrated solutions of riverine NOM with only an average loss of 3% of total organic carbon.     

Disinfection byproduct formation in reverse-osmosis concentrated and lyophilized natural organic matter from a drinking water source

Drinking water treatment and disinfection byproduct (DBP) research can be complicated by natural organic matter (NOM) temporal variability. NOM preservation by lyophilization (freeze-drying) has been long practiced to address this issue; however, its applicability for drinking water research has been limited because the selected NOM sources are atypical of most drinking water sources. The purpose of this research was to demonstrate that reconstituted NOM from a lyophilized reverse-osmosis (RO) concentrate of a typical drinking water source closely represents DBP formation in the original NOM. A preliminary experiment assessed DBP formation kinetics and yields in concentrated NOM, which demonstrated that chlorine decays faster in concentrate, in some cases leading to altered DBP speciation. Potential changes in NOM reactivity caused by lyophilization were evaluated by chlorination of lyophilized and reconstituted NOM, its parent RO concentrate, and the source water. Bromide lost during RO concentration was replaced by adding potassium bromide prior to chlorination. Although total measured DBP formation tended to decrease slightly and unidentified halogenated organic formation tended to increase slightly as a result of RO concentration, the changes associated with lyophilization were minor. In lyophilized NOM reconstituted back to source water TOC levels and then chlorinated, the concentrations of 19 of 21 measured DBPs, constituting 96% of the total identified DBP mass, were statistically indistinguishable from those in the chlorinated source water. Furthermore, the concentrations of 16 of 21 DBPs in lyophilized NOM reconstituted back to the RO concentrate TOC levels, constituting 86% DBP mass, were statistically indistinguishable from those in the RO concentrate. This study suggests that lyophilization can be used to preserve concentrated NOM without substantially altering the precursors to DBP formation.     

Reverse osmosis desalination: Water sources, technology, and today's challenges

Reverse osmosis membrane technology has developed over the past 40 years to a 44% share in world desalting production capacity, and an 80% share in the total number of desalination plants installed worldwide. The use of membrane desalination has increased as materials have improved and costs have decreased. Today, reverse osmosis membranes are the leading technology for new desalination installations, and they are applied to a variety of salt water resources using tailored pretreatment and membrane system design. Two distinct branches of reverse osmosis desalination have emerged: seawater reverse osmosis and brackish water reverse osmosis. Differences between the two water sources, including foulants, salinity, waste brine (concentrate) disposal options, and plant location, have created significant differences in process development, implementation, and key technical problems. Pretreatment options are similar for both types of reverse osmosis and depend on the specific components of the water source. Both brackish water and seawater reverse osmosis (RO) will continue to be used worldwide; new technology in energy recovery and renewable energy, as well as innovative plant design, will allow greater use of desalination for inland and rural communities, while providing more affordable water for large coastal cities. A wide variety of research and general information on RO desalination is available; however, a direct comparison of seawater and brackish water RO systems is necessary to highlight similarities and differences in process development. This article brings to light key parameters of an RO process and process modifications due to feed water characteristics.     

韶钢生活水厂投加NaOH替代石灰工艺的技术改造

水厂制水过程中投加石灰调节pH值存在许多缺点,如石灰浆容易堵塞计量泵、易产生大量粉尘等.针对原水水质特点,采用微絮凝直接过滤工艺,用NaOH替代石灰解决了石灰投加存在的诸多弊端.在韶钢生活水厂的实际应用情况表明,这项改造在技术上是可行的,并且可以大大节省制水成本,产生可观的经济效益.     

Ozone-biological activated carbon as a pretreatment process for reverse osmosis brine treatment and recovery

Ozonation was used in this study to improve biodegradability of RO brine from water reclamation facilities. An ozone dosage ranging from 3 to 10 mg O₃/L and contact times of 10 and 20 min in batch studies were found to increase the biodegradability (BOD₅/TOC ratio) of the RO brine by 1.8-3.5 times. At the same time, total organic carbon (TOC) removal was in the range of 5.3-24.5%. The lab-scale ozone-biological activated carbon (BAC) at an ozone dosage of 6.0 mg O₃/L with 20-min contact time was able to achieve 3 times higher TOC removal compared to using BAC alone. Further processing with Capacitive Deionization (CDI) process was able to generate a product water with better water quality than the RO feed water, i.e., with more than 80% ions removal and a lower TOC concentration. The ozone-BAC pretreatment has the potential of reducing fouling in the CDI process.     

UASB+A/O+MBR+两级RO处理垃圾焚烧发电厂渗滤液

垃圾焚烧发电厂产生的渗滤液具有污染物成分复杂、水质水量波动大、有机物和氨氮浓度高、处理难度大的特点,以国内某垃圾焚烧发电厂450 m³/d的渗滤液处理项目为例,针对垃圾焚烧发电厂渗滤液的特点,采用UASB+A/O+MBR+两级RO组合处理工艺,确保处理后出水稳定达到《生活垃圾填埋场污染控制标准》(GB 16889—2008)。RO浓缩液采用高压管网式反渗透(STRO)减量化处理后回喷焚烧炉。近两年的工程运行结果表明,该组合工艺具有耐冲击负荷能力强、处理出水稳定达标、占地省等优点,对COD、BOD5、NH3-N、TN的平均去除率分别为99.8%、99.9%、99.0%、98.7%,渗滤液处理系统运行成本为47.05元/m³。     

Integrated pretreatment with capacitive deionization for reverse osmosis reject recovery from water reclamation plant

Reverse osmosis (RO) reject recovery from the water reclamation process was demonstrated feasible using an integrated pretreatment scheme followed by the Capacitive Deionization (CDI) process. The RO reject had an average total dissolved solids (TDS) of 1276 ± 166 mg/L. Water recovery of 85% with water quality comparable with the RO feed was achieved. Pretreatments using biological activated carbon (BAC) and BAC–ultrafiltration (UF) attained total organic carbon (TOC) removal efficiencies of 23.5 ± 6.0% and 39.9 ± 9.0%, respectively. Organics removal of RO reject was attributed to simultaneous adsorption and biodegradation in the BAC pretreatment, while further biodegradation in the submerged UF membrane tank provided additional organics removal. Membrane and CDI fouling was reduced by pH adjustment of the pretreated RO reject to approximately 6.5, which prolonged the CDI operation time by at least two times. The CDI process was able to achieve more than 88 and 87% TDS and ion removals, respectively, while PO₄³⁻ and TOC removals were at 52–81% and 50–63%, respectively.