Performance of a ZVI‐UASB reactor for azo dye wastewater treatment

BACKGROUND: Zero valent iron (ZVI) is expected to be helpful for creating an enhanced anaerobic environment that might improve the performance of the anaerobic process. Based on this idea, a ZVI packed upflow anaerobic sludge blanket reactor (ZVI‐UASB) was developed to enhance azo dye wastewater treatment. RESULTS: The ZVI‐UASB reactor was less influenced by a decrease in the operational temperature from 35 °C to 25 °C than a reference UASB reactor that did not contain ZVI. In addition, chemical oxygen demand (COD) and color removal efficiencies of the ZVI‐UASB reactor at an HRT of 12 h exceeded those of the reference reactor at an HRT of 24 h. The hydraulic circulation in the ZVI bed enhanced the function of ZVI so that it improved the COD and color removal efficiencies. Moreover, fluorescence in situ hybridization experiments revealed that the abundance of Archaea in the sludge of the ZVI bed was significantly higher than that at the reactor bottom, which made the reactor capable of greater COD removal under low temperature and short HRT conditions. CONCLUSION: This ZVI‐UASB reactor could adapt well to changes in the operational conditions during wastewater treatment. Copyright © 2010 Society of Chemical Industry     

Assessing the feasibility of a vertical double submerged membrane modules system for wastewater reclamation under different conditions

Nowadays, water is deteriorating for several reasons, such as an increase in wastewater that flows into rivers and the limitation of water resources. Therefore, we have concentrated our plans on securing water resources by reusing wastewater treatment effluent. In this study the reuse system was organized using a submerged membrane bioreactor (SMBR) consisting of an anoxic, select, and aerobic tank. Our plan to solve the problems mentioned above involved optimizing the operating hydraulic retention time (HRT), which was done by comparing the characteristics of water treatment for several HRTs. Also, the simple and vertical double membrane modules were analyzed to find more effective operating condition in SMBR. The Specific characteristics of the SMBR system were represented as follows. We could know below 10 mg/L of BOD, below 5 mg/L of COD, 0 mg/L of SS without changes of HRT, which was satisfied with the standard of reuse water. Optimized HRT was 2.3 h and by composing the vertical double membrane modules, air flow rate could be reduced by 28.5%, lower than that of the simple membrane module.     

污泥负荷对UBF处理农村污水的影响

研究了在常温条件下不同污泥负荷对UBF反应器污水处理性能的影响。结果表明在进水浓度为1200 mg/L、水力停留时间（HRT）为10 h、污泥负荷为0．59 kg COD/kg MLSS·d时,UBF对COD的去除效果最佳,达80．14％;在污泥负荷达到1．01 kg COD/kg MLSS·d之前,污泥中生物量比例随着污泥负荷的增加而增加,MLVSS/MLSS值可达0．89;UBF反应器对污水可生化性有较好的改善效果,BOD5/CODCr比值增幅可达28．52％,且低污泥负荷更有利于污水可生化性的改善。     

EM技术在MBR中的应用研究

实验采用投加EM菌强化的MBR工艺处理某印染厂排放废水,考察了强化MBR的处理效果和对活性污泥特性的影响,以及对膜过滤性能的影响。EM菌按0.5%的比例投入MBR,并启动反应器,在水温25℃,pH=7,水力停留时间12 h,溶解氧浓度3~5 mg/L的条件下运行60 d。实验表明,EM菌强化的MBR工艺对TOC的平均去除率高于未强化组20%,具有更好的出水水质。此外,EM菌的强化作用使活性污泥具有更好的生物活性和更大的粒径,同时在一定程度上缓解了膜污染。     

一体化膜生物反应器处理印刷线路板综合废水

采用自制一体化膜生物反应器(SMBR)处理印刷线路板(PCB)综合废水,对系统驯化过程的污泥生物相变化,SV30(污泥沉降比)、SVI(污泥沉降指数),MLSS(混合液悬浮固体浓度)、MLVSS(混合液挥发性悬浮固体浓度)等污泥特性,以及系统pH,铜离子浓度、化学耗氧量(COD)等水质指标进行了监测.试验结果表明:污泥培养驯化过程中,游泳型纤毛虫、固着型纤毛虫(累枝虫、钟虫)、轮虫、红斑顠体虫、表壳虫、固着型纤毛虫交替成为优势种群.进水铜离子质量浓度为12 mg/L左右驯化完成,此时污泥MLSS为6 100 mg/L,SV30为29%～38.5%,SVI为75～90 mL/g.系统出水COD、铜离子浓度和pH均达广东省水污染物排放限值一级标准,COD和铜离子的去除率分别超过85%和95%.     

UASB处理纤维素乙醇废水的启动运行研究

以厌氧UASB反应器处理纤维乙醇废水为研究对象,探讨分析了UASB的启动和稳定运行过程。结果表明,采用城市污水处理厂的厌氧消化污泥作为接种污泥,在COD有效容积负荷为0.33~1.11 kgCOD/(m3·d)的条件下,UASB反应器成功启动,COD的去除率达到70%以上。启动初期,出水pH会明显高于进水,污泥呈先减少后增加的趋势,当增加进水SO42-浓度到7 250 mg/L,COD/SO42-比值2.7∶1时,会导致纤维素乙醇废水UASB处理系统的崩溃。UASB反应器运行稳定后,污泥浓度增至30~40 g/L,MLVSS/MLSS比值也达到90%左右,在HRT为14~41 h,回流比3∶1~13∶1,有效容积负荷3.45~14.67 kg COD/(m3·d)的条件下,对纤维乙醇生产废水均能保持90%以上的COD去除率,出水COD小于1 000 mg/L。     

高效厌氧反应器处理中药提取废水中试研究

应用新型高效厌氧反应器处理中药提取废水。从有机物去除率、产气效率及颗粒污泥增殖等方面评估了系统的运行效果。结果表明,经过2个多月的启动运行,该系统的COD去除率平均达到98%以上,出水COD500 mg/L,COD容积负荷高达25 kg/(m~3·d),甲烷产率为0.31 L/g COD。水力停留时间为12~24 h,系统运行稳定,抗冲击负荷能力较强。启动过程中,颗粒污泥粒径增大到1.8~2.5 mm。     

Submerged Membrane Bioreactor for Vegetable Oil Wastewater Treatment

A bench‐scale submerged membrane bioreactor (SMBR) was employed to treat vegetable oil plant wastewater with complete sludge retention. Treatment performance and membrane fouling of the SMBR were investigated. The system stably removed high amounts of total organic carbon, oil, and ammonia from vegetable oil wastewater and reduced the chemical oxygen demand, demonstrating the great potential of the SMBR in removing pollutants. The membrane fouling layer was not only governed by deposition of organic substances composed of extracellular polymeric substances like proteins, polysaccharides etc., and oil substances but also by inorganic elements. Organic foulants coupled to inorganic precipitation enhanced the formation of a gel layer and triggered severe membrane fouling in the SMBR.     

投加氯化铁对SMBR工艺效能及膜污染的影响

试验研究了浸没式膜生物反应器(SMBR)中FeCl_3不同投加量对出水水质以及膜污染的影响.结果表明,不同投加量对于COD、NH_3-N的去除效率影响不显著;随着FeCl_3投加量的增加,总氮(TN)去除效率略有提高.投加适量FeCl_3,可以增强化学和生物协同除磷作用.溶解性胞外聚合物(EPSs)中多糖浓度、松散附着胞外聚合物(LB)中蛋白质和腐殖酸浓度与半透膜压(TMP)的增长存在明显的相关性,说明EPSs中多糖、LB中蛋白质和腐殖酸均是导致膜污染的主要因素.FeCl_3最佳投加量范围为15～30mg·L~(-1),此时活性污泥形成了良好的菌胶团,TMP增长速度最慢,膜污染程度最轻.而当投加量进一步增大到60 mg·L~(-1)和120 mg·L~(-1)时,生物铁结构变得密实,膜污染程度加剧;其次过多FeCl_3本身也增加了的膜污染负荷.     

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.     

A comparative study of tertiary membrane filtration of industrial wastewater treated in a granular and a flocculent sludge SBR

Membrane fouling has been identified by many researchers as an inconvenience for the industrial application of membranes in wastewater treatment plants. Membrane fouling decreases permeability and therefore permeates flow, increasing costs. Although fouling is the result of complex phenomena not completely known, it can be said that fouling takes place by the presence of three different kinds of compounds in the water: suspended solids, colloids and solutes. In this sense, the characteristics of the suspended solid aggregates might be an important aspect in order to diminish the impact of suspended solids on membrane fouling. The main objective of this study was to compare the operation of two similar tertiary membrane filtration units treating the effluent of two different SBRs, respectively: A granular sludge SBR (GSBR) and a membrane flocculent sludge SBR system, at laboratory scale. Two PVDF microfiltration membrane modules were used for tertiary filtration of the effluent treated in the SBRs. Both reactors were used for treating the wastewater generated in a factory of the fish freezing sector. COD of the wastewater was between 700 and 1100 mg/L, total nitrogen concentration was between 110 and 180 mg N/L and total phosphorus ranged around 110 mg P/L. The chemical characteristics of both permeates were similar. Moreover, the presence of either granules or flocs in the tertiary membrane filtration systems did not have an appreciable impact on the membrane filtration. Nevertheless, it was observed that the operation of the membrane on the flocculent system tends to be more instable, showing a major tendency to achieve critical flux.     

AO工艺同步脱氮除磷效能的研究

采用A／O同步脱氮除磷工艺处理模拟污水,调整DO、HRT、内回流、进水污染物的浓度等影响因素,考察了该工艺单位活性污泥处理污水中TN、TP的能力。结果表明,当好氧区DO控制在0．6mg／L左右,HRT控制在10h,内回流比控制在1：1时,单位活性污泥处理污水TN、TP的能力最强,单位活性污泥TN去除速率达到14×10^-3mg／（L·mg MLVSS·h）,单位活性污泥TP去除速率达到0．14×10^-3mg／（L·mg MLVSS·h）,AO系统实现了同步硝化反硝化和反硝化除磷。     

生物膜反应器组合工艺对COD、氮类物质去除研究

针对北方冬季寒冷低温条件下,废水中COD、氮类物质降解效果低下的缺点,采用生物膜反应器脱氮组合工艺,投加一定比例悬浮性填料,在温度12℃以下进行小试研究,结果显示,HRT=18h,污泥回流比Qr=200%,混合液回流比Qr=80%,控制填料填充率在35%,曝气溶解氧控制在2~3mg/L,能够使出水中的COD、NH_3-N和TN达到国家一级A标准。     

Anaerobic/aerobic sequential treatment of a cotton textile mill wastewater

The treatment of a wastewater taken from a cotton textile mill was investigated using an anaerobic/aerobic sequential system during an operational period of 87 days. The process units consisted of an upflow anaerobic sludge blanket (UASB) reactor and a continuous stirred tank reactor (CSTR). Wastewater characterization was performed before feeding the reactor system. Glucose‐COD, and azo dyes were added to the textile wastewater for comparative purposes in the final period of operation. The pH values in the effluent of the UASB reactor were suitable for optimal anaerobic treatment in all runs. The biodegradable part of the COD in wastewater was removed effectively, with the anaerobic stage improving the biodegradability of wastewater entering the aerobic stage. The UASB reactor permitted COD and color removals of 9–51% and 46–55%, respectively, at a hydraulic retention time (HRT) of 30 h. COD removal efficiencies were between 40 and 85% and color removal efficiencies were 39–81% in normal and artificially‐colored wastewaters at a total HRT of 5.75 days in the UASB/CSTR reactor system. Benzidine produced from the cleavage of azo bond in the anaerobic stage was effectively removed in the aerobic stage, and was identified by comparison of its HPLC spectrum with that of an authentic specimen. Copyright © 2004 Society of Chemical Industry     

新型厌氧反应器COD去除影响因素研究

以模拟高浓度有机废水为研究对象,采用新型厌氧反应器对COD去除影响因素进行了为期4个月的试验研究,考察了污泥负荷、水力停留时间(HRT)、容积负荷、进水COD、VFA、出水SS等因素对COD去除的影响。结果表明,影响COD去除的主要因素是污泥负荷、HRT和容积负荷,次要因素是进水COD、VFA和出水SS,当反应器内COD污泥负荷在0.297 2～0.464 7 kg.kg-1.d-1之间、HRT=7 h时,COD的去除效率维持在72%～90%。     

MBR与Fenton试剂工艺处理维生素C生产废水的可行性研究

针对现有的维生素C生产废水处理工艺出水不能达标的问题,采用MBR和Fenton试剂对原有废水处理工艺进行提标改造。在MBR系统进水COD的质量浓度为350～650 mg/L,污泥质量浓度为8 000 mg/L,溶解氧的质量浓度为2～3 mg/L,停留时间为20 h时,出水COD的质量浓度可降至120～135 mg/L。再通过Fenton试剂氧化(硫酸亚铁和H2O2的投加量分别为120和80 mg/L),最终出水COD的质量浓度稳定在80 mg/L以下。对于维生素C生产废水处理工艺的选择,MBR-Fenton试剂氧化可作为推荐工艺。     

A Novel Sponge‐Submerged Membrane Bioreactor (SSMBR) for Wastewater Treatment and Reuse

Abstract

Membrane fouling has been regarded as one of the biggest challenges to widespread application of membrane bioreactor (MBR). This study focuses on minimizing the membrane fouling and improving the performance of submerged membrane bioreactor (SMBR) by porous sponge addition. The effects of sponge addition on sustainable flux and membrane fouling were investigated. Acclimatized sponge could significantly increase the suspended growth in SMBR with biomass of 16.7 g/L_(sponge). With the sponge volume fraction of 10%, SSMBR could enhance sustainable flux up to 50 L/m² · h compared with sustainable flux of SMBR (only 25 L/m² · h). SSMBR also exhibited excellent results in terms of DOC removal (over 95%), COD removal (over 97%), lower transmembrane pressure development, and oxygen uptake rate. Over 89% of NH₄‐N and 98% of PO₄‐P were removed when SSMBR was operated with a MLSS concentration of 15 g/L.     

一体式平板膜生物反应器处理维生素制药废水中试研究

采用规模为5 m~3·h~(-1)左右的一体式平板膜生物反应器对维生素制药废水进行了中试研究.试验结果表明,用此装置处理维生素制药废水,出水水质稳定良好.工艺对COD和NH_4~+-N的去除率分别达到80%和90%以上,出水完全达到了发酵类制药工业水污染物排放标准(GB21903-2008)的排放要求;当HRT分别取12,22、26h时,对系统去除率有较大的影响;污泥浓度是影响膜通量的一个重要因素,污泥质量浓度应控制在7 g·L~(-1)左右;虽然污泥的沉降性能非常差,SV平均值为97.8%,但由于膜的高效截留作用,反应器不受污泥的性状的影响.     

Development of the wastewater reclamation and reusing system with a submerged membrane bioreactor combined bio-filtration

Recently there have been many wastewater treatment processes combining different units of process to improve the dissolving and suspension of pollutants in water. The submerged membrane bioreactor (SMBR) system uses a membrane that can produce high quality water for reusing with minimal land demand, instead of using secondary clarifier as biological treatment, sand filters, ozonation, GAC or disinfection processes as a tertiary treatment. For the development of the bio-filter membrane bioreactor (BMB) system as a submerged membrane bioreactor in this study the new wastewater treatment system will consist of a rapid bio-filter clarifier, a bioreactor and a hollow fiber membrane and plate membrane, to help find the optimal process to meet the regulations for reused water. This study was performed to evaluate the BMB reusing system, made up of a rapid bio-filter clarifier, an activated sludge bioreactor and a membrane module. The rapid bio-filter clarifier replaced a conventional primary sedimentation and removed SS, BOD and COD to 40, 20, and 20%, while the turbidity and color were removed by 30 and 10% respectively. This means that the rapid bio-filter clarifier having an HRT value 5.2 min can replace the conventional primary sedimentation of the HRT value of 1.5–2.5 h. Also the BMB reusing system could achieve the effluent quality of BOD < 5 mg/L, COD < 10 mg/L, turbidity < 0.5 NTU, and color < 20 unit respectively, and total coliforms did not appear. This means this system can meet water quality standard for water reusing systems. The flux of the plate membrane and hollow Fiber membrane were 120–140 L/m² h bar and 60–90 L/m² h bar; much more water could permeate the plate type membrane than hollow fiber type membrane. Plus the total resistance of hollow fiber type membrane was higher than plate type membrane.     

缺氧/好氧膜-生物反应器处理高浓度含碳和氮工业废水

采用缺氧 /好氧膜 生物反应器 (MBR)处理高浓度含碳和氮工业废水 ,在缺氧反应器的水力停留时间 (HRT)为 5h ,好氧MBR的HRT分别为 1 5、1 0、6h时 ,考察了系统的同时除碳脱氮性能。结果表明 ,好氧MBR的HRT在试验范围内对系统的处理效果没有明显影响 ,即使MBR的HRT降低到 6h,系统对化学需氧量 (COD)、氨氮和总氮的去除率仍可达到 94%、90 %和 73 %以上 ,出水水质达到国家一级排放标准 ;系统中的生物反应对有机物和氮的去除起主要作用 ,但膜对混合液上清液COD有一定去除 ,主要对相对分子质量大于 1 0万的有机物有截留 ;由于膜的高效截留作用 ,MBR中可保持高浓度的污泥量和高硝化活性 ,确保了硝化反应的高效进行