Methodologies for feasibility studies related to wastewater reclamation and reuse projects

About 20% of the total surface water in Europe is strongly threatened due to pollution problems, and 60% of European cities over-exploit their groundwater resources. The European Framework Water Directive established that by the year 2015 “a good ecological state” of all European water resources and a sustainable use of water must be achieved. Wastewater reuse presents a promising solution to the growing pressure on Europe's water resources. However, wastewater reuse implementation in Europe faces obstacles that include insufficient public acceptance; technical, economic and hygienic risks; and lack of regulations. On the other hand, a very important aspect to implement a water reuse project is the feasibility study that was previously developed. Some of the work carried out in a European project called Integrated Concepts for Reuse of Upgraded Wastewater is described herein. One of the most important tasks of this project is to prepare guidelines on feasibility studies for water reuse systems. The defined structure to carry out feasibility studies and some guidelines to obtain an ecological, social and economical assessment is described.     

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.     

Membrane bioreactor technology for wastewater treatment and reuse

Treatment technology for water recycling encompasses a vast number of options. Membrane processes are regarded as key elements of advanced wastewater reclamation and reuse schemes and are included in a number of prominent schemes world-wide, e.g. for artificial groundwater recharge, indirect potable reuse as well as for industrial process water production. Membrane bioreactors (MBRs) are a promising process combination of activated sludge treatment and membrane filtration for biomass retention. This paper will provide an overview of the status of membrane bioreactor applications in municipal wastewater reclamation and reuse in Europe and will depict their potential role in promoting more sustainable water use patterns. Particular attention will be paid to the impact of MBR technology on emerging pollutants. A case study will be presented on a full-scale MBR plant for municipal wastewater which is operated by Aquafin in Belgium.     

Water reuse of south Barcelona's wastewater reclamation plant

The use of water from the wastewater reclamation plant serving the south of Barcelona, Spain, will contribute with new resources to help to solve the water scarcity problem that the Barcelona metropolitan area suffers at present. When the plant starts to operate, it is scheduled to reuse 50 Mm³/y of reclaimed water that will be used for supplying the ecological flow in the lower part of the Llobregat River, irrigation of farm areas and supplying water to wetlands in the river deltaic areas. Another scheduled use pretends to solve the salt-intrusion problem in the Llobregat lower delta aquifer through the implementation of an hydraulic barrier using reclaimed water. For obtaining water with the quality required for all the reuse purposes, it is necessary to modify the existing biological treatment to remove nutrients (nitrogen and phosphorus) and the construction of a tertiary reclamation facility, which for recharge purposes includes a reverse osmosis plant. A pumping station and pipelines for transporting the reclaimed water to the different application areas and a different pipeline for transporting the water to the injection wells where it is introduced into the aquifer at a depth of 60 m are being built.     

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.     

MBR处理聚氯乙烯工业废水的研究

采用聚丙烯中空纤维微滤膜,设计和建立了日处理50t聚氯乙烯工业废水MBR装置。在温度30~42℃、活性污泥(MLSS)4.0~7.2g/L、曝气量75m3/h的条件下,通过与现有生化法进行比较,结果表明:MBR法出水的COD和SS均<100mg/L,废水COD和SS的去除率可分别达到68%和67%以上,出水中氯化物浓度、NH3-N浓度和生化法的差别不大,且变化规律相似,而MBR法出水的磷浓度较生化法有较大下降,磷的脱除较为完全。因此,MBR法处理聚氯乙烯工业废水明显优于生化法,可推广应用。     

化工废水处理过程中MBR的调试及管理

采用MBR处理化工废水终端出水,对膜处理调试及运行阶段遇到的问题提出相应的解决方法,可使出水COD60 mg/L,并达到江苏省《化学工业主要水污染物排放标准》(DB 32/939—2006)的规定,出水回用至循环水装置。     

膜生物反应器处理制药工业废水中试研究

膜生物反应器组合工艺是近年来发展起来的新型废水处理工艺.试验采用混凝气浮 厌氧 好氧MBR处理制药工业废水,并重点考察了MBR中试装置的运行特性和对有机物的去除能力.结果表明,在整个流程连续运行过程中,当进水CODCr为13000～24800 mg/L时,总去除率可达96.47%.MBR对CODCr的去除负荷为1.90～2.49kg/(m3·d);当SO42-质量浓度为3510～4420 mg/L时,去除率为38.86%～60.61%,平均为50.71%.MLVSS/MLSS为0.65～0.75.而且膜的过滤作用有效地缓冲了进料负荷波动对系统运行效果的影响.     

电厂生产废水的处理与回用

采用水解酸化+曝气生物滤池(BAF)工艺处理某电厂废水。介绍了各处理构筑物、运行参数。运行结果表明,在进水CODCr,BOD5,SS的质量浓度分别为320￣490,100￣160,80￣160mg/L,pH值为6￣9时,用该工艺处理电厂废水,其出水水质可达《生活杂用水水质标准(》CJ25.1-89)的要求。该BAF工艺投资少,处理效率高,操作简单,无需投加化学药剂、不产生二次污染。     

利用生化处理和膜分离技术处理回用化工废水的设计

化工生产废水具有污染程度高、pH变化大、可生化性较差、并且含盐量较高的特点,为了实现废水回用的目的,采用物化预处理、水解酸化 接触氧化 超滤 反渗透相结合的处理工艺.出水回用于循环冷却水补充水,同时达到了节水治污的目标.本技术推动了膜分离技术在化工废水回用中的应用.     

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.     

工业污水处理水再生处理初步研究

通过在聚合氯化铝絮凝处理焦化工业污水处理水的过程中引入一种精细化学品作絮凝增效剂,对焦化工业污水处理水进行再生处理。实验表明,絮凝过程中加入絮凝增效剂能大大提高焦化工业污水处理水色度和COD去除率;单独使用聚合氯化铝絮凝时,色度去除率为64．3％,COD去除率为47．3％,引入絮凝增效剂后,色度去除率可以提高到90％,COD去除率可以提高到55．7％,使焦化工业污水处理水的COD由200mg／L降低到88mg／L,色度由600度降低到55度。     

膜生物反应器在废水处理中的优势

在查阅大量国内外文献资料的基础上,论述了膜生物反应器与传统好氧生物处理方法相比所存在的优势,以期为好氧生物处理方法的改进提供有益参考。     

Performances of RO and NF processes for wastewater reuse: Tertiary treatment after a conventional activated sludge or a membrane bioreactor

Wastewater reclamation requires processes and technologies having the ability to reduce the presence of micropollutants which are not wholly treated in conventional WWTP. Due to the complexity of membrane-solute interactions and the diversity of secondary treatment effluent (STE) matrices, deeper investigations are required to identify the major foulant species and more specifically their behaviour at high concentration in real waters. This study investigates the rejection and fouling potential of nanofiltration (NF) and low-pressure reverse osmosis (RO) membranes with two STEs sampled from i) a conventional activated sludge process coupled with ultrafiltration (CAS-UF) and from ii) a membrane bioreactor MBR (AquaRM^®, SAUR (France)). Whatever the origin of the effluent, RO seems to be the best solution to prevent pollution of tertiary effluents (expected result) but also to obtain low fouling levels. The different composition and molecular weight distribution of MBR and CAS-UF effluents can explain the different fouling behaviours that were observed.     

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.     

石化污水深度净化回用技术研究

中石化西安分公司建成一套由预处理系统和双膜系统组成的污水回用装置,目的是将污水处理厂达标污水做深度处理后,用作循环冷却水系统补充水。整个系统在建成后,通过运行调试,预处理部分产水(平均值)pH 8.72,石油类0.52 mg/L,悬浮物6.2 mg/L,氨氮0.07 mg/L,COD 29.27 mg/L,产水水质良好,能达双膜部分的进水设计指标。双膜部分产水(平均值)石油类0.35 mg/L,电导20.8μs/cm,氨氮0.28 mg/L,硬度11.3 mg/L,硬度去除率92%,脱盐率基本都在98%以上,各项指标都能达到双膜部分的产水设计指标,总体运行效果良好,但还存在一些问题有待进一步解决。     

全膜法在焦化废水回用的应用

焦化行业由于具有耗水量大、污染物成分复杂、环境污染严重等特点,严重影响着社会环境及地区发展。随着《炼焦化学工业污染物排放标准》(GB 16171—2012)的实施,对焦化废水的深度处理成为各企业亟待解决的难题。着重介绍了全膜法在焦化废水深度处理中的应用情况,一年来的运行效果表明该方法对经生化处理后的焦化废水进行再回收利用有着良好的应用效果。     

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     

两种膜生物反应器工艺在养殖废水处理中的运行效果

采用动态膜生物反应器（dynamic membrane bioreactor,DMBR）和膜生物反应器（membrane bioreactor,MBR）两种处理工艺,研究在相同条件下对养殖废水的处理效果和运行条件。结果表明,不同溶解氧（dissolve oxygen,DO）条件下,DMBR和MBR对CODMn的去除率可达95%以上。DO为0～1 mg/L条件下,DMBR和MBR的总氮平均去除率分别达到71.4%、75.8%;在DO为2～3 mg/L条件下,DMBR和MBR的总氮平均去除率分别为46.3%、44.1%。DMBR和MBR两种工艺均能达到较好的污染物去除效果。MBR的过滤压差明显高于DMBR,低DO条件下（0～1 mg/L）的运行周期约为5天,DMBR采用重力流出水,运行周期约为10天,过滤压差最高时仅为3.97 kPa,在一定程度上克服MBR成本高、易污染等缺点。