工业废水回用的实践与思考

各个行业的工业废水的水质差别很大,回收用途也不相同.以实际工程为例,分别介绍了超滤-反渗透(RO)工艺在火电、钢铁、石化工业回用水项目的应用情况.同时提出,有效的预处理、细菌的污染防治和操作人员的培训是回用水处理工程顺利运行的保障,应制定相关法规进一步推进回用水工作的发展.     

Membrane bio-reactor for advanced textile wastewater treatment and reuse.

Textile wastewater contains slowly- or non-biodegradable organic substances whose removal or transformation calls for advanced tertiary treatments downstream Activated Sludge Treatment Plants (ASTP). This work is focused on the treatment of textile industry wastewater using Membrane Bio-reactor (MBR) technology. An experimental activity was carried out at the Baciacavallo Wastewater Treatment Plant (WWTP) (Prato, Italy) to verify the efficiency of a pilot-scale MBR for the treatment of municipal wastewater, in which textile industry wastewater predominates. In the Baciacavallo WWTP the biological section is followed by a coagulation-flocculation treatment and ozonation. During the 5 months experimental period, the pilot-scale MBR proved to be very effective for wastewater reclamation. On average, removal efficiency of the pilot plant (93% for COD, 96% for ammonium and 99% for total suspended solids) was higher than the WWTP ones. Color was removed as in the WWTP. Anionic surf actants removal of pilot plant and WWTP were very similar (92.5 and 93.3% respectively), while the non-ionic surfactants removal was higher in the pilot plant (99.2 vs. 97.1). In conclusion the MBR technology demonstrated to be effective for textile wastewater reclamation, leading both to an improvement of pollutants removal and to a draw-plate simplification.     

Experimental study on municipal and industrial reclaimed wastewater refinement for agricultural reuse

The present study is aimed at verifying the possibility of reusing municipal and industrial reclaimed wastewaters for the irrigation of container-grown ornamental shrubs, paying attention to the refinery treatment. The research has been carried out in the district of Pistoia (Central Italy), which represents one of the main nursery areas in Europe. Two experimental sites, each consisting of a refinery treatment pilot plant (filtration and disinfection) and an agronomic area, were set-up. In this paper the attention is focused on the selection of the refinery treatment. The combined process of peracetic acid (PAA) and ultraviolet irradiation (UV) chosen for the disinfection treatment proved to be very effective for the inactivation of microorganisms for both municipal and industrial wastewaters. The high efficiency is recognised as being brought about by the formation of free radicals due to the photolysis of the PAA when in the presence of the UV rays. A preliminary cost analysis has been carried out in order to highlight the most economically advantageous solution which guarantees the compliance to the Italian limits for wastewater reuse in agriculture (Escherichia Coli 10 CFU/100 mL).     

集成膜技术工业废水深度处理回用试验研究

试验采用超滤+反渗透集成膜分离技术,目的是研究其集成工艺处理有色冶金工业废水的合理性和可行性。超滤试验主要测试了在不同水质情况下超滤膜的相关运行参数,主要测定指标有超滤系统的进水、产水和反冲洗水的水量,运行压力,出水浊度,SDI值等;反渗透试验主要测定指标有电导率,反渗透系统的进、出水量,运行压力等。试验研究表明:以预处理+超滤+反渗透组成的集成膜处理工艺,能够满足有色冶金工业废水处理回用的要求。     

城市污水回用

<正>1水资源特点及开发利用现状1.1水资源特点根据20世纪80年代水资源评价工作的结果,全国多年平均年水资源总量为28124亿m3。北方6个流域多年平均年水资源总量为5358亿m3,占全国水资源总量的19%,南方4个流域     

Colloidal silica removal in coagulation processes for wastewater reuse in a high-tech industrial park.

Four experiments of coagulation and flocculation were conducted to investigate the characteristics of colloidal silica removal in a high-tech industrial wastewater treatment plant for reclamation and reuse of the effluent. Experimental results illustrated that poly-aluminium chloride (PACl) showed higher performances on colloidal silica removal than alum. Interestingly, the two coagulants demonstrated the same capacity on silica removal. The specific silica removal capacity was approximately 0.135 mg SiO2/mg Al2O3 when the dosage of coagulants was in the range 30-150 mg/L Al2O3. In addition, the silica was reduced significantly at the condition of pH above 8. Experimental data implied that precipitation of aluminium flocs was the major mechanism for colloid silica removal in PACl and alum coagulation, besides, charge adsorption was also important for improving removal efficiency. Moreover, the addition of polyacrylic acid (PAA) as a flocculant could slightly advance silica removal in the PACl coagulation. The combined PACl/PAA/flocs coagulation was effective for the removal of colloidal silica, soluble COD, and turbidity and also suitable as a pretreatment unit in wastewater reclamation and reuse processes.     

城市污水回用问题分析

城市污水回用可以缓解水资源短缺问题。在分析城市污水回用的必要性和可行性的基础上,强调污水回用技术的重要意义。重点评述了污水回用的途径和目前存在的问题:污水处理水平较低,污水灌溉理论研究滞后,水价偏低阻碍回用水技术推广等。     

Membrane bioreactors in industrial wastewater treatment--European experiences, examples and trends.

In wastewater treatment, micro- and ultra-filtration membranes are used for the separation of the activated sludge (biomass) from the treated water. This offers the advantages of a complete removal of solids and bacteria, as well as most of the viruses, namely those attached to the suspended solids. Compared to the conventional activated sludge process (CAS) this technology allows a much higher biomass concentration (MLSS) whereby the reactor volume and the footprint decreases. With increasing MLSS, the viscosity of the sludge increases, which leads to reduced oxygen transfer rates. Depending on the type of membrane and membrane module, the pre-treatment has to be more sophisticated to prevent clogging and sludging of the modules. Due to fouling and scaling, the flux through the membranes will decrease with time. The decrease depends on the water quality as well as on the measurements taken to minimize fouling. Mainly, three strategies are available: lowering the flux, increasing the "crossflow" and cleaning of the membranes. Different strategies including backwash and chemical cleaning "in situ", "on air" and "ex situ" can be applied. It has been proven more effective to apply preventive regular cleaning. Besides the energy demand for oxygen supply--which is typically in the range of 0.3 kWh/m3 for municipal wastewater--the energy for fouling prevention is substantial. Immersed membranes need approximately 0.4 to 1 kWh/m3 for the coarse bubble aeration, whereas tubular modules require 1 to 4 kWh/m3 pump energy. For proper design of industrial wastewater treatment, the verification of applicability and the development of adequate cleaning strategies, it is a precondition to run pilot tests for a sufficient period of time with the wastewater to be treated. More than 100 industrial wastewater treatment membrane bioreactors (MBR) are in operation in Europe. Data of three case studies for a sewage sludge dewatering plant in UK (12,000 m3/d), a plant for the treatment of pharmaceutical wastewater in Germany (3600 m3/d), as well for revamping of an chemical WWTP >2000 m3/d in Italy, are given. MBRs will be used in future wherever high quality effluent is required, because of a sensitive receiving water body or due to the fact of water reuse as process water. MBRs are a perfect pre-treatment in industrial applications when further treatment with nanofiltration or reverse osmosis is considered. The technique is advanced and can be applied both in municipal and industrial wastewater treatment. Higher operational costs must be balanced by superior effluent quality.     

An integrated wastewater reuse concept combining natural reclamation techniques, membrane filtration and metal oxide adsorption.

In a Sino-German research project, a sustainable water reclamation concept was developed for different applications of municipal water reuse at the Olympic Green 2008 in Beijing, China. Results from pilot-scale experiments in Beijing and Berlin show that selective nutrient removal by adsorption onto granular ferric hydroxide (GFH) after a membrane bioreactor (MBR) can maintain a total phosphorus concentration of <0.03 microg L(-1) P, thus preventing eutrophication of artificial lakes. Operation time of GFH adsorption columns can be extended by regeneration using sodium hydroxide solution. A subsequent ultrafiltration (UF) membrane after bank filtration creates an additional barrier for pathogens and allows for further urban reuse applications such as toilet flushing. Short term bank / bio-filtration prior to UF is shown to effectively remove biopolymers and reduce membrane fouling.     

炼油废水处理与资源化

对炼油废水处理工艺各单元的处理状况进行了分析,实践证明在原水CODCr≤1 000 mg/L, 氨氮≤<40 mg/L,油≤500 mg/L,硫化物≤10 mg/L,pH 6-9的情况下,处理后出水经过滤及消毒后可直接回用作为循环水的补充水,其主要指标能够达到中国石化集团公司循环水的要求,从而实现炼油废水的资源化。     

污水再生利用进程中的误区

综述了我国污水再生利用进程中存在的主要误区,包括标准的选用、再生水的使用、再生工艺的选择以及再生水的推广主体等,并结合多年经验对造成这些误区的原因进行了分析,给出了走出误区的具体建议。     

计算机控制技术在中水回用工程中的应用

介绍了一种由计算机、人机界面(HMI)、可编程控制器、变频器及相应传感器组成的针对中水处理站的计算机控制系统的设计方案,可实现中水处理的高效率自动运行与远程监控、管理。     

SBR工艺在中水处理工程中的应用

介绍了序批式活性污泥工艺 (SBR)处理学校洗浴废水的工程实例。该工艺对洗浴废水中COD ,BOD ,SS及LAS有较高的去除率 ,处理后出水用于学生公寓冲厕 ,其水质符合《城市污水再生利用　城市杂用水水质标准》(GB/T1892 0 - 2 0 0 2 )。该工艺设备简单 ,占地少 ,运行方便。     

造纸废水处理及回用工程

针对某造纸厂生产废水SS及难降解污染物含量高的特点,采用强化物化预处理-MBR-RO工艺.工程实践表明,MBR出水达到<造纸工业水污染物排放标准>(GB 3544-2001)一级排放标准,RO深度处理出水可达到该厂回用水标准.     

冷轧综合废水的再生与回用

采取微滤、超滤、反渗透为主体的集成膜工艺处理冷轧综合废水,工艺中融合磁过滤技术和生化处理技术,强化膜前的预处理工艺,对膜污染进行了有效的防治.利用生活污水以废制废,出水水质达到<城市污水再生利用工业用水水质>(GB/T 19923-2005)标准.整个工艺形成了废水的排放、处理、回用的资源循环链,体现了废水处理与生态治污相结合的理念.     

棉针织印染废水不同回用工艺经济性分析

针对目前棉针织印染行业废水回用率低的问题,根据废水源头控制原则,结合太湖流域实际情况,设计了两种回用工艺方案.方案一是对废水进行分质分流,将较清洁的废水直接回用,高污染的废水进行处理后达标排放,可以实现27.23％的废水回用率;方案二是将较清洁的废水直接回用,同时将高污染的废水进行脱盐处理,回用于印染生产过程,可实现71.45％的废水回用率.对两种方案进行经济分析,结果表明,在目前的条件下,方案二比方案一具有更好的经济与环境效益.     

MBR与接触氧化工艺用于中水处理的比较

某高校中水处理工程采用MBR代替接触氧化工艺进行改造,在实际运行情况的基础上,对MBR和接触氧化工艺在工艺流程、处理效果、投资成本和运行维护管理等方面进行比较,结果表明,MBR在各方面均体现出较强的优势,为MBR的实际应用和发展提供参考。     

MBR pilot plant for textile wastewater treatment and reuse.

An experimental study was carried out in order to evaluate the possibility of upgrading the conventional activated sludge WWTP of Seano (Prato, Italy) which treats municipal and textile wastewaters, by using membrane bioreactor (MBR) technology. The MBR pilot plant, set up within Seano WWTP, was fed with mixed municipal-industrial wastewaters during the first experimental period and with pure industrial wastewaters during the second. Performances and operation of the MBR were evaluated in terms of permeate characteristics and variability (COD, colour, surfactants, total N and P) and other operational parameters (sludge growth and observed yield). According to the experimental results the MBR permeate quality was always superior to the Seano WWTP one and it was suitable for industrial reuse in the textile district of the Prato area. Respirometric tests provided a modified IWA ASM1 model which fits very well the experimental data and can be used for the design and the monitoring of a full-scale MBR pilot plant.     

Pharmaceutical rejection by membranes for wastewater reclamation and reuse.

Various membranes, which have different materials and nominal molecular weight cut-offs (MWCO), were compared in terms of rejection of ibuprofen and removal of effluent organic matter (EfOM) from membrane bioreactor (MBR), because pharmaceutical compounds contain a potential risk and EfOM is the precursor of carcinogenic disinfection by-products when reusing for drinking water source. To provide equivalent comparison with respect to hydrodynamic condition, mass transfer parameter, J0/k ratio, was used. A tight-UF membrane with a molecular weight cut off of 8,000 daltons exhibited 25 approximately 95% removal efficiencies of ibuprofen with a molecular weight of 206 with and without presence of EfOM(MBR). EfOM(MBR) caused the reduction of ibuprofen removal efficiency for UF membrane. Rejection of EfOM(MBR) by UF and NF membranes ranged 29 approximately 47% and 69 approximately 86%, respectively. UF membrane could successfully remove ibuprofen at lower J0/k ratio range (< or = 1) in organic free water but could not efficiently reject ibuprofen with a relatively hydrophilic EfOM(MBR) (SUVA < or = 3).     

石家庄市污水资源化探讨

从石家庄市缺水和水污染谈起,指出污水资源化是实现石家庄市水资源永续利用的必然选择。通过对污水处理、回用现状及存在问题进行分析,提出了相应的对策措施。