论生物膜法A/O~2工艺处理城市小区污水并回用的研究

随着全球性水资源短缺、人口的快速增长和经济的快速发展,水资源危机已经成为威胁全球生存与发展的最大危机之一。目前各国纷纷出台相关政策,用以保护水资源,提高水资源利用率。其中,废水处理回用受到各个国家的认可和重视,在经过了十多年的研究与发展,新型的膜生物反应器污水处理工艺已趋于成熟,其以处理能力高、出水水质稳定、工艺简单、污泥产出率低、占地面积小、投资运行费用低、安装灵活方便且易于实现自动化控制等传统污水处理系统所不具有的优点,在水污染防治方面受到广泛的重视和采用。本文所讨论的A/O2工艺以膜生物反应器为基础,设计以A段的厌氧池以及O段含氧池设计工艺来对城市小区生活污水进行处理回用。通过模拟实验,在室温(15～25℃)环境下进行仿真实验,在系统稳定运行后进行相关数据测试,并进行分析,最终得出生物膜法A/O2工艺能够很好的处理小区生活污水,且出水水质完全达标国家杂用水水质标准,可用于小区绿化以及道路清洗降尘等。     

膜生物反应器的工艺应用现状综述

膜生物反应器(MBR)是一种膜分离单元与生物处理单元相结合的新型污水处理技术,在污水处理与回用、垃圾渗滤液处理方面有良好的应用前景.本文阐述了膜生物处理法(MBR)的处理机理;综述MBR的工艺应用现状及其工业应用;最后就MBR工艺的发展做展望。     

EMBR技术处理工业园区综合废水试验研究

国内工业园区排放的综合废水中会产生复合污染且污染物具有多样性,致使目前常用的废水处理工艺难以达到国家废水处理的标准。本研究在膜生物反应器的基础上构建了电场-膜生物反应器,研究了电流密度和冲击负荷对COD_(cr)、氨氮和TN的影响。发现了电流密度对电场-膜生物反应器去除COD_(cr)效率没影响,而对TN去除率有很大的影响,冲击负荷对氨氮的去除效率没有影响。经过63 d连续运行,中试试验结果显示:电场-膜生物反应器的耦合对解决工业园区综合废水处理的难题有明显的效果,出水水质基本达到《城镇污水处理厂污染物排放标准》(GB18918-2002)的一级B标准。     

中水回用反渗透系统中微生物污染的解决方案

文章对某钢铁厂中水回用车间反渗透膜系统的微生物污染状况进行现场采样(包括水样和反渗透膜系统中的黏滞性物质)，并对样品进行全面的微生物污染评估，从中找出主要污染源。同时针对污染微生物开展杀菌实验，找出合适的非氧化性杀菌剂（在此之前多用氧化性杀菌剂进行反渗透系统的杀菌，但是因为氧化性杀菌剂易氧化反渗透膜导致膜的脱盐率下降，尤其余氯，因此反渗透膜系统不建议使用氧化性杀菌剂）并探索该杀菌剂的最适添加量和作用时间。根据以上结果，基于节约成本的要求，结合微生物污染对反渗透膜系统清洗和周期影响的了解，设计性价比高的非氧化性杀菌剂添加方案，以解决钢厂中水回用车间反渗透膜系统的微生物污染问题，降低反渗透膜系统的清洗频率，延长反渗透膜的使用寿命，节约运行成本。该方案在实施过程中取得了良好的处理效果。     

厌氧膜生物反应器及其应用研究实例

厌氧膜生物反应器(anaerobic membrane bioreactor,AnMBR)是一种耦合了厌氧发酵和膜工艺的新型废水生物处理技术。其优点包括出水水质优良、有机负荷高、污泥产率低以及生物甲烷回收等。归纳了厌氧发酵的原理,常见厌氧膜生物反应器的结构和种类,以及厌氧膜生物反应器的发展历程及其应用。详细介绍了笔者的最新研究成果:厌氧膜生物反应器在高浓度厨余垃圾处理中的应用,及其在城市污水处理中的研究进展。最后总结了该工艺的应用及发展现状,指出其在高浓度有机废水处理中拥有广阔的应用前景。     

猪场污水的A2/O-深度处理和中水回用

猪场污水采用A²/O-生物接触氧化-混凝沉淀-砂滤消毒组合方法处理,可以实行中水回用。原污水经过固液分离、调解池、竖流式初沉池、厌氧消化池、缺氧池、传统活性污泥曝气池、竖流式二沉池、接触氧化池、药剂混合池、斜板沉淀池、砂滤池、pH调解和消毒池处理后进入排放池,系统正常运行后处理废水可以达到GB8978-1996中规定的二级以上标准,处理水没有检测到病原微生物。中水引入中水塔,通过独立设计的中水道,可以应用到猪舍冲栏使用。而污泥通过污泥干化场得到干化。     

膜生物反应器污水处理技术在我国的工程应用现状

膜生物反应器(membrane bioreactor,MBR)是将膜分离技术与生物处理工艺有机结合的新型污水处理与回用技术。自2006年我国第一座万吨/日以上级MBR投运以来,其工程应用发展迅速,大规模MBR的总处理能力已于2010年达到100万吨/日,2014年突破400万吨/日。文章概述了2006年以来我国MBR工程应用的情况,处理水类型包括市政污水、工业废水和受污染地表水。介绍了MBR市场现状,给出了工程数量与规模的统计数据,评述了工艺特点与典型案例,并对工程投资和运行能耗进行了分析。从环境、政策和市场方面,剖析了MBR在我国推广应用的驱动力。最后结合MBR的特点,对其未来发展进行了展望。     

湛江市中水回用的发展现状及对策

水资源日益短缺已经成为了制约城市发展的一个世界性的问题。中水回用已被国内外许多城市作为城市节水的一项有效措施来实施。通过对湛江市污水处理和中水回用现状的调查,阐述了中水回用潜力巨大, 既可控制水污染,又可节约水资源,实现再生水利用,更能节约能源和工程投资,真正达到节能减排的目的,具有非常高的经济效益、社会效益和生态效益。目前中水回用的发展还存在着人们认识不足,缺乏法规支持,融资困难等问题,但是可以通过立法、宣传、制定规划、利用经济手段和吸引外资等手段推动中水回用的发展。科学合理的使用中水,既能减少水环境污染,又可以提高水资源综合利用率、缓解水资源紧缺的矛盾,是贯彻可持续发展的重要措施。     

膜生物反应器的研究进展

膜生物反应器是近年来发展的废水处理新技术,具有活性污泥浓度高、污泥龄长、占地面积小、投资省的特点。利用膜生物反应器进行污水处理不仅可以大大节约水资源,还可以大大节约能源,节省设备和运行费用,已成为二十一世纪研究热点。膜生物反应器是通过高效膜分离技术与活性污泥相结合,增大污泥中的特效菌来加快生化反应速率,提高废水处理效果。目前处理对象已从生活污水扩展到高浓度的有机废水和难降解的工业废水。本文综述了膜生物反应器在废水中的应用研究情况,并分析比较了各种膜材质的特点、适用范围以及膜的污染因素和清洗方法,展望了膜生物反应器的应用前景及进一步研究方向。     

两个污水处理系统的能值与经济综合分析

运用改进的能值评价指标和经济指标对构建的两个污水处理综合系统("污水处理厂处理+脱水污泥填埋"及"污水处理厂处理+脱水污泥填埋+中水回用")进行了环境可持续性和经济竞争力的综合分析。改进的能值指标(能值产出率SEYR、环境负载率SELR、环境可持续发展指数SESI和能值受益率SEBR)是在考虑研究对象废物及产物能值对环境影响的基础上提出的,更好地反映了系统的特征。结果表明,中水回用系统的增加有利于提升系统的环境可持续发展能力;"污水处理厂处理+脱水污泥填埋+中水回用"系统较"污水厂处理+脱水污泥填埋"系统的经济竞争力差,但却拥有更强的可持续发展能力,有利的经济政策能够刺激其更好的推广运用。     

Nitrogen removal in constructed wetland systems

Since the mid 1990s, constructed wetlands have been increasingly used as a low‐energy ‘green’ technique, in the treatment of wastewater and stormwater, driven by the rising cost of fossil fuels and increasing concern about climate change. Among various applications of these wetlands, a significant area is the removal of nitrogenous pollutants to protect the water environment and to enable effective reclamation and reuse of the wastewater. This paper provides a review of the current state of nitrogen removal technology, focusing on existing types of wetlands, the mechanisms of nitrogen removal, major environmental factors relative to nitrogen removal, and the operation and management of the wetlands.     

Designing constructed wetlands for reclamation of pretreated wastewater and stormwater

Wastewater reclamation is getting greater attention as an alternative to conventional approaches to wastewater treatment and water supply due to increasing water stress coupled with more stringent water quality limitation for discharge of treated wastewater. Among the few technologies adopted in the field for wastewater reclamation, constructed wetlands have been used to reclaim both primary and secondary treated wastewater in regions with arid and humid climates. This paper summarizes the widely adopted guidelines that need to be considered when designing constructed wetlands for wastewater reclamation, discusses the capacity of wetland treatment systems for water reuse while assessing the status of full-scale constructed wetlands designed for wastewater reclamation, and develops contaminant loading charts as a design tool based on the performance of existing full-scale constructed wetlands deployed for wastewater reclamation. It is evident that constructed wetland systems provide a viable means to treat wastewater to the levels required for low-quality reuses such as restricted irrigation and impoundment. It is challenging for constructed wetlands to consistently meet microbiological guidelines for high-quality reuses such as unrestricted agricultural and urban reuses. Wastewater reclaimed through constructed wetlands is used mainly for agricultural and landscape irrigation, groundwater recharge, indirect potable reuse, and environmental reuse. Surface area and hydraulic loading rate of constructed wetlands to be deployed for wastewater reclamation can be estimated with contaminant loading charts derived from monitoring data of existing full-scale operations.     

Membrane bioreactors and their uses in wastewater treatments

With the current need for more efficient and reliable processes for municipal and industrial wastewaters treatment, membrane bioreactor (MBR) technology has received considerable attention. After just a couple of decades of existence, MBR can now be considered as an established wastewater treatment system, competing directly with conventional processes like activated sludge treatment plant. However, MBR processes still suffer from major drawbacks, including high operational costs due to the use of anti-fouling strategies applied to the system to maintain sustainable filtration conditions. Moreover, this specific use of membranes has not reached full maturity yet, as MBR suppliers and users still lack experience regarding the long-term performances of the system. Still, major improvements of the MBR design and operation have been witnessed over the recent years, making MBR an option of choice for wastewater treatment and reuse. This mini-review reports recent developments and current research trends in the field.     

Rigorous Approach to Modeling of a Continuous Aerobic Membrane Bioreactor

A rigorous approach to mathematical modeling of a continuous aerobic membrane bioreactor (MBR) for the treatment of wastewater is reported. The idea is to apply the activated sludge model ASM3 to the special configuration of a membrane bioreactor. Therefore, the biochemical processes modeled by the ASM3 were implemented together with mass balances typical of a MBR running at constant TSS. The model parameters were adapted to the properties of an artificial wastewater by using a global search algorithm. The model could be validated by comparing effluent chemical oxygen demand (COD), sludge production and CO₂ concentration in the exhaust to the experimental data.     

Factors affecting the removal of organic micropollutants from wastewater in conventional treatment plants (CTP) and membrane bioreactors (MBR)

As a consequence of insufficient removal during treatment of wastewater released from industry and households, different classes of organic micropollutants are nowadays detected in surface and drinking water. Among these micropollutants, bioactive substances, e.g., endocrine disrupting compounds and pharmaceuticals, have been incriminated in negative effects on living organisms in aquatic biotope. Much research was done in the last years on the fate and removal of those compounds from wastewater. An important point it is to understand the role of applied treatment conditions (sludge retention time (SRT), biomass concentration, temperature, pH value, dominant class of micropollutants, etc.) for the efficiency of conventional treatment plants (CTP) and membrane bioreactors (MBR) concerning the removal of micropollutants such as pharmaceuticals, steroid- and xeno-estrogens. Nevertheless, the removal rates differ even from one compound to the other and are related to the physico-chemical characteristics of the xenobiotics.     

Upgrading of Existing Municipal Wastewater Treatment Plants with the “Non‐Conventional Low MLSS MBR Technology”

In the future, upgrading of existing wastewater treatment plants (wwtps) will be more important than the erection of entirely new plants, as most of the plants necessary in Germany already exist. Thus far, membrane bioreactor (MBR) technology is not used as an alternative for plant upgrading in Germany. However, at several locations the preconditions indicate that the application of the MBR technology for upgrading of plants may be favorable. These preconditions include the need for a substantial enlargement of the aeration tank volume and/or the need to improve the efficiency of the final sedimentation tanks, and also require that the existing tanks be in a good state, so that the tanks can be used in the future. The relevant preconditions and the basic upgrading concept using the MBR technology were presented earlier. Depending on the local preconditions regarding the existing tank volume, a specific aspect of this application can be an operation mode using “non‐conventional low MLSS (mixed liquor suspended solids) concentrations” (5 kg MLSS/m³ through 7 kg MLSS/m³) due to the amount of the existing tank volume. Two research projects were carried out covering the operation of five pilot plants on a cubic meter scale to demonstrate the feasibility of this kind of MBR process. This paper presents the core results of this research work.     

The potential for constructed wetlands for wastewater treatment and reuse in developing countries: a review

Constructed wetlands are among the recently proven efficient technologies for wastewater treatment. Compared to conventional treatment systems, constructed wetlands are low cost, are easily operated and maintained, and have a strong potential for application in developing countries, particularly by small rural communities. However, these systems have not found widespread use, due to lack of awareness, and local expertise in developing the technology on a local basis. This paper summarizes information on current methods used for wastewater treatment in developing countries, and briefly gives basic information on wetlands. The paper further examines the potential of constructed wetlands for wastewater treatment and reuse in developing countries by looking at the results of current research initiatives towards implementation of the technology in these countries. Future considerations in choosing constructed wetlands as wastewater treating systems in developing countries are highlighted.     

Microalgae and wastewater treatment

Organic and inorganic substances which were released into the environment as a result of domestic, agricultural and industrial water activities lead to organic and inorganic pollution. The normal primary and secondary treatment processes of these wastewaters have been introduced in a growing number of places, in order to eliminate the easily settled materials and to oxidize the organic material present in wastewater. The final result is a clear, apparently clean effluent which is discharged into natural water bodies. This secondary effluent is, however, loaded with inorganic nitrogen and phosphorus and causes eutrophication and more long-term problems because of refractory organics and heavy metals that are discharged. Microalgae culture offers an interesting step for wastewater treatments, because they provide a tertiary biotreatment coupled with the production of potentially valuable biomass, which can be used for several purposes. Microalgae cultures offer an elegant solution to tertiary and quandary treatments due to the ability of microalgae to use inorganic nitrogen and phosphorus for their growth. And also, for their capacity to remove heavy metals, as well as some toxic organic compounds, therefore, it does not lead to secondary pollution. In the current review we will highlight on the role of micro-algae in the treatment of wastewater.     

Comparison of different pilot scale bioreactors for the treatment of a real wastewater from the textile industry

Wastewater from textile industry usually undergoes activated sludge biotreatment ahead of refining treatments, final discharge or reuse. To identify the most effective bioreactor typology for the secondary treatment of a wastewater resulting from a textile industry of the Biella district (Italy), four pilot units characterized by a different configuration and fluid dynamics (i.e., Bioflotation^®, Fixed Bed Biofilm Reactor (FBBR), flow-jet aeration and standard aerobic sludge reactors) were operated in parallel, inoculated with the same microbial consortium and fed with identical streams of wastewater discharged from wet textile processes of the industy. COD, TC and non-ionic surfactants were monitored in effluents of the compared bioreactors working under continuous mode and the cultivable heterotrophic microorganisms prevailing in each of them were isolated and characterized as the end of the study. The results demonstrated that the air supply system greatly influenced the treatment efficiency which reached the highest value in the case of Bioflotation^® and FBBR technology. A highly specialized bacterial biomass mostly composed by strains of the Pseudomonas, Stenotrophomonas and Ochrobactrum genera was isolated in such reactors, thus suggesting that a direct correlation between reactor configuration, decontamination performances and microbial biomass composition exist.     

Strategies and Practices for Sustainable Use of Water in Industrial Papermaking Processes

The problem of water use in industrial sectors is analyzed in the context of sustainability, and the manufacturing process as one of the most important water consumers is scrutinized. Some practices of water conservation and reduction of water consumption, as well as the implementation of advanced treatment processes for wastewater recycling are considered under the general aspect of process integration and control in order to minimize environmental discharges. Reduction of effluents in papermaking processes are discussed as well as preventative approaches. It is emphasized that four groups of methods can be applied in order to minimize water consumption: process changes, water reuse, regeneration reuse and regeneration recycling. Minimizing the water consumption and thus reducing the hydraulic load may help to improve effluent treatment, reduce operating costs and, when subsequent disposal is to sewers, minimize effluent disposal charges. The data presented show that initially producing less effluents will reduce the demands on the effluent treatment plant and thus save both money and efforts. Separation techniques for minimizing effluents and effluent loads are presented, as well as potential practices to ensure a sustainable use of water, grouped as short term and long term measures. Prevention measures for water consumption in a Romanian paper mill are considered and discussed in relation with best available techniques (BAT), taking into account both economical and environmental benefits.