Performance of a Horizontal Flow Constructed Reed Bed Filter for Municipal Wastewater Treatment: The Case Study of the Prototype Installed at Gaston Berger University, Saint-Louis, Senegal

In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed only a slight temperature variation, from an influent average of 26.3°C to an effluent of 24.7°C. Electrical conductivity decreased from 1331 mS/cm to 974.5 mS/cm post-primary treatment, with suspended solids (SS) dramatically reduced from 718.9 mg/L to 5.7 mg/L in the final effluent. Biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) saw a notable decrease, from initial levels of 655.6 mg/L and 1240 mg/L to 2.3 mg/L and 71.3 mg/L, respectively. Nitrogenous compounds (N-TN) and phosphates () also decreased significantly, indicating the system’s nutrient removal capacity. Microbiological analysis revealed a reduction in fecal coliforms from 7.5 Ulog/100ml to 1.8 Ulog/100ml and a complete elimination of helminth eggs. The presence of Phragmites and Typha was instrumental in enhancing these reductions. The system’s compliance with the Senegalese standards for disposal into natural environments, WHO recommendations for unrestricted water reuse in irrigation, and the European legislation for water reuse was established. The effluent quality met the stringent criteria for various classes of agricultural reuse, illustrating the system’s potential for sustainable water management. This wetland model presents a robust solution for water-stressed regions, ensuring environmental protection while supporting agricultural needs. The study calls for ongoing research to further refine the system for optimal, reliable wastewater treatment and water resource sustainability.

Reuse rate of treated wastewater in water reuse system

A water quality model for water reuse was made by mathematics induction. The relationship among the reuse rate of treated wastewater（R）, pollutant concentration of reused water（ Cs ）, pollutant concentration of influent（ C0）, removal efficiency of pollutant in wastewater（ E）, and the standard of reuse water were discussed in this study. According to the experiment result of a toilet wastewater treatment and reuse with membrane bioreactors, R would be set at less than 40%, on which all the concerned parameters could meet with the reuse water standards. To raise R of reuse water in the toilet, an important way was to improve color removal of the wastewater.

Assessment of Wastewater Reuse in Kuwait and Its Impact on Amounts of Pollutants Discharged into the Sea

Kuwait has recently implemented a vigorous campaign that aims to reclaim and reuse all treated wastewater in an at- tempt to alleviate water scarcity problem and to preserve seawater quality. This paper assesses the present status of wastewater treatment, reclamation and reuse in Kuwait, and discusses the impact of wastewater reuse on the amounts of pollutants discharged into the sea. Through analysis of the historical records of the wastewater treatment plants, it has been found that reuse of reclaimed wastewater in Kuwait has greatly reduced the amounts of pollutants discharged into the sea. Results showed that more than 50% reduction in volumes of wastewater discharged into the sea had been achieved from year 2000 to year 2010. However, this study has predicted that the amounts of wastewater discharged into the sea will start increasing again by the year 2020 due to shortages of storage capacity for reclaimed wastewater and due to the limitation of wastewater reuse applications to basically agricultural and landscape irrigations. In contrary, the on-going works and future plans of the Ministry of Public Works (MPW) are expected to overcome this problem and lead to a zero discharge of wastewater into the sea.

A Grey Water Dam Design for the Treatment and Reuse of Grey Water from Single and Multiple Households

An innovative design for the treatment and reuse of grey water is presented in the form of a grey water dam which is an outgrowth of the vertical grey water tower. A hydraulic equation has been formulated and is presented in this paper which is used to determine the seepage path within the grey water dam, and determine the dimensions of the dam components. The hydraulic equation model also helps in avoiding soil piping problems by keeping the phreatic line within the grey water dam. Vegetables are planted around the surface of the dam as a reuse option while helping recycling of water in the form of evapotranspiration. A successful pilot trial of this dam was run in Mnyamatsini area in Swaziland which can accept grey water from multiple households.

Sustainable wastewater treatment and reuse in space

Exploring the vast extraterrestrial space is an inevitable trend with continuous human development.Water treatment and reuse are crucial in the limited and closed space that is available in spaceships or long-term use space bases that will be established in the foreseeable future.Dedicated water treatment technologies have experienced iterative development for more than 60 years since the first manned spaceflight was successfully launched.Herein,we briefly review the related wastewater characteristics and the history of water treatment in space stations,and we focus on future challenges and perspectives,aiming at providing insights for optimizing wastewater treatment technologies and closing the water cycle in future.

Renovated water reuse for rapid infiltration system

The renovated water in the rapid infiltration system (RI) as area for fish and duck farming is feasible. The flesh of fish and duck is edible. The farming of fish for 5 months and duck for 120 - 130 days can be accepted. It is beneficial to environment and economy, especially in developing countries. The production of fish and duck can make up for the cost of wastewater treatment.

Coking wastewater treatment for industrial reuse purpose: Combining biological processes with ultrafiltration, nanofiltration and reverse osmosis

A full-scale plant using anaerobic, anoxic and oxic processes （A1/A2/O）, along with a pilot-scale membrane bioreactor （MBR）, nanofiltration （NF） and reverse osmosis （RO） integrated system developed by Shanghai Baosteel Chemical Co. Ltd., was investigated to treat coking wastewater for industrial reuse over a period of one year. The removals reached 82.5% （COD）, 89.6% （BOD）, 99.8% （ammonium nitrogen）, 99.9% （phenol）, 44.6% （total cyanide （T-CN））, 99.7% （thiocyanide （SCN-）） and 8.9% （fluoride）, during the A1/A2/O biological treatment stage, and all parameters were further reduced by over 96.0%, except for fluoride （86.4%）, in the final discharge effluent from the currently operating plant. The pilot-scale MBR process reduced the turbidity to less than 0.65 NTU, and most of the toxic organic compounds were degraded or intercepted by the A1/A2/O followed MBR processes. In addition, parameters including COD, T-CN, total nitrogen, fluoride, chloride ion, hardness and conductivity were significantly reduced by the NF-RO system to a level suitable for industrial reuse, with a total water production ratio of 70.7%. However, the concentrates from the NF and RO units were highly polluted and should be disposed of properly or further treated before being discharged.

Design of Water Network with Multiple Contaminants and Zero Discharge

The paper presents a procedure to design water network. First of all, water reuse system, water regeneration reuse system (including regeneration recycle) and wastewater treatment system are designed separately. But the interaction between different parts demands that each part is designed iteratively to optimize the whole water network. Therefore, on the basis of the separated design a water netvrork superstructure including reuse, regeneration and wastewater treatment is established from the system engineering point of view. And a multi-objective adaptive simulated annealing genetic algorithm is adopted to simultaneously integrate the overall water netvrork to balance the economic and environmental effects. The algorithm overcomes the defect of local optimum of simulated annealing (SA), avoids the pre-maturation of genetic algorithm (GA) and finds a set of solutions (pareto front) in acceptable computer time. Prom the pareto front, a point with minimum fresh water consumption will be extended to zero discharge as our ultimate goal.

Environmental Efficiency in Water Use in Offshore Platforms in Campos Basin-RJ-Brazil

In drilling and production of oil at sea, potable water is most commonly transported to oil platforms using offshore supply vessels (OSV). This transport generates a series of environmental impacts, such as the emission of greenhouse gases and risks to human health. Furthermore, transporting high volumes of water requires large vessels and consequently, very high fuel consumption. To minimise the environmental impacts, water supply options were studied. The desalination of seawater and the reusing of streams from grey water (light and dark) and black water were evaluated and compared with the characteristics of the current supply via OSV. The amount of fuel consumed was collected in the logistics department of the oil company that used the OSVs. Air emissions were quantified using the methodology that the IPCC recommended. The information on the types of sewage treatment was found in the technical manuals from the manufacturers. It was concluded that the reused water could achieve up to 70% reduction in atmospheric emissions, the use of chemicals in the water treatment plant, sludge generation and the consumption of marine diesel fuel for the transport of water. On the other hand, the same reduction can be observed both from the effluent disposal at sea and in the chlorine of the sewage treatment plant. Therefore, the source of water used and the reduction of air emissions can be maintained without impairment of the normal water use in offshore platforms in the Campos Basin. The objective of this study was to diagnose problems related to the current form of water supply, to quantify them and to propose measures for increasing environmental efficiency.

Assessment of the Viability of the Reuse of Sedibeng District Municipal Secondary Effluent in Southern Gauteng, South Africa

Population growth, urbanization, water resources pollution, environmental awareness, uneven distribution of water resources and water scarcity have necessitated water reuse especially in arid and semi-arid countries. Influent and effluent data of chemical and biological analyses from four wastewater treatment plants (WWTPs) in the Sedibeng district municipality (SDM) were used to assess the viability of water reuse. Available worldwide water reuse criteria of Water Reclamation Plants (WRPs) for different reuse options were used to characterize the SDM’s four WWTPs for potable water, power and steel industrial water reuse. Only WWTP4 does not meet the influent design criteria of the New Goreangab WRP in Windhoek, Namibia of 43 mg/l and the DWAF general limit of discharge of 75 mg/l used by Beaufort West WRP in South Africa for COD. WWTP2 and 4 do not meet the DWAF general limit of 25 mg/l for suspended solids. Some of the water quality parameters of the effluents from these plants were non-compliant to the requirements for reuse in power generation and steel manufacturing. However, the implementation of advance treatment technologies such as membrane or advanced oxidation processes (AOPs) as part of the treatment train in a potential WRP would address the water quality issues. Water reclamation of SDM effluent either through direct (DPR) or indirect potable (IPR) water reuse, power generation and steel manufacturing industry has the potential of reuse in the Southern Gauteng region. The success of the selected option would be depended on cost effectiveness, stakeholder commitment and public acceptance of the reuse strategy.

Performance of an Ultrafiltration Membrane Pilot System for Treatment of Waste Stabilization Lagoon Effluent

Bali Tourism Development Corporation＇s lagoon （BTDC lagoon） has been used for treating wastewaters that come from all facilities available in the Nusa Dua Resort tourist area. Reuse of the lagoon effluent is limited for some applications due to salt and suspended solid contents. Application of an integrated membrane system for improving the water quality of the lagoon effluent which is suitable for various uses is under consideration. In this work an ultraflltration （UF） pilot performance for possible pretreatment of Reverse Osmosis （RO） was investigated. The results showed that permeate quality was stable （less than 0.5 NTU）, regardless of concentrating and diluting retentate in each cycle and fouling for a long duration of operation. However, the water quality obtained with this membrane was not enough to be directly used. The permeate quality obtained from the UF system fulfils the requirement for the optimal operation of reverse osmosis. Moreover, appropriate intermittent-backwash operation was fairly effective to maintain the fluxes at a reasonable level.

鞍钢鲅鱼圈焦化废水减量及回用改造实践

介绍了鞍钢鲅鱼圈焦化废水处理工艺运行概况,分析了焦化废水工艺存在的问题,通过提升预处理单元、生化处理系统和深度处理系统的功能,新增膜脱盐处理系统,大大提升了焦化废水系统出水水质,中水回用率达到70%以上。最终膜脱盐处理系统的浓水水质指标达到了《炼焦化学工业污染物排放标准》(GB 16171—2012)中的间排标准,全部回用于烧结混料,净水全部回用于循环水系统,实现了焦化废水零排放的目标。

废水处理中纳滤膜化学清洗技术研究现状、挑战与展望

纳滤技术由于其操作压力较低、对二价离子截留率高等优势,在市政污水、纺织废水、制药废水等废水处理领域有广阔的应用前景。然而膜污染问题的存在限制了纳滤技术的发展,膜污染不仅会导致膜通量衰减、分离性能下降,还会大大缩短膜的使用寿命。化学清洗可有效缓解膜污染,但常用的清洗剂均会对膜结构和分离性能产生影响,还可能引发生物耐药性及膜清洗废水二次污染等问题。本文对不同类型废水处理中纳滤膜的污染特征及化学清洗方法进行综述,并且重点阐释了酸、碱、次氯酸钠等化学清洗剂与聚酰胺纳滤膜的作用机制,以及频繁的化学清洗对膜面微生物的影响和所引发的生物风险,最后对有关问题的解决措施提出展望,以期为膜污染控制方法的优化提供参考。

灰水处理与资源化技术应用综合分析

灰水在生活污水中占有较大比重,且污染负荷和致病因子含量较低,因此,对灰水进行处理并实现资源化回用对于实现水资源持续供给,保障水资源安全具有重要意义。文章基于灰水的水质和水量特点,介绍了目前主流的灰水处理技术,对其作用原理、技术特点、应用条件进行了系统论述,并且综合对比了不同处理技术的优劣势。其中,生态处理法建设成本低,运维简单,具有一定的抗水质水量冲击能力,具有较好的推广应用价值。在此基础上,进一步总结了国内外再生水回用标准,分析灰水资源化回用的经济和生态效益,明确了处理灰水资源回用的可行性。最后,针对目前面临的问题和挑战,提出了未来的发展方向,即开发多种技术耦合、低成本的集成规模化灰水处理回用系统。

污水回用技术在城市节水与环境保护中的应用

随着社会的发展,工业、农业生产以及生活用水量不断增加,可用淡水资源日渐紧缺。在此背景下,社会愈发关注城市污水的处理与回用工作。应用污水回用技术,对于城市节水与环境保护具有重要意义。基于此,分析污水处理以及污水回用技术,阐述其在城市节水与环保中的应用,以期为相关工作提供参考。

某焚烧厂水处理工艺设计研究

某焚烧厂水处理主要分为纯水处理和污水处理。针对纯水处理设计采用“活性炭过滤器+超滤+反渗透+EDI”工艺,纯水处理后作为生产用水进行回用。处理的污水主要包括无机废水和有机废水,污水成分复杂、含有大量重金属,设计无机废水通过“一体化沉淀装置(pH调节池+混凝池+絮凝池+沉淀池)”处理去除废水中重金属后,进入生化进水均质池;有机废水直接进入生化进水均质池,废水通过均质均量后采用“生物接触氧化池+二沉池+中间水池+多介质过滤器+滤后水池+回用水池”工艺。综上,对于该行业水处理,使用组合工艺处理效果好、投资和运行成本较低,既达到厂内节水用水要求,又实现了废水处理的资源化利用。

化工企业生产废水处理与中水回用方案分析

为进一步探究化工企业生产废水处理与中水回用的有效方案,本次研究以某化工企业的印染废水处理为例,搭建综合应用混凝气浮、酸化水解、缺氧、接触氧化和沉淀等五个方面的技术模式进行较为全面的工艺设计,并在此基础上进一步引入人工湿地和消毒等环节,进行中水回用方案的设计。从实际应用效果来看,本次工艺在经济效益和环境效益方面均取得了一定的成绩,表明其具有一定的实际应用价值。

煤矿废水处理技术提升工艺应用研究

以某矿矿井水处理站为例,对其原有污水处理站出水进行水质检测、水样数据分析,确定超标污染物含量。根据超标污染物的特性及现有工艺进行实验,选择研究合适的污水处理工艺改造方案,确保出水满足相关标准要求。同时,针对该矿的废水排放量、污水处理厂处理能力以及回用水量之间进行平衡分析,确保排放的污水经处理后全部用于该矿生产、生活用水。

电镀废水中水回用系统处理工艺与处理效果探析

电镀废水处理工艺主要是通过电化学方法,对金属和非金属表面进行有效装饰,从而保证回水系统工作效能与质量提升的有效性。由于电镀废水的危害性较大,因此加强对电镀废水中水回用系统处理工艺的重视非常必要。在此大环境背景下,本文从电镀废水中水回用系统处理工艺的设计依据、电镀废水中水回用系统的主要处理工艺、电镀废水中水回用系统处理效果研究三个层面展开更为深入地研究与分析,以更好地保障周边环境的安全与健康。

石油化工企业含油污水处理和回用水处理工艺设计研究

在石油生产过程中,不可避免地会产生含油污水,若未经妥善处理直接排放,对生态环境造成严重影响。对此,需企业采用多种方法进行科学处理,包括物理、化学和生物等,提高处理效率,降低处理成本,确保处理后的水质达到排放标准。同时,加大对回用水处理工艺的研究力度,实现水资源的循环利用,减少对新水资源的依赖,提升石油化工企业的环保水平。