Development and application of some renovated technologies for municipal wastewater treatment in China

China has been experiencing fast economic development in recent decades at the cost of serious environmental deterioration. Wastewater discharge, especially municipal wastewater discharge, and non-point pollution sources are becoming the major water pollution source and research focus. Great efforts have been made on water pollution control and a number of renovated technologies and processes for municipal wastewater treatment and reclamation as well as non-point pollution control have been developed and applied in China. This paper discusses the development and application of the appropriate technologies, including natural treatment systems, anaerobic biological treatment, biofilm reactors and wastewater reclamation technologies, for water pollution control in the country.     

基于umu遗传毒性效应的饮用水致癌风险评价的尝试

化学物质暴露是导致癌症发生的重要诱因,通过饮用水暴露导致的人类致癌风险在饮用水处理技术中日益引起重视.由于水中化学物质种类繁多、组成复杂,准确地检测每个致癌物质的浓度和毒性非常困难.为了控制饮用水的安全,根据DNA损伤诱导SOS反应而表达umuC基因这一基本原理建立的SOS/umu测试法,已经广泛应用于饮用水遗传毒性的检测.论文建立了基于umu遗传毒性效应的饮用水致癌风险评价方法,并对北方某水厂饮用水的遗传毒性进行了umu测试,计算了该地区饮用水的致癌风险,提出了可能的饮用水遗传毒性基准值.结果表明,该水厂常规工艺出水的致癌风险均值为1.55×10-6,存在一定的安全隐患;而深度处理工艺能有效地削减出水致癌风险均值至5.3×10-7,达到目前先进国家水质管理的要求,保障了饮用水的安全.样品中4-硝基喹啉-1-氧化物(4-NQO)的等当量浓度(TEQ4-NQO)0.0948μg·L-1可作为饮用水遗传毒性基准值。     

What have we known so far about microplastics in drinking water treatment? A timely review

• 23 available research articles on MPs in drinking water treatment are reviewed. • The effects of treatment conditions and MP properties on MP removal are discussed. • DWTPs with more steps generally are more effective in removing MPs. • Smaller MPs (e.g.,<10 μm) are more challenging in drinking water treatment. Microplastics (MPs) have been widely detected in drinking water sources and tap water, raising the concern of the effectiveness of drinking water treatment plants (DWTPs) in protecting the public from exposure to MPs through drinking water. We collected and analyzed the available research articles up to August 2021 on MPs in drinking water treatment (DWT), including laboratory- and full-scale studies. This article summarizes the major MP compositions (materials, sizes, shapes, and concentrations) in drinking water sources, and critically reviews the removal efficiency and impacts of MPs in various drinking water treatment processes. The discussed drinking water treatment processes include coagulation-flocculation (CF), membrane filtration, sand filtration, and granular activated carbon (GAC) filtration. Current DWT processes that are purposed for particle removal are generally effective in reducing MPs in water. Various influential factors to MP removal are discussed, such as coagulant type and dose, MP material, shape and size, and water quality. It is anticipated that better MP removal can be achieved by optimizing the treatment conditions. Moreover, the article framed the major challenges and future research directions on MPs and nanoplastics (NPs) in DWT.     

Hexavalent chromium in drinking water: Chemistry,challenges and future outlook on Sn(II)- and photocatalyst-based treatment

• Wide occurrence of Cr(VI) in US source drinking water. • A strong dependence of occurrence on groundwater sources. • Elucidate Redox and equilibrium chemistry of Cr(VI). • Sn(II)-based and TiO₂-based reductive treatments hold extreme promise. • Key challenges include residual waste, Cr(VI) re-generation and socioeconomic drivers. Chromium (Cr) typically exists in either trivalent and hexavalent oxidation states in drinking water, i.e., Cr(III) and Cr(VI), with Cr(VI) of particular concern in recent years due to its high toxicity and new regulatory standards. This Account presented a critical analysis of the sources and occurrence of Cr(VI) in drinking water in the United States, analyzed the equilibrium chemistry of Cr(VI) species, summarized important redox reaction relevant to the fate of Cr(VI) in drinking water, and critically reviewed emerging Cr(VI) treatment technologies. There is a wide occurrence of Cr(VI) in US source drinking water, with a strong dependence on groundwater sources, mainly due to naturally weathering of chromium-containing aquifers. Challenges regarding traditional Cr(VI) treatment include chemical cost, generation of secondary waste and inadvertent re-generation of Cr(VI) after treatment. To overcome these challenges, reductive Cr(VI) treatment technologies based on the application of stannous tin or electron-releasing titanium dioxide photocatalyst hold extreme promise in the future. To moving forward in the right direction, three key questions need further exploration for the technology implementation, including effective management of residual waste, minimizing the risks of Cr(VI) re-occurrence downstream of drinking water treatment plant, and promote the socioeconomic drivers for Cr(VI) control in the future.     

Review of water pollution control in China

Water resource shortage and pollution has seriously threatened the survival and development of developing countries. Because of China’s specific economical and social circumstances, complete adoption of developed countries’ experience is unrealistic. At present, China needs to develop strategies and technologies in source water pollution control and municipal environmental remediation that embrace the country’s specific need to battle the water resource problem. Among them, efficient source water pretreatment is a critical step to ensure a safe municipal water supply. Unlike developed countries, it is not yet feasible in China to treat water supplied to the household and have it meet the standard of direct drinking; therefore, it is more appropriate to refer to it as service water. As a beneficial supplement, an additional community drinking water network and household drinking water apparatus can be considered.     

Ecological compensation based on willingness to accept for conservation of drinking water sources

Ecological compensation is a powerful environmental economic tool for environmental protection in areas where drinking water sources are located. We established an ecological compensation accounting system based on respondents’ willingness to accept (WTA). In this system, stakeholder preferences and the factors that influence them can be gauged effectively using logit and tobit models. We applied this accounting system to ecological compensation for the Miyun Reservoir, Beijing, China. The average WTA value for Miyun Reservoir residents was approximately 1186 CNY per family in 2012, which could be set as a suitable compensation standard, since it is slightly higher than the local protection cost. Thus, the annual total ecological compensation could be 58.73 million CNY. Distance from the reservoir, job types, and attitude to environmental protection were variables with significant effects on WTA. In addition, trends for individual preferences were identified via an analysis of key influential factors. The results suggest some useful information for establishing ecological compensation mechanisms for conservation of drinking water sources. Suggestions include popularizing the concept and meaning of ecological compensation among residents, setting different compensation levels based on distance from the reservoir, considering the requirements of farmers, and taking various in-kind and out-of-kind compensation approaches.     

水体突发污染事件在线生物监测技术的发展和应用分析

自1800s以来,经过2个世纪的发展,针对水体突发污染事件的在线生物监测技术越来越完善,其所采用的分析指标主要包括生物行为变化(1900s至目前)、生物新陈代谢变化(1800s至目前)和生物电变化(1980s至目前)等3种,其中,应用最广泛、发展最完善的为基于生物行为指标的在线生物监测技术。进入21世纪以来,在线生物监测技术得到快速发展和普遍应用。中国、美国、德国、韩国和瑞典等国家已经大规模应用基于不同生物指标的在线生物监测技术,以实现对水体突发污染事件的有效监管。随着计算和分析技术的进一步发展,在线生物监测技术也会越来越完善,在维持社会稳定、保证经济可持续发展以及保障人民饮水安全方面将会发挥越来越重要的作用。     

Gentoxische Substanzen in Wässern

Waste waters with genotoxic potential are produced in various technical processes. Diffuse sources such as traffic and agriculture as well as point sources as mining, power plants, waste and waste water treatment facilities may emit water which shows mutagenic activity in bacteria test systems. A variety of compounds is known as mutagenes but in case studies it was not possible to assign the mutagenic potential of water to specific compounds. The chlorination and ozonation of drinking water may also generate genotoxic and cancerogenic compounds but at present it is not possible to assess the health risk of various drinking water disinfection methods.     

Municipal wastewater treatment in China: Development history and future perspectives

The history of China’s municipal wastewater management is revisited. The remaining challenges in wastewater sector in China are identified. New concept municipal wastewater treatment plants are highlighted. An integrated plant of energy, water and fertilizer recovery is envisaged. China has the world’s largest and still growing wastewater sector and water market, thus its future development will have profound influence on the world. The high-speed development of China’s wastewater sector over the past 40 years has forged its global leading treatment capacity and innovation ability. However, many problems were left behind, including underdeveloped sewers and sludge disposal facilities, low sustainability of the treatment processes, questionable wastewater treatment plant (WWTP) effluent discharge standards, and lacking global thinking on harmonious development between wastewater management, human society and the nature. Addressing these challenges calls for fundamental changes in target design, policy and technologies. In this mini-review, we revisit the development history of China’s municipal wastewater management and identify the remaining challenges. Also, we highlight the future needs of sustainable development and exploring China’s own wastewater management path, and outlook the future from several aspects including targets of wastewater management, policies and technologies, especially the new concept WWTP. Furthermore, we envisage the establishment of new-generation WWTPs with the vision of turning WWTP from a site of pollutant removal into a plant of energy, water and fertilizer recovery and an integrated part urban ecology in China.     

北方某市城区水环境中轮状病毒的初步检测

轮状病毒(Rotavirus,RV)是引起全世界婴幼儿肠胃炎的最主要病原体.在我国,儿童秋季腹泻发病达到高峰,也主要由轮状病毒引起.论文改进了RT-nested-PCR检测水中轮状病毒的方法,于2006年10月对北方某市城区水环境(包括污水、地表水和饮用水)中的轮状病毒进行了初步检测.结果表明,该市某污水厂进水和不同工艺段出水、主要公园的景观水体、主要自来水厂进水和出水以及城区管网水,均检出轮状病毒.综合分析从水源到管网的过程,认为管网水中的轮状病毒可能与水源水污染有关.管网水中有轮状病毒检出,说明秋季该市饮用水中存在潜在的轮状病毒传染源.同期对管网水进行的细菌学指标检测,没有发现总大肠菌群、耐热大肠菌群、粪链球菌,可见目前城市供水水质标准中的细菌学指标并不能准确反映病毒污染状况.     

Improved source,improved quality? Demand for drinking water quality in rural India

This paper tests the hypothesis that the expansion of improved drinking water supplies in rural India reduced household expenditure on water quality, offsetting some of the quality benefits from source protection. I estimate demand for in-home treatment using geological characteristics to predict a household's drinking water source. The probability of treatment and in particular boiling reduces by 18–27 percentage points in response to source protection, offsetting 4% of the water quality gains and saving households 0.5–1% in monthly expenditure. Behavioral choices partly counteract the water quality gains from source protection.     

Redox processes in water remediation

Groundwater is the main source of drinking water and water for agricultural and industrial usage. Therefore, groundwater contamination is prevented and contaminated groundwater is remediated to protect public health and the environment. Methods to remediate groundwater contamination have been recently developed. The use of redox processes in water remediation technologies has not been properly reviewed. Numerous water remediation technologies, such as ultrasonication, bioremediation, electrokinetics and nanotechnology, are closely related to redox processes. Redox processes control the chemical speciation, bioavailability, toxicity, mobility and adsorption of water pollutants in environment. Here, we review (1) general introduction of redox processes, (2) applicability of redox processes in water remediation, and (3) catalytic enhancement of redox potentials to explore its wide applicability in environmental remediation.     

中国南方地区12个城市水源水的水质特征

对中国南方地区具有代表性的武汉、长沙、成都等12个城市饮用水水源的水质状况进行了调查、监测与分析，结果显示，南方地区的水源普遍存在着低浊、高藻、微污染的特征．据统计，78．6％的水源浊度平均值处于50NTU以下，63．6％的水源藻类污染严重，57．1％的水源微污染状况正逐渐加剧。     

Presence of metals in drinking water distribution networks due to pipe material leaching: a review

Drinking water quality should remain constant from the drinking water treatment plant to the consumer's tap. However, water quality characteristics might be affected by interactions with pipe materials. This review describes the iron, copper, lead, zinc, aluminum, chromium, and cadmium in drinking water leached from the pipe material present in drinking water, as well as the factors and mechanisms that affect leaching processes. Data analysis suggests that monitoring the water quality in distribution systems is important for their proper management; however, the low measured concentrations highlight the need for sensitive sensors. In addition, further research is necessary to anticipate possible future effects before the installation of new materials/infrastructure or changes in water source/treatment.     

Improved source,improved quality? Demand for drinking water quality in rural India

This paper tests the hypothesis that the expansion of improved drinking water supplies in rural India reduced household expenditure on water quality, offsetting some of the quality benefits from source protection. I estimate demand for in-home treatment using geological characteristics to predict a household's drinking water source. The probability of treatment and in particular boiling reduces by 18–27 percentage points in response to source protection, offsetting 4% of the water quality gains and saving households 0.5–1% in monthly expenditure. Behavioral choices partly counteract the water quality gains from source protection.     

Provision of safe domestic water for the promotion and protection of public health: a case study of the city of Beirut,Lebanon

Securing adequate safe drinking water and proper sanitation is a major challenge facing the developing world. The “Water for Life Decade” emphasizes the importance of upgrading national water quality and sanitation services. This study assessed the domestic water profile in the city of Beirut. Samples were collected from three types of household water sources (municipality, private wells, and vended water bottles) and assessed for their physiochemical and microbiological profile. At the same time, a cross-sectional survey assessing water consumption patterns and the prevalence of water-borne diseases was conducted. The results showed a deficient water quality profile in all three water sources. The measured physiochemical and bacteriological parameters reflected the high frequency of water-borne diseases. Action to secure a safe domestic water supply is essential. The plan should guarantee the protection of water sources, ensure sufficient treatment of domestic water and upgrade the national program for potable water quality control. Periodic quality monitoring and legislating the chaotic water-vending sector are indispensable. Additionally, the deterioration of private well sources by sea and wastewater infiltration necessitates the enforcement of legislation associated with the use and management of private wells. Consumer awareness and active contributions to promote and protect public health are important.     

Hybrid energy harvesting systems for self-powered sustainable water purification by harnessing ambient energy

● Energy harvesters harness multiple energies for self-powered water purification. ● Hybrid energy harvesters enable continuous output under fluctuating conditions. ● Mechanical, thermal, and solar energies enable synergic harvesting. ● Perspectives of hybrid energy harvester-driven water treatment are proposed. The development of self-powered water purification technologies for decentralized applications is crucial for ensuring the provision of drinking water in resource-limited regions. The elimination of the dependence on external energy inputs and the attainment of self-powered status significantly expands the applicability of the treatment system in real-world scenarios. Hybrid energy harvesters, which convert multiple ambient energies simultaneously, show the potential to drive self-powered water purification facilities under fluctuating actual conditions. Here, we propose recent advancements in hybrid energy systems that simultaneously harvest various ambient energies (e.g., photo irradiation, flow kinetic, thermal, and vibration) to drive water purification processes. The mechanisms of various energy harvesters and point-of-use water purification treatments are first outlined. Then we summarize the hybrid energy harvesters that can drive water purification treatment. These hybrid energy harvesters are based on the mechanisms of mechanical and photovoltaic, mechanical and thermal, and thermal and photovoltaic effects. This review provides a comprehensive understanding of the potential for advancing beyond the current state-of-the-art of hybrid energy harvester-driven water treatment processes. Future endeavors should focus on improving catalyst efficiency and developing sustainable hybrid energy harvesters to drive self-powered treatments under unstable conditions (e.g., fluctuating temperatures and humidity).     

我国水污染及饮用水源中有机污染物的危害

本文阐述了我国水污染环境的状况和危害，以及微污染饮用水源的水质特征和饮用水源中的有机污染物及其危害。     

天津引滦入津水源保护与生态恢复技术

介绍了引滦入津水系的生态特征、水质问题及发展趋势,在此基础上对引滦入津水源保护的应采取的战略方针及生态恢复技术进行了讨论。提出了从汇水区域生态管理入手,控制水体富营养化,建立流域管理与区域管理相结合的新管理模式,水源保护管理工程实行企业化经营管理方式等建议;以及面源污染防治技术、湿地处理系统的设计与建设等研究内容。     

广州市饮用水中挥发性有机物的研究

饮用水中的挥发性有机化合物（VOCs）来源于水源水受到的环境污染或是在净化消毒工艺处理工程中反应产生的副产物,可对人体健康造成极大的危害。改革开放以来,广州人口和经济得到突飞猛进的发展,也带来了包括饮用水安全在内的诸多严重的社会和环境问题。虽然饮用水中VOCs的研究已经得到越来越多的重视,但是目前对广州市饮用水中挥发性有机物的研究还鲜有报道。本文在广州市中心城区选取15个不同位置的采样点进行了自来水水样采集,并利用吹扫-捕集-气相色谱-质谱（GC-MS）联用系统分析技术测定水中 VOCs 的种类和三卤甲烷的质量浓度。结果表明,广州市中心城区的自来水中VOCs有20种,以三卤甲烷（THMs）和芳香烃类为主,占了所检出的物质总量的78%以上。THMs中四种化合物（氯仿、一溴二氯甲烷、二溴一氯甲烷、溴仿）的检出率达100%,总三卤甲烷的平均质量浓度为46.46μg· L-1,最大值为53.31μg· L-1,最小值39.91μg· L-1。根据2006版国家饮用水标准,四种三卤甲烷质量浓度均低于标准限值,符合标准要求。对市面上一般的瓶装水的研究发现,瓶装水中三卤甲烷的质量浓度非常低,总三卤甲烷平均质量浓度仅为1.47μg·L-1,约是自来水中质量浓度的1/30。为了解温度及煮沸对自来水中 THMs 质量浓度的影响,本研究设计了实验进行探究。结果发现加热至沸腾过程中,THMs质量浓度随温度升高而升高,而沸腾后THMs骤降,煮沸5 min可降低水中约95%的THMs,接近瓶装水中THMs质量浓度。