Integrated water resources management for emergency situations: A case study of Macau

Integrated urban water management (IUWM) is a useful tool that can be used to alleviate water resource shortages in developing regions like Macau, where 98% of the raw water comes from mainland China. In Macau, scarce water resources deteriorate rapidly in emergency situations, such as accidental chemical spills upstream of the supply reservoir or salty tides. During these times, only the water from the two freshwater reservoirs in Macau can be used. In this study, we developed urban water management optimization models that integrated the raw water supply from the two reservoirs with various proposed governmental policies (wastewater reuse, rainwater collection, and water saving). We then determined how various water resource strategies would influence the urban water supply in Macau in emergency situations. Our results showed that, without imported raw water, the water supply from only the two Macau reservoirs would last for 7.95 days. However, when all the government policies were included in the model, the supply could be extended to 13.79 days. Out of the three non-conventional water resources, wastewater reuse is the most beneficial for increasing the Macau water supply, and rainwater collection also has great potential.     

Wastewater reclamation and reuse in China: Opportunities and challenges

The growing water stress both in terms of water scarcity and quality deterioration promotes the development of reclaimed water as a new water resource use. This paper reviewed wastewater reuse practices in China, and the opportunities and challenges of expanding reclaimed water use were analyzed. Rapid urbanization with the increasing of water demand and wastewater discharge provides an opportunity for wastewater reuse. The vast amount of wastewater discharge and low reclaimed water production mean that wastewater reuse still has a great potential in China. Many environmental and economic benefits and successful reclamation technologies also provide opportunities for wastewater reuse. In addition, the overall strategy in China is also encouraging for wastewater reuse. In the beginning stage of wastewater reclamation and reuse, there are many significant challenges to expand wastewater reuse in China including slow pace in adopting urban wastewater reuse programs, the establishment of integrated water resources management framework and guidelines for wastewater reuse programs, incoherent water quality requirements, the limited commercial development of reclaimed water and the strengthening of public awareness and cooperation among stakeholders.     

城镇污水处理厂进水中地下水、河水及雨水混入比例研究

进水污染物浓度低及比例失调是目前许多城镇污水处理厂面临的问题,然而鲜有关于渗漏来源及定量分析的相关文献报道。为定量分析河水、地下水、雨水、管道中污染物降解等因素对污水浓度降低的影响,通过水量平衡三角法,并结合典型位点的24 h采样测试分析及S-P降解模型,对目标城镇污水处理厂进水组成进行分析。历史水量数据结合降雨情况分析表明,该污水处理厂进水中实际原生污水量仅为60.0%左右,其余40.0%左右为地下水及河水渗入量或雨水混入量。在连续晴天无降雨的情况下,小区自建管网和市政排水管网是主要的渗漏源,其对于进水有机物浓度降低的贡献分别为20.2%和26.4%。此外,在25 mm降雨量情况下,小区自建管网是主要的渗漏源,对于进水浓度降低的贡献达到39.5%。因此在污水处理提质增效工作中,小区自建管网的完善程度应引起关注。     

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.     

基于污染物受纳量的城镇生活污水处理率指标研究

我国通过污水处理率来评价生活污水处理水平,但污水处理率仅考虑了污水处理设施进水处理的水量,忽略了雨污合流、地下水混入、抽取河水处理等原因导致的污染物收集水平不足.以成都市岷江外江流域为研究区域,开展了城镇生活污水收集和评价指标优化研究,提出了基于污染物受纳量的城镇生活污水污染物处理率概念和核算方法体系,在划分控制单元基础上,核算生活污水污染物的产生量和处理量.研究发现,该流域污水处理厂进水浓度普遍偏低,进水水质存在季节性波动,说明可能存在丰水期雨水、河水或地下水混入稀释的情况,枯水期的进水数据更能反映区域生活污水排放情况;传统污水处理率计算显示该流域污水处理率高于100%,但全流域的COD_Cr、氨氮和总磷污染物处理率分别为37.50%、36.25%和30.14%,与该流域的水环境质量特征和污水管网建设水平相符;在污水管网未完善的地区,采用污染物处理率更能有效评价和反映区域污水收集和处理程度.     

污水回用中的循环浓缩水质模型与污水回用率

污水回用中因循环浓缩,存在着水质变差问题．探索其变化规律,定量确定运行参数,做到既节水又保证回用水质合格、稳定,具有重要理论和实用意义．通过数学归纳法推导出一个循环浓缩水质数学模型和计算杂用水质和污水回用率的公式．应用该模型,以厕所污水回用为例,就污水水质、污染物去除率、处理水质和杂用水质标准对杂用水质、污水回用率的影响进行讨论．结果表明,在符合城市杂用水水质标准的前提条件下,分别按生化需氧量、浊度、氨氮及色度等水质指标计算得出的污水回用率是65．3％,82．9％,57．5％和37％．在厕所污水回用中,色度为水回用率的限制指标．由于色度指标的限制,经计算水循环厕所的污水回用率一般不宜超过40％。     

中国工业废水污染状况及影响因素分析

文章基于我国“九五”和“十五”期间全国工业废水及主要污染物排放量,探讨了工业废水排放变化规律,对工业行业结构、工业经济规模增长速度、工业水重复利用率以及环境治理投资的年度变化趋势进行对比,并进一步利用最小二乘回归模型进行了多元线性回归,分析了这些因素对工业废水排放量影响的相关关系,结果表明改进工艺技术、提高水重复利用率至关重要,就如何减轻工业废水的污染提出了建议。     

污水回用系统水质模型探讨

在分别对部分污水回用系统和全部污水回用系统进行稳定状态条件下的理论分析基础上,建立了相应水质数学模型,据此推论出当污水处理设施去除率E一定时处理水质与循环次数的数学关系,证明了在回用状态下E与其他各项参数的相互关系,进而求得了无限循环处理时的处理水质表达式,并对水质模型各相关参数特性进行了分析讨论.     

城镇污水处理厂低浓度进水原因分析及提升措施

城镇污水处理厂进水浓度偏低是污水治理提质增效的难题之一。以无锡市某污水处理厂为例,基于水质分析和调研资料,采用水量平衡三角法分析了进水浓度偏低的原因分析,提出了整治措施。分析结果表明:该厂进水中地下水或河水渗入量和雨水混入量比例分别为28.9%和9.8%;晴天时进水浓度偏低的原因为污水管网渗漏和低浓度工业废水纳管,雨天时进水浓度偏低的主要原因是小区管网雨水混入,COD和BOD₅降幅分别可达到65.4%和52.9%。针对上述问题,提出了完善排水管理体制、工业企业排水实行三管分设整改、细化管网渗漏的检测排查和有效修复、加强管网验收和质量监管、尽量降低管网水位4项整治措施。     

An overview of reclaimed water reuse in China

China is facing severe water problems including scarcity and pollution which are now becoming key factors restricting developments. Creating an alternative water resource and reducing effluent discharges, water reuse has been recognized as an integral part of water and wastewater management scheme in China. The government has launched nationwide efforts to optimize the benefits of utilizing reclaimed water. This article reviewed the water reuse activities in China, including: (1) application history and current status; (2) potentials of reclaimed water reuse; (3) laws, policies and regulations governing reclaimed water reuse; (4) risks associated with reclaimed water reuse; (5) issues in reclaimed water reuse. Reclaimed water in Beijing and Tianjin were given as examples. Suggestions for improving the efficiencies of reusing urban wastewater were advanced. Being the largest user of reclaimed wastewater in the world, China's experience can benefit the development of water reuse in other regions.     

基于产品水足迹核算的印染企业生产节水潜力分析:案例研究

针对目前我国工业企业节水潜力分析准确程度不足的现状,以纺织印染企业为对象,根据水足迹评价方法建立了印染企业产品水足迹精确测算方法,从产品层面说明回用水和雨水收集对于水足迹的削减作用.结果表明,应用水回用及雨水收集利用后,单位产品新鲜水用量降低了11.3%,单位产品总工业用水量降低了10.4%.本研究将水平衡分析、水足迹评价与印染企业自身特点相结合,为企业内产品生产层面的节水分析提供了依据,并为企业的精细化节水路线设计提供了支持.     

Towards sustainability in urban water: a life cycle analysis of the urban water system of Alexandria City,Egypt

Urban water authorities and water planers in many countries are struggling to satisfy the growing urban water and sanitation demands, while at the same time achieving sustainability of the urban water system. This research focused on the assessment of the environmental impact of today's Alexandria's urban water system and on the identification of options to improve the sustainability of the system. Therefore, a life cycle assessment (LCA) methodology was used. The urban water system was modelled using SimaPro software, and the impacts of various options on the system were analyzed based on the Eco-indicator 99 assessment method. The results show that the highest impact in today's system is generated by the disposal of primary treated wastewater (68% of the total impact) and by high-energy-consuming water treatment plants (18% of the total impact). The research assessed different scenarios for improving the environmental performance of the system and a paradigm shift (decentralization and separation at-source of different kinds of household wastewater) was found to be the preferred long-term scenario.     

基于IKONOS影像的城市住宅区中水回用空间分布估算

中水回用是解决城市水资源短缺和水环境污染问题的有效途径。开展分散式中水可行性研究,需要考虑中水原水与回用需求的数量、空间分布及平衡关系。论文以南京市住宅区为例,探索了基于IKONOS高分辨率遥感影像分类,估算中水回用空间分布的方法。通过引入单位面积用水定额,将遥感和GIS 分析得到的用地信息与中水原水产量和回用需求关联起来,计算了研究区域中27 个地块的中水原水产量和回用需求量,并分析了两者在空间上的水量平衡关系。结果表明,研究区域存在较大的中水原水供给潜力3.52 L/（m²·d）和较大的利用需求5.37 L/（m²·d）。住宅小区的单位面积原水产量与其建筑容积率成正比;以中高层住宅区为主的地区,中水原水产量能够基本满足本地区的中水回用需求。因此,在这些地区建立分散式污水处理系统,可减少废污水排放,节约自来水取用量,提高水资源利用率。     

Are megacities viable? A cautionary tale from Mexico City

This article describes the poor environmental and living conditions in Mexico City due to its huge size. Mexico City's size is a challenge to sustainability, and the outcome is unknown. Mexico City and the geographic basin surrounding it included about 18.5 million population in 1995. The basin and surrounding volcanic ranges include nine major environmental zones. Urban growth followed four stages. Different cultures applied different solutions to water supply problems. The basin shifted from self-sufficiency to reliance on 31% of supplies from external watersheds. The water table is declining and canals are polluted. Irrigated agriculture is disappearing. There is an average water deficit of over 800 million cubic meters per year. Mexico City is actually sinking due to groundwater exploitation. There is bacterial contamination of wells due to improper seals. About 75% of the population has access to wastewater treatment and sanitation, but sewage treatment plants operate at under 50% efficiency and treat only about 7% of the total wastewater. Atmospheric pollution from suspended particles has been a problem for decades. Ozone was the most significant air contaminant in 1994. Lead was the most harmful pollutant in 1986. Air pollutants may be the source of submucosal inflammations. Industrial areas are contaminated with suspended particles and sulfur dioxide. High traffic areas have high carbon monoxide levels. Atmospheric pollution has affected the quality of the rainwater. The city survives by importing food, energy, wood, water, building materials, and other products. The development model aims to improve quality of life. The city has been the center of political power since Aztec times, and its preeminent position forces government action. The author concludes that there are limits to urbanization, which the city is approaching rapidly.     

城市雨水系统中低影响开发与绿色水基础设施及其实例

城市化进程的急剧加快使得中国城市饱受暴雨侵袭的困扰。传统的排水机制是雨水排得越快越好,这就需要加大排水管径、增加排水泵站等,因此更多的的成本和更大的地下空间不可避免。另一方面,雨水完全可以成为资源,而不是污染源。基于以上事实,低影响开发(LID)技术被提出并正在成为城市雨水系统发展的趋势。LID技术从源头减少并延迟暴雨径流和峰值,使开发后的城市水文循环接近开发前的自然水文状态。而基于LID技术的绿色水基础设施如雨水花园、透水性铺装、植被浅沟和景观雨水调蓄池等正在越来越多的应用在城市,尤其是一些发达国家在这方面的技术十分成熟。中国起步较晚,只有少数发达城市进行了LID技术的尝试。但从可持续发展的角度来看,LID技术必将得到推广和应用。可以将LID技术与现有的雨水处理设施相结合,构建符合中国国情的城市雨水系统。     

基于生命周期评价的页岩气开采返排-产出水处理技术选择

为探究页岩气开采废水(即返排-产出水)处理技术对环境生态的影响,针对页岩气开采废水的处理后内部回用以及达标排放两种管理模式,结合生命周期评价的理念,运用Simapro分析工具,创建LCA模型,对典型处理技术进行清单分析,评估处理技术中的资源、能源消耗和环境负荷,量化分析其对人群健康、生态环境质量和资源方面的影响,建立一种页岩气开采返排-产出水处理技术选择的评价方法.同时,以国内某页岩气田产出水处理工程为例,评估所选用处理技术的潜在环境影响.结果表明,内部回用模式下选用的混凝-絮凝处理技术对环境生态影响最小;达标排放模式下针对有机物去除,选用铁电极的电絮凝技术或曝气生物滤池对环境生态的影响较小.对于较低含盐量的开采废水的脱盐,选用的脱盐技术正渗透对环境的影响比反渗透小,但反渗透的脱盐效果更好.对于较高含盐量开采废水的脱盐,选用的多效蒸发-机械蒸汽再压缩技术对环境生态的影响较小.     

温岭市排水工程的规划设计

从温岭市的排水工程规划设计出发,针对其水资源缺乏和水环境恶化的现状,从水资源可持续发展的角度提出了污水厂水量平衡、相邻城镇污水分散处理、中水回用和采用生物生态组合型污水处理工艺等策略,并提出了促进城市水资源合理利用的有效措施,对城市排水工程规划设计具有重要的参考价值。     

水生植物法再生景观回用水水质稳定技术研究

建立了污水处理和景观回用中试试验系统,景观回用试验水量为11 m3,研究了城市污水经二级生物处理再生后用作景观环境用水的水质稳定性;构建了不同结构的水生植物系统,研究了该系统对再生景观环境用水水质的影响. 结果表明:在晴朗天气,白天水温为(28±2)　℃,夜间水温为(20±2)℃的条件下,二级生物处理的再生水在瓷砖水池中最多可以稳定3 d;结构完善的“挺水-浮叶-沉水-浮水”水生植物系统能够有效抑制再生景观回用水中藻类的滋生,并可降低其有机物和氮、磷的含量,在9 d内使ρ(COD_Cr),ρ(TP)和ρ(NH₃-N)分别降低76.9%,95.8%和95.2%,从而使水质保持稳定并得以改善,使回用水水质完全符合再生景观回用水国家标准. 因此,构建结构完善的水生植物系统可实现污水再生景观回用.      

Reducing mine water requirements

Mining is a water intensive activity, and reducing water consumption is a key requirement in moving toward a more sustainable mining industry. This paper identifies mine water reduction, reuse and recycle options, and demonstrates cases where these options have been implemented around the world. A mine water system model is developed and used to show potential water saving strategies through six scenarios. Apart from the base case, these scenarios include the introduction of evaporation reduction strategies, paste tailings disposal, filtered tailings disposal, ore pre-sorting and a combination of the most effective options. The results of the modeling show how an open-pit copper mine with a traditional layout can move from having an average water withdrawal of 0.76 m³/t of ore processed to 0.20 m³/t of ore processed or lower. A key result of the modeling is the discovery that a combination of ore pre-concentration and filtered tailings disposal can reduce water consumption by 74% or more. This finding demonstrates an opportunity to significantly lower water consumption on mine sites.     

基于结构分解法的长江经济带产业排水量驱动因素评估

为分析长江经济带产业排水量变化的驱动因素,以2002年、2007年和2012年长江经济带11省市投入产出表、排水估计量为基础,利用基于投入产出的结构分解法对各省市数据进行比较静态分析,对驱动产业排水量变化的因素进行分解及定量评估,包括节水减排效应、投入结构效应、需求结构效应及规模效应.结果表明:①长江经济带产业排水量由增长趋势变为下降趋势,2002—2007年排水量增长了16.9%,2007—2012年排水量降低了0.4%,2002年、2007年、2012年产业平均耗水率为46%,上海市、江苏省等省市产业排水量下降趋势明显.②规模效应是驱动各省市产业排水增加的主要因素,其在2002—2007年、2007—2012年带动排水量分别增长了67%和61%;规模效应影响逐渐分化,上海市、江苏省、浙江省规模效应带动产业排水量增幅逐渐减弱.③节水减排效应是驱动排水量减少的最主要因素,其在2002—2007年、2007—2012年带动排水量分别减少了35%和60%,节水减排效应影响逐渐增强,各省市排水强度明显降低.④长江经济带大部分省市的需求结构效应驱动产业排水量不断减少,其驱动力的绝对值呈增长趋势;投入结构效应对产业排水量的驱动力较弱且变化规律性不明显.建议长江经济带通过技术进步、应用创新等提高清洁生产能力,通过需求及投入结构优化带动产业结构调整,对进一步降低产业排水量具有一定价值.