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.     

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％。     

Assessment of water pollution control strategies: a case study for the Dianchi Lake

Lake eutrophication has increasingly become a major environmental issue in China.Although significant efforts have been made towards its resolution in the last decade,most of the implemented control strategies are fragmented,and the formation of policy lacks of sound scientific basis and long-term objectives.Taking the well-known Dianchi Lake as a case study,this paper presented a comprehensive assessment for the effectiveness of various eutrophication control strategies.It is expected that the concluding lessons would have a major implication to future eutrophication control.     

Business frameworks for sustainable society: a case study on reuse industries in Japan

This paper presents a new perspective on the reuse businesses of independent reuse business companies (IRBCs) in Japan. A majority of previous studies on reuse and remanufacturing have focused on the businesses of original equipment manufacturers (OEMs). During the past twenty years, however, in Japan, IRBCs have grown rapidly, especially those that launched new types of secondhand shops. The author proposes that the reuse businesses of IRBCs can provide useful information for academics, OEMs, and policy makers. A key finding is the strategies developed by IRBCs to ensure the volume of used products collected and to stimulate demand for used products. This paper compares the features of IRBC reuse businesses with those of OEMs, and discussed the results and implications of an interview survey with select IRBCs.     

水质型缺水城市污水再生回用探讨

系统分析了水质型缺水城市污水再生回用的意义、可行性和用户的选择,对回用中存在的障碍及其相应的对策进行分析,以期为水质型缺水城市污水再生回用提供参考.     

Development of systems for detection, early warning, and control of pipeline leakage in drinking water distribution: A case study

The integrated system for the detection, early warning, and control of pipeline leakage has been successfully developed to manage the pipeline networks of Beijing.     

污水处理厂进水数据特征识别与案例分析

污水处理厂进水水量和水质呈现复杂的变化模式,准确掌握进水数据的变化特征已经成为改善工艺运行的关键.已有定性分析方法一般难以准确解释和预测变化特征,而已有定量分析模型常常结构复杂和实现难度大,需要针对应用需求进行改进.本研究使用统一模型描述进水特征并简化了实现方式.基于经典统计分析和开源Prophet模型,进行了污水处理厂进水数据的预处理、统计、建模和可视化.最后使用3座污水处理厂的实际数据,识别了多重季节性、长期趋势、节假日等的影响特征,说明了统一模型对污水处理厂进水特征的解释和预测能力.结果可供污水处理工艺优化运行和环境时序数据解析等参考.     

Development of a simulation model for reuse businesses and case studies in Japan

To discuss measures to promote reuse in society, a holistic understanding of reuse businesses and markets is indispensable. This paper presents a simulation model for reuse businesses. To formulate the model, first, prerequisites for reuse businesses are outlined. The simulation model includes these prerequisites as its parameters, and its outcomes yield patterns of reuse markets. The paper presents the formulation of the model and simulation outcomes under four parameter settings. The correspondences between the simulation outcomes and case studies of reuse businesses in Japan are discussed to verify the propriety of the model.     

Integrated water quality management in Tolo Harbour,Hong Kong: a case study

Tolo Harbour is an almost land-locked semi-enclosed sea inlet with a narrow outlet in the South China Sea. With the rapid growth in economic development and urbanization, evidence of increasing eutrophication is seen by the drastic increase in the severity and frequency of algae blooms, which are closely correlated to the excessive nutrient loading. The bottom waters in Tolo Harbour exhibit serious dissolved oxygen depletion. A co-ordinated sequence of pollution control activities are being undertaken by the Hong Kong Government. Technological advances can be utilized in effective water quality management in the coastal zone. This paper presents the application of a robust three-dimensional numerical eutrophication model, integrating hydrodynamics with water quality, for simulation of the algal growth dynamics and water quality processes. After calibration and verification, the tool is used to predict different eutrophication scenarios as well as the effectiveness of alternative management solution strategies.     

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.     

一种新型滤料在循环养殖水处理中的应用

实验研究了填充新型无剩余污泥悬浮型生物滤料的曝气生物滤池处理养殖废水的挂膜情况及水力停留时间（HRT）变化对曝气生物滤池处理效果及运行特性的影响。结果表明，含氨氮和亚硝酸氮浓度较高的模拟养殖污水用活性污泥挂膜，大约1个月就能使生物滤池启动。当模拟养殖污水氨氮起始浓度在2mg／L左右时最佳水力停留时间（HRT）为0．6h循环6d能使氨氮浓度降到0．03mg／L左右，亚硝酸氮有短期积累问题，但最终都能被降到0．05mg／L以下。水力停留时间影响氨氮的去除时间，从而影响亚硝酸氮的积累。水力停留时间（HRT）对有机物（CODMn）去除影响不大，且该种滤料对有机物（CODMn）去除效果较差，去除率在28％左右。     

Water footprint: methodologies and a case study for assessing the impacts of water use

The methodologies, approaches and indicators for assessing the impacts of freshwater usage are still evolving. The development of the water footprint concept has been an important step in this direction but the existing methodologies mainly assess the quantity of water used rather than the related impacts. Although there is a recognised need to consider the latter, particularly on a life cycle basis, the difficulty is that there are little or no reliable data on water usage in life cycle databases; furthermore, there is no agreed life cycle impact assessment method for estimating impacts related to freshwater use. However, there have been some methodological developments which propose methods for inventory modelling and impact assessment for water use in life cycle assessment. This paper reviews some of these approaches and discusses their strengths and limitations through a case study, which considers the impacts of freshwater consumption from corn-derived ethanol produced in 12 different countries. The results show a huge variation in the results between different methods and demonstrate the need for a standardised methodology for assessing the impacts of water use on a life cycle basis. Specific recommendations for further research in this field have been made accordingly.     

Carbon footprint analysis for increasing water supply and sanitation in South Africa: a case study

This study investigates the environmental burdens due to the provision of potable water and sanitation in the eThekwini Municipality (Durban), South Africa. This was achieved by employing LCA studies for the individual parts of the urban water system (impoundment, water treatment, distribution, collection, sewage treatment and water recycling). Based on the results of the individual LCAs a base case was constructed.For the provision of potable water and sanitation to new customers, which have not been previously served, two different scenarios (200 000 new customers in an urban environment with waterborne sewage and in a peri-urban environment with on-site sanitation) and three different options (maximising use of existing assets, recycling water and building new infrastructure) were considered and analysed. With regard to the impact scores calculated for both scenarios (urban and peri-urban), the recycling of water is followed by maximising the use of existing assets as the most environmentally friendly options. The construction of new infrastructure carries a higher environmental burden and the use of bottled water for drinking (an additional scenario) carries the highest environmental burden.     

海岛污水处理厂中水回用环境可行性分析—以平潭金井湾污水处理厂为例

基于污水处理厂的特点和区域的规划资料,本研究利用经验系数法、湖泊完全混合衰减方程和二维扩散方程解析解近似方程等方法,分析了平潭金井湾污水处理厂中水回用环境可行性。中水水量和水质可满足湖泊景观用水、冲厕用水、绿化用水、道路洒水等用途; 中水排入湖泊后可以满足相邻海域的环境功能区水质要求。在事故性排放情况下,湖泊出海口处的有小面积水域的水质超过了海域功能区的水质要求,应采取相应措施加强管理,防范事故性排放; 随着城市化的推进和工业的发展,中水用途将更趋于多样化。     

Changes of surface water pollution of Suzhou region:a case study in Taicang County, China

Environmental pollution is a by-product of industrialization when economy of a region is developing. China also suffers from such a problem, especially in the southern part like Suzhou region in Jiangsu Province. In this paper, data covering situations of surface water pollution and social and economic development showed that the surface water pollution in Taicang County, a typical economic zone of Suzhou region, is significantly correlated to the economic growth of this region.     

Developing industrial water reuse synergies in Port Melbourne: cost effectiveness, barriers and opportunities

Urban water scarcity from ongoing drought and an increasing population are driving a range of water saving options to be explored in Melbourne (Australia). This paper assesses the cost effectiveness of five water treatment and industrial reuse options in the Fishermans Bend industrial area at Port Melbourne. In consultation with industrial stakeholders and the local water utility, the study design began by identifying potential water sources and sinks in the area. Treatment technologies for each option - using a combination of membrane bioreactors (MBR) and in some cases reverse osmosis (RO) technologies - were developed. In evaluating the potential for future implementation, the cost effectiveness ($/kiloLitre) was assessed relative to water supply augmentation and water demand management options available in Melbourne. Additionally, the opportunities and barriers for option implementation in Port Melbourne were contrasted with the Kwinana Industrial Area, Western Australia where many regional synergy projects have been undertaken. This research identifies that the future implementation of industrial ecology opportunities requires strong and ongoing stakeholder involvement as described in this paper.     

基于水质目标管理的河流治理方案制定方法及其案例研究

针对我国河流污染程度高,污染类型复杂的现状,实施水质目标管理是河流治理的根本选择.我国在水污染总量控制的研究起步比较早,但缺少基于水质目标的治理方案编制方法的系统性研究.本文提出了适合于我国国情的基于水质目标的河流治理方案制定方法,基本框架包括水质问题诊断、目标确定与负荷分配、河流治理任务实施和实施效果评估4个基本部分.该方法以河流容量总量控制为基础,突破了传统了目标总量控制方式,并在滏阳河邢台段进行了实际应用.水环境诊断结果显示,氨氮是滏阳河邢台段主要超标污染物.以国控及省控断面为基础,在滏阳河邢台段设定了4个考核断面,设置氨氮小于10、11、12 mg·L-1,COD小于80、55、50 mg·L-1等多个组合目标情景.划定控制单元13个,核算了各控制单元水环境容量和现状负荷,并按等比例分配的原则将需削减负荷分配到排污口.基于负荷分配结果,提出通过重点工业企业和污水处理场治理控制点源污染,通过农村生活污水治理控制面源污染,通过河岸垃圾治理减少河道负荷存量,通过河流湿地建设增加负荷去除能力等一系列治理措施.     

Water pricing towards sustainability of water resources: a case study in Beijing

The role of water pricing for managing water resources is widely recognized in many areas of the world because of the increasing scarcity of water resources, a high competition between water uses and environmental degradation. Based on the analysis of cost of water, this paper explores which types of cost should be reflected in the water pricing enhancing the sustainability of water resources. The principle of full cost pricing in which the cost should include supply cost, opportunity cost and externalities is proposed as a means to achieve the sustainability of water resources. In a case study of Beijing, low water price is analyzed as one reason for unsustainable water consumption. Thus water pricing justified is necessary and pressing. It is proposed to justify water price in phased manner and eventually towards full cost pricing. The assessment of impacts on water resources by raising water price shows water pricing could alleviate the conflict between water supply and demand. This paper concludes that water pricing can play an effective role in enhancing the sustainability of water resources in Beijing.     

黑臭水体综合整治案例分析——以海口市美舍河为例

阐述了海口市的母亲河——美舍河黑臭的主要原因以及整治工程措施,总结了黑臭水体治理的成效。由于市政基础设施薄弱,美舍河沿线存在生活污水直排,雨污错接、混接,合流溢流污染等情况,导致水体常年黑臭。自2015年以来海口市以流域为单元,遵循海绵城市、生态河道的先进理念,按照控源截污、内源治理、生态修复三步走原则,对美舍河开展黑臭水体整治。在控源截污方面,新建合流制排放管、布设截污管道共7.2 km,一体化污水处理设施3个,增加污水处理量7 500 m³/d;内源治理方面,采用挖掘机和绞吸清淤船配合的清淤方式清除污染底泥;生态修复方面,采用环境修复剂对底质进行改良,种植沉水植被36万m²,建设1.0 m×22 m橡胶坝2座,全水域投放水生态修复剂等。此外,美舍河采用梯级潜流人工湿地技术,在增强处理效果的同时,营造出良好的景观。通过上述综合整治,美舍河于2017年消除黑臭。     

Advances in chemical technologies for water and wastewater treatment： preface

Chemical technologies have been applied for water and wastewater treatment since more than 150 year ago,and are still playing the leading role in this field. With the fast development of sciences and technologies especially in the last