【作者】 张燕；

【导师】 陈东辉； Andrew Grant； Ashok Sharma；

【作者基本信息】 东华大学 ， 环境工程， 2009， 博士

【摘要】 由于气候变化、人均用水量增加、以及过度开采及严重污染水资源等原因,目前很多国家面临着水资源危机。因此,雨水及灰水等非传统水资源的应用研究日益得到各国学者的重视;对水资源进行合理开发、高效利用、全面节约、有效保护和综合治理已成为研究热点。城市化进程的不断加快导致城镇人口剧增,这对城市供水系统的承受能力是严峻的考验。居民区内雨水的合理利用可缓解城市供水管网的压力,灰水回用则可起到节水减污的双重作用。非传统水资源的利用是解决水资源危机的重要手段之一,同时,水资源的综合治理是保证非传统水资源合理应用的重要措施。针对城市水资源短缺现状,本文探讨了利用非传统水资源(雨水和轻度污染的灰水)提供居民区中绿化景观用水及冲厕用水的可行性研究。文章基于城镇水资源综合管理(Integrated Urban Water Management,IUWM)这一理念,运用水量及水质平衡模型UVQ(Urban Volumes and Quality),对研究区域Burwood site居民区进行水量及水质平衡模拟和分析;利用生命周期法(Life Cycle Costing,LCC)对文中阐述的各种方案进行经济分析;全面考虑水量、水质、经济和社会因素,运用多因素决策法(Multi-Criteria Assessment,MCA)得出研究区域内最优方案。同时,本文对在研究区域内采用不同耗水量设备所得出的不同结果进行了研究。Burwood site位于澳大利亚墨尔本市中心东南部,城镇水资源综合管理(IUWM)理念在非传统水资源利用过程中的作用在本研究区域得到充分验证。其旨在将城市供水、雨水排放及污水排放作为有机的整体进行分析。研究区域包括2栋居民楼,其中第一栋高3层(24户),共有居民42人,第二栋为5层(50户),共有居民80人。本文主要得出以下结论:1.分质供水系统(雨水/灰水系统和城镇供水管网)安装在研究区域居民楼内,其中非传统水资源供给绿地灌溉和/或冲厕用水,城镇供水管网提供其他用水。水量平衡模拟探讨了雨水/灰水利用量、用水量年平均体积百分比、雨水排放量及排污减少量/率等。蓄水池体积由用水量年平均百分比这一因素决定,其数值为非传统水资源利用量与终端设备需水量的比值。2.研究结果表明:雨水作为绿化灌溉用水的各个方案所需蓄水池体积较冲厕用水方案大;雨水作为绿化灌溉用水,比较第一栋居民楼和第二栋居民楼储水池的大小,前者明显大于后者,其原因为前者所需灌溉面积(1409m~2)远大于后者(783m~2),即前者需水量比较大导致蓄水设备体积较大。但雨水作为冲厕用水的结果反之于雨水用于绿地浇灌用水,主要原因是雨水利用量与居民人数成正比;如果雨水同时用于浇灌绿地和冲厕,所需储水设备体积明显大于其中任何一种终端应用的储水设备体积。在灰水利用系统中,蓄水池体积的最大差异产生在处理后的灰水用于绿地浇灌和冲厕之间,其原因为绿地浇灌需水不连续而冲厕用水比较稳定。3.节水量由终端使用设备的类型/绿地面积大小决定,即:普通型设备、节约型设备,居民楼周围绿地面积大小。显然,无论雨水利用系统还是灰水利用系统,非传统水资源同时供给绿地浇灌和冲厕用水均可获得最大节水量。节约型设备可大大减少城镇供水管网的供水量及污水排放量。4.污染物的去除量取决于其去除率及雨水/灰水用水量。所研究污染物中,TSS去除量最大,主要原因为TSS去除率最高。节水型设备需水量较普通型设备小,因此其雨水/灰水利用量较小,导致其污染物去除量比较小。显然,非传统水资源同时供给绿地浇灌和冲厕可最大量去除污染物。5.采用生命周期法(LCC)中的常用方法净现值(Net Present Value,NPV)法对雨水及灰水应用系统中各方案进行经济分析。分析年限为50年。文中分别分析了水的输送系统、蓄水池及其安装、维修系统、灰水处理以及节约(雨水及灰水的应用)费用。研究结果表明,非传统水资源同时供给绿地浇灌和冲厕位为最小经济收益方案。雨水用于绿地灌溉可收到最大经济效益。6.文中运用‘DecisionLab 2000’,结合水量、水质、年平均用水百分比、供水减少量,经济及社会影响等因子,对雨水系统和灰水回用系统进行了综合评价。研究结果表明:经济因素对各方案产生最大影响;水量与水质、年平均用水量百分比与供水减少量的影响表现出相容性;第一栋楼、第二栋楼及研究区域Δ值(可靠性)均超过90%;终端使用为绿地冲厕用水且采用节水型设备表现为最佳方案;就整个研究区域而言,灰水供给绿地浇灌表现出最大φ值,即为最优方案。更多还原

【Abstract】 Water resources such as rainwater and treated greywater have attracted increasing interest in recent years around the world due to water crisis. The water crisis is chiefly resulted from excessive consumption of raw water, climate change, groundwater and surface water pollution, and unsustainable water resource consumption. The application of these alternative water services not only contributes to diminish surface water and ground water resources but also, eases the pressure of reliance on wastewater treatment plants and reduces energy consumption.This thesis introduced water conservation and put rainwater use and greywater recycling into the context of a water conservation strategy with adoption of the new conception of Integrated Urban Water Management (IUWM). The integration of water, stormwater and wastewater services and systems are considered in the integrated water management approach.The performance of alternative water use/reuse systems were monitored at the Burwood site experimental study in the south east of Central Business District (CBD) of Melbourne, Australia. This site consists of 2 residential units with the occupancy of 42 for Building 1 (3 levels) and 80 for Building 2 (5 levels). A dual water supply system (rainwater/greywater and mains water) was used to supplement mains water supplies for toilet and/or garden irrigation on the urban water cycle which was examined in residential developments.Water balance and contaminants balance were simulated based on the model of UVQ (Urban Volumes and Quality). The investigation of water balance for residential buildings of Burwood site was developed in terms of alternative water usage, the average annual volumetric reliability (VR), as well as stormwater and wastewater discharge reduction. Storage dimensions were determined by VR which is the proportion of the demand supplied and is defined as the volume of supplied water divided by the total water requirement (i.e. demand) during the entire simulation period.In light of tank capacities of rainwater use schemes, the tank dimensions for irrigation use options were significantly larger than those for toilet purpose options. The tank sizes of rainwater supplying irrigation for Building 1 were about twice of Building 2, which was resulted from that Building 1 covered larger garden area (1409m2) than Building 2 (783m2). Whilst for the end use of toilet schemes, the conditions were on the opponent way due to Building 2 occupied 80 residents while Building 1 occupied 42 persons. It has been found that the required tank values for end uses of irrigation coupling with toilets were significantly larger than irrigation or toilet considered alone.The significant difference of tank sizes occurred between greywater for irrigation and toilet considered alone, which was due to the unsteady water demand for irrigation whilst the regular water supply and constant water demand for the end use of toilet.In case of the conservation of imported water supply, which was determined by the connected fixtures and their types, end uses of irrigation plus toilets outperformed end use of irrigation or toilet considered alone. Water efficient domestic facilities reduced drinking water supply dramatically, as well as the wastewater disposal.The contaminants removal in mass was evaluated based on the percentage removal values and alternative water usage volumes. The greatly difference of contaminant loads between ’Reference Option’ and alternative water services options was TSS, which was the basis of that the highest removal for TSS comparing with others. The water efficient appliances installed offered low water consumption, which resulted in low potable water substituted. Thus, the high demand management (6 stars appliances used) produced less contaminants discharge in comparison to usual demand management (3 stars appliances installed). From the results and analysis of the contaminants balance it could be concluded that alternative water using for irrigation service integration with toilet flushing outranked other considered end uses in terms of reducing contaminants to receiving waters.An economic analysis was performed in order to evaluate the benefits of utilizing rainwater or greywater strategy. Life cycle costing (LCC) is the technique for the estimation of total cost over the life of the service provision. LCC of water supply, stormwater and wastewater services over an analysis period of 50 years was calculated by applying the Net Present Value (NPV) method in this study. This thesis assessed the financial cost for all modeled scenarios for both rainwater harvesting system and greywater reuse system with regards to the cost of conveyance, pump, tank cost and installation, maintenance, greywater treatment plant, savings, as well as the total cost. For the scenarios of the combination of garden irrigating and flushing purpose, it was found that these cases accounted the largest financial cost either within the condition of single buildings investigated or the whole area evaluated.This study simulated the rainwater use and greywater recycling options by incorporating the multi-criteria of water quantity, VR, water quality, financial cost, social and PW (Potable Water) reduction impact. These associated results were obtained by adopting the software ’DecisionLab 2000’. This investigation provided an assessment of potential preferences of alternative water serving options. Twelve cases were modeled for each single building and six for the study area. These schemes were plotted by using methodologies of profile (performance) analysis, GAIA (Geometrical Analysis for Interactive Assistance) Analysis, and PROMETHEE (Preference Ranking Organization Method for Enrichment Evaluations) Ranking. It has been seen that economy was the most significant impact factor due to the highest weight value. The criteria of water quantity and water quality were agreed with each other, as well as VR and PW reduction (bar Building 2). The△values of both individual buildings and the study area were over 90%, which identified the high quality of simulation reliability. The options of alternative water to flush toilets ranked the first for either individual buildings or the study area. In light of the whole study area, recycled greywater supplying irrigation conducted the most preferred option than others if 3 stars rating domestic facilities installed.更多还原