【作者】 任佶；

【导师】 张兴文；

【作者基本信息】 大连理工大学 ， 环境科学， 2007， 硕士

【摘要】 世界上的淡水供给有限且受到污染的威胁,工业、农业和城市供水需求量的不断提高导致了有限淡水资源在分配上的竞争。为了避免水资源危机,各国致力于保护水资源,对供水和需水进行管理,减少污染和降低不断增长的人口对环境的影响。城市污水回用是指将城市污水加以处理再生后回用于可用再生水的地方,取代干净的优质原水,是缓解我国当前水资源紧张的有效措施之一。城市污水回用的途径主要有农业灌溉、工业、娱乐景观水体以及地下水回灌等。污水处理回用开辟了第二水源,减少了城市新鲜水的取用量,提高了供水的可靠性,只用较少的淡水就能满足人类更大的需求,从而减轻了人类生存对世界水环境造成的影响。结合各地的实际情况,采用不同的污水回用途径,对城市污水进行再生利用是缓解水资源短缺的紧张局面,实现水资源的可持续利用的重要手段,具有明显的经济效益、社会效益和环境效益。城市污水回用于电厂循环冷却水补水,不仅可以扩大中水回用规模,而且也为电厂提供了一个水量充足的水源,为电厂用水提供一定的保障。大连北海热电厂中水回用系统采用先进的反渗透技术作为主要的脱盐工艺,以高效生物氧化塔+混凝沉淀+纤维素、石英砂两级过滤系统作为预处理工艺,将大连市春柳河污水处理厂二级标准出水进行深度处理,作为该热电厂循环冷却水补水及锅炉补给水的源水。整个中水回用系统连续运行了240多天,预处理系统出水浊度基本维持在0.1NTU以下,SDI值稳定在3.5-4.5之间,出水基本不含余氯,完全满足反渗透系统对进水水质的要求;反渗透系统出水电导率控制在20μs/cm以下,脱盐率保持在98%以上。监测了反渗透系统运行产水电导率、产水量、运行压力、压差等参数的变化,分析了变化原因及它们之间的相互关系;通过对反渗透系统脱盐率、产水量、运行压差数据的标准化,对反渗透系统的运行状况进行了客观的评价。更多还原

【Abstract】 Supply of fresh water in the world is finite and threatened by pollution. Increasing water demands for agriculture, industry and urban water supply leaded to competition for the allocation of limited fresh water resources. In order to avoid water crisis, every country aims to protect water resource, manage water supply and demand, reduce pollution, and lessen the impact of increasing population on the water environment. Municipal sewage reuse is a way to save clean and top - quality water by recycling treated sewage to places where it can be used. It is one of the effective measures to ease the problem of freshwater shortage in China. Agricultural irrigation, industry, scenic water and groundwater recharge are the main approaches of wastewater reuse. The treatment and reuse of sewage establish the second water source and reduce the fresh water needed by the city and increases the reliability of water supply, and then greater demand of human can be fulfilled with less fresh water. So the impact of human life on the water environment was lessened. According to the local actual situation, different wastewater reuse approaches be selected in different regions of china to reuse the municipal wastewater is the important method to alleviate the shortage of water resources and realize the goal of sustainable water resources utilization, and has the visible economic benefit, social benefit and environmental protection benefit.Sewage treatment and reuse as cooling-water can not only enlarge the scale of wastewater reused, but also supply a sufficient headwater. Dalian Beihai Thermoelectricity Generation Company used effective moving-bed bioreactor + coagulation, precipitation + two-stage filtration + Reverse Osmosis system to treat secondary effluent from Chunliu wastewater treatment plant, the produced water reused as cooling-water and boiler make-up.The whole system operated stable during 240 days, the turbid of pre-treatment water is less than 0.1NTU, the SDI of pre-treatment is stable between 3.5 and 4.5, and pre-treatment has no surviving C1, which are in line with the requirements of RO system. Conductivity of water from RO system was controlled below 20μs/cm while desalination ratio is more than 98%. Through the observation on the variation of electric conductivity, water yield, operational pressure, pressure difference, the reason on their variation and the relation between them were discussed. RO system was evaluated impersonally by standardization of desaltification ratio, water production and pressure difference.更多还原