中水回用—城市水利发展的必然趋势

随着经济发展和人口增长,我国水资源短缺问题日益严重,中水回用可以防治水污染,保护水环境,为我国水污染防治开辟了新路。文章在阐述中水回用基本内涵的基础上,重点探讨了我国中水回用应采取的措施,旨在说明中水回用是城市水利发展的必然趋势。     

我国水循环经济实施机制探究

循环经济是可持续发展的战略选择,构筑水资源利用新机制是创立"循环型社会"的重要任务.循环经济的3原则是:减量化、再利用、资源化.依据3原则,水资源开发利用要做到控制用水量,提高用水效率,加快城市中水回用.对国内外水资源利用状况进行了分析对比,我国水资源利用效率与国外相比还有很大差距,提出了提高水资源利用效率的措施.     

浅论城镇中水回用的可行性

结合浙江省当前水资源短缺的实际,阐述了发展中水回用技术在有效解决水资源短缺、促进水资源可持续利用方面的必要性及当前中水回用技术推广应用中存在的一些问题.以慈溪市教场山污水深度处理厂的运行情况为例,对城镇中水回用的可行性进行了分析.     

热电厂中水回用深度处理技术与国内应用进展

综述了我国中水深度处理工艺的发展历程、相关工艺在国内电厂的主要研究与应用情况及其主要问题与控制策略。石灰混凝法是热电厂中水回用的第二代处理工艺,应用广泛;双膜法及全膜法具有更高的污染物去除效率,已成为目前热电厂中水回用的主流深度处理工艺。膜污染是膜法深度处理工艺的限制因素,膜污染形成机制与控制策略研究成为中水回用领域的研究热点和难点。随着水处理技术及设备的发展,一些新型的材料、技术和设备也逐渐推广应用于热电厂的中水深度处理;未来城市中水将成为热电厂的第一水源,膜法将成为中水深度处理与回用的最关键工艺,其预处理和深度处理工艺将实现多样化与高效化的发展。     

利用小型污水处理设施和中水解决城镇水资源问题

水资源短缺和水环境污染已经成为城市和小城镇可持续发展的制约因素，中水回用则是解决这两个问题的重要举措。在调查分析了石家庄市水资源、污水处理和中水回用情况的基础上，回顾了污水处理和中水回用的发展历程，分析了中水回用的不同方法，以石家庄为例进行中水回用的经济效益分析。分析表明大力推行小型污水处理设施并进行中水回用是城市和小城镇水资源可持续发展的重要举措。     

中水回用技术及应用

论述国内外中水回用的现状和意义，介绍中水的分类和用途，提出中水回用的系统处理工艺，并进行了技术经济分析，认为中水回用技术符合水资源循环使用和可持续发展思想，必将在我国拥有广阔的发展前景。     

中水回用现状与发展前景

概述了国内外中水回用的研究进展状况,阐明了中水回用的意义,提出了中水回用存在的问题及解决办法.     

西南大学宿舍区中水回用可行性分析

结合西南大学的实际情况,以橘园宿舍区为例,分析了西南大学宿舍区中水回用的可行性,对校园中水回用方案进行了选择;同时分析比较了中水回用系统工艺,提出适合高校校园的中水回用工艺,并对所选工艺进行了技术和经济可行性分析.     

浅议高校校园中水回用工艺

分析了高校校园中水回用的必要性,对位于市区和郊区新建高校提出了有针对性的校园中水回用工艺,并对中水回用项目的效益进行了探讨.     

高校校园中水回用系统处理工艺方案比选研究

随着城市水资源供需矛盾的日益尖锐,中水回用为城市用水提供了新水源的可能.在系统分析了高校校园建设中水回用系统的必要性和可行性基础上,以云南某高校新校区为案例,从中水的工艺流程、技术特征和经济指标等方面对校园中水回用系统的三个典型处理工艺方案进行比选,提出了适合高校校园中水回用系统的处理工艺.     

洗衣房废水的循环利用

结合近年国外洗衣房洗涤废水的循环利用研究成果,针对国内洗衣房洗涤废水现状,提出洗涤废水循环利用方案,对废水进行分质循环,只将漂洗二次和漂洗三次的水处理循环利用回洗涤和漂洗一次阶段。对洗涤废水进行了混凝沉淀实验研究,结果表明,混凝沉淀处理方法基本可以满足洗涤废水循环利用的要求。     

城市再生水利用规划中再生水用户的确定

城市再生水利用规划对一个城市再生水系统的建设起着重要的引导作用。再生水用户的确定是再生水利用规划首要及关键的环节,涉及到再生水厂规模、工艺,同时也决定着整个再生水输配系统的布置。景观、工业、城市杂用等低质用水户是首要的考虑对象,同时各个城市还需要根据自身水资源供需及经济发展情况,合理地确定用户,以确保再生水利用规划的系统性、科学性和可行性,对城市的再生水系统建设真正起到引导作用。     

洗浴废水回收利用工艺

以燕山大学西校区的浴池为例,采用定点采样的方法,测定废水中的浊度、LAS、COD等,制订了控制洗浴废水的处理措施,使其达到排放标准,并提出对策来控制洗浴废水的排放量.     

小区中水回用工程实例

介绍了水解酸化———曝气生物滤池(BAF)———过滤工艺在小区中水回用中的运用,分析了实际工程的设计及运行情况,并对曝气生物滤池运行中有关问题进行了总结,最后对其应用前景作了展望。     

Life Cycle Assessment of Water Recycling Technology

Environmental performance of different water recycling technologies is compared on the basis of the associated potential environmental impacts using the technique of Life Cycle Assessment (LCA). The LCA method is used here to support decision making in water recycling in terms of (1) comparison and selection of suitable technology and (2) identification of opportunities to enhance the environmental performance of the water recycling train. In addition to the conventional impact categories used in LCA, a new soil salinisation potential is included. The environmental impact contribution from the construction phase of each technology is estimated using the Missing Inventory Estimation Tool (MIET) approach which relies on the input–output analysis technique. LCA results are reported and discussed in detail in this paper and areas of potential improvement are identified including: (1) sludge quality and quantity, and (2) energy consumption. The suitability of using the LCA technique in the context of water recycling is discussed and the limitations of LCA for this particular purpose are outlined and further research needs identified.     

论实施可持续污水回用战略

在水资源短缺的情况下，污水资源化具有节约供水、改善环境和产生经济价值三方面的效益。虽然经过处理的污水在发达国家已经被较广泛地用于农业、工业、居民及社区的非饮用水和环境用水等诸多方面，而且越来越受到世界水行业的关注，但更广泛的污水回用仍存在一些障碍。制定可持续污水回用战略必须坚持一系列的基本原则，而且应从八个方面为实施可持续污水回用战略制定相应的行动计划。     

污泥的处置及利用技术探讨

在总结国内外相关文献资料的基础上,对国内外常用的污泥处置及利用技术进行总结与归纳,包括污泥的填埋、焚烧、农用、固化以及生物修复技术等,并对各种处置方法的适用性与优、缺点作出科学的分析与评价,可为污泥的处置及利用提供一定的参考作用。     

Recycling mineral nutrients to farmland via compost application.

Increased cultivation of farmland has resulted in nutrient deficiency and consequently fertility degradation of soils. This research examined the application of composted wastes in terms of the feasibility and effectiveness of recycling plant essential minerals. Minerals in composts (derived from sewage sludge, livestock excrement, and municipal solid wastes, respectively) and in amended soils were observed. Ca/Mg ratios in amended soils and the effect of compost applications (mineral nutrients and heavy metals) on plant uptake were also studied. Results showed that composts, especially those made from sewage sludge and livestock excrement, were richer in mineral nutrients but also contained more heavy metals than untreated soil. The increase in some elements and plant-growth-essential Ca/Mg ratios were found in amended farmlands, implying that compost applications have made up for the nutrient deficiency and have adjusted chemical conditions of the soil. The soil contamination from heavy metals was noticeable. However, some results showed that the large existence of mineral nutrients and heavy metals in soils has caused no significant increase in the plant uptake of elements. The controlled composting process and farmland uses are believed necessary for reducing the heavy metal accumulation in agricultural plants.     

Recycling of sludge with the Aqua Reci process.

Supercritical Water Oxidation (SCWO) is an innovative and effective destruction method for organics in sewage sludge. The SCWO process leaves a slurry of inorganic ash in a pure water phase free from organic contaminants, which opens possibilities for a simple process to recover components like phosphates and/or coagulants from the sewage sludge, a process marketed as the Aqua Reci. In a continuous pilot plant for the SCWO process digested sludge has been treated. The ash has been extracted in lab- and pilot scale with both caustic and acids in order to recover phosphates and coagulants. The particle size of the inorganic contaminants in the water after the SCWO process is between 1-10 microm, which means that it is very reactive. The phosphate, and partly the aluminium, can be extracted with caustic as iron and heavy metals are completely insoluble in caustic. This is a method to separate the phosphates from the rest of the contaminants. However, high calcium content will bind the phosphate as calcium phosphate insoluble in caustic. In most cases the calcium content is too high and the best solution is to dissolve phosphates and all metals with sulphuric acid. From this solution first iron phosphate can be separated and thereafter in a second step aluminium and finally heavy metals in a third step. Iron can be separated from the phosphate, either by leaching the phosphate with caustic off to sodium phosphate leaving a precipitate consisting of iron hydroxide, or the iron phosphate can be dissolved in hydrochloric acid followed by a liquid extraction process where ferric chloride can be separated leaving a phosphoric acid. By the acid dissolving process it is possible to recover phosphate, iron, aluminium, and heavy metals from the inorganic since the Aqua Reci process only leaves a silica residue representing about 10% of the DS content in the original sludge.