Advanced phosphorus removal for secondary effluent using a natural treatment system

Mechanisms for low concentrations phosphorus removal in secondary effluent were studied, and a process was developed using limestone filters (LF), submerged macrophyte oxidation ponds (SMOPs) and a subsurface vertical flow wetland (SVFW). Pilot scale experimental models were applied in series to investigate the advanced purification of total phosphorus (TP) in secondary effluent at the Chengjiang sewage treatment plant. With a total hydraulic residence time (HRT) of 82.52 h, the average effluent TP dropped to 0.17 mg L(-1), meeting the standard for Class III surface waters. The major functions of the LF were adsorption and forced precipitation, with a particulate phosphorus (PP) removal of 82.93% and a total dissolved phosphorus (TDP) removal of 41.07%. Oxygen-releasing submerged macrophytes in the SMOPs resulted in maximum dissolved oxygen (DO) and pH values of 11.55 mg L(-1) and 8.10, respectively. This regime provided suitable conditions for chemical precipitation of TDP, which was reduced by a further 39.29%. In the SVFW, TDP was further reduced, and the TP removal in the final effluent reached 85.08%.     

基于盈亏平衡的农村饮水安全工程运行管理经济效益分析

农村饮水安全工程供水效益差,运行管理难以维持,而工程能够长效运行的前提是收入大于正常运行成本。在对影响农村饮水安全工程收入和运行成本相关因素的变化进行分析的基础上,模拟9个情景,运用盈亏平衡分析法对调查数据进行经济评价,得出影响农村饮水安全工程运行经济效果的主要问题,提出提高农村饮水安全工程运行效率的对策和建议。     

甘肃省水资源监控能力建设初探

水资源监控能力建设是提高水资源动态管理的有效方式,为水资源高效配置和合理利用提供技术支撑。针对甘肃省水功能区监管能力薄弱、水资源监测信息滞后、农村饮水安全水质监测能力不足等水资源监控方面存在的问题,提出基于节水型社会建设、农村饮水安全、水权制度和水资源信息系统的水资源监控能力建设思路,从而为区域水资源规划、管理和配置乃至经济社会发展提供科学的决策依据。     

苏州水利水务信息化发展研究

水利信息化作为水利现代化的基础和标志,是防洪减灾、水资源管理、水环境监测和水土保持的重要手段和技术支撑。从苏州市水利水务信息化发展存在的问题、主要任务着手研究,围绕重点抓好"六大体系"建设,构建水安全、水资源、水环境、水文化"四位一体"新格局的发展战略,提出了今后十年苏州市水利水务信息化的总体思路、目标任务、建设重点和保障措施。     

基于水管理对象的数字流域顶层设计技术方法研究

水利信息化是实现水利现代化的基础和重要标志。以水管理对象为基础,利用现代信息技术构造数字流域,集中管理流域内的水事问题,是实现流域现代化管理的有效途径。从数字流域体系架构、水管理对象构造及全息化描述、基础平台构建、业务系统的构件化开发、数字功能流域等方面详细介绍了基于水管理对象的数字流域构造技术方法。     

甘肃坡耕地水土流失综合治理试点工程建设实践与启示

甘肃省在国家坡耕地水土流失综合治理试点工程建设中,按照“山、水、田、林、路、村”综合治理的建设思路,采取项目整合和综合治理两种方法、行政推动和利益驱动两种手段、规范建设和机制创新两种措施、特色产业和旱作农业两个结合,实现了水土保持建设由综合治理到综合开发的转变,为国家坡耕地试点工程建设总结和探索了一些在同类型地区可供借鉴的经验模式.     

EFFECT OF ESCAPE DEVICE FOR SUBMERGED FLOATING TUNNEL （SFT） ON HYDRODYNAMIC LOADS APPLIED TO SFT

This paper presents a potential approach to settle the problem of surviving major safety accidents in Submerged Floating Tunnel (SFT) that detachable emergency escape devices are set up outside SFT. The Computational Fluid Dynamics (CFD) technology is used to investigate the effect of emergency escape devices on the hydrodynamic load acting on SFT in uniform and oscillatory flows and water waves by numerical test. The governing equations, i.e., the Reynolds-Averaged Navier-Stokes (RANS) equations and standard turbulence equations, are solved by the Finite Volume Method (FVM). Analytic solutions for the Airy wave are applied to set boundary conditions to generate water wave. The VOF method is used to trace the free surface. In uniform flow, hydrodynamic loads, applied to SFT with emergency escape device, reduce obviously. But, in oscillatory flow, it has little influence on hydrodynamic loads acting on SFT. Horizontal and vertical wave loads of SFT magnify to some extend due to emergency escape devices so that the influence of emergency escape devices on hydrodynamic loads of SFT should be taken into consideration when designed.     

碳酸钙沉淀势理论计算模型及其应用

水质化学稳定性评价指数较多,其中碳酸钙沉淀势(CCPP)是一个能定量分析CaCO3溶解或沉淀的精确指数.从理论上推导了CCPP计算模型,并基于Matlab计算求解.模型计算结果与已有相关软件的计算结果相比,该理论模型的计算值更接近试验结果,可以用其代替试验值进行水质化学稳定性分析.     

绍兴滨海新城分质供水运行实践经验

根据绍兴市水资源现状与绍兴滨海新城开发实际情况,在分析绍兴滨海新城分质供水的必要性和可行性基础上,介绍了滨海新城分质供水的模式、范围,以及为提高供水安全性,在分质供水的两路供水管适当位置设置连通管等具体实施办法.总结了滨海新城分质供水实践中存在的水质、水量、水压等方面的问题,指出了分质供水运行管理制度、操作规程和紧急事故应对措施以及国家关于工业水质方面规范制度的不足.