Product and by-product formation in laboratory studies on disinfection electrolysis of water using boron-doped diamond anodes

Boron-doped diamond (BDD) electrodes were studied with respect to the formation of inorganic by-products in water electrolysis. Experiments in non-divided cells were performed with systems containing sulphate, chloride, chlorite, chlorate and nitrate ions. Discontinuous experiments in thermostated cells with rotating disk diamond anodes and expanded mesh IrO₂ cathodes were carried out at 20 °C. Current density was varied between 50 and 300 A m⁻². Ion chromatography was mainly used for species detection.

It was not possible to demonstrate the decomposition of sulphate although a slight tendency seems to exist in some experiments. Hydrogen peroxide is one of the anodic and cathodic by-products. Active chlorine is detectable at higher chloride concentrations compared with the use of mixed oxide anodes (MIO). One reason for this is the reaction of formed chlorine with ozone or hydrogen peroxide. Chlorate can be formed electrolysing chloride, hypochlorite and chlorite solutions. Perchlorate formation was detected. Cathodic processes are responsible for the formation of nitrite ions and ammonia. If chlorine is present, the formation of monochloramine is one possible side reaction. Results show that the processes are very complex. Reaction spectra may vary from case to case. Perchlorate formation is a high risk in drinking water treatment.     

Analysing the Diversity of Water Pricing Structures: The Case of France

This paper presents the results of a 2003 national survey of urban water pricing structure implemented by 429 district level water utilities. After providing some background elements on the diversity of existing water pricing structures, the paper shows how each structure can be used to achieve different management objectives (water allocation efficiency, costs recovery, and equity). It then describes the structures adopted by French water utilities, showing that flat rate are rarely adopted; declining blocks frequently used; and increasing blocks pricing which should be used to promote water use efficiency remain extremely rare. A statistical clustering is then conducted and a typology of situations elaborated. The paper concludes with highlighting that current pricing structures are influenced by past practices and that the dominant objective of water utilities is to cover costs.     

永久式防倒灌隔水采油工艺在长庆油田的应用

长庆油田存在严重的套管腐蚀损坏,采取的主要治理措施是隔水采油工艺技术。原有隔水采油工艺存在隔采周期短、检泵时水层倒灌污染油层、多次隔采后坐封难度大等问题,为此,试验应用了永久式防倒灌隔水采油工艺。现场试验、应用表明,该工艺具有隔采成功率高、隔采周期长等优点,能有效防止检泵时上部水层倒灌污染油层,具有很好的应用价值和推广前景。     

隆德县大水沟饮水工程建设与管理措施分析

隆德县在大水沟农村饮水工程建设管理中，科学规划，优化设计方案，完善政策措施，创新管理体制和运行机制，尤其是用水户全过程参与工程建设管理、实行“两部制”水价、实施工程定期检查养护制度、建立工程管理单位目标责任考核制度、执行水费统一管理和提留统筹费等一系列做法．确保了国家投资效益的充分发挥和工程的可持续利用．     

全国农田水利建设先进县的经验与启示

针对农田水利建设下滑的被动局面，各地积极探索，从加强领导、拓宽投入渠道、创新体制和机制等方面积极采取措施，取得了很大成效。对国务院2006年表彰的100个全国农田水利建设先进县（市、区）中的35个县（市、区）进行了调研，总结了它们的主要做法、经验，提出农田水利建设先进县的三点启示。     

Digital Yellow River Model

Soil erosion is one of the key concerns in land use management for the Loess Plateau of the Yellow River, where serious soil loss is the root cause of environmental and ecological degradation of the basin. In this paper, a physically-based, distributed-parameter, and continuous erosion prediction model at the river basin scale was developed with the aim of assisting in developing better land use management strategies. The framework, the major supporting techniques, and the typical erosion processes are described. The physical processes of sediment yield and transport in the Loess Plateau are divided into three sub-processes, including the runoff and sediment yield on hillslopes, gravitational erosion in gullies, and hyperconcentrated flow routing in channels. For each sub-process, a physically-based simulation model was developed and embedded into the whole model system. The model system was applied to simulate the runoff and sediment yield in several typical years in the coarse sediment source area of the Loess Plateau, and the simulated results were in reasonably good agreement with the measured values.     

DFMC在水利机械产品开发中的应用研究

分析了DFMC(大规模定制设计)关键技术及相关技术,提出了运用该项技术开发产品企业应作好的前期准备,研究了水利机械产品"大型移动启闭机"的定制开发。     

漳河灌区末级渠系农业水费补贴机制的思考

农村税费改革以来，漳河灌区末级渠系面临着建设与管理缺位、投入不足、责任不明等问题，虽然灌区管理单位也进行了水价改革等积极有效的探索与实践，取得了一定成效，但仍有一些问题亟待破解。结合漳河灌区实际．应加强末级渠系建设奖补基金筹措并改进补发方式，要充分发挥农民用水户协会的作用；在农业水费补贴机制方面．建议将基本水费纳入财政直补范围，建议将农业水费直补金统一发放到末级渠系农民用水户协会。     

数字电台在水库雨情遥测系统中的应用

用数传电台实现远程数据采集、监视与控制,具有造价低廉、施工快捷、运行可靠、维护简单、适应性强、扩展方便等优点。在水库雨情遥测子系统中应用,效果很好。     

Design of new systems for transfer hydrogenolysis of polychlorinated aromatics with 2-propanol using a Raney nickel catalyst

A multipurpose study deals with the transfer hydrogenolysis of 1,3,5-trichlorobenzene to benzene in the 2-propanol–Raney nickel system in the presence of KOH. At 70 °C, no reaction occurs without KOH or with weaker bases, e.g. amines or poorly soluble inorganic bases; however saturated KOH as well as water over 1% suppress the reaction rate, presumably due to the competitive adsorption of these species on the catalyst. The catalytic activity also drops with time because of the deposition of the solid KCl on the catalyst but can be recovered at washing the catalyst with water. The deactivation by KCl can be mitigated with the addition of promoters, e.g. quaternary ammonium salts (Aliquat 336, CTAC) or trioctylamine. Aliquat 336 also promotes hydrodechlorination in the hydrothermal system using a 10% solution of 2-propanol in water, Raney nickel and potassium carbonate as base at 150–200 °C and 10–20 bar. Under these conditions, hexachlorobenzene was also selectively dechlorinated to benzene.