Monitoring of Distribution Water Qualities Under Various Source Water Blending

The main goal of this large-scale pilot distribution study was to systematically investigate the impacts of blending different source waters on distribution water qualities. The principal source waters investigated were conventionally treated ground water (G1), surface water processed by enhanced treatment (S1), and desalted seawater by reverse osmosis membranes (RO). Due to the nature of raw water quality and associated treatment processes, G1 water had high alkalinity, while S1 and RO sources were characterized as high sulfate and high chloride waters, respectively. One year of pilot pipe study demonstrated that water quality was significantly deteriorated by increased color when source water blends with characteristics different from historic groundwater were introduced to pipe distribution systems. Elevated color was associated with release of iron corrosion products, mainly from aged unlined cast iron pipes. Iron release increased significantly when exposed to RO and S1 waters: that is, the greater iron release was experienced with alkalinity reduced below the background of G1 water. Lead and copper release to water, on the other hand, enhanced with the application of RO and G1 waters, respectively.     

反渗透膜法海水淡化技术在大连石化公司的应用

大连石化公司采用反渗透膜法海水淡化工艺为生产装置提供淡水资源,其用水取自炼化装置冷却换热后的海水,不额外增加海水的取用量,降低了成本。装置采用常规预处理加三级反渗透膜分离技术,同时配备了能量回收装置,将反渗透高压"浓水"的能量转换到低压的原海水中,使得能耗大大降低。文章介绍了该工艺的流程及其技术特点,该装置节能、节水,其产品水质量达到甚至超过了中压锅炉补给水的要求。工程运行稳定,对沿海同类企业有借鉴意义。     

金属在固定与浮动海水全浸方式下的腐蚀差别

依据表面海水环境因素的垂直分布，分析了金属在固定和浮动两种海水全浸方式下的腐蚀行为差别，并通过9种金属材料在固定与浮动海水全浸方式下的暴露试验．对分析得出的结论进行了验证。表面海水的盐度、溶解氧含量、pH的垂直分布均匀．不会对固定和浮动两种全浸方式下暴露试样的腐蚀行为带采差别。表面海水温度的垂直分布不均匀性小。对固定和浮动两种全浸方式下暴露的试样的腐蚀行为不会造成可测量的差别。表面海水的流速、生物污损的差别不会对固定和浮动两种全浸方式下暴露试样的腐蚀行为产生明显的影响。同一种金属在固定。浮动两种海水全浸方式下的腐蚀行为不会有明显的差别。