双极膜电渗析法在自来水出厂水化学稳定性的应用研究

发布时间：2018-04-23 22:16

本文选题：化学稳定性 + 双极膜电渗析　；参考：《浙江工业大学》2015年硕士论文

【摘要】：城市自来水管网生垢、侵蚀等导致出厂水水质化学不稳定困扰着广大用户。目前,绍兴出厂水、供水管网的水质较理想,但是由于水厂原水的pH较低,使得水的化学稳定性较差,腐蚀现象一直存在,“黄水”问题频发。本文旨在研究应用双极膜电渗析技术,开发一种高效调节自来水出厂水的化学稳定性的水质调质工艺。以氯化钠和碳酸钙为原料,采用双极膜技术,将水直接解离成H+和OH-,不生成气体,能耗低,产物氢氧化钠可以直接加入水中提高出水的pH值。副产物盐酸可淋洗碳酸钙生成溶解性的碳酸氢钙,提高出水的碳酸盐平衡,增加出厂水中的碱度和硬度,提高水质的化学稳定性,从而达到调理出厂水水质的目的。通过对绍兴宋六陵水厂采用双极膜法水质调质技术工艺与石灰工艺运行经济性比较研究可知,在不考虑设备投资的情况下,与采用商品氢氧化钠调节出厂水pH相比,双极膜装置产酸产碱有一定的经济效益。双极膜法水质调质技术调节出厂水pH和硬度等指标可控性强,能解决提高出厂水硬度时pH可能超标的问题。同时也解决了石灰投加过程管路易堵塞,出厂水pH不稳定等问题。但经济性比较表明与目前水厂采用的熟石灰工艺相比,双极膜法水质调质技术工艺经济性有差距,还需要更多深入的研究来推广双极膜法水质调质技术。
[Abstract]:Urban water pipe network scale, erosion and so on leading to chemical instability of factory water quality puzzles the majority of users. At present, the water quality of Shaoxing water supply network is ideal, but due to the low pH of raw water, the chemical stability of water is poor, corrosion has always existed, and the problem of "yellow water" occurs frequently. The purpose of this paper is to develop a high efficiency water quality conditioning process for regulating the chemical stability of tap water by using bipolar membrane electrodialysis technology. Using sodium chloride and calcium carbonate as raw materials, water was dissociated into H and OH-directly by bipolar membrane technology, no gas was generated, and the energy consumption was low. Sodium hydroxide could be added directly to the water to increase the pH value of the effluent. The by-product hydrochloric acid can wash calcium carbonate to form soluble calcium bicarbonate, improve the carbonate balance of effluent, increase the alkalinity and hardness of the effluent, improve the chemical stability of the water quality, and thus achieve the purpose of regulating the water quality of the factory water. By comparing the operation economy of water quality conditioning technology with lime process by using bipolar membrane method in Shaoxing Song Liuling Water Plant, it can be seen that, without considering the investment of equipment, it is compared with adjusting the pH value of raw water by commercial sodium hydroxide. The production of acid and alkali in bipolar membrane plant has certain economic benefits. The bipolar membrane water quality conditioning technology can regulate the pH and hardness of the factory water, which can solve the problem that pH may exceed the standard when increasing the hardness of the water. At the same time, the problems such as easy blockage of pipeline and unstable pH of factory water are also solved. However, the economic comparison shows that compared with the current hydrated lime process, the bipolar membrane water quality conditioning technology has a gap in economy, and more in-depth research is needed to popularize the bipolar membrane water quality conditioning technology.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU991.2

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