淡化海水进入水泥砂浆内衬管后的水质化学稳定性

发布时间：2018-06-30 02:20

本文选题：淡化海水 + 水泥砂浆内衬　；参考：《中国给水排水》2016年17期

【摘要】：淡化海水由于氯离子浓度高、碱度低而具有侵蚀性,在进入供水管网前一般需进行矿化来提高硬度和碱度;使用有内衬的管网输送也可以进一步减轻其侵蚀危害。利用水泥砂浆内衬管搭建管段模拟反应器,测试了不同条件下淡化海水在其中长时间输送时的水质变化。结果表明,对于未矿化和矿化后的淡化海水,运行前5 d管段反应器内水的pH值、总碱度、溶解性SiO_2均显著升高,之后下降,后15 d基本平衡。未矿化水在管段反应器停留时,其钙离子浓度(以CaCO_3计)在初期从1 mg/L急剧升高到50 mg/L,矿化水则从50 mg/L降低到10 mg/L左右,后期都达到基本相同的平衡浓度;镁离子浓度基本保持不变,在1~5 mg/L之间。矿化水加氯组和不加氯组的TOC均是初期较高,而后呈下降趋势,加氯组的TOC浓度高于不加氯组。两组均出现铝严重超标现象,铁浓度维持在0.3 mg/L上下,铬仅在初期超标。因此,建议使用水泥砂浆内衬管输送淡化海水之前,需要通水冲洗4~5 d以使水质达到稳定。
[Abstract]:Desalination seawater is erosive because of its high concentration of chloride ion and low alkalinity, so it is necessary to increase hardness and alkalinity before entering the water supply network. The water quality of desalinated seawater was measured under different conditions by using cement mortar liner tube to build a pipe section simulation reactor. The results showed that the pH value, total alkalinity and dissolved SiO-2 of the water in the reactor were significantly increased 5 days before the operation, then decreased, and the balance was basically in the last 15 days for the desalinated seawater without mineralization and mineralization. The results showed that the pH value, total alkalinity and dissolved SiO2 in the reactor were significantly increased in the first 5 days of operation. When the unmineralized water stays in the tubular reactor, the calcium ion concentration (in terms of CaCO3) increases sharply from 1 mg / L to 50 mg / L at the initial stage, while the mineralized water decreases from 50 mg / L to about 10 mg / L, and reaches the same equilibrium concentration in the later stage. The concentration of mg ~ (2 +) is almost unchanged in the range of 1 mg / L ~ (-1) mg 路L ~ (-1). The concentrations of TOC in chlorinated and non-chlorinated water groups were higher at the beginning and then decreased. The concentration of TOC in the chlorine-added group was higher than that in the non-chlorinated group. In both groups, the concentration of iron was about 0.3 mg / L, and chromium was only in the initial stage. Therefore, it is suggested that before desalination is carried out with cement mortar liner, it is necessary to flush water for 4 ~ 5 days in order to make the water quality stable.
【作者单位】：清华大学环境学院;北京市市政工程设计研究总院有限公司;
【基金】：国家水体污染控制与治理科技重大专项(2012ZX07404002)
【分类号】：TU991

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