Nitrate Removal from Ground Water by Combination of Ion Exchange and Biological Denitrification

地下水中硝酸盐浓度的增加正成为几个国家的一个重要问题。在日本，饮用水中总硝酸盐和亚硝酸盐的最高允许浓度为10 mg/L。有几种技术可用于去除地下水中的硝酸盐和亚硝酸盐。但生物脱氮工艺不适用于给水处理，因为会产生致突变的有机副产物和生物污染物。本文介绍了一种离子交换与生物反硝化相结合的去除地下水中硝酸盐的新技术。在这个过程中，树脂的再生是通过反硝化反应器在闭路循环中实现的。但反硝化反应器的原水含盐量很高，很难形成厌氧条件。本实验研究的目的是在厌氧条件下实现生物反硝化，明确高盐浓度对反硝化的影响。结果表明：1)在好氧条件下，可以发生生物反硝化；2)高盐浓度对反硝化没有影响

Increased nitrate concentration in ground water is becoming an important problem in several countries. In Japan then maximum admissible concentration of total of nitrate and nitrite in drinking water is 10 mg/L.Several techniques are available for removal of nitrate and nitrite from ground water. But biological denitrification process is not available for water supply treatment, because of formation of mutagenic organic by-products and biological contaminants. Only ion exchange is considered practical process.In this study, a new technique, a combination of ion exchange and biological denitrification is described for nitrate removal from ground water. In this process the regeneration of resin in a closed circuit is achieved with a denitrification reactor. But raw water of denitrification reactor is very high salt concentration and it is very difficult to make anaerobic condition.The purpose of this experimenta study is to achieve biological denitrification in anaerobic condition and to clear effect of high salt concentration on denitrification. Results are as follows.1)In aerobic condition, biological denitrification can be generated.2)No effect of high salt concentration on denitrification