反渗透除氟除氨氮技术在饮用水中的应用

反渗透工艺可有选择地将氟离子、氨氮与水分离。水质监测表明,宁夏B市A水厂出水氟化物和氨氮浓度超标,针对现有工艺状况及水质特征,A厂采用了反渗透除氟除氨氮技术进行水质提标改造。为了节省投资及运行成本,采用原水+反渗透膜处理水勾兑方案,近远期勾兑比例分别为3.5∶1和10∶3。主体工艺为多介质过滤器+反渗透装置。长期运行的结果表明,反渗透工艺对氟化物与氨氮的去除效率分别为97%和88%。A厂改造后的出水氟化物浓度、氨氮浓度及其他指标均满足饮用水卫生标准要求,运行成本仅增加0.31元/m³。此工程为国内首次较大规模采用反渗透除氟除氨氮的供水厂,对于以地下水为水源且氟化物、氨氮等特征因子超标的原有水厂提标改扩建、新建水厂除氟、除氨氮具有推广及示范意义。

Application of Enhanced Fluoride and Ammonia Removal by Reverse Osmosis in Drinking Water

Reverse osmosis(RO)can selectively separate fluoride ions and ammonia nitrogen from water.Water quality monitoring shows that fluoride and ammonia nitrogen concentration in the effluent of A water plant in a city of Ningxia to be exceeding the standard.According to the existing technological status and water quality characteristics of A water plant,the reverse osmosis technology of fluoride and ammonia nitrogen removal are adopted to carry out the bid modification.In order to save investment and operation cost,the water blending scheme of raw water reverse osmosis membrane treatment is adopted.Near and long term blending ratio are 3.5:1 and 10:3 respectively.Main process is multi-medium filter reverse osmosis device.Long-term operation results show that the removal efficiency of fluoride and ammonia nitrogen is above 97%and 88%,and the fluoride concentration,ammonia nitrogen concentration and other indicators in effluent after the transformation meet the requirements of drinking water sanitation standards altogether,and the operation cost only increases by 0.31 yuan/m³.This project is the first-time for large-scale water supply plant in China to use reverse osmosis fluoride and ammonia nitrogen removal technology.It is of great significance to popularize and demonstrate the relevant technology in those water plants with groundwater as the original water source,i.e.,the characteristic factors such as fluoride and ammonia nitrogen of the original water exceeding the standard.