船舶反渗透海水淡化水矿化重碳酸盐适宜浓度分析

摘要

目的 探讨船舶反渗透海水淡化水矿化重碳酸盐的适宜浓度.方法 通过分析重碳酸盐对腐蚀指数影响、船舶淡化水矿化方法,以及相关水质标准,从多角度提出船舶反渗透海水淡化水矿化重碳酸盐的适宜浓度,再利用我国城市饮用水水质验证.结果 重碳酸盐浓度增加对反渗透海水淡化水腐蚀性改善作用显著,HCO3-浓度>90 mg/L对淡化水的腐蚀性改善作用降低;多数国家针对腐蚀性(软)水推荐碱度HCO3->30 mg/L;船舶反渗透海水淡化水矿化宜采用直接投加药剂法,但碳酸氢钠溶解度较低.结论 综合船舶环境特性和保障条件,建议反渗透淡化水矿化重碳酸盐适宜浓度采用30～90 mg/L,50％城市饮用水重碳酸盐平均浓度在此范围.%Objective To research the proper bicarbonate concentration for shipboard seawater reverse osmosis ( RO) remineralization. Methods Comprehensive analyses were made on the effects of HCO3- l on the desalination corrosion index, the methods of shipboard seawater reverse osmosis remineralization and related remineralization criteria. Then, the range of proper bicarbonate concentration of soft water remineralization was recommended for shipboard seawater reverse osmosis remineralization from different angles, which was verified by municipal drinking water quality survey results. Results HCO3- concentration greater than 90 mg/L could significantly reduce corrosiveness of desalinated water. Nevertheless, the contribution ration for Langelier index ( LSI) was debased when HCO3- was greater than 90 mg/L. At present, the minimum quality criteria for HCO3-concentration was equal or greater than 30mg/L proposed by most countries. Shipboard desalination remineralization was more preferable with direct addition of agent, but the dissolution of bicarbonate was quite low in water. Conclusion In consideration of the shipboard environment and support capability, the applicable bicarbonate concentration of shipboard RO desalination remineralization was 30-90 mg/L, which was within the range of drinking water bicarbonate concentration for 50％ of the cities in our country.