反渗透淡化水水质特征及调质目标研究

Study on Water Quality Characteristics and Adjusting Target for Reverse Osmosis Desalination

对海水淡化的一级反渗透和二级反渗透产水进行水质分析,结果表明所产淡水水质特征为:TDS小于500 mg/L,Ca2+、Mg2+浓度均小于1 mg/L,总硬度和总碱度均小于5 mg/L (以CaCO3计)。与饮用天然矿泉水相比,反渗透淡化水的总硬度、总碱度及Ca2+浓度、Mg2+浓度均较低,影响饮用口感,并可能会造成管路和海水设备腐蚀,故应对其进行调质。根据饮用矿泉水水质特征分析,建议调质目标:总硬度和总碱度分别为50~200 mg/L和30~200 mg/L (以CaCO3计),Ca2+浓度为10~40 mg/L,Mg2+浓度为5~20 mg/L。结合以上水质特征分析比较,并参考国内外相关饮用水的标准,最终确定推荐调质目标为:总硬度50~200 mg/L (以CaCO3计),总碱度为30~150 mg/L (以CaCO3计),Ca2+浓度为10~50 mg/L,Mg2+浓度为5~20 mg/L。

The water quality of primary reverse osmosis and secondary reverse osmosis water of seawater desalination is analyzed.The results show that the characteristics of fresh water quality are:TDS is less than 500 mg/L,Ca2+,Mg2+concentrations are all less than 1 mg/L.The total hardness and basicity are less than 5 mg/L(in CaCO3).Compared with drinking natural mineral water,the total hardness,total basicity,Ca2+concentration and Mg2+concentration of desalination water are all lower,which affects the drinking taste and may cause corrosion of pipe network and seawater desalination equipment,so it should be adjusted and tempered.According to the characteristic analysis of drinking mineral water quality,it is suggested that the remineralization target should be:total hardness and total basicity are 50-200 mg/L and 30-200 mg/L(in CaCO3),Ca2+concen-tration is 10-40 mg/L,Mg2+concentration is 5-20 mg/L,respectively.Based on the analysis of the above water quality characteristics,and referring to the standards of drinking water at home and abroad,the final decision of the recommended regulation is made.Quality objectives:total hard-ness is 50-200 mg/L(in CaCO3),total basicity is 30-150 mg/L(in CaCO3),Ca2+concentration is 10-50 mg/L and Mg2+concentration is 5-20 mg/L.