以硫酸亚铁为原料生产电池级磷酸铁过程中产生大量的含硫酸根、磷酸根、钠离子的废水。为减少废水排放并使之得到循环利用,采用反渗透膜技术对中试生产电池级磷酸铁的废水处理进行了零排放设计和实验研究,考察了进水压力、进水浓度、温度、pH等因素对硫酸根和磷酸根的截留率、膜通量和产水率的影响。实验结果表明所采用的反渗透膜对硫酸根、磷酸根的截留率达99.15%以上,进水压力、进水浓度、温度、pH等因素对截留率影响较小,但对膜通量和产水率影响较大。截留率随着进水压力的增加略有增加,随进水浓度增加和温度的升高而略有减小,膜通量和产水率随进水压力和温度的升高而增大,随进水浓度的增大而减小,pH=6.5时截留率、膜通量和产水率最高。同时采用生产废水制备了硫酸钙晶须,实现了废水零排放。

In the process of producing battery grade iron phosphate with ferrous sulfate as raw material,a large amount of waste water containing SO₄^2-,PO₄^3- and Na⁺ is produced.In order to reduce the waste water discharge and recycle them,the reverse osmosis membrane process design and experimental study were carried out for a zero-discharge waste water of the pilot produc-tion of battery grade iron phosphate.The effect of input pressure,feed concentration,temperature and pH value on the retent-ion rate of SO₄^2- and PO₄^3-,membrane flux and water yield were investigated.Experimental results showed that the retention rate of SO₄^2- and PO₄^3- by the reverse osmosis membrane was over 99.15%.The input pressure,feed concentration,temperature and pH value had little influence on the retention rate,but showed great influence on the membrane flux and water yield.The retention rate increased slightly with the increase of input pressure and decreased slightly with the increase of feed concentration and temperature.The membrane flux and water yield increased with the increase of input pressure and temperature,and decreased with the increase of feed concentration.The interception rate,membrane flux and water yield were highest at pH=6.5.The calcium sulfate whisker was also prepared from the wastewater,and the zero discharge of waste water was realized.