反渗透膜在磷酸铁废水(铵法)中的应用

Application of Reverse Osmosis Membrane in Iron Phosphate Wastewater(Ammonium Method)

磷酸铁生产废水包括洗水废水和母液废水,洗水与母液废水都含有大量的高浓度氨氮、硫酸根、磷酸根、重金属离子及无机盐的酸性废水,上述废水除了成分复杂外还有一个显著特点就是TDS高,母液废水TDS可达50000~60000 mg/L,洗水废水TDS可达5000~10000 mg/L,为处理这些废水并实现零排放,需要先进行预处理使其满足反渗透膜系统运行的要求,之后利用反渗透系统进行浓缩和回用,反渗透产水满足回用标准后进行回用,其浓水则进入蒸发结晶系统,蒸发结晶系统利用不同盐分的溶解度区别实现分盐并实现资源回收,其冷凝水则进入反渗透系统进行回收利用。

The wastewater generated during the production of ferric phosphate includes washing water and mother liquid,which contains high concentrations of ammonia nitrogen,sulfate,phosphate,heavy metal ions,and acidic wastewater with inorganic salts.Washing water also contains some ammonia nitrogen,sulfate,phosphate,etc.In addition to its complex composition,one remarkable feature of these wastewaters is their high TDS(total dissolved solids).The TDS of mother liquid can reach 50000~60000mg/L,while that of washing water can reach 5000~10000 mg/L.To treat these wastewaters,reverse osmosis(RO)systems are generally used for concentration and reuse.The RO effluent meets the reuse standards before being reused,while the concentrated water enters an evaporation crystallization system for recovery.However,to meet the influent requirements of the reverse osmosis concentration and reuse system,wastewater pretreatment is necessary to ensure the stability of the reverse osmosis reuse system and subsequent evaporation crystallization system.