高硬度富锶地下水的软化沉淀-超滤膜联用工艺

针对一种高硬度富锶地下水,分别采用石灰和石灰-碳酸钠两种方法,利用药剂软化/超滤膜工艺对其进行软化处理,同时考察了药剂投量对出水锶含量的影响。结果表明,采用石灰软化/超滤膜法,Ca(OH)2最佳投加量为270 mg/L时,出水总硬度(以CaCO3计)由287.12 mg/L降低到96.44 mg/L,硬度去除率为66.41%,出水锶含量也由原水中的0.37 mg/L下降为0.21 mg/L;而采用石灰-碳酸钠软化/超滤膜法,Ca(OH)2和Na2CO3最佳投加量分别为270 mg/L、160mg/L时,出水总硬度降低到60.34 mg/L,硬度去除率达78.98%,锶含量仅为0.02 mg/L。2种处理方法出水总硬度均达到预期目标,石灰软化/超滤膜法可使出水锶含量满足富锶水的要求,而石灰-碳酸钠软化/超滤膜法则造成了对人体有益微量元素锶的大量损失。

Treatment of high hardness and strontium-rich groundwater by chemical softening-ultrafiltration process

Chemical softening-ultrafiltration processes with lime or lime-sodium carbonate composite as the softening agents were investigated on the treatment of high hardness and strontium-rich groundwater,and the effects of chemical dosage on the strontium content in the effluents were studied.The results showed that the total hardness was reduced from 287.12 mg/L to 96.44 mg/L with its removal of 66.41% and strontium content in the effluent was from 0.37 mg/L to 0.21 mg/L at the optimal dosage of 270 mg/L Ca(OH)₂,while for the lime-sodium carbonate method the total hardness was 60.34 mg/L with 78.98% of the removal and strontium content was 0.02 mg/L at the optimal dosage of 270 mg/L Ca(OH)₂ and 160 mg/L Na₂CO₃.Both the lime and lime-sodium carbonate composite methods by the chemical softening/ultrafiltration process can get the effluent total hardness to the requirement for groundwater softening treatment.The effluents by the lime softening/ultrafiltration method still maintain its high-level content of trace strontium,which is beneficial to man's health and makes them suitable for the quality of strontium-rich mineral water,whereas a great loss of trace strontium in the groundwater was resulted in by the lime-sodium carbonate composite softening/ultrafiltration method.