双碱法耦合聚合氯化铝预处理高矿化度矿井水实验研究

Experimental Study on the Pretreatment of High Salinity Mine Water by Double Alkali Method Coupled Polyaluminum Chloride

膜技术脱盐常用于高矿化度矿井水回用处理,但在运行过程中钙、镁离子会影响膜性能,开展预处理降低硬度及浊度,对减轻膜污染、降低运行费用起着重要的作用。采用双碱法耦合聚合氯化铝去除矿井水的硬度及浊度,通过单因素试验考察了药剂投加量、反应时间、沉淀时间对去除效果的影响。结果表明:投加800 mg/L氢氧化钠、80 mg/L碳酸钠及20 mg/L聚合氯化铝,反应20 min,沉淀15 min,此时水样的总硬度含量为8.09 mg/L,总硬度去除率为92.30%,浊度去除率为99.75%。

Membrane technology has a good desalination effect used by high mineralization mine water,but the precipitation contamination caused by calcium and magnesium ions during operation greatly affects the membrane performance.Pre-treatment to reduce hardness plays an important role in reducing membrane contamination,improving effluent quality and reducing operating costs.The double alkali method coupled PAC were selected to remove the hardness and turbidity of mine water,and the effects of chemical dosage,reaction time and precipitation time on the removal effect were investigated using single-factor experiments.The optimum conditions were:the dosage of NaOH was 800 mg/L;the dosage of NaCO 3 was 80 mg/L;the dosage of PAC was 20 mg/L;the reaction was 20 min,and the precipitation was 15 min.The total hardness content of the water sample at this time was 8.09 mg/L,with a total hardness removal rate of 92.30%and a turbidity removal rate of 99.75%.