机械力活化方解石复合硫酸亚铁去除水中镉/砷复合污染研究

Efficient removal of Cd/As combined pollution in water by mechanically activated calcite with FeSO_4

水体中的镉、砷等重金属污染严重威胁人类的健康安全,其中镉/砷复合污染去除难度更大。通过水中镉/砷复合污染去除试验,探究机械力活化方解石复合硫酸亚铁去除镉/砷复合污染的性能,发现机械力活化方解石可显著提升水中镉/砷复合污染的去除效果。试验结果表明,活化方解石复合硫酸亚铁在30 min内对溶液中镉、砷离子的去除率可达到99%以上。采用SEM-EDS、XRD、XPS等方法对活化方解石复合硫酸亚铁高效去除水中镉/砷复合污染机理进行研究,结果表明,方解石在机械力活化的作用下改变了自身的结晶度和溶解活性,其在水体中溶解水解产生CO_(3)^(2-)与OH^(-)的性能明显提升,OH^(-)促进硫酸亚铁在溶液中与砷形成稳定的铁氧结合态沉淀,CO_(3)^(2-)与溶液中的镉结合形成稳定的碳酸镉沉淀。

Heavy metal pollution such as cadmium and arsenic in water seriously threatens human health and safety,and the removal of Cd/As combined pollution is more difficult.In this work,the performance of mechanically activated calcite composite FeSO_(4) to remove Cd/As combined pollution was investigated by Cd/As combined pollution removal test in water.It was found that mechanically activated calcite can significantly improve the removal efficiency of Cd/As combined pollution in water.The results showed that the removal rate of Cd and As can reach 99% in 30 min by activated calcite composite FeSO_(4).The removal mechanism of Cd/As combined pollution in water by activated calcite and FeSO_(4) was studied by SEM-EDS,XPS,and XRD.The results showed that the crystallinity and dissolution activity of calcite were changed by mechanical activation,and the hydrolysis of calcite to produce CO_(3)^(2-) and OH-was enhanced.OHpromoted the formation of a stable iron oxide bound precipitate of FeSO_(4) with arsenic,and CO_(3)^(2-) binded with cadmium to form a stable precipitate of cadmium carbonate.