煅烧牡蛎壳粉对水体中Pb^(2+)和Cd^(2+)的吸附研究

Research on Removal Adsorption of Pb^(2+) and Cd^(2+) in Water by Calcined Oyster Shell Powder

通过SEM和XRD等手段对800℃煅烧前后的牡蛎壳粉的显微形貌和组成进行了分析,探索了pH、温度、投加量等因素对煅烧后的牡蛎壳粉吸附水中Pb^(2+)和Cd^(2+)的影响,研究了煅烧后的牡蛎壳粉吸附水中重金属Pb^(2+)和Cd^(2+)的吸附动力学和吸附热力学特征。结果表明,煅烧后的牡蛎壳粉表面比未煅烧的牡蛎壳粉多了很多微小孔隙,牡蛎壳中的CaCO_3几乎完全变成CaO,煅烧后的牡蛎壳粉对重金属Pb^(2+)和Cd^(2+)的吸附过程符合Freundlich模型和拟二级动力学模型。因此,煅烧后的牡蛎壳粉对水中重金属Pb^(2+)和Cd^(2+)有较强的吸附性能,可净化受Pb^(2+)和Cd^(2+)污染的水体。

Phases and microstructure of pre-calcined and post-calcined were investigated by SEM and XRD.Adsorption kinetic and thermodynamic of heavy metals Pb2＋and Cd2＋on calcined oyster shell powder were studied.The effect of different pH,different temperature and different dosage of calcined oyster shell powder on adsorption of Pb2＋and Cd2＋was explored.The results show that particle size of the powder changed obviously and precursor powders undertake a series of decomposing during calcining.The study of adsorption isotherm model and adsorption kinetic model showed that the adsorption process of Pb2＋and Cd2＋on calcined oyster shell powder was fitted with the Freundlich model and the pseudo-second-order kinetic model.Therefore,the calcined oyster shell powder has strong adsorption properties for heavy metals Pb2＋and Cd2＋in water,and can purify water body polluted by Pb2＋and Cd2＋.The study on the removal of Cd2＋and Pb2＋in water by calcination of oyster shell powder will provides a theoretical basis for the resource utilization of wasted oyster shell.