黄铁矿净化水中低浓度磷

以产自安徽铜陵新桥矿的黄铁矿为典型样品,研究黄铁矿对磷的吸附作用。静态实验考察黄铁矿粒度、固液比、pH值、离子强度、温度、吸附时间等因素对黄铁矿去除磷效果的影响,XPS和FE-SEM研究吸附磷后黄铁矿颗粒表面形貌和成分特征。结果表明：黄铁矿粒径越小（50～180目）,去除磷效率越高（9.3%～90.7%）;提高固液比（0.2～2 g/L）,磷的去除率增加（6.5%～97.1%）;在pH值3～9.65范围内黄铁矿对磷都有很好的去除效率（95%以上）;NO3-对磷的去除效果表现为微弱的促进作用,Cl-有微弱的抑制作用,溶液中SO42-、HCO3-对黄铁矿吸附磷表现出较强的抑制作用。温度对黄铁矿吸附效率基本没有影响。黄铁矿对磷吸附动态实验表明除磷效率在16 h后接近最大值。除磷作用机理是黄铁矿表面缓慢氧化产生的三价铁对磷的化学吸附。成果表明黄铁矿用于净化污水中低浓度磷具有很大的潜力。

Removal Phosphate in Low Concentration by Pyrite

Pyrite,collected from Xinqiao ore of Tongling City,Anhui Province,China as typical sample,was used to study its adsorption of phosphate.In this paper,the influence of particle size of pyrite,solid/liquid ratio,suspension pH,ionic strength,temperature,and sorption time on phosphate removal was investigated by conducting a series of batch sorption experiments to study low concentration of phosphate removal by pyrite.In addition,the modified samples had been characterized with XPS and FE-SEM image.As the result of this study,the efficiency of phosphate removal increases(9.3%～90.7%,6.5%～97.1%) by smaller particle size(50～180 mesh) of pyrite and higher solid/liquid ratio(6.5%～97.1%).Within in pH 3～9.5,efficiencies of phosphate removal are similar,in excess of 95%.In the presence of nitrate anions,phosphate removal by pyrite is weak.Slight impacts were seen with chloride and sulfate,and large were seen with bicarbonate anions.The temperature had a little effect on phosphate removal.Kinetics shows that the maximum removal efficiency by pyrite occurs after 16 hours of contact.The mechanism of uptake phosphate is in virtue of chemisorption between phosphate and ferric ion released by pyrite oxidation.Therefore,removing phosphate in low concentration by pyrite oxidation had great potential for application in wastewater.