纳米级天然黄铁矿去除水中Cr6+,Cd2+和Pb2+

利用机械球磨的方法可以提高天然黄铁矿的活性，通过XRD和TEM对机械球磨后黄铁矿粉末的表面形态和物理性质进行表征。通过批实验的方法探讨在不同的pH，不同的球磨黄铁矿用量，不同的反应时间和温度的条件下黄铁矿对Cr6+，Cd2+和Pb2+的去除效果。研究结果表明，金属离子的吸收受到pH的影响，随着pH的升高，3种金属离子的吸附趋势出现了很大的不同。并且在分析pH对反应效果的影响时，需要考虑金属生成沉淀时的pH。同时，随着反应时间和温度的增加，3种金属离子的吸收量都有不同程度的升高。通过实验比较，球磨黄铁矿对Cr6+，Cd2+和Pb2+的去除能力大小为Pb2+ > Cr6+ > Cd2+。纳米级黄铁矿与Cr6+，Cd2+和Pb2+的反应过程符合准二级动力学方程。

Adsorption of Cr6+, Cd2+ and Pb2+ from aqueous solutions by nanoscale pyrite

The use of mechanical ball milling to prepare pyrite nanoparticles can improve the activity of natural pyrite. Physical properties and surface morphologies of the pyrite nanoparticles after ball milling were monitored by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The removal effects of Cr6+, Cd2+, and Pb2+ under conditions of different pH values, different dosages of the milled pyrite, different reaction times, and different temperatures were investigated by batch experiments. The results showed that metal ion adsorption was affected by the pH and with increasing pH, the adsorptions of Cr6+, Cd2+, and Pb2+ were different. Furthermore, the precipitation pH of metal ions should also be considered. With increasing reaction time and temperature, the uptakes of Cr6+, Cd2+ and Pb2+ increased. The Cr6+, Cd2+, and Pb2+ adsorption capacities decrease in the order of Pb2+ > Cr6+ > Cd2+. The dynamic adsorption data of Cr6+, Cd2+, and Pb2+ on nano-sized pyrites were well described by a pseudo second-order kinetic equation.