考察了摇床转速、Fe0粒径、溶液pH、溶解氧以及背景电解质等条件对Fe0去除As(Ⅲ)速率的影响,并探讨了不同影响因素下的作用机制.结果显示,转速高于100 r·min-1时,Fe0腐蚀速率明显加快,As(Ⅲ)去除速率提高,在50 r·min-1时,Fe0腐蚀速率和As(Ⅲ)去除速率接近静止状态;Fe0粒径显著地影响As(Ⅲ)去除速率,粒径减小,速率增大.随着pH升高,As(Ⅲ)去除速率降低;低的pH能加速Fe0腐蚀,同时导致更多的具有吸附活性的新生态铁氧化物生成;空气环境可以显著促进Fe0的腐蚀从而加速As(Ⅲ)的去除速率.CaSO4作为背景电解质时,Fe0的腐蚀行为更接近其在天然水体中的腐蚀行为.
Batch tests were performed to evaluate the removal kinetics of As(Ⅲ) by zero valent iron(ZVI) in different reaction or operational conditions such as the shaking intensity,particle size,solution pH,dissolved oxygen,electrolytes and so on,and to investigate the reaction mechanism under the influences of these factors.The results showed that the corrosion rate of ZVI increased remarkably when the shaking speed was faster than 100 r · min-1,and the removal efficiency of As(Ⅲ) increased correspondingly.A 50 r · min-1,the corrosion rate and the removal efficiency of As(Ⅲ) were close to static state.The particle size of ZVI had significant effect on the removal kinetics of As(Ⅲ),and the removal kinetics increased when the particle size decreased.The removal efficiency of As(Ⅲ)decreased with the increase of pH value.At low pH conditions,the corrosion rate of ZVI was accelerated,and more corrosion products were produced and more active sites were available for As(Ⅲ) removal.The presence of oxygen accelerated the corrosion rate of ZVI,speeding up the removal efficiency of As(Ⅲ).When CaSO4 was used as the electrolyte,the corrosion behavior of ZVI was closer to natural water.