花岗岩母质红壤吸附水中砷(Ⅴ)的影响因素试验

为探讨花岗岩母质红壤吸附水中砷(Ⅴ)的效果和机理, 采用静态吸附实验, 研究溶液砷初始浓度、反应时间、温度、pH值等因素对红壤吸附水中砷的影响.当溶液砷初始浓度小于5.0 mg/L时, 红壤对砷的去除率均大于97%;随着砷初始浓度增大, 去除率逐渐降低; 反应初期(0~120 min), 红壤对砷的去除率迅速增大至95.0%左右.此后, 去除率缓慢增大, 直到720 min后, 去除率达到97.0%左右, 并趋于稳定; 在砷初始浓度一定时, 红壤对砷的吸附量随着温度的升高逐渐增加, 但增加幅度较小; 红壤对砷的去除率随着体系pH值的增大呈减小趋势; 正交试验表明, 在砷初始浓度为5.0 mg·L-1、反应时间为120 min、pH为5.0及反应温度为40℃的组合下, 红壤对砷的去除率最大. 

Experiments of Factors Influencing Adsorption of As (V) in Water by Granite Red Soil

In order to study the effects and mechanism of adsorption of As (V) in water by granite-derived red soil, the batch experiments were conducted and the influence on the adsorption of As (V) by granite-derived red soil of the initial As concentration, the reaction time, the reaction temperature and the pH value were studied respectively. When the initial As concentration was below 5.0 mg/L, the removal rate of As was higher than 97%. With the increase of the initial As concentration, the removal rate decreased gradually. In the initial stage of the reaction(0-120 min), the removal rate increased rapidly to about 95%, and then it increased slowly to about 97% at 720 min. The system temperature had a small effect on the adsorption. And with the rising temperature, the removal rate only increased a little. The removal rate decreased gradually while the pH value increased. The orthogonal test indicates that the removal rate was highest when the initial As concentration, the reaction time, the pH value and the reaction temperature were respectively 5.0 mg/L, 120 min, 5.0 and 40℃.