Mohapatra Debasish, Mishra Debaraj, Park Kyung Ho
DAEIL Development Co. Ltd., Research and Development Center, Ansan 425 836, Korea.
J Environ Sci (China). 2008;20(6):683-9. doi: 10.1016/s1001-0742(08)62113-0.
The present work deals with the As(V) removal from an aqueous medium by calcined refractory grade bauxite (CRB) as a function of solution pH, time, As(V) concentration and temperature. The residual As(V) was lowered from 2 mg/L to below 0.01 mg/L in the optimum pH range 4.0-7.0 using a 5 g/L CRB within 3 h contact time. The adsorption data fits well with Langmuir isotherm and yielded Langmuir monolayer capacity of 1.78 mg As(V)/g of CRB at pH 7.0. Presence of anions such as silicate and phosphate decreased As(V) adsorption efficiency. An increase temperature resulted a decrease in the amount of As(V) adsorbed by 6%. The continuous fixed bed column study showed that at the adsorbent bed depth of 30 cm and residence time of 168 min, the CRB was capable of treating 340 bed volumes of As(V) spiked water (C0 = 2 mg/L) before breakthrough (Ce = 0.01 mg/L). This solid adsorbent, although not reusable, can be considered for design of adsorption columns as an efficiency arsenic adsorption media.
本研究探讨了煅烧耐火级铝土矿（CRB）从水介质中去除五价砷（As(V)）的情况，该过程是溶液pH值、时间、As(V)浓度和温度的函数。在最佳pH范围4.0 - 7.0内，使用5 g/L的CRB，接触时间为3小时，残余As(V)从2 mg/L降至0.01 mg/L以下。吸附数据与朗缪尔等温线拟合良好，在pH 7.0时，CRB的朗缪尔单层吸附容量为1.78 mg As(V)/g。硅酸根和磷酸根等阴离子的存在会降低As(V)的吸附效率。温度升高导致As(V)吸附量减少6%。连续固定床柱研究表明，在吸附剂床层深度为30 cm、停留时间为168分钟时，CRB能够在穿透（Ce = 0.01 mg/L）前处理340个床体积的As(V)加标水（C0 = 2 mg/L）。这种固体吸附剂虽然不可重复使用，但作为一种高效的砷吸附介质，可考虑用于吸附柱的设计。
