文章基本信息

标题：Adsorption of Arsenite from Water by Rice Husk Silica
本地全文：下载
作者：Taimur Khan ; Shahril Anwar Bin Ab Wahap ; Malay Chaudhuri 等
期刊名称：Nature, Environment and Pollution Technology
印刷版ISSN：0972-6268
出版年度：2012
卷号：11
期号：2
语种：English
出版社：Technoscience Publications
摘要：Arsenic occurs in groundwater in two valence states, as trivalent arsenite [As(III)] and as pentavalent arsenate[As(V)]. As(III) is more toxic and more difficult to remove from water by adsorption on activated alumina. Inthis study the ability of rice husk silica to adsorb As(III) from water was examined. Silica was prepared byburning rice husk in a muffle furnace at 500°C. Batch adsorption tests showed that extent of As(III) adsorptiondepends on pH, initial As(III) concentration and the contact time. Equilibrium adsorption was attained within180 min, with maximum adsorption occurring at a pH value of 7-8 which is in the pH range for groundwater.The adsorption of As(III) by rice husk silica followed pseudo second-order kinetics. Equilibrium adsorptiondata were well described by the Langmuir and Freundlich isotherm models. According to the Langmuirisotherm, As(III) adsorption capacity of rice husk silica is 1.897 mg/g which is 10.5x higher than that (0.180mg/g) of activated alumina. Hence, rice husk silica would be an effective substitute for activated alumina inthe removal of As(III) from groundwater at wells or in households.