CSIR-Indian Institute of Toxicology Research, Lucknow, 226001, India.
Environ Sci Pollut Res Int. 2013 Jun;20(6):4000-8. doi: 10.1007/s11356-012-1342-x. Epub 2012 Dec 4.
To evaluate the biosorption efficacy of submerged aquatic plant Hydrilla verticilata for arsenic uptake from drinking water. H. verticillata, a submerged aquatic plant was utilized successfully for arsenic uptake from aqueous solution. Batch studies with various parameters viz. pH, sorbent dose, contact time, initial metal ion concentration, and temperature were carried out. Data were utilized to plot Lagergren graph along with pseudo-second-order graphs for kinetic studies to estimate the removal efficacy and to determine the nature of reaction. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) have been performed for characterization of metals on biomass. The study showed 96.35 % maximum absorption of arsenic by H. verticilata at initial concentration of 100 ppb with 0.5 g of biomass/100 ml for 5 h contact time at pH 6.0 with 150 rpm agitation rate. Data followed Langmuir isotherm showing sorption to be monolayer on homogeneous surface of biosorbent. The negative values of ΔG° indicated spontaneous nature; whereas ΔH° indicates exothermic nature of system and negative value of ∆S° entropy change correspond to a decrease in the degree of freedom to the adsorbed species followed by pseudo-second-order adsorption kinetics. FTIR and SEM results showed apparent changes in functional group regions after metal chelation and the changes in surface morphology of biosorbent. This is a comparatively more effective, economic, easily available, and environmentally safe source for arsenic uptake from solution due to its high biosorption efficacy than other biosorbents already used.
为了评估水生植物水蕴草从饮用水中摄取砷的生物吸附效果。水生植物水蕴草成功地被用于从水溶液中摄取砷。进行了各种参数的批量研究，如 pH 值、吸附剂剂量、接触时间、初始金属离子浓度和温度。数据用于绘制 Lagergren 图以及伪二阶图进行动力学研究，以估计去除效率并确定反应的性质。对生物量上的金属进行了扫描电子显微镜 (SEM) 和傅里叶变换红外光谱 (FTIR) 表征。研究表明，在初始浓度为 100ppb、生物质用量为 0.5g/100ml、接触时间为 5h、pH 值为 6.0、搅拌速度为 150rpm 的条件下，水蕴草对砷的最大吸收量为 96.35%。数据遵循 Langmuir 等温线，表明吸附是在生物吸附剂均匀表面上的单层吸附。ΔG°的负值表明是自发的；而 ΔH°表明系统是放热的，熵变的负值对应于吸附物种的自由度降低，随后是准二级吸附动力学。FTIR 和 SEM 结果表明，在金属螯合后，官能团区域和生物吸附剂表面形貌发生了明显变化。与已经使用的其他生物吸附剂相比，由于其高生物吸附效率，水蕴草是一种更有效、经济、易得且环境安全的从溶液中摄取砷的来源。
