PDF(Pubmed)
Abstract：
Pomelo, Citrus maxima, peel was chemically modified with lime water and then loaded with Fe(III) to develop anion exchange sites for effective sequestration of As(V) from water. Biosorbent characterizations were done by using FTIR, SEM, XRD, EDX, and Boehm\'s titration. The batch biosorption studies were carried out at various pHs using modified and non-modified biosorbents and optimum biosorption of As(V) occurred at acidic pH (3.0-5.0) for both the biosorbents. A kinetic study showed a fast biosorption rate and obtained results fitted well with the pseudo-second-order (PSO) model. When isotherm data were modeled using the Langmuir and Freundlich isotherm models, the Langmuir isotherm model fit the data better and produced maximal As(V) biosorption capacities of 0.72 ± 03, 0.86 ± 06, and 0.95 ± 05 mmol/g at temperatures 293± 1K, 298± 1K and 303± 1K, respectively. Desorptionof As(V) was effective using 0.1 M NaOH in batch mode. Negative values of ΔG° for all temperatures with positive ΔH° confirmed the spontaneous and endothermic nature of As(V) biosorption. The existence of co-existing chloride (Cl-), nitrate (NO3 -), sodium (Na+), and calcium (Ca2+) showed insignificant interference whereas a high concentration of sulphate (SO4 2-) and phosphate (PO4 3-) significantly lowered As(V) biosorption percentage. Arsenic concentrations in actual arsenic polluted groundwater could be reduced to the WHO drinking water standard (10 μg/L) by using only 1 g/L of investigated Fe(III)-SPP. The dynamic biosorption of As(V) in a fixed bed system showed that Fe(III)-SPP was effective also in continuous mode and different design parameters for fixed bed system were determined using Thomas, Adams-Bohart, BDST, and Yoon-Nelson models. Therefore, from all of these results it is suggested that Fe(III)-SPP investigated in this study can be a potential, low cost and environmentally benign biosorbent material for an effective removal of trace amounts of arsenic from polluted water.
摘要：
柚子,柑橘,用石灰水对果皮进行化学改性，然后负载Fe（III）以形成阴离子交换位点，以有效地将As（V）从水中隔离。使用FTIR对生物吸附剂进行了表征，SEM,XRD,EDX,和Boehm的滴定。使用改性和未改性的生物吸附剂在各种pH下进行分批生物吸附研究，并且两种生物吸附剂在酸性pH（3.0-5.0）下都发生了As（V）的最佳生物吸附。动力学研究显示了快速的生物吸附速率，并且获得的结果与伪二阶（PSO）模型很好地拟合。当等温线数据使用Langmuir和Freundlich等温线模型建模时，Langmuir等温线模型更好地拟合了数据，并在293±1K温度下产生了0.72±03、0.86±06和0.95±05mmol/g的最大As（V）生物吸附能力，298±1K和303±1K，分别。在分批模式下使用0.1MNaOH对As(V)的脱盐是有效的。对于具有正ΔH°的所有温度，ΔG°的负值证实了As（V）生物吸附的自发和吸热性质。共存氯化物(Cl-)的存在，硝酸盐（NO3-），钠（Na+），和钙（Ca2）的干扰不明显，而高浓度的硫酸盐（SO42-）和磷酸盐（PO43-）显着降低了As（V）的生物吸附百分比。通过仅使用1g/L的研究Fe（III）-SPP，可以将实际砷污染的地下水中的砷浓度降低到WHO饮用水标准（10μg/L）。在固定床系统中对As（V）的动态生物吸附表明，Fe（III）-SPP在连续模式下也是有效的，并且使用Thomas确定了固定床系统的不同设计参数，亚当斯-博哈特,BDST,和Yoon-Nelson模型.因此,从所有这些结果表明，Fe（III）-SPP在这项研究中研究可以是一个潜在的，低成本和环境友好的生物吸附剂材料，可有效去除污染水中的痕量砷。
