Biswas Biplob Kumar, Inoue Jun-ichi, Inoue Katsutoshi, Ghimire Kedar Nath, Harada Hiroyuki, Ohto Keisuke, Kawakita Hidetaka
Department of Applied Chemistry, Saga University, Honjo 1, Saga 840-8502, Japan.
J Hazard Mater. 2008 Jun 15;154(1-3):1066-74. doi: 10.1016/j.jhazmat.2007.11.030. Epub 2007 Nov 17.
Orange waste, produced during juicing has been loaded with zirconium(IV) so as to examine its adsorption behavior for both As(V) and As(III) from an aquatic environment. Immobilization of zirconium onto the orange waste creates a very good adsorbent for arsenic. Adsorption kinetics of As(V) at different concentrations are well described in terms of pseudo-second-order rate equation with respect to adsorption capacity and correlation coefficients. Arsenate was strongly adsorbed in the pH range from 2 to 6, while arsenite was strongly adsorbed between pH 9 and 10. Moreover, equimolar (0.27 mM) addition of other anionic species such as chloride, carbonate, and sulfate had no influence on the adsorption of arsenate and arsenite. The maximum adsorption capacity of the Zr(IV)-loaded SOW gel was evaluated as 88 mg/g and 130 mg/g for As(V) and As(III), respectively. Column adsorption tests suggested that complete removal of arsenic was achievable at up to 120 Bed Volumes (BV) for As(V) and 8 0BV for As(III). Elution of both arsenate and arsenite was accomplished using 1 M NaOH without any leakage of the loaded zirconium. Thus this efficient and abundant bio-waste could be successfully employed for the remediation of an aquatic environment polluted with arsenic.
榨汁过程中产生的橙子废料已负载锆（IV），以研究其对水环境中五价砷和三价砷的吸附行为。将锆固定在橙子废料上可形成一种非常好的砷吸附剂。就吸附容量和相关系数而言，不同浓度下五价砷的吸附动力学可以用准二级速率方程很好地描述。砷酸盐在pH值为2至6的范围内被强烈吸附，而亚砷酸盐在pH值为9至10之间被强烈吸附。此外，等摩尔（0.27 mM）添加其他阴离子物种，如氯离子、碳酸根离子和硫酸根离子，对砷酸盐和亚砷酸盐的吸附没有影响。负载锆（IV）的橙子废料凝胶对五价砷和三价砷的最大吸附容量分别评估为88 mg/g和130 mg/g。柱吸附试验表明，对于五价砷，在高达120床体积（BV）时可实现砷的完全去除，对于三价砷则为80 BV。使用1 M NaOH可实现砷酸盐和亚砷酸盐的洗脱，且负载的锆不会有任何泄漏。因此，这种高效且丰富的生物废料可成功用于修复受砷污染的水环境。
