Two biomass agricultural waste materials; rice husks (RH) and potato peels (PP) were used as precursors for preparation of activated carbons by chemical activation using phosphoric acid for adsorption of hexavalent chromium [Cr(VI)] from tannery effluents. The prepared rice husk (RH–AC) and potato peel activated carbon (PP–AC) were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction. Adsorption experiments were performed by varying pH, agitation speed, contact time, adsorbent dose and initial metal ion concentration. Freundlich, Langmuir and Temkin isotherms were used to analyze the equilibrium data obtained at different adsorption conditions. It was found that the adsorption isotherms were well fitted by the Freundlich equation and the adsorption process was found to follow pseudo-second-order rate kinetics. Adsorption results obtained show a maximum Cr(VI) uptake being attained at pH 2.0, with chromium removal efficiency of 99.88% and 99.52% for RH–AC and PP–AC, respectively. RH–AC and PP–AC are effective adsorbent for the removal of chromium(VI) ions from wastewater.

两种生物质农业废弃物；稻壳 (RH) 和马铃薯皮 (PP) 被用作前体，通过化学活化使用磷酸从制革废水中吸附六价铬 [Cr(VI)]，制备活性炭。通过傅里叶变换红外光谱、扫描电子显微镜和 X 射线衍射对制备的稻壳 (RH-AC) 和马铃薯皮活性炭 (PP-AC) 进行表征。通过改变pH、搅拌速度、接触时间、吸附剂剂量和初始金属离子浓度来进行吸附实验。Freundlich、Langmuir 和 Temkin 等温线用于分析在不同吸附条件下获得的平衡数据。发现吸附等温线符合 Freundlich 方程，吸附过程遵循准二级速率动力学。所获得的吸附结果表明，在 pH 2.0 时获得了最大的 Cr(VI) 吸收，RH-AC 和 PP-AC 的铬去除效率分别为 99.88% 和 99.52%。RH-AC 和 PP-AC 是去除废水中铬 (VI) 离子的有效吸附剂。