改性玉米芯及其对废水中Cr6+的吸附研究

选取玉米芯作为吸附剂，对废水中Cr⁶⁺进行吸附研究，因玉米芯本身吸附效果不佳，故对其进行改性。经H₃PO₄、NaOH、NaNO₂溶液改性后的玉米芯可以使其孔隙扩展、比表面积变大，能够较高效地去除废水中Cr⁶⁺。实验结果表明：当模拟废水中Cr⁶⁺初始浓度为20 mg/L、体积为50.00 mL时，玉米芯经NaOH溶液改性后，投加量为0.040 g，pH为5.00，吸附时间为20 min时，吸附效果最佳，废水中Cr⁶⁺的去除率为96.83%。此时，改性后玉米芯吸附Cr⁶⁺的过程与Freundlich吸附等温模型和准二级动力学模型拟合度较高。

Modified corncob and its adsorption of Cr6+ in wastewater

Corncob was selected as an adsorbent to study its adsorption of Cr⁶⁺ in wastewater. Corncob was modified due to its poor adsorption effect. Subsequent to being modified with H₃PO₄, NaOH, and NaNO₂ solutions, corncob had expanded pores and increased specific surface area so that it could efficiently eliminate Cr⁶⁺ in wastewater. The experimental results show that when the initial concentration of Cr⁶⁺ in the simulated wastewater is 20 mg/L and its volume is 50.00 mL, modified corncob dosage of 0.040 g, pH of 5.00, and adsorption time of 20 min, corncob modified using NaOH solution exhibit best adsorption effect. The highest Cr⁶⁺ removal in wastewater is 96.83%. At this time, the Cr⁶⁺ adsorption process by modified corncobs is fairly consistent with the Freundlich adsorption isotherm model and the pseudo-second-order kinetic model.