采用农业废弃物棉杆改性处理含铬废水,研究其对废水中Cr⁶⁺的吸附性能,考察了废液pH、棉杆用量、吸附时间、温度以及废液浓度等对Cr⁶⁺去除率的影响。结果表明,将棉杆置于0.015mol/L高锰酸钾溶液中改性4h,当废液pH=1、棉杆用量为0.3g、吸附温度为45℃、吸附时间为60min时,废水中Cr⁶⁺离子的去除率可达99.9%,较未改性的棉杆提高了26.3%。扫描电镜观察发现,改性前后棉杆吸附位点数量明显增加。采用Lagergren准二级动力学模型和Langmuir等温吸附模型可准确描述吸附模型,拟合实验数据所得平衡吸附量为3.08mg/g,与实验结果相符。这种改性处理含铬废水的方法操作简单、价格低廉,适合于低浓度废水处理,有利于固体废弃物的资源化利用。

Chromium-containing wastewater was treated with modified agricultural waste cotton stalk to study the adsorption performance for Cr⁶⁺. The effects of pH value,amount of cotton stalk,adsorption time,temperature and concentration of waste liquid on the removal rate of Cr⁶⁺ were investigated.The results showed that when the pH value of the waste liquid was 1,the amount of cotton stem was 0.3g,the adsorption temperature was 45℃,the adsorption time was 60 min,The removal rate of Cr⁶⁺ was up to 99.9%,which was 26.3% higher than that of unmodified cotton.At the same time,the scanning electron microscope scanning showed that the number of adsorption sites increased obviously.The adsorption model can be accurately described by the Lagergren quasi-second-order kinetics model and Langmuir isothermal adsorption model.The equilibrium adsorption capacity was 3.08mg/g,which was in accordance with the experimental data.The modified chromium-containing wastewater treatment method was simple in operation and low in cost,and was suitable for the treatment of low concentration waste water and was favorable for the utilization of solid wastes.