改性香蕉皮生物质炭对Cr(Ⅵ)的吸附研究

Absorption on Property of Modified Banana Peel Biochar for Cr(Ⅵ)

以香蕉皮为原料,采用化学改性和高温热解的方法制备了新型改性香蕉皮生物质炭并用作吸附剂去除水体中的Cr(Ⅵ)。分别探究了不同改性方法、pH值和吸附时间等因素对改性生物质炭吸附Cr(Ⅵ)的影响。结果表明,用ZnCl2改性的生物质炭对Cr(Ⅵ)的去除能力较强;在改性生物质炭用量为2 g/L,吸附时间为120 min,温度为25℃,pH=2,Cr(Ⅵ)初始质量浓度为100 mg/L时,Cr(Ⅵ)吸附量为43.46 mg/g,对Cr(Ⅵ)去除率达86.9%。该生物质炭对Cr(Ⅵ)的吸附符合Langmuir等温吸附模型,吸附过程符合准二级动力学方程,吸附反应为吸热过程。

A new type of modified banana peel biochar was prepared from banana peel by chemical modification and high temperature pyrolysis,which was used as an adsorbent to remove Cr(Ⅵ)from water.The effects of different modification methods,pH value and adsorption time on the adsorption of Cr(Ⅵ)by modified biochar were investigated.The results showed that the biochar modified by ZnCl2 had a strong ability to remove Cr(Ⅵ).When the dosage of modified biochar was 2.00 g/L,adsorption time was 120 min,temperature was 25℃,pH was 2,and the initial mass concentration of Cr(Ⅵ)was 100 mg/L,the adsorption capacity of Cr(Ⅵ)was 43.46 mg/g,and the Cr(Ⅵ)removal rate reached 86.9%.The adsorption of Cr(Ⅵ)by biochar conforms to Langmuir isothermal adsorption model,the adsorption process conforms to the quasi-second-order kinetic equation,and the adsorption reaction is an endothermic process.