辣木树皮对Cr(Ⅵ)吸附性能的研究

Study on Adsorptive Performance of Chromium(Ⅵ) by Moringa oleifera Bark

采用废弃的辣木树皮,经加工处理后用于吸附去除水溶液中的Cr(Ⅵ),研究考察了辣木皮粉的用量、吸附时间、pH值、吸附温度、Cr(Ⅵ)溶液初始浓度等因素对吸附效果的影响。结果表明,吸附量随着pH值的增大而减小,随着吸附时间的延长、吸附温度的提高而增大;辣木皮粉用量增加,吸附去除率提高;Cr(Ⅵ)溶液初始浓度增大,单位吸附量增加,吸附去除率下降。适宜的吸附条件为:辣木皮粉用量4.0 g/L,溶液初始浓度为20 mg/L,pH值1,温度30℃,吸附时间4 h,Cr(Ⅵ)吸附去除率可达97.3%。研究表明,辣木皮粉对水中Cr(Ⅵ)有良好的吸附效果。

In this paper, the Moringa oleifera bark(MOB)was employed to be as biosorbent to remove Cr(Ⅵ) from aqueous solution. The affecting factors on the adsorption of Cr(Ⅵ) from aqueous solution by MOB, such as pH, temperature, shaking time, dosage of material, and initial concentration of Cr(Ⅵ), were investigated. The results showed that, the adsorptive capacity increases with the extension of time and rise of temperature, and decreases with the rise of pH. The removal rate of Cr( Ⅵ)increases with the increment of MOB dosage, and decreases with the rise of initial concentration of Cr( Ⅵ).The suitable conditions for the adsorption were as following: MOB, 4.0 g/L; Cr(Ⅵ) ion initial concentration of 20 mg/L;pH, 1; temperature 30 ℃;shaking time, 4 h; Cr(Ⅵ) ion removal rate of up to 97.3%. Research showed adsorption efficiencies of Cr(Ⅵ) in aqueous solution by MOB were good.