改性松树叶对六价铬的去除研究

Research on the removal of chromium(Ⅵ) with modified pine needles

采用氢氧化钠-异丙醇对松树叶进行化学改性,同时将改性松树叶用于对Cr(Ⅵ)的吸附实验。通过单因素实验,考察了处理条件对Cr(Ⅵ)吸附效果的影响。结果表明,对50 mL质量浓度为10.0 mg/L的Cr(Ⅵ)溶液,在溶液pH=3.0,投加改性松树叶0.2 g,温度30℃,接触时间90 min的条件下,Cr(Ⅵ)的去除率可达82%以上。改性松树叶在20～30℃对Cr(Ⅵ)的吸附是吸热过程,以离子交换吸附为主,吸附过程遵循Freundlich吸附等温线。

The pine needles have been modified synchronously with the solution of sodium hydroxide-isopropanol. Then,the modified pine needles are used for adsorbing chromium （Ⅵ）. The effects of treating conditions on adsorbing efficiency are studied through single-factor tests. The results show that when pH =3.0,the dosage of modified pine needles 0.2 g, temperature 30 ℃, and contact time 90 min, the Cr （ Ⅵ ） removing rate for 50 mL of Cr （ Ⅵ ） solution,whose mass concentration is 10.0 mg/L,reaches above 82%. The adsorption of Cr（ Ⅵ ） by modified pine needles at 20 ℃ to 30 ℃ is an endothermic process. It is mainly ion exchange adsorption. The adsorbing process follows the Freundlich adsorption isotherm.