Fenton活化制备污泥炭对水中Cr(Ⅵ)的吸附性能

Preparation of sludge carbon with Fenton activation and adsorption characteristics of hexavalent chromium

利用Fenton活化法活化脱水污泥制备活性炭,研究了Fenton试剂投加量、活化时间、炭化温度、炭化时间和升温速率5种因素对制备污泥炭的影响。污泥炭的最佳制备工艺:Fenton试剂投加量为150 m L,活化时间为2.5 h,炭化温度为350℃,炭化时间为1 h,升温速率为20℃·min-1。污泥炭碘吸附值达到331.90 mg·g-1,BET比表面积为24.265 m^2·g-1。总孔容为0.146 cm^3·g-1,微孔率为17%。分析了吸附时间、pH值和吸附温度3种因素对污泥炭吸附水中Cr(Ⅵ)的影响。在吸附时间为90 min,pH=3,吸附温度为50℃时,污泥炭对Cr(Ⅵ)的吸附量为9.93 mg·g-1。吸附动力学符合准二级动力学模型描述,吸附过程符合Langmuir和Tempkin等温吸附模型描述。

Using Fenton activation method to prepare activated carbon through dewatered sludge. The effects of Fenton＇s reagent dosage,activation time,carbonization temperature,residence time and heating rate on the preparation of sludge carbon were studied. The optimum preparation conditions are as the following： Fenton＇s reagent dosage is 150 mL,activation time is 2. 5 h,carbonization temperature is 350 ℃,residence time is 1 h,heating rate is 20 ℃ ·min^-1. The iodine adsorption value of sludge carbon under this optimum preparation condition is 331. 90 mg·g^-1,and BET specific surface area is 24. 265 m^2·g^-1,the total pore volume is 0. 146cm^3·g^-1,microporosity is 17%. The effects of contact time,pH value and temperature on the adsorption of Cr（Ⅵ） in sludge carbon had been analyzed. In the condition of 90 min contact time,pH value of 3 and temperature of 50 ℃,the adsorption capacity of Cr（Ⅵ） is 9. 93 mg·g-1in sludge carbon. The adsorption kinetics fit the pseudo-second order kinetics model,and the adsorption process is described well with the Langmuir and Tempkin isotherm model.