花生壳基污泥活性炭的制备及其对含油废水的处理效果研究

Preparation of peanut hull sludge-based activated carbon and application for oily wastewater treatment

以延安某污水处理厂剩余污泥为原料,采用氢氧化钾活化法制备了花生壳基污泥活性炭,在对其进行性能表征的基础上,研究了吸附动力学过程。通过正交实验确定了花生壳基污泥活性炭的最佳制备条件为碳化温度350℃、碳化时间40min、氢氧化钾摩尔浓度0.5mol/L、花生壳添加比例(质量分数)20%。通过比表面积、傅立叶红外光谱、扫描电子显微镜、能谱分析发现,花生壳基污泥活性炭表面粗糙,呈多孔结构,比表面积为226.39m^2/g,平均孔径为5.170nm,C元素质量分数为67.52%,出现了酚羟基、醚键、内酯键等基团。当花生壳基污泥活性炭投加量为2.0g/L时,处理含油量为120 mg/L的含油废水,油类污染物去除率可达94%,其吸附过程符合伪二级动力学方程。

The municipal sewage sludge from a sewage treatment plant in Yan＇an was used to prepare the pea-nut hull sludge-based activated carbon through KOH activation method. The property characterization and the asdorption process were studied. The optimum conditions for the preparation of the peanut hull sludge-based activated carbon by orthogonal experiment were carbonization temperature of 350 °C,carbonization time of 40 min, KOH molar concentration of 0.5 mol/L,and peanut hull mass fraction of 20%. The specific area,Fourier transform infrared spec-troscopy, scanning electron microscope and energy dispersive spectrometer results showed that the surface of peanut hull sludge-based activated carbon was coarse and porous with hydroxy of phenol,ether bond and ester bond appeared; the specific surface area was 226.39 m2/g and the average pore size was 5.170 nm ; the mass fraction of C element was 67.52%. When 2.0 g/L peanut hull sludge-based activated carbon was added,the removal rate of oil achieved 94% for treament of 120 mg/L oily wastewater. The adsorption process was well described by the pseudo second-order kinetic equation.