污泥灰对Cd(Ⅱ)和Ni(Ⅱ)的吸附作用研究

Adsorption and Removal of Cd^(2+) and Ni^(2+) Ions in Electroplating Wastewater by Urban Sewage Sludge Ash

在静态条件下,以改性城市污泥为吸附剂,研究了污泥灰(MSSA)对重金属离子的吸附性能,着重探讨了改性污泥灰去除工业电镀废水中重金属离子Cd(Ⅱ)、Ni(Ⅱ)的适宜条件。结果表明,pH值是影响污泥灰对重金属离子吸附的重要因素,镉(Ⅱ)、镍(Ⅱ)吸附的最佳pH值为6.0和6.5;当吸附剂最佳用量为10 g/L时,Cd(Ⅲ)、Ni(Ⅱ)的吸附容量分别达到1.21 mg/g和1.02 mg/g;吸附等温线可以用Freundilich和Langmuir模型描述,吸附过程基本符合Langmuir和Freundilich吸附等温式。该吸附剂吸附性能优越,可有效地去除废水中的相关金属离子。

Urban sewage sludge ash, a kind of industrial solid waste from wastewater treatment plant, was used for the adsorption and removal of Cd2+ and Ni2+ from electroplating wastewater under static conditions. The effects of various operating variables, including the pH value of the solution, dose of the adsorbent, temperature, and particle size, on the removal of Cd2+ and Ni2+ had been studied. Results indicated that pH value plays a key role in the adsorption of Cd2+ and Ni2+ by sewage sludge ash, and the optimal pH value for the adsorption of Cd2+ and Ni2+ was 6.0 and 6.5, respectively. At the optimized dose of 10 g/L of the absorbent, the maximum adsorption capacity for Cd2+ and Ni2+ was as much as 1.21 mg/g and 1.02 mg/g, respectively. Moreover, the adsorption of the both metal ions increased with increasing temperature, indicating endothermic nature of the adsorption process which well follows Langmuir model and Freundlich model as well. And the absorbent showed good adsorption capacity and could be effectively applied to remove relevant heavy metal ions in electroplating wastewater.