改性污泥基吸附剂对水中铬(Ⅵ)的吸附性能研究

Adsorptive Property of Cr(Ⅵ) by Modified SludgeBased Adsorbent with Foaming Agent

摘要: 以城市污水厂脱水污泥为原料，采用添加发泡剂辅助的方法制备了污泥基吸附剂，并对部分污泥基吸附剂进行3 mol/L HNO_3改性，研究了2种改性污泥基吸附剂对Cr(Ⅵ)的吸附行为.结果表明：HNO_3改性改善了污泥基吸附剂对Cr(Ⅵ)的吸附性能，pH是影响污泥基吸附剂吸附去除Cr(Ⅵ)的关键因素，最适pH在1.0~3.0，最佳吸附时间为3 h.25 ℃下改性污泥基吸附剂吸附Cr(Ⅵ)符合Langmuir吸附模型，准二级动力学模型能很好地描述HNO_3改性前后污泥基吸附剂的吸附行为.

Abstract: Using the dewatered sludge from municipal wastewater treatment plant (WWTP), the sludgebased adsorbent (SBA) was prepared by means of carbonization with the addition of foaming agent, and the prepared adsorbent was further modified with 3 mol/L nitric acid. The adsorption behavior of two SBAs was compared for Cr(Ⅵ) removal. The results showed that the adsorption performance of SBA modified with nitric acid was improved. The pH value was a key factor for Cr(Ⅵ) removal by SBA and the optimum pH value was in the range of 10 to 30, the optimum adsorption time was 3 h. The SBA modified with nitric acid for Cr(Ⅵ) removal fitted well with the Langmuir isotherm model at 25℃. The sorption kinetic data fitted well with a pseudosecondorder model for two SBAs.