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

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 HNO3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：HNO3改性改善了污泥基吸附剂对Cr（Ⅵ）的吸附性能,p H是影响污泥基吸附剂吸附去除Cr（Ⅵ）的关键因素,最适p H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HNO3改性前后污泥基吸附剂的吸附行为。

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 p H value was a key factor for Cr（ Ⅵ） removal by SBA and the optimum p H 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.