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.