Abstract:This study investigated the efficiency and kinetics of adsorptive removal of heavy metals by sludge-based activated carbon (SAC) prepared from municipal sludge. Surface physicochemical properties of SAC and its adsorption capacities for four heavy metals, i.e., Cu(II), Pb(II), Cr(VI) and Cd(II), with an initial concentration of 50 mg/L were analyzed in comparison with two types of commercial activated carbon: coal-based activated carbon (MAC) and coconut shell-based activated carbon (YAC). The results showed that specific surface area and micropore volume of SAC were only 1/3~1/2 of those for either MAC or YAC. Adsorption of the four heavy metals onto SAC was relatively slower than that onto MAC or YAC. However, the equilibrium adsorption capacities of SAC for Cu(II), Pb(II), Cr(VI) and Cd(II) were 9.9, 8.9, 8.2 and 5.4 mg/g, respectively, being much greater than those of the two commercial adsorbents. This revealed that the SAC surface with rich acidic functional groups played a crucial role in the adsorption of heavy metals. The adsorption of Cu(II) and Pb(II) onto SAC had a close agreement with both Langmuir and Freundlich models and the adsorption of Cr(VI) agreed better with Langmuir models. In terms of the adsorption of Cd(II), neither of the models described the isotherms satisfactorily, suggesting that the quantity of binding sites for Cd(II) on the surface of SAC was small.
包汉峰, 杨维薇, 张立秋, 封莉. 污泥基活性炭去除水中重金属离子效能与动力学研究[J]. 中国环境科学, 2013, 33(1): 69-74.
BAO Han-Feng, YANG Wei-Wei, ZHANG Li-Qiu, FENG Li. Efficiency and kinetics of heavy metal removal from water by sludge-based activated carbon. CHINA ENVIRONMENTAL SCIENCECE, 2013, 33(1): 69-74.