Abstract:Sanitary landfill was considered to be a predominant disposal of sewage sludge, due to its mass consummation and feasibility as well as low cost. Commonly, sewage sludge was landfilled directly or solidified before landfill. However, it was very important that how to recycle the landfilled sludge to save more spaces for sludge disposal. Removal of heavy metals from water was an important environmental problem and the search for economically feasible technologies continues. As adsorbents, mainly activated carbons, clays, iron oxides, and other natural adsorbents have been investigated. Recently, sewage sludge based adsorbents were indicated as promising media for removal of such metals as copper and zinc. The behaviour of Cu2+, Zn2+ adsorption onto solidifying landfilled sludge were comparatively studied. The results showed that both Cu2+ and Zn2+ adsorption capacity reached optimum when initial pH was 3.0. When initial Cu2+ or Zn2+ concentration being 150mg/L, the removal efficiency could reach more than 90% for both C u2+ and Zn2+ with dosage of solidifying landfilled sludge being 6g/L. Moreover, the adsorption isotherm for Cu2+ or Zn2+ could significantly conform to Henry, Freundlich and langmiur equations, and the solidifying landfilled sludge had much higher adsorption capacities for Zn2+ but much higher adsorption strength for Cu2+ respectively. The desorption ratio for adsorbed Cu2+ or Zn2+ only reached above 90% by HCl with pH value being 1.0, however, with increasing concentration of EDTA, the desorption ratio for Cu2+ adsorbed reached above 100% with 0.5mmol/L EDTA, but it was only about 10% for Zn2+ to release from solidifying landfilled sludge despite of EDTA concentration.
朱维琴, 单监利, 张志, 郭丹, 赵由才. 固化填埋污泥对Cu2+、Zn2+吸附特征的比较研究[J]. 中国环境科学, 2011, 31(9): 1503-1508.
ZHU Wei-Qin, DAN Jian-Li, ZHANG Zhi, GUO Dan, ZHAO You-Cai. Comparative study on adsorption behaviour of copper and zinc from aqueous solution by solidifying landfilled sludge. CHINA ENVIRONMENTAL SCIENCECE, 2011, 31(9): 1503-1508.