Leaching behavior of Pb and Zn in air pollution control residues and their modeling prediction

• Published in: Journal of environmental sciences (China) Vol. 18; no. 3; pp. 583 - 586
• Main Authors: Zhang, Hua, He, Pin-Jing, Shao, Li-Ming, Feng, Jun-Hui, Cao, Qun-Ke
• Format: Journal Article
• Language: English
• Published: Netherlands State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, China 2006
• Subjects: Air Pollution - prevention & control; China; Hazardous Substances - analysis; Incineration; Lead - analysis; Lead - chemistry; Models, Chemical; Thermodynamics; Zinc - analysis; Zinc - chemistry; 大气污染; 残留物; 淋洗作用; 重金属; China; China, People's Rep., Shanghai; China, People's Rep; air pollution control residues; MINTEQA2; incineration plant; heavy metals; leaching behavior
• ISSN: 1001-0742; 1878-7320
• DOI: 10.3321/j.issn:1001-0742.2006.03.029

Increasing attention has been paid to air pollution control （APC） residues in China recently due to the rising proportion of waste incineration and the hazardous characteristics of the residues, among which heavy metal leaching toxicity plays an important role. Leaching behavior and potential risk of Pb and Zn in the APC residues from a Shanghai municipal solid waste （MSW） incinerator was studied, based on the leaching tests under different conditions and theoretical calculation using a geochemical thermodynamic equilibrium model MINTEQA2. Results showed that, extractant species and liquid to solid （L/S） ratio predominantly controlled the leaching toxicity of Pb and Zn, while ionic strength, vibration method and leaching time had less effect on the metals release. Leachate/final pH determined the metal leaching behavior, which changed the speciation of heavy metals in the extraction system. The equilibrium aqueous speciation, precipitation-dissolution of Pb and Zn was investigated according to the model computation, which was well in agreement with the experimental results.