Adsorption behaviors towards As and structural change of iron and manganese oxide sludge by thermal treatment
ZENG Hui-ping1, ZHAO Yun-xin1, LÜ Yu-feng1, LI Dong1, ZHANG Jie1,2
1. Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China;
2. State Key Laboratory of urban Water Resource and environment, Harbin Institute of technology, Harbin 150090, China
Structural change of iron and manganese oxide sludge which were calcined in air at different temperatures, was analyzed by X-ray powder diffraction, transmission electron microcopy, differential thermogravimetry and nitrogen adsorption analysis for specific surface area, respectively. And also the adsorption behaviors towards As was investigated. The results show that the iron and manganese oxide sludge is amorphous structure, with high efficiency of arsenical removal, due to its characteristics of small particle size and big specific surface area. Crystallization water beganto lose at 150℃, and specific surface area and pore volume had a little change, with As (Ⅲ) and As (V) removal rate increased slightly corresponding. Dehydroxylation reaction at 500℃ made the micropores gradually merge into mesopores, leading to the decrease of specific surface area, and further dramatically decrease of As (Ⅲ) and As (V) removal rate by 30% of the original value. As the temperature rising to 800℃, the micropores and mesopores gradually merged into macropores, resulting in the increase of the average pore diameter by 10nm, and the reduce of the specific surface area and pore volume to 12.755m2/g and 0.052cm3/g, meanwhile the sintering phenomenon generated between hematite crystal particles,which made the removal rate of As (Ⅲ) and As (V) plunge to about 10% of the original value.
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ZENG Hui-ping, ZHAO Yun-xin, LÜ Yu-feng, LI Dong, ZHANG Jie. Adsorption behaviors towards As and structural change of iron and manganese oxide sludge by thermal treatment. CHINA ENVIRONMENTAL SCIENCECE, 2017, 37(8): 2986-2993.
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