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51 results on '"Teng Yanguo"'

3. Comparison of the catalytic performances of different commercial cobalt oxides for peroxymonosulfate activation during dye degradation

Author

Wang Ying, Teng Yanguo, Xiang Weixu, Zhang Botao, and Zhang Yang

Subjects
Chemistry, Radical, Inorganic chemistry, chemistry.chemical_element, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Heterogeneous catalysis, 01 natural sciences, 0104 chemical sciences, Catalysis, chemistry.chemical_compound, Catalytic oxidation, Oxidizing agent, Degradation (geology), 0210 nano-technology, Cobalt, Methylene blue
Abstract

The catalytic performances of different commercial cobalt oxides(Co x O y , i.e., Co2O3, Co3O4, and CoO) for peroxymonosulfate(PMS) activation in dye degradation were compared in this study. The CoO/PMS system exhibited the highest catalytic oxidation performances with more than 96% methylene blue(MB) removal at 90 min. The concentration of dissolved cobalt ions from CoO was 1.474 mg/L at neutral pH and 5.231 mg/L at acidic pH at 90 min which accounted for the high MB removal and CoO activated PMS homogeneously compared to the associated CoSO4/PMS. Co3O4 and Co2O3 exhibited similar catalytic performances and characteristics. The MB removal in Co3O4/PMS and Co2O3/PMS system were more than 88% at neutral pH and over 64% at acidic pH, respectively, in 90 min. The concentration of dissolved cobalt ions from Co3O4 and Co2O3 was less than 0.018 mg/L at neutral pH and 0.036 mg/L at acidic pH at 90 min. The MB removal achieved by Co3O4/PMS and Co2O3/PMS were approximately three times higher than that achieved by their associated CoSO4/PMS systems and the heterogeneous catalysis played a principal role in the processes. According to scavenger experiments, the contributions of the hydroxyl radicals in the MB degradation were negligible compared to sulfate radicals in the CoO/PMS system. Hydroxyl radicals contributed one-third or more and sulfate radicals were the dominant oxidizing species in the Co3O4/PMS and Co2O3/PMS systems. Co x O y could also effectively activate PMS to generate free radicals for degradation of other dyes. The dyedegradation processes in Co3O4/PMS, Co2O3/PMS and CoSO4/PMS systems followed pseudo-first-order kinetic model and dye degradation rates in different systems were also compared.

Published
2017

14. Eco-environmental geochemistry of heavy metal pollution in Dexing mining area

Author

Wang Jin-sheng, Deng Jian, Zhang Chengjiang, Ni Shijun, Jiao Pengcheng, and Teng Yanguo

Subjects
Pollution, geography, Topsoil, geography.geographical_feature_category, media_common.quotation_subject, Sediment, Geochemistry and Petrology, Environmental chemistry, Soil water, Smelting, Environmental science, Effluent, Surface water, Riparian zone, media_common
Abstract

An eco-environmental geochemical investigation was carried out in and around the Dexing mining area to determine the concentrations of heavy metals in the surface water, sediments, soils and plants. The main objective of this study is to assess the environmental situation and evaluate the transferring of heavy metals from mining activities into the food chain. Some samples of water, sediment, topsoil and plant were collected along the Lean River in the Dexing mining area. The total concentrations of Cu, Pb, Zn, Cd, and As were determined by AAS, and Hg was analyzed by cold-vapor AAS. Some indices such as ‘contamination degree’, ‘geoaccumulation index’, and ‘biological absorption coefficient’ were used to assess eco-environmental quality. The investigation indicated a highly localized distribution pattern closely associated with the two pollution sources along the Le' an, River bank: one is strong acidity and a large amount of Cu in the drainage from the Dexing Cu mining area; and the other is the high concentrations of Pb and Zn in the effluents released from many smelters and mining, processing and extracting activities in the riparian zone. Results from the investigated localities indicated, at least in part, that some problems associated with environmental quality deterioration should be solved in the future.

Published
2004

15. Environmental geochemistry of heavy metal contaminants in soil and stream sediment in Panzhihua mining and smelting area, Southwestern China

Author

Teng Yanguo, Tuo Xianguo, Zhang Chengjiang, Xu Zhengqi, and Ni Shijun

Subjects
Pollution, media_common.quotation_subject, Metal contaminants, Sediment, Contamination, Environmental geochemistry, Mining engineering, Geochemistry and Petrology, Environmental chemistry, Smelting, Soil water, Trace metal, Geology, media_common
Abstract

Mining and smelting activities are the main causes for the increasing pollution of heavy metals in soil, water body and stream sediment. An environmental geochemical investigation was carried out in and around the Panzhihua mining and smelting area to determine the extent of chemical contamination in soil and sediment. The main objective of this study was to investigate the environmental geochemistry of Ti, V, Cr, Mn, Cu, Pb, Zn and As in soil and sediment and to assess the degree of pollution in the study area. The data of heavy metal concentrations reveal that soils and sediments in the area have been slightly contaminated. Geochemical maps of Igeo of each heavy metal show that the contaminated sites are located in V-Timagnetite sloping and smelting, gangues dam. The pollution sources of the selected elements come mainly from dusts resultant from mining activities and other three-waste-effluents. The area needs to be monitored regularly for trace metal, especially heavy metal enrichment.

Published
2003

16. Geochemical baseline and trace metal pollution of soil in Panzhihua mining area

Author

Ma Yuxiao, Zhang Chengjiang, Teng Yanguo, Tuo Xianguo, and Ni Shijun

Subjects
Baseline values, Pollution, Topsoil, business.industry, media_common.quotation_subject, Coal mining, Environmental engineering, Mining engineering, Geochemistry and Petrology, Smelting, Trace metal, business, Enrichment factor, Baseline (configuration management), Geology, media_common
Abstract

A total of 31 topsoil samples were systematically collected from the Panzhihua mining area including steel smelting, coal mining, urban and rural districts. A normalization procedure was adopted to establish the environmental geochemical baseline models for this area. By using the above baseline models, the regional geochemical baseline values of As, Cr, Cu, Ni, Pb and Zn were determined. On the basis of the baselines, the enrichment factors were used to analyze the mechanism of trace metal pollution in topsoil from anthropogenic sources, and the results showed that the serious trace metal pollution is caused by human activities in coal mine, iron mine, smelting factory, tailing dam and other industrial districts in the Panzhihua area.

Published
2002

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