TN526 : Investigation of Heavy mextal Removal from Acid Mine Drainage by Natural Attenuation
Thesis > Central Library of Shahrood University > Mining, Petroleum & Geophysics Engineering > PhD > 2015
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Abstarct: Soil is as the main element is natural attenuation. The physical, chemical and biological processes that cause the reduction of the pollutants and their retention is defined natural attenuation. Natural attenuation is a sub-category of environmental sciences which has been of great attention to the scientists, industrialists and miners in the last few decades. In the current study, the attention has been concentrated on the investigation of the soil efficiency, as the main element in attenuation of the heavy mextals, in the Sarcheshmeh copper mine. The soil capability in continuous and batch systems for removal of Cu and Zn ions, which are of high concentrations in the effluents of Sarchechmeh copper mine, has been studied. Results confirm that different phases of soil were of different importance for the attenuation of target ions such that the carbonate and exchangeable phases were among the highest active phases. The maximum adsorption of Cu and Zn by various soil samples were measured 4.02 mg/g and 3.81 mg/g, respectively. Kinetic and isotherm models were studied for both Cu and Zn in the soils and the results indicated that the pseudo second order kinetic model and Langmuir isotherms show the best fit with experimental data. In addition, the results from the competitive adsorption of these ions in the presence of each other showed the Zn adsorption has experienced significant reduction. To enhance capability of soil for adsorption and retention of target ions and also to improve the soil properties, the use of amendment was taken into account. Elementary experiments were conducted to study the effects of various amendment. baxsed on their efficiency and production costs, two amendments, biochar and vermicompost, were utilized. The experiments were carried out using single components and two components. The adsorption capacity of biochar for Cu and Zn were 19.84 mg/g and 13.26 mg/g, respectively, which was of higher efficiency contrast to the produced biochars produced at the same conditions. In the two component system, the adsorption of Zn was significantly decreased as if in the presence of Cu, none of Zn were adsorbed on the biochar. Maximum adsorption capacity of vermicompost for Cu and Zn was obtained 46.2 mg/g and 36.1 mg/g, respectively. In two component adsorption process for vermicompost, Cu and Zn adsorption was decrease in their presence with together. These results imply higher selectivity of Cu in comparison with Zn. The investigation of Cu and Zn retention by Biochar and vermicompost indicates that the retention capacity of Biochar is higher than vermicompost. The attenuation experiments in column for synthetic wastewaters and acid mine drainage were conducted and the findings show high capacity of soil, soil with biochar and soil with vermicompost for attenuation of synthetic wastewaters. Moreover, further investigations show a reduction in the adsorption capacity of soil column in attenuation of acid mine drainage.
Keywords:
#Natural attenuation #Soil #Biochar #Vermicompost #Heavy mextal #Acid Mine Drainage
Keeping place: Central Library of Shahrood University
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Keeping place: Central Library of Shahrood University
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