مقالههای Ahmad Khodadadi
توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقالههای نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده میشوند.
اطلاعات انتشار: پنجمین همایش تخصصی مهندسی محیط زیست، سال ۱۳۹۰
تعداد صفحات: ۱۶
In recent years, heavy metals have been considered as a serious risk for survival of living organisms. Arsenic is a toxic element found in nature as sulfide minerals such as arsenopyrite. Absorption of small amounts of this element in the body can cause severe damage. It can be spread in the environment due to natural and industrial procedures and pollute soil and water resources. The purpose of this paper was to review the various aspects of environmental pollution by this element. Arsenic chemistry and its distribution in the environment was evaluated according to various arsenic species. We then assessed toxicity of this element for human health and the damages caused by it. The existing technologies for remediation of soil and water sources contaminated with arsenic have been listed and compared.<\div>
نویسنده(ها): Fatemeh Izadi Tame، Ali Motalebi Damuchali، Gholamreza Asadollah Fardi، Ahmad Khodadadi
اطلاعات انتشار: اولین همایش بین المللی بحران های زیست محیطی ایران و راهکارهای بهبود آن، سال ۱۳۹۱
تعداد صفحات: ۶
Many environmental problems associated with the mining industry, involve the understanding and analysis of the contaminant transport processes and results. Both experimental work and numerical models can provide the necessary information to understand and solve any problem. The long term pyrite oxidation, acid mine drainage generation and transport of the oxidation products and heavy metals are noted to be the most important problems that can be modeled in order to predict the transport of the contaminants through groundwater and river flow systems to interpret the geochemistry and achieve a better understanding of the process involved. This study investigated the effects of the initial pH and the grain size distribution on the reactive transport of three metals (Cd, Ni and Mn) from Zanjan Zinc leaching plant tailings. The migration of these metals was simulated using a multicomponent reactive transport model (PHREEQC) in a 30 days period. Not surprisingly, lower pH, and smaller effective particle size increased metal transport. The simulation results generally agreed well with results from a previously conducted column study. We conclude that different grain size distribution and pH values induce variable metal speciation and suggest accounting site–specific risk assessments for the above mentioned issues.<\div>
اطلاعات انتشار: Journal of Mining and Environement، چهارم،شماره۱، ۲۰۱۳، سال ۰
تعداد صفحات: ۹
Arsenic is one of the heavy metals and nearly all its compounds, especially organic compounds, are toxic. The wide spectrum of diseases caused by this element has led to evaluation of the toxicity of different arsenic species and identification of the major natural and anthropogenic pollution sources of it in the nature. Mining activities are among the main sources of anthropogenic pollution of soil and water by arsenic. The purpose of this study was geochemical modeling of different arsenic species in the wastewater of the tailings dam of Mouteh Gold processing plant in Iran to evaluate the effect of pH and temperature on the stability of these components. Modeling was done using MINTEQ software. The results showed that arsenic species at different pH values under study were H3AsO3, H2AsO3– and HAsO32–, and their actual concentration in the plant wastewater were negligible. MINTEQ software introduced H3AsO4, H2AsO4–, HAsO42– and AsO43– as arsenic V species at different pH values, of which HAsO42– and AsO43– were the main components of arsenic in plant wastewater. Given the low toxicity of arsenic V species and their easier elimination relative to arsenic III species, in the current conditions, the plant wastewater is in a good status in terms of arsenic pollution. Also temperature changes have little effect on the concentration of various arsenic species in the wastewater.
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