Acidic mine drainage (AMD) contains large amounts of heavy metal ions and SO42, which can pose serious risks to human and environmental health. Anaerobic bioreactors are considered to be suitable methods for the treatment of acidic effluents due to some advantages such as the need for a small area, easy control, and simultaneous removal of sulfate and metals even in low concentrations. In this study, sulfate-reducing bacteria (SRB) performance was investigated in a semi-pilot scale down-flow fluidized-bed (DFFB) anaerobic reactor for SO42- and metals removal from the Sungun copper tailings AMD. The results indicated that utilizing SRB in the DFFB anaerobic bioreactor was an efficient, cost-effective, and environmentally friendly method for the treatment of effluents containing large amounts of SO42- and metals. All contaminants except Cr showed more than 70% removal after 24 h. The SO42- and Cu which had the highest initial concentrations showed removal efficiencies of 98.64% and 98.75%, respectively. Besides the removal of hazardous contaminants, the alkalinity of effluent increased remarkably. Also, the SRB had acceptable stability even after six consecutive cycles due to using AC granules as a support in the reactor which is an important parameter in industrial applications. پرونده مقاله

The lack of proper strategies for the management of the urban environment has made the relevant organizations face with numerous and complex problems in this regard. The present study was conducted in Tabriz metropolis as one of the major cities in the northwest of Iran. Using Delphi method, strategies for the management of the urban environment including strengths, weaknesses, opportunities, and threats (SWOT), the results obtained could be used as the key strategies for the urban environment management. The analysis of variance and the comparison of the SO, ST, WO, and WT strategies showed that the differences between the groups are not statistically significant suggesting that all the strategies have the same priority. SO strategies and ST strategies had the highest mean scores.. The ANOVA results indicated that there are no significant in-group and inter-group differences between the strategies and all the strategies had the same priority. The results showed that although all the studied urban environment management strategies have the same priorities for improving the present environment conditions of Tabriz, the strength opportunity (SO) strategies are the first priority among other strategies. پرونده مقاله