Evaluation of Environmental Hazards from Heavy Metals Using ELECTRE III Method (Case Study: Sarcheshmeh Copper Mine)

Because of the stability، atomic and biological accessibility problems of the heavy metals، they are considered as serious pollutants of the environment. The sediments of Sarcheshmeh copper mine in Iran contain high concentrations of these pollutants. and thus environmental evaluation and ranking them based on emission levels is important for timely environmental measures with the lowest operating costs. The first aim of this study is the environmental risk evaluation of these sediments by determining the contamination factor، pollution load index، enrichment factor and Geoaccumulation index. The second aim is ranking these metals based on the level of critical risk using the Multi Attribute Decision Making (MADM) methods. In this study، first، by determining risk evaluation indices، we set out to assess heavy metals contamination (Co، Cu، Mo، Zn، Cr، Mn، Ni، Pb، Ti and Fe) in the sediments of Sarcheshmeh copper mine which conduce to the tailings dam. Then، by collecting expert opinions on the relative importance of each of the mentioned indicators، through final weighting of the indices using Antropy Shanoon method، heavy metals in the sediments of the study area were ranked and clustered using ELECTRE III method. Based on measured results of the risk evalution indices، the intensity of contamination to these metals were as Fe> Cu> Co> Ti> Mn > Pb > Cr، and all the metals except for copper، zinc and iron cited almost in the unpollutant limit. Also based on ranking results، the ten risks were clustered in seven categories with iron and copper having the highest pollution and critical risk amongst the heavy metals in the sediments under study، respectively.