Investigating the effects of heavy metals in the waste leachate on the groundwater quality near the landfill (case study: Landfill of Saravan, Rasht)

Abstract

The main and fundamental scientific reason of scientific community attention to the issue of leachate pollution and its treatment is the possible danger of contamination of water, soil and to some extent air. The reason is that the leachate of landfill in fact is acomplex waste withhigh pollution. Today, in our country, especially in northern areas due to high groundwater levels, the problem of waste disposal and the effects of their leachate entering alluvial groundwater and aquifer contamination downstream based on hydrodynamic thickness in the movement of water is highly regarded andentering a considerable amount of pollution (nitrates, heavy metals, etc.) to underground water sources used for drinking and agriculture, in the long term become a social problem. Saravan landfill is located on 15 km road Rasht of to Tehran is like a black spot in the in the green Hyrcanian forest and receives more than 500 tons of waste daily from provinces cities,particularly Rasht which with no environmental assessment for selected waste disposal, waste disposal is inadequate in Saravan and because of evaporation, fermentation and decomposition of the waste and leachate percolation into the soil and water resources it is associated with high pollution and unleashed leachate river in the heart of nature and based on the ranking of Index criteria it is unacceptable. In this study, sampling was conducted in 2 upstream wells, 3 downstream wells of Saravan landfill then the samples were analyzed by atomic absorption.  The results indicate the presence of heavy metals (chromium - lead – zinc -iron - manganese) in water of downstream wells of the landfill compared to upstream wells and the control wells or in other words, it was significantly more than the control and upstream wells and the average concentrations of Pb, Cr, MN, Fe higher than drinking water standards and the mean concentration of MN and Cr in the research water wells was more than standard water for irrigation and agricultural. It shows the leachate percolation into soil and ground water that has been polluted the nearby water of the landfill.

Keywords: Groundwater, Landfill, Leachate, Heavy Metals, Saravan