Investigation of Heavy Metals in the Soil around Municipal Waste Landfill

Even in engineered landfills in developed countries, leachate production cannot be avoided and it contains different types of heavy metals. Therefore, landfills are one of the main sources of increased concentrations of heavy metals in the soil. The purpose of this study was to evaluate the severity of contamination of soils around Sabzevar landfill with heavy metals and to prepare a soil contamination map with heavy metals.

Samples of surface and deep soils were collected in 18 stations according to the type of soil and distance from landfill Sabzevar. The concentrations of heavy metals Arsenic, Zinc, Lead, Chromium, Copper, Mercury and Cadmium were analyzed by ICP-OES. The intensity of soil contamination was assessed using Index Geoaccumulation Potential ecological risk index.

The mean concentrations of Arsenic, Zinc, Lead, Chromium and Copper in surface soil, respectively are, 6.013, 41.04, 6.31, 26.77 and 31.45 mg/kg of Mercury and Cadmium, respectively, 60.79 and 61.60 μg/kg, respectively. But the mean concentration of Arsenic, Zinc, Lead, Chromium and Copper in depth soil, respectively are, 5.75, 38.33, 6.25, 22.68 and 31.04 mg/kg, Mercury and Cadmium, respectively, 66.57 and 59.98 μg/kg, the value of all proportion to Natural background values are higher.

Based on estimates of Igeo and RI indices for heavy metals Arsenic, Lead, Zinc, Chromium and Copper in the soil showed no contamination but for Mercury and Cadmium showed severe contamination.