Analysis And Spatial Distribution of Heavy Metals in Soil at A Sanitary Landfill in Kedah

Environmental contamination by toxic heavy metals has emerged as a significant issue for preserving the quality and sanitation of water and soil. The disposal of industrial effluents via landfilling poses a risk to human health and the environment. The research is to assess heavy metal pollution in soil and delineate its distribution by geostatistical mapping at the Padang Cina Sanitary Landfill in Kulim, Kedah. Boiling aqua regia, an acid digestion process, is used to evaluate the type, concentration, spatial distribution, and waste disposal sources of soil heavy metals. ICP-OES was used to examine 30 soil samples collected at a depth of 15 cm from the dump site. With Fe (300 mg/kg) > Zn (10.28 mg/kg), Cu (3.95 mg/kg), Pb (0.702 mg/kg), and Cr (0.56 mg/kg) > Ni (0.117 mg/kg), landfill heavy metal concentrations decreased. Inverse distance weighting interpolation was used in ArcGIS 10.6 to investigate heavy metal distribution. Most coverage regions had variable quantities of Cr (0.139–0.12 mg/kg), Cu (0.078–0.492 mg/kg), Fe (244–263 mg/kg), Pb (0.27–0.36 mg/kg), Ni (0.02-0.04 mg/kg), and Zn (1.40–2.50 mg/kg). In conclusion, Padang Cina Sanitary landfill soil heavy metal concentrations are below the Malaysian Department of Environment land contamination limit.