City landfill leachate effects on groundwater pollution

A three-year monitoring of groundwater and surrounding soil is described for a garbage landfill site in a western suburb of Beijing Ammoniacal nitrogen M, iron and manganese were found to be the major pollutants, so their chemistry was studied by laboratory experiments. The high concentration of ammoniacal N in the landfill soil inhibits soil nitrification and soil offers no adsorptive capability. Consequently, a great deal of ammoniacal N is only removed by leachate, which passes into the groundwater. The result is serious ammoniacal N pollution of groundwater. A high concentration of micro-organisms in landfill soil, linked with specific redox conditions, could mobilise iron and manganese within soil. So concentrations of available iron and manganese were enhanced in the leachate and led to a net removal of iron and manganese from soil at the land fill site. This explains the iron and manganese pollution of groundwater at the landfill site.