Leaching Characteristics of Manganese and Iron from Artificial Soil

Abstract

A leaching experiment was carried out over a period of 90 days to determine the manganese (Mn) and iron (Fe) leaching characteristics from artificial soils composed of sewage sludge and fly ash. The leachates of artificial soils were collected every 15 days and the concentration of manganese and iron in leachates of the artificial soil was measured. Results showed that the concentration of Fe and Mn in leachates of artificial soils got to a stable level by the end of the experiment. Moreover, plant Robina pseudoacacia and Amorpha fruticosa had different effect on the leachate Fe and Mn concentration. Robina pseudoacacia resulted in higher leachate Fe concentration, while Amorpha fruticosa resulted in higher Mn concentration. However, the leachate Fe and Mn concentrations from artificial soils was high, and it will also be transported to the surface and ground water. Therefore, some measures should be taken to reduce the concentration of heavy metals in the leachates before these artificial soils being applied on the ecological rehabilitation in mine spoil areas.