Soil and Groundwater Contamination as a Result of Sewage Sludge Land Application

The leaching of chemical compounds (NNO3, NNH4, Norg, PPO4 and Ptot) and trace elements (Cd, Cu, Cr, Ni, zn, and Pb) from sewage sludge and their migration through the soil profile is the subject of this study. The column experiments were carried out under atmospheric conditions corresponding to naturally occurring storm events – sewage sludge amended soil was irrigated with high rates of water. The column filter media used in the laboratory tests were similar to the soils present in degraded areas: coal fly ash (FA), coarse grained sand (CGS) and medium grained sand (MGS). Sewage sludge was applied on the top of each column in the quantity corresponding to the best land reclamation practice. The data obtained in the experiments showed the dynamics of chemical compounds’ leaching from the sewage sludge and their further transport through the column beds to the effluents. It was discovered that nitrogen compounds, such as nitrate (NNO3) and ammonium (NNH4), as well as some heavy metals (Ni and Cd) – originating from the sewage sludge – can reach deeper than 0.8 m and cause the contamination of potential shallow aquifers.