Mass balances for heavy metals in arable land amended with sewage sludge
Farmers amend arable land with municipal sewage sludge primarily to supply organic matter and phosphorus where animal manure is in short supply, as is the case in, i.e., the south-western part of Scania. At the same time it is important that the sewage sludge does not have negative effects on crops and soil.
Since 1981, i.e., for 40 years and ongoing, two field experiments have been conducted, where the effects of sewage sludge application to arable land have been monitored. The monitoring programme includes analysis of heavy metals in applied sludge, harvested crop and in the soil. The two field experiments are situated outside Malmö and Lund, and receive sewage sludge from Sjölunda wastewater treatment plant in Malmö and Källby wastewater treatment plant in Lund, respectively.
Over the years, results from the experiments, including those for heavy metals, have been published in reports and scientific articles, but mass balances have not been made.
Establishment of mass balances for heavy metals (Cd, Cr, Cu, Hg, Ni, Pb, Zn) based on data available in the project ‘Slamspridning på åkermark’ (heavy metal content in applied sludge, harvested crop and soil), and data from other sources on content in mineral fertilizers and atmospheric deposition. Possible contribution from wear of agricultural machinery may also be considered. Since these long-term field experiments are unique, it is an ambition to publish the results in a scientific article.
Collection and organization of data in MS Excel (data from the project ‘Slamspridning på åkermark’ are already available in MS Excel). Basic statistic calculations and mass balance calculations.
Background in environmental and/or agricultural science/engineering. Ability to read Swedish. However, the report may written in either Swedish or English.
Hans Bertil Wittgren, Head of Research & Development, VA SYD (HansBertil.Wittgren@vasyd.se)