Strategies to mitigate diffuse phosphorus pollution during rewetting of fen peat soils.

The cultivation of fen peat soils (Eutric Histosols) for agricultural purposes, started in Europe about 250 years ago, resulting in decreased soil fertility, increased oxidation of peat and corresponding greenhouse gas fluxes to the atmosphere, nutrient transfer to aquatic ecosystems and losses in total area of the former native wetlands. To prevent these negative environmental effects set-aside programs and rewetting measures were promoted in recent years. Literature results and practical experiences showed that large scale rewetting of intensively used agricultural Histosols may result in mobilisation of phosphorus (P), its transport to adjacent surface waters and an accelerated eutrophication. The paper summarises results from an international European Community sponsored research project and demonstrates how results obtained at different scales and from different scientific disciplines were compiled to derive a strategy to carry out rewetting measures. Based on this findings a simple decision support system (DSS) for a hydrologically sensitive area in the Droemling catchment in north-eastern Germany was developed and since 2005 practically used to prevent freshwater resources from non point P pollution.

Sorption of sulfonamide pharmaceutical antibiotics on whole soils and particle-size fractions.

Residues of pharmaceutical antibiotics are found in the environment, whose fate and effects are governed by sorption. Thus, the extent and mechanisms of the soil sorption of p-aminobenzoic acid and five sulfonamide antibiotics (sulfanilamide, sulfadimidine, sulfadiazine, sulfadimethoxine, and sulfapyridine) were investigated using topsoils of fertilized and unfertilized Chernozem and their organic-mineral particle-size fractions. Freundlich adsorption coefficients (K(f)) ranged from 0.5 to 6.5. Adsorption increased with aromaticity and electronegativity of functional groups attached to the sulfonyl-phenylamine core. Adsorption to soil and particle-size fractions increased in the sequence: coarse silt < whole soil < medium silt < sand < clay < fine silt and was influenced by pH. Sorption nonlinearity (1/n