Mini-Review: Pharmaceuticals in sewage sludge and their degradation during composting – recent studies in Estonia

Abstract

Pharmaceuticals are present in sewage sludge and its compost. This may cause severe health problems due to the plant uptake of pharmaceuticals by food plants when sewage sludge compost is used for fertilizing agricultural soils. Recently studies were conducted for estimating the efficiency of composting technologies in the view of the degradation of pharmaceutical residues. Experiments on plant uptake of pharmaceutical residues showed, that this phenomenon could not be ignored when using sewage sludge compost as a fertilizer. Novel approaches were developed via optimising the composition of the compost mixture with the aim of utilising sewage sludge compost as a nutrient-rich source for the improvement of soil properties. Sawdust as a bulking agent clearly speeded up the degradation of most of the studied pharmaceutical residues present in sewage sludge and its compost. More work in this field is needed for increasing the efficiency of the sewage sludge composting process. Efficient express methodologies should be developed with the aim of assessing the safety of sewage sludge compost.

Keywords

• sewage sludge
• pharmaceutical
• plant uptake
• compost