Application of Bioaugmentation to Improve Pharmaceutical Wastewater Treatment Efficiency

Abstract

Ecological harm and human health risks caused by environmental pollution with active pharmaceutical ingredients (API) nowadays is recognised as issue of growing concern. Widespread presence of human and veterinary API in aquatic environment clearly indicates persistence and low removal efficiency of these compounds at conventional pharmaceutical and municipal wastewater treatment plants (WWTP). Bioaugmentation of activated sludge systems with specialized microorganisms could be a powerful and environmentally friendly tool to enhance the removal efficiency of recalcitrant API. Selection of inoculum strains, that have appropriate enzymatic pathways to metabolise complex molecules of API, belonging to different therapeutic classes, is of great importance. This study evaluated the potential of pure cultures of 10 bacteria, 10 yeasts and 3 filamentous fungi previously isolated from activated sludge of pharmaceutical WWTP to degrade less investigated API – Oxytocin, Zopiclone and Meldonium dihydrate as sole carbon source and in cometabolic manner with presence of skim milk powder as additional nutrient source. Bacteria Sphingobacterium thalpophilum and filamentous fungi Fusarium solani and Fusarium udum showed very high treatment efficiency of all tested API in laboratory-scale bioaugmentation tests and were recognized as culture with high metabolic potential to be used in bioaugmentation for removal of pharmaceutical micropollutants.