Reduction of micropollutants and bacteria in a constructed wetland for combined sewer overflow treatment after 7 and 10 years of operation

摘要: Repeated investigations on constructed wetlands for the treatment of combined sewer overflows, also named bioretention filters or retention soil filters, are necessary to provide information their long-term performance. In this study, a sampling campaign was conducted micropollutants, indicator microorganisms and standard parameters ten years after such were in operation three first investigation; it revealed that lost capacity remove chemical substances with no only slow biological degradability. This case e.g. phosphate (decrease from 29 11%), diclofenac (67 34%) TCPP (34% negative reduction). They continued easily degradable as COD (stable around 75%) stably. The Escherichia coli (1.1/0.8 log10), intestinal enterococci (1.3/0.8 log10) somatic coliphages (0.6/1.0 showed comparably low process variations given difficulties analysing microbial representatively well natural behaviour growth. Additionally, bisphenol A, we found temperature-related difference removal efficiencies: while cold months (winter), 53% average, increased 90% warm (summer). As prospective decision-makers need identify most important pollutants specific catchment area adapt filter design accordingly. If targeted lead an exhausted filtration capacity, post exchange charged material is necessary. However, biologically substances, so far, there limit use.