Removal of micropollutants, facultative pathogenic and antibiotic resistant bacteria in a full-scale retention soil filter receiving combined sewer overflow

Abstract

Combined sewer systems collect surface runoff as well as wastewater of industrial and domestic origin. During periods of heavy rainfall the capacity of the sewer system is exceeded and the overflow is discharged into receiving waters without any treatment. Consequently, combined sewer overflow (CSO) is considered as a major source of water pollution. This study investigates the effectiveness of a retention soil filter (RSF) for the removal of micropollutants as well as facultative pathogenic and antibiotic resistant bacteria from CSO. The removal of organic group parameters like total organic carbon was excellent and the removal efficiency for micropollutants of the RSF and the wastewater treatment plant (WWTP), which treats wastewater of the same origin during dry and normal weather conditions, was comparable. Compounds of high environmental concern like estrogens or certain pharmaceuticals, e.g. diclofenac, were completely eliminated or removed to a high degree during RSF passage. RSF treatment also reduced the number of E. coli, enterococci and staphylococci by 2.7, 2.2 and 2.4 log-units (median values), respectively. Obviously, some Staphylococcus species can better adapt to the conditions of the RSF than others as a shift of the abundance of the different species was observed when comparing the diversity of staphylococci obtained from the RSF influent and effluent. RSF treatment also decreased the absolute number of antibiotic resistant bacteria. The percentage of antibiotic resistant E. coli and staphylococci isolates also decreased during passage of the RSF, whereas the percentage of resistant enterococci did not change. For E. coli ampicillin and for enterococci and staphylococci erythromycin determined the antibiotic resistance level. The results demonstrate that RSFs can be considered as an adequate treatment option for CSO. The performance for the removal of micropollutants is comparable with a medium sized WWTP with conventional activated sludge treatment. The number of facultative pathogenic and antibiotic resistant bacteria was considerably decreased during RSF passage. However, as RSF effluents still contained antibiotic resistance genes and traces of micropollutants; receiving waters may still be at risk from negative environmental impacts.

Pathogenic members of Escherichia coli & Shigella spp. Shigellosis

“…Similarly to sand filters, retention soil filters (RSF) remove 2 log 10 units of facultative pathogenic and antibiotic resistant E. coli from combined sewer systems that collect surface runoff as well as wastewater of industrial and domestic origin (Scheurer et al, 2015).…”

Freshwater ecosystems profit from activated carbon-based wastewater treatment across various levels of biological organisation in a short timeframe

“…Further information on the applied methods for chemical analyses can be found in Scheurer et al [35] and Triebskorn [25].…”

“…Detailed information on the microbiological analyses can be found in Scheurer et al [35] and Heß et al [36].…”

“…The respective methods used for the statistical analyses of method-specific data have been described elsewhere [25,27,30,32,35,37,43,47,54]. For the overall statistical analyses on which Figs.…”

Extraction of parathion by hydroxyl-functionalized ionic liquid aqueous two-phase system

“…The presence of organic phosphorus residues in complicated samples has encouraged the development of various sample preparation techniques [2]. Sample preparation has been identified as the bottleneck of analytical methodologies for the determination of contaminants in complicated samples.…”