Degradation of mecoprop in polluted landfill leachate and waste water in a moving bed biofilm reactor

Mecoprop is a common pollutant in effluent-, storm-and groundwater as well as in leachates from derelict dumpsites. Thus, bioremediation approaches may be considered. We conducted batch experiments with moving bed biofilm (MBBR)-carriers to understand the degradation of mecoprop. As a model, the carriers were incubated in effluent from a conventional wastewater treatment plant which was spiked to 10, 50 and 100 mg L-1 mecoprop. Co-metabolic processes as well as mineralization were studied. Initial mecoprop concentration and mecoprop degradation impacted the microbial communities. The removal of (S)-mecoprop prevailed over the (R)-mecoprop. This was associated with microbial compositions, in which several operational taxonomic units (OTUs) co-varied positively with (S)mecoprop removal. The removal-rate constant of (S)-mecoprop was 0.5 d(-1) in the 10 mg L-1 set-up but it decreased in the 50 and 100 mg L-1 set-ups. The addition of methanol prolonged the removal of (R)mecoprop. During mecoprop degradation, 4-chloro-2-methylphenol was formed and degraded. A new metabolite (4-chloro-2-methylphenol sulfate) was identified and quantified. (C) 2017 Elsevier Ltd. All rights reserved.