Mecoprop (MCPP) removal in full-scale rapid sand filters at a groundwater-based waterworks.

Contamination by the herbicide mecoprop (MCPP) was detected in groundwater abstraction wells at Kerteminde Waterworks in concentrations up to 0.08μg/L. MCPP was removed to below detection limit in a simple treatment line where anaerobic groundwater was aerated and subsequently filtered by primary and secondary rapid sand filters. Water quality parameters were measured throughout the waterworks, and they behaved as designed for. MCPP was removed in secondary rapid sand filters — removal was the greatest in the sand filters in the filter line with the highest contact time (63min). In these secondary sand filters, MCPP concentration decreased from 0.037μg/L to below the detection limit of 0.01μg/L. MCPP was removed continuously at different filter depths (0.80m).