Résumé - Abstract
Carbonaceous materials can be used as amendments to reduce the pharmaceutical contamination from biosolids during land application. This study evaluated the effectiveness of 360-d composting and two carbonaceous amendments, biochar (BC) and woodchips (WC), for reducing the concentration and leachability (mobility) of four pharmaceuticals [carbamazepine (CBZ), ibuprofen (IBU), gemfibrozil ( GEM), and naproxen (NAP)] in biosolids derived from wastewater treatment plants in southern Ontario, Canada. Composting decreased total and leachable concentrations of pharmaceuticals in unamended and BC- and WC-amended biosolids to various degrees, from 20% up to 99% depending on the compound. Amendment of biosolids with BC or WC greatly increased the removal rate of the target pharmaceuticals, while simultaneously decreasing their half-lives (t 0.5 ), compared to unamended biosolids. Biochar and WC exhibited different (neutral, positive, or negative) effects on the leachability of individual pharmaceuticals; however, BC and (or) WC generally reduced the total and (or) leachable (mobile) amount of target pharmaceuticals during composting compared to unamended biosolids. Biochar and WC are effective amendments that can reduce the environmental impact of biosolid land applications with respect to pharmaceutical contamination.