Bivalves and bivalve shells have been suggested as possible approaches for wastewater treatment, but comparison of the efficiency of both approaches under similar conditions is rarely reported. In this context, this study aims to assess the efficiency of clams and clam shells (fresh and dry) of the bivalve Corbicula fluminea in removing pharmaceutical contaminants from urban wastewater and in decreasing its environmental hazardous potential. Experiments were conducted under batch conditions using secondary effluent from an urban wastewater treatment plant (WWTP). To evaluate the efficacy of these processes in reducing the environmental hazardous potential of treated wastewater, an integrative approach was adopted, encompassing chemical removal, physicochemical alterations, and ecotoxicological effects. Both approaches increased pH and pronouncedly increased inorganic carbon, whereas decreased total suspended solids; fresh shells increased turbidity. The bulk removal of the quantified compounds varied as follows: fresh shells (34 %) > clams 24 h and clams 48 h (30 %) > dry shells (20 %) > aeration (2 %). The compounds removed to a larger extent were acetaminophen (> 77 %) and atenolol acid (> 69 %). Both approaches caused minor changes in the toxicity of the wastewater to daphnids, microalgae and lettuce. The results suggest that shell-based removal of contaminants might have better applicability in wastewater treatment than clams, especially considering the challenges of maintaining these organisms in real treatment settings.
Jesus et al. (Fri,) studied this question.