Nutrients Recovery From Aquaculture Wastewater Using Thermally Treated Gastropod Shells

Abstract

Various technological options are currently being assessed towards phosphorus recovery from waste streams. Premised on the development of sustainable appropriate technology, gastropod shell was thermally modified in this study to enhance its sorption capacity as a substrate material for P recovery from aquaculture used water. It was revealed that the thermal treatment impacted enhanced defects in the surficial morphologies of the gastropod shell leading to an increased P recovery efficiency; this was contrary to the general view that high P recovery efficiency of calcined calcium – rich materials was as a result of conversion of CaCO3 to CaO. Furthermore, about 60% P recovery was obtained and a substantial recovery of the total Nitrogen was also achieved. There was a significant improvement in the overall characteristics of the treated used water for safe disposal or reuse.