Pyrolysis of Municipal Sewage Sludge to Investigate Char and Phosphorous Yield together with Heavy-Metal Removal—Experimental and by Thermodynamic Calculations

Sewage sludge is regarded as a potential source for soil fertilizer However, the direct utilization of sewage in agricultural land restricted since it also contains heavy metals, pathogens, and toxic compounds. Pyrolysis destroys organic pollutants partly volatilizes metals. In this study, pyrolysis was carried out order to determine optimum residence time temperature recover phosphorous remove metals from resultant char (SSC). conducted on dried (DSS) by means thermogravimetric analysis (TGA) high-temperature oven with an N2-atmosphere. Microwave Plasma-Atomic Emission Spectroscopy (MP-AES) used concentration P trace elements resulting solid fraction. A combination chemical fractionation (step-by-step leaching) DSS thermodynamic equilibrium calculations were utilized estimate availability removal SSC fraction at different temperatures. The results thermodynamics calculation line measured composition SSC. Furthermore, energy contents obtained temperatures measured. evaluation indicate that enriched char, while lead, zinc, cadmium significantly removed.