Valorization of Meat and Bone Meal through pyrolysis for soil amendment or lead adsorption from wastewaters

The valorization of Meat and Bone Meal material through the pyrolysis process was investigated. Evolved gases were quantitatively analysed and the energy potential was determined. The biochars were characterized by physical and chemical analyses as a function of temperature in a fixed bed unit. The leachability of biochar through soil was studied and its feasibility for lead adsorption from wastewaters was investigated. The higher heating value of pyrolysis gases was satisfactory for the energy requirement of pyrolysis units. The pH of biochar was alkaline, the level of nutrients Ca, Mg and P are high, while that of toxic heavy metal is low. The leachability of all species through the soil was low. Removal efficiency of lead from the solution reached a maximum value of 80.5% for a great range of initial concentrations tested, following the Freundlich isotherm model. The mechanism of lead sorption was complex including surface precipitation, complexation and aromatic coordination. The dominant mechanism was the formation of Pb-phosphate and Pb-carbonate precipitates onto the biochar. Meat and Bone Meal biochar showed potential for soil amendment or remediation of lead in contaminated waters.