Wastewater treatment plant sludge valorization in co-digestion with biomass wastes to produce bioenergy and biochars

Because water is consumed excessively, sludge from wastewater treatment plants is produced in high amounts, which required their management. Instead of landfilling, land-spreading and combustion, thermochemical and biological processes could be applied to sludge, so that to extract valuable bio-products from it. These products are bioenergy in form of biogas and biofuels (bio-oils) and biochar which could be used for polluted water detoxification, for greenhouse gases adsorption and as amendment for soil. The purpose of this paper is to introduce the current study having as a goal the design of an ecological process combining anaerobic digestion and pyrolysis to valorize wastes. This process will consume lower energy that could be recovered by the process itself via bio-methane burning; in addition, it will not generate any residue and provide a good alternative for waste volumes reduction and recycling