Possibility of Enhancing Methane Productivity in Anaerobic Reactors in the Treatment of Excess Sludge from Wastewater Treatment Plants

This paper describes technological possibilities to enhance methane production in the anaerobic stabilisation of wastewater treatment plant excess sludge. This objective can be achieved by the addition of waste residues: crude glycerol from biodiesel production and residues from fishery. The addition of glycerol in the amount of 2–5% by weight causes the enhancement of methane production of about 250–400%. At the same time, the percentage increase of total solids concentration in the outgoing sludge is ten or more times less. The content of methane in biogas is higher in the case of admixed substrate.