State of the Art in Technologies of the Biogas Production Increasing During Methane Digestion of Sewage Sludge

Abstract

At present many WWTPs are focused on increasing quantity of biogas generated during sewage sludge processing. Various disintegration methods can be used for this purpose - thermal heating, ultrasonic disintegration, chemical treatment. The limiting step in sewage sludge digestion is hydrolysis, increasing the rate of this process allows for shortening solids retention time in digester, increasing soluble COD concentration in the reject water and as a result also biogas production. In technical scale ultrasonic and thermal disintegration are used. The most effective are ultrasounds below 100 Hz. In thermal conditioning various technological parameters are applied (from 60 - 80 °C to even 250°C, retention times from 15 min. to 2 hours). Effectiveness of the processes can be increased by using combined processes, e.g. thermal treatment and chemical stabilization. Chemical methods are at present mainly applied in laboratory scale. They include alkaline and acidic pretreatment or advanced chemical oxidation methods.

Co‐Digestion of Water Hyacinth and Duck Manure for Potential Low‐Cost Biogas Production by Rural Communities

“…The increase in COD could be the result of the increase in temperature as the digestion progressed which led to an increase in soluble COD (sCOD) and a higher biogas yield. [ 45 ] Sandriaty et al. [ 46 ] also reported the emergence of sCOD after the biochemical methane potential test conducted in their experiment.…”