method for pretreating sludge before anaerobic digestion

摘要

sludge, for example, primary sludge or sludge activated by waste or both from a wastewater treatment plant, is pre-treated before anaerobic digestion. pretreatment includes an optional mechanical treatment to reduce the viscosity of the sludge and a biological hydrolysis treatment. the treatment of biological hydrolysis can be carried out in a series of reactors, some of which are maintained at a temperature in the range of 50 to 70 ° c. the reactors provide a combined retention time in the range of 0.5 to 6 days. optionally, ph measurements of sludge during or after biological hydrolysis, or biogas production from an downstream anaerobic digester, can be considered in adjusting the temperature of one or more of the biological hydrolysis reactors.