Septic Tank Sludges as Part of The Optimized Sewage Treatment Process

Abstract

Rural areas without sewage coverage rely strongly on on-site sanitation systems such as septic tanks for disposal of sewage. Separation of solid matter from the liquid part will occur and sludge is formed on the bottom of the tank. Septic tank sludges can be feeded into municipal wastewater treatment process in their current form or after pretreatment. Suitable pretreatment techniques can be physical, chemical or biological, for instance sedimentation, centrifugation, ultrasound treatment and chemical oxidation. Anaerobic digestion is an effective method for sludge treatment and recycling. Optimally septic tank sludges can be mixed with other sludges (such as pre-clarified sludge) at wastewater treatment plant before sending them for anaerobic digestion process for biogas and methane production. Phase separation of material flows will maximize utilization of process technologies, increase cost-effectivess and have positive impact on quantity and quality of final products.