A biodigester septic tank is a long-term waste and sewerage management system that allows us to recycle water and produce biogas using environmentally friendly procedures. The system consists of a sealed chamber where bacteria break down organic (usually from waste from wastewater) in an oxygen-free environment. Septic-tank is primary treatment structures which remove the suspended matter in domestic sewage by adopting sediment and anaerobic fermentation principle, domestic sewage contains plenty of feces, Paper Scrap, parasite etc impurity, the suspended solid concentration is 100-350mg, organism concentration BOD5 is between 100-400mm, the suspended organism BOD is 50-200mg among of them. sewage enter into bio digesterseptic-tank will remove 50%-60% suspended matter are 12-24h sediment, the sediment sludge will anaerobically digest on above 3 months, which will make the organism decompose stable inorganics, corruptable raw sludge translate to ripe sludge, it changed sludge structure, reduce sludge water ratio, clear it and transport out regular. Landfill or reuse it as fertilizer. If you use the bacteria per week properly then bacteria will digest the solids.