Designing process and operational effect of modified septic tank for the pre-treatment of rural domestic sewage. (1st December 2019)

• Record Type: Journal Article
• Authors: Singh, Rajendra Prasad; Kun, Wei; Fu, Dafang
• Is Part Of: Journal of environmental management. Volume 251(2019)
• Publication Date: 2019-12-01
• Subjects: Modified septic tank -- Rural domestic sewage -- Numerical simulation -- RTD tracer experiment -- Effluent water quality; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2019.109552
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Structure and performance of a newly designed four-chamber septic tank were investigated in current study. A three-layer orifice plate was fitted in the first compartment in an upward direction, and a baffle was arranged in the second compartment of the septic tank. The filter placed in the third and fourth compartment was used to collect water for field irrigation or connect subsequent devices for further processing. Flow field distribution in the first chamber was numerically simulated by Fluent software, and simulation results were verified by residence time distribution tracer experiment. The improved treatment effects of the modified septic tank with optimal parameters of 20 mm (diameter), 60 mm (gap) and 180 mm (distance) were validated by simulation experiments. High removal rates of chemical and biological oxygen demand reflected the effectiveness of modified septic tanks. Graphical abstract: Image 1 Highlights: Horizontal flow pattern in 3 compartment septic tank make it easy to form short-flow and dead zone. Optimized the structure of modified four-chamber septic tank. Flow field distribution was simulated by Fluent software. The simulation results verified with RTD tracer experiments. Removal of COD and BOD was improved in modified septic tank.