The lateral‐flow sand‐filter system for septic‐tank effluent treatment

Abstract

The lateral-flow sand filter (LFSF) is an alternative system for household septic-tank effluent treatment that utilizes periodic or continuous surface discharge. The purpose of this study was to document the LFSF system, evaluate its treatment capabilities in laboratory models, and optimize design parameters. Three 5.0-meter-long laboratory models, each with a different permeability sand fill, were dosed with septic-tank effluent for six months. After an initial development period, percentage removals for biochemical oxygen demand (BOD), total organic carbon (TOC), suspended solids, and coliform bacteria from all the models were excellent. Orthophosphate initially was attenuated but showed increasing values after a few months. Recommendations are made as to a suitable permeability range of sand fills to use in the LFSF system, adequate depth of sand fill and overall system dimensions. Laboratory modeling shows that the LFSF system is capable of providing a high level of treatment to household wastewater and that it should be suitable as a remedial or alternative system for household wastewater disposal. Water Environ. Res., 66,919 (1994).

Measurement of fecal coliform bacteria from domestic waste

“…A new alternate system developed by Check et al (1994), the lateral flow sand filter (LFSF) for household septic-tank effluent treatment utilizes periodic or continuous surface discharge, provides an excellent percentage removal of BOD, total organic carbons, suspended solids, and coliform bacteria. Novel methods for removal of bacteria, viruses, and high BOD material, such as proteins, from industry wastes and sewage are discussed by Lewis et al (1995).…”

Tratamento de esgotos pelo sistema combinado filtro anaerobio e filtros de areia

“…Outra possibilidade seria em locais com terrenos de baixa permeabilidade ou quando há um leito rochoso próximo à superfície (CHECK et al, 1994).…”

“…Em um experimento com areias de três diferentes diâmetros efetivos (0,15; 0,23 e 0,29 mm) Check et al (1994) encontraram resultados discrepantes dos mostrados no parágrafo anterior. Os efluentes dos três filtros geraram dados semelhantes quanto a concentração de nitrito, nitrato, amônia, nitrogênio total Kjeldahl e remoção de sólidos suspensos e carbono orgânico total.…”

Tratamento de efluente anaeróbio

“…No Outra possibilidade seria em locais com terrenos de baixa permeabilidade ou quando há um leito rochoso próximo à superfície (CHECK et al, 1994).…”