Septic Tank Effluent Percolation Through Sands Under Laboratory Conditions

Temporal changes in hydraulic conductivity of sand porous media biofilters during wastewater infiltration due to biomat formation

“…This reduction in K bm /b nm from Week 2 to 20 can be attributed to either a decrease in hydraulic conductivity of the biomat, an increase in biomat thickness, or both. According to the literature (Jones and Taylor, 1965;Thomas et al, 1966;Bouma, 1975;Siegrist and Boyle, 1987;Tyler et al, 1991;Tyler and Converse, 1994) biomat development results from both the accumulation of suspended solids within soil pores and microbial growth as a result of microbiological activity. Therefore, it seems reasonable to assume that a decrease in permeability due to pore filling, as well as increase in biomat thickness is contributing to the overall increase in hydraulic resistance of the biomat zone.…”

“…The mechanisms of biomat development are not fully understood, although several studies have been completed in the attempt to characterize biomat formation in subsurface PMBs. According to the literature, the development of a biomat layer at or just below the infiltrative surface seems to result from both the accumulation of suspended solids within soil pores and microbiological growth (Jones and Taylor, 1965;Thomas et al, 1966;Bouma, 1975;Siegrist and Boyle, 1987;Tyler et al, 1991;Tyler and Converse, 1994).…”

“…Based on data and information in the literature, the formation of basal and sidewall biomats at the infiltrative surfaces of soil PMBs decreases the infiltration rate and effective hydraulic conductivity of the system (Jones and Taylor, 1965;Bouma, 1975;Siegrist, 1987;Siegrist and Boyle, 1987;Keys et al, 1998;Beach and McCray, 2003). Reductions in the overall 'effective' hydraulic conductivity of PMBs are due to decreases in the biomat conductivity, as well as decreases in the unsaturated conductivity that occur as the biomat forms.…”

Soil Clogging Genesis in Soil Treatment Units Used for Onsite Wastewater Reclamation: A Review

“…These stages have been referred to as phases of clogging. Although researchers have observed 2-4 phases, most have observed three (Jones and Taylor, 1965;Otis, 1984;Siegrist, 1987;Thomas et al, 1966). When three phases were observed, they generally consisted of (a) an initial gradual decline in infiltration rate, (b) a rapid decrease in infiltration rate, and (3) a stabilization of infiltration rate at a low long-term acceptance rate ( Figure 5).…”

Innovative anaerobic submerged media in small waste treatment plants in Hungary

“…For a good settling process "porous" soil layers are needed, preferably with adequate, maximum ground water levels (Jones & Tayler, 1965; Pradhan et al, 2011¸ Veres et al, 2015. The above listed advantageous conditions are not available in every country, but in most cases can be created as realistic or necessary solutions.…”