Use of Recycled Rubber Particles for Leach Field Media in On-Site Wastewater Treatment Systems

Three different laboratory scale biofilter systems were demonstrated for septic tank effluent treatment to evaluate the use of recycled rubber particles (RRP) filter media compared to gravel and peat moss. The lab-scale RRP biofilter removed BOD5, ammonia nitrogen, and solids with over 90 % removal efficiency at various hydraulic loading rates ranging from 1.4 gal/ft2/d to 5.0 gal/ft2/d. The gravel system also showed good performance similar to the RRP system at similar hydraulic loading rates, with the exception of high effluent TSS (up to 100 mg/L) due to biomass sloughing. The peat moss biofiltration system showed lower removal efficiency in terms of COD and BOD5 removal than the other systems at loading rates from 1.4 gal/ ft2/d to 4.0 gal/ft2/d. The RRP system performed better than other in terms of organic and ammonia removal as well as fecal coliform control after system stability.