USE OF PEAT IN SOIL INFILTRATION SYSTEMS FOR DOMESTIC WASTEWATER TREATMENT IN TROPICAL AREAS

摘要

Peat has been found to be an effective medium in soil infiltration systems for the treatment of municipal wastewater. Several studies in the literature show the capacity of the peat to remove substantial amounts of organic matter. In this study, laboratory columns were used to determine the treatment capacity of peat in tropical areas at varying hydraulic and organic loadings and depth. The columns with 30,40 and 50 cm of peat were studied treating synthetic wastewater with similar characteristics to domestic wastewater in Colombian Caribbean Coast. All columns were dosed at uniform rates of 20,40, 60 and 80 cm/d. Each one of these hydraulic loadings was evaluated at two different organic matter concentrations (BOD_5 of 150 and 250 mg/L) for periods of six weeks. Results of column studies showed suspended solids removal in the 58 to 96% range and BOD and COD removals exceeded 83%. Nutrient removal was very low. Total nitrogen removal was in the 15 to 21% range; although nitrification was nearly complete. Phosphorus removal was in the 13 to 15% range. In general, for the different operating conditions studied, the use of locally available peats in wastewater treatment showed excellent BOD_5, COD and TSS removals. Thus, using peat in soil filtration system is an efficient and low cost method to treat domestic wastewater in rural communities from Colombian Caribbean Coast.