Concentração de matéria orgânica em sistema de tratamento de esgoto doméstico por escoamento superficial.

Abstract

In order to evaluate the concentration and removal of organic matter in domestic wastewater, an experiment was developed using the overland flow method for different application rates: 0.24, 0.36 and 0.48 m 3 h-1 m -1 . The highest removal rates for samples collected at 8 m from the beginning of the borders occurred for the application rate of 0.24 m 3 h-1 m -1 : 66,4% for 5-day biochemical oxygen demand (BOD5) and 62,5% for chemical oxygen demand (COD). The coefficients for the stage 1 of the exponential model were k = 0,0020 and n = 2,3154, for BOD; and k = 0,0200 and n = 0,7846, for COD. Soils samples were collected at two layers at 1 m from upper end: L1 (0 to 10 cm) and L2 (50 to 60 cm). For all treatments the amount of organic matter at L1 decreased at the end of the experiment. At L2 the amount of organic matter increased for the treatments with application rates of 0.24 and 0.48 m 3 h-1 m -1 , and decreased for the 0.36 m 3 h-1 m -1 . The treatment with 0.36 m 3 h-1 m -1 of application rate presented the highest values of biomass production.