Potential removal of biochemical pollutants in biofilters operating with domestic sewage

Abstract

The present study aimed to analyze the removal of Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) in biofilters operating with domestic sewage. Experimental tests were conducted at the Universidade Federal de Viçosa (UFV), Viçosa-MG. The experiment was a split split plot scheme, and in the plots different rates of sewage (0.5, 1.0 and 1.5 m3 m2 d-1) were applied, in the subplot, types of organic material (waste compost, sugar cane bagasse and sawdust) were tested and in the subsubplots, five dates of measurements (August, September, October, November and December 2009) were evaluated, in a randomized block with three replications. Samples of domestic sewage were collected upstream and downstream of 27 biofilters for determination of BOD and COD, monthly for five months. The results showed that the effluent from biofilters meets the national standard for release in water streams, with regard to the BOD, after stabilization of the filter elements, and the use of biofilters for the treatment of domestic sewage is a viable technology for small scale because it has low cost, easy operation and good ability to remove biochemical pollutants.