Removal of oil and total solids in biofilters operating with primary domestic sewage

Abstract

The release of untreated domestic sewage in environment negatively impacts the quality of life of populations. The present study aimed to analyse the removal of oil (O) and total solids (TS) in biofilters operating with primary domestic sewage. Experimental tests were conducted at the Federal University of Viçosa (UFV) in Viçosa - MG, Brazil. The experiment was carried out in a split split plot scheme, in plots the rates of application of domestic sewage (0.5, 1.0, and 1.5 m³ m^-2 d^-1), subplots consisted of types of organic material (composted waste, sugar cane bagasse and sawdust) and split-splitplots the time of evaluations (August, September, October, November and December 2009), in a completely randomized design with three replications. Upstream and downstream of the biofilter, 27 samples of sewage were collected monthly for determination of O and TS for five months. The results indicated that the biofilter made of composted waste, sugar cane bagasse and sawdust show promising capacity in removing oil and grease stemming from domestic sewage, and that application rates of 0.5, 1.0 and 1.5 m³ m^-2 d^-1 of sewage in all biofilters evaluated showed no significant differences regarding the removal of TS from the second month of observation.