Application rates and filtering materials for biofilters in house sewage

Abstract

Application rates and organic filtering materials for the removal of nitrogen and phosphorus in biofilters in primary house sewage are determined. An assay was prepared with 27 biofilters in an experimental area of the Universidade Federal de Viçosa, Viçosa MG Brazil. Nitrogen and phosphorus concentrations were determined monthly during 153 days of the experiment which followed the sub-subparcel scheme. Whereas parcels consisted of application rates of home sewage (0.5; 1.0; 1.5 m 3 m 2 d -1 ), the subparcels comprised types of organic matter (composted urban organic wastes, sugarcane bagasse and sawdust) and the sub-subparcels were the evaluation periods (August, September, October, November and December 2009), in totally randomized blocks, with three repetitions. Results showed that the filtering organic matters sugarcane bagasse and sawdust were more adequate for N and P removal in home sewage. However, composted urban organic wastes raised their rates in the effluents collected by the biofilters. There was no significant effect of application rates of house sewage on N and P removal of the effluent by biofilters filled with composted urban organic wastes, sugarcane bagasse and sawdust. Biofilter effluents have high N and P quantities for fertilizationirrigation of non-raw consumed cultures.Key words: sustainability; water re-use; treatment; earthworm. RESUMEN