Analysis of the use of dairy effluent for the production of organic fertilizer

Abstract

The dairy industries generate waste at their effluent treatment stations (ETE), in which a fatty portion is removed in the first stages of treatment. In order to reduce the disposal of this waste and create a circular economy, in which waste becomes a source of raw material, the composting process was used, in which microorganisms degrade the organic matter present and result in an organic fertilizer. In addition to the ETE residues, other residues were used as raw materials: tanned bovine manure, eucalyptus ash and eucalyptus wood shavings. After the selection of raw materials, a 30: 1 carbon / nitrogen ratio (C / N) was calculated and divided into a method without microorganisms and one containing microorganisms, to assess whether there is an increase in micronutrients in the final compound. Both methods, with and without microorganisms, were satisfactory, however the use of microorganisms did not obtain significant results in the increase of the physical-chemical parameters, making its application unfeasible since there are costs involved. Regarding the legislation of the Ministry of Agriculture, Livestock and Supply (MAPA), both methods obtained satisfactory results, being above all the minimum required parameters.