Microbial mixtures in the treatment of liquid waste from a milking parlor

Abstract

The wastewater from a milking parlor is made up of solid and liquids waste. For the treatment of these residues, microorganisms such as Saccharomyces cerevisiae (SC), lactic acid bacteria (LAB) and species of the genus Bacillus were used. For this reason, in this work it was treated the wastewater of a milking parlor applying microbial mixtures (MM). The test was carried out under a randomized design, with three replicates per analysis and mixtures (MM1 (SC-LAB) and MM2 (Bacillus species)), divided into two parts in which were measured: pH, soluble solids, electrical conductivity (EC), Total Dissolved Solids (TDS) and the plate count of the microorganisms under study and total coliforms (TC). The first part was performed in Erlenmeyer flasks, inoculating the MMs into 100 mL of liquid waste in different flasks. While in the second part, the most efficient mixture was applied in situ, collecting the samples weekly. Analysis of variance (ANOVA, α = 0.05) and the test of the least significant difference (LSD) were performed on the data collected. In this research, the MM2 (applied in situ) managed to reduce EC (from 1,800 to 1,100 μs/cm) and TDS (from 812 to 687 ppm), as well as inhibit the TC growth.