Avaliação microbiológica em processos de compostagem de resíduos agroindustriais em pequena escala

Abstract

This work aims to contribute to the study and improvement of agro-industrial waste composting processes generated in small properties, seeking the production of organic quality compost. For this we carried out a microbiological evaluation in composting processes on a small scale. Samples were collected with different residence times in the composter three distinct properties of the Alto Uruguay region and the Catarinense West, known as property 1, 2 and 3. Among the parameters analyzed was the pH, considered important when related to the composting process. Also, microbiological testing for verification of bacteria were performed, fungi and other microorganisms existing in this type of waste, including the pathogenic character. The study focused on the detection of pathogenic microorganisms such as Total Coliforms, Coliforms thermotolerant and Salmonella sp. and still Yeast and Molds. The methodology used was based on studies of food waste. As the results, it detected the presence of thermotolerant coliforms in some samples, however, even at levels allowed by law. The accounting of these was done through the NMP. There was the presence of Salmonella sp. which can be associated with waste food hygiene. In this case it was observed the presence or absence in the sample. It was also observed the presence of yeasts and molds in the samples of the three properties, accounted for by the UFC. This is related to the natural occurrence of these microorganisms in compost and also associated the presence of substrates with high sugar content. It can be concluded that the longer the residence time in the lower composting the amount of pathogenic. And the process control greatly influences the quality of the final compound. One of the suggestions for improvement in small-scale composting processes is the turning of the compost windrow. This contributes to the introduction of oxygen inside the windrow favors microbial activity and increases the temperature of the windrow, eliminating pathogenic microorganisms.