Qualidade do composto gerado no tratamento de resíduos sólidos de restaurante e diferentes resíduos orgânicos

Abstract

The objective of this work was to evaluate the quality of the final compost from different sources of carbon and nitrogen during the composting process of organic residues from the University Restaurant (UR) of the Federal University of Lavras, and assess this compost according to production and use regulations of organic compounds. Four types of treatment were used: T1 - grass and UR residue, T2 - grass, UR residue and sewage sludge, T3 - sawdust/UR residue, and T4 - sawdust/shavings, UR residue and sewage sludge. Two replicates were performed for each treatment. Each compost pile had a conical shape with approximately 1.30 meters of height and 2 meters of base. The experiment was conducted at 40% humidity. After 120 days in the field, the final pH of the treatments were 8.6, 7.7, 6.7 and 6.8 for treatments T1, T2, T3 and T4, respectively. Treatments T1 and T2 obtained a better C/N ratio than treatments T3 and T4, where the respective values were 13.1 and 11.4 for T1 and T2, and 32.2 and 48.4 for T3 and T4. Among the micronutrients and heavy metals found in the final compound, zinc and copper had values below the standards suggested by MAPA and Conama for all treatments. In conclusion, the compost produced from restaurant waste and sewage sludge met the standards assessed and can be applied to the soil as an organic fertilizer.