Valorização de resíduos de alimentos: comparação entre os processos de compostagem e vermicompostagem em composteira unifamiliar

Abstract

The increasing generation of organic waste represents a significant environmental and logistical challenge in our modern societies. Leftover food, green waste, and wood make up a considerable portion of solid waste, and improper disposal can lead to a range of issues. However, composting stands out as an effective solution to address this issue. The process can utilize a variety of organic waste, is a cost-effective alternative, and does not require much space to operate. Related to composting is vermicomposting, where the process is carried out through the decomposition of organic matter using worms and microorganisms. Composting can be especially done in containers such as barrels, which can be made at home. This method of home composting aims to treat organic waste at the source on a small scale. Despite being less popular in Brazil, it is a significant ally in solid waste disposal. Given the issues raised, the objective of this study is to compare the efficiency of composting and vermicomposting in domestic composting equipment and determine which is more viable and how they can promote pollution reduction and contribute to solid waste disposal. As a preliminary phase of this study, a search was conducted in the Scopus database to identify published works on composting. A total of 119 articles were used in the literature review, where relevant studies were identified. Additionally, a bibliometric analysis was performed to evaluate the inherent patterns and trends in the works used as theoretical bases. In the development of the home composter, two 20- liter plastic barrels were used, totaling a volume of 0.02 m³. The physical-chemical and biological parameters evaluated included density, temperature, humidity, pH, and germination capacity. The results revealed that the bibliometric analysis identified the predominant trends in research and provided valuable guidance for more detailed investigations in related topics. Both compartments of the composter showed an increase in density throughout the composting process. Temperatures remained in the mesophilic range. Humidity levels were in compliance with standards, with the upper compartment reaching approximately 60.2%. Although pH values fluctuated, they remained within the expected ranges (7.5 to 8.5) for composting and (6.5 to 8.5) for vermicomposting. Germination tests highlighted the potential of lower concentrations of leachate and the quality of the compost in the upper compartment. The production of organic liquid coincided with the complete decomposition of kitchen waste and the presence of pregnant worms. Possible improvements include the prior fragmentation of sawdust, more effective management of leachate, and ongoing research to evaluate composting over the long term and the evolution of the resulting compost.