Comparação entre as técnicas de compostagem e vermicompostagem em composteira unifamiliar de baixo custo

Abstract

Since the 1970s, concerns about the management of solid waste have gained visibility. Composting of organic solid waste emerged as an alternative to reduce the volume of landfills, which have negative environmental impacts. The composting process reduces leachate production and gas emissions, and the resulting compost is a nutrient-rich fertilizer for plants, improving soil quality. To carry out the technique, it is necessary to separate organic waste and add a structuring material. The addition of worms to the compost, known as vermicomposting, accelerates the process, making nutrients more readily available and reducing the presence of pathogens, which benefits plant absorption.This present study aimed to compare the techniques of composting and vermicomposting in a low-cost single-family compost bin. For this purpose, a search was conducted in the Web of Science database for published works on composting and vermicomposting. The search yielded 1725 scientific productions, which were refined. Finally, reading the works provided insights into the subject matter. The single-family composter was constructed with two compartments: the upper one containing leaves and worms, totaling 17 liters, and the second one composed solely of leaves, occupying 9.4 liters. Over 38 days, physical-chemical parameters were monitored, including daily temperature, humidity, and pH at three different times, in addition to density at the beginning and end of the process. Germination tests were also conducted using the compost and both raw and diluted leachate.It was observed that the leaves showed a higher final density compared to those in contact with the worms. There was a 48.1% reduction in the total volume of composted waste in the compartments during the process. The leachate production was 151 mL. The temperatures only reached the mesophilic range, and on the twentieth day, they equalized with ambient temperature, indicating a reduction in microbial activity and the stabilization of the compost. Humidity ranged from approximately 66 ± 1.4 to 69.5 ± 1.2% for the first part of the composter, and for the second part, values ranged from 66 ± 1.3 to 75.6 ± 0.9%. The pH ranged from 5.4 to 7.3, with only the leaves reaching values of 5.4 to 6.8. The germination test using the compost and leachate resulted in low germination rates. Additionally, bibliometric analysis highlights a widespread global dissemination of scientific works on the subject, with Brazil progressively gaining visibility in this area. It is worth noting that relevant productions align with 13 out of 17 Sustainable Development Goals. The use of household organic waste in the form of compost plays a significant role in promoting environmental sustainability, resulting in a 48.1% reduction in the total volume of waste that no longer ends up in landfills. Furthermore, both composting and vermicomposting offer opportunities for nutrient recycling and the mitigation of adverse environmental impacts resulting from improper disposal of solid waste.