| dc.description.abstract | Considering the environmental impacts caused by the consumption of materials made of synthetic polymers, biopolymers come up with an alternative, as they are produced from renewable sources, such as cellulose. One possibility, therefore, for its final destination is to compost so that its biodegradation occurs together with organic waste. This study aimed to evaluate the compostability of cellulose-based biopolymers, produced in different degrees of hydroxyl group substitution, in a compost system consisted of vegetable garden residues and tree pruning. The composting lasted 60 days and was carried out in a commercial compost of 435L, where 145 liters were occupied with residues of vegetable garden and 290 liters with tree pruning. At the beginning of the process, the following biopolymers were inserted: Cellulose triacetate obtained from soybean hull (film), cellulose diacetate obtained from soybean powder hull, cellulose triacetate obtained from soybean hull (powder) and cellulose monoacetate obtained from oat hull (powder). The biopolymers were removed from the compost for visual analysis of its degradation and mass reduction, after 30 and 60 days from the beginning of the process. The following composting parameters were also monitored: temperature, C/N ratio, total organic carbon, total nitrogen, pH, electrical conductivity, solids series, humidity, waste decharacterization and mass and volume reduction. At the end of the process, compostable material was submitted to a physical-chemical characterization. Monoacetate and Diacetate showed the highest mass reduction after 60 days of composting: 98.5% and 98.9%, respectively. These treatments presented the highest visual mischaracterization at the end of the composting period. The thermophilic phase of the compost lasted about 20 days and the maximum temperature observed was 66°C, at the 2nd day, which lasted 4 hours, enough to indicate the potential of the compost in pathogen inactivation. The final C/N ratio of the compound was 5.16 and the organic carbon and total nitrogen contents were 9.39% and 1.82%, respectively. The pH of the final compound was 7.65 and the humidity was 52.58%, a value considered high according to IN 61/2020 of MAPA. The residues of the vegetable garden showed complete decharacterization at the end of the 60 days of composting. Tree pruning presented only a decrease in its granulometry. The reduction of volume and mass was 29.6% and 55%, respectively, an interesting result from the point of view of the management of such residues. It was concluded that composting was efficient for the degradation of vegetable garden residues and that the biopolymers that presented the highest compostability potential were cellulose diacetate obtained from soybean hull (powder) and cellulose monoacetate obtained from oat hull (powder). | |
