Efeito da aeração e da estação do ano na compostagem de resíduo de pescado

Abstract

Composting presents itself as an excellent alternative to recycle waste generated during fish production and the use of aeration during this process can contribute to the occurrence of greater degradation of these wastes as well as better quality of the generated compost. The objective of this work was to evaluate the effect of forced aeration during the winter and summer seasons on the composting of fish waste. A completely randomized design was used in a 2x2 factorial scheme represented by aeration (with and without) and two seasons of the year (winter and summer), with plot subdivided in time represented by the turning times (50, 70 and 90) and 3 replications (cells). The windrows were formed in layers, interspersing fish residues and bulking agent, in the proportion of 3:1, respectively, and using compost cells with a capacity of 200 kg of natural material. For aeration of the windrows, PVC tubes were inserted between the layers of waste formed, these tubes being perforated along the length, allowing the injection of air with a continuous flow of 0.6 L.kg.SV-1 .min-1 . The composting period was 90 days from the date of formation of the windrows, and the temperature was monitored daily, and samples of the windrow profile were periodically collected to control moisture. The reductions of (ST, C and N) were influenced (p<0.01) by the presence of aeration, season of the year and composting time. ST reductions were verified at 50 days in winter (86.66%) with aeration and (45.5%) without aeration, in summer (79.98%) and (66.82%) respectively. Regarding carbon degradation, there was an influence (p<0.01) of aeration only up to 50 days of the process, with greater reductions in winter (77.77%) compared to those verified in summer (76.33%).