Effects of aeration and season of the year on fish waste composting and compost quality

ABSTRACT

Employing forced aeration (FA) in composting static windrows (SW) from fish waste (FW) has the potential to enhance the development of process and, organic fertiliser quality. However, due to the impact of season, the FA may lead to excessive drying of SW and, difficulty in thermophilic temperature maintenance. The aim of this study was to assess the effects of passive aeration (PA) and FA on the composting of FW in SW during the summer and winter seasons. The temperatures of the windrows remained within the thermophilic range for most of the composting period, with peak temperatures observed shortly after starting and turning the windrows (at 50 and 70 days). The aeration benefited the initial TS degradations, resulting in 86.66 and 45.99% of the TS total reduced to FA and PA piles, at 50 days during the winter. The C organic reduction was 77.77 and 76.33% in summer and winter to FA piles, respectively, but this reduction was 59.24% and 67.82% for winter and summer, respectively, in PA windrows. At 50 days, the N reduction in FA piles was already at 70.32% and 71.87% for winter and summer. The volatile solids reductions were significantly higher (p < 0.01) in FA piles during the summer. Although the FA has been shown to enhance the organic constituents’ degradation during the composting of FW, its adoption was not enough to improve the compost composition. Thus, by conducting piles on a small scale, with the perforated wall, as described in this study, the FA could be dispensed.

GRAPHICAL ABSTRACT

KEYWORDS:

• Organic constituents
• degradation
• compost quality

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author, AOAC, upon reasonable request.

Additional information

Funding

This work was supported by the National Council for Scientific and Technological Development (Conselho Nacional de Desenvolvimento Científico e Tecnológico – CNPq) [grant numbers 305886/2017-7 and 421842/2018-0], the Federal University of Grande Dourados (Universidade Federal da Grande Dourados – UFGD) [Edital number 25/2022], and by the Coordination for the Improvement of Higher Education Personnel (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – CAPES) through the granting of scholarships to graduate students.