Composting of fish wastes in a full-scale in-vessel system

This study carried out in a full-scale fish waste composting facility examined the effects on the 'active' stage of composting of two bulking agents (alder and fir), and two amendments (peat moss and vermiculite). The rise in temperature which occurred as composting progressed was accompanied by an increase in ammonia and volatile fatty acid production. This overall pattern was observed in all four mixes whereby the concentrations of ammonia and volatile fatty acids increased rapidly and then declined gradually over the course of monitoring. The changes in their concentrations over time proved to be a reliable indicator of the progress of the composting process. Ammonia emissions from the composting piles were reduced by the additions of peat moss, vermiculite, and alder in comparison to the headspace ammonia level for the fir mix. The results indicated that ammonia management during the composting process could be easily accomplished by the use of suitable amendments or bulking agents. Feat moss and vermiculite were found to be good amendments for fish composting and alder was found to be a good bulking agent. (C) 1997 Elsevier Science Ltd.