Evaluation and characterization of the fish waste composting process

Abstract

Most fish waste is discarded without any previous treatment, thus generating a serious environmental problem. One of the means of treatment and recovery of these residues would be the composting method, which, through biodegradation, has the function of transforming the residue into organic fertilizer. In this context, the present study had the objective of evaluating and characterizing the composting process of fish residues from open fairs, using as a source of carbon, shavings, grass cutting and pruning of trees. The parameters evaluated were: temperature, humidity, hydrogen ionic potential (pH), ashes, total organic matter, total organic carbon, total nitrogen, C/N ratio and mineralization index. The data were submitted to analysis of variance ANOVA and the variables that will not present normal distribution were analyzed by Kruskall-Wallis ANOVA and the means were compared by the Tukey test at 5% significance. The results of the physical-chemical parameters evaluated at the end of the composting process are used to evaluate the effectiveness of the process. Thus, noting that the composting method is a viable alternative for the use of fish waste, even the results of the present study presented values for humidity and C/N ratio higher than those recommended by the Brazilian legislation for the use of organic fertilizers for both the compounds, thus suggesting the use of a larger nitrogen source for the preparation of organic compounds under the experimental conditions of the present study.