Composting of household organic waste: effect on control parameters and final compound quality

Abstract

It is estimated that 51% of Brazilian urban solid waste is composed of organic material, which has a high recyclability potential via alternative processes. One means of optimization and recycling this fraction would be the popularization of household composting and the dissemination of means of attaining it. The current study objective, therefore, was to evaluate control characters of the household organic residue composting process, test final organic compound product quality and investigate the feasibility of conducting such processes in urban dwellings. Organic residues were collected for three days, distributed over a week, in 20 residences of the urban area of Marmeleiro municipality, Paraná State, southern Brazil. A compost heap was set up with an initial mass of 137.21 kg of organic material. During the degradation process, temperature, dry mass, volume, pH, electrical conductivity, phytotoxicity, volatile solids, total organic carbon exothermic accumulation, and loss of organic matter were measured. At the end of the process, the CTC, CTC:COT, total nitrogen and C:N ratio were also determined. Throughout the composting process it was recorded that the germination index went from 45.27 to 109.43, as the material changed from being dominated by phytotoxic compounds to phytostimulants. In addition, organic compound CTC increased from 27.2 to 57.8, showing organic material degradation occurred in only 37 days. The experimental analysis of the degradation process, has shown that treatment of urban organic waste in compost heaps is both viable and safe under domestic circumstances.