Abstract
Cardboard box composting has been widely recommended by many local governments and practiced by many citizens to reduce household solid waste disposal and to make organic fertilizers from kitchen food waste in Japan. However, little scientific information is available on box compost. In this study, we evaluated the quality of box compost by measuring the changes in compost temperature during composting and determining the mass balance, physicochemical properties, and biological aspects, including the germination index and hygiene-indicator bacteria. During composting for 90 days, 61.6kg of kitchen food waste and 11.0 kg of rice bran were added to a box. The temperature of the compost was in a range of 36.8 - 67.1 °C (55.3 ℃ on average). On a raw weight basis, 66.6 % of the total load (returned compost as basal material, kitchen food waste, and rice bran) was reduced by decomposition and evaporation. On a dry weight basis, 46.2 % of the total input was decomposed. The cation exchange capacity of the product was 69.8 cmolckg−1. Plant germination and bacterial examinations showed the products were free of harmful germs and plant growth inhibitors. These results indicate that box composting can significantly reduce the amount of household waste and produce sanitary organic fertilizer.
