LOSSES OF ORGANIC MATTER AND NITROGEN DURING COMPOSTING OF MUNICIPAL SOLID WASTES

摘要

The authors analysed the level of losses of organic matter and nitrogen during five months of composting of municipal solid wastes (MSW) with the addition of nitrogen in the form of urea. The object of the research was raw compost from MSW, pre-treated using MUT-DAMO technology. The compost, with 0.5 kg H_2O kg~(-1) of dry mass moisture content, was composted for a period of 5 months as follows: A - on a pile, B - in a perforated plastic container of total capacity of approximately 1000 1, C - in aplastic container of total capacity of approximately 10001 with the addition of 2.5 gN kg~(-1) of dry mass, D - in a plastic container of total capacity of approximately 10001 with the addition of 5.0 g N kg~(-1) of dry mass. The results show that losses of organic matter ranged from 64 to 66% and losses of its water-soluble forms from 93 to 95%. Addition of urea to the compost contributed to high losses of total nitrogen (40-45%), especially of its water-soluble forms (96-98%), and decreased compost fertility. Composting of MSW on the pile, with a C/N ratio of approximately 30, limited the loss of nitrogen and enriched the compost in nitrogen and its water-soluble forms.