PRODUCTION OF COMPOST BY AEROBIC DECOMPOSITION OF SOLID WASTE IN THE MOSUL CITY

Abstract

The study was conducted during the winter season of 2021-2022 to determine the possibility of preparing Combo Six from a mixture of organic waste with a ratio of C:N 1:30 consisting of food residues, paper, cardboard, sawdust, animal and plant residues in a homemade reactor, and the biological reactor was working aerobically. Due to the microorganisms responsible for this process, the decomposition process lasted for 34 days for the ideal case and about 40 days for the normal case under ideal conditions of heat, humidity and stirring. In the end, the study reached to give a dry product like about a quarter of the volume of waste used in this process called (compost). Some factors affecting the decomposition process have been studied, including air temperature, pH, moisture content and volume variance. The pH was neutral on the first day, then the pH values decreased to about 5.5, as the activity of the fungi increased because they love the acidic medium, and then the pH returned to the neutral state and eventually settled at neutral to basic values. As for the heterogeneity of size, it decreased to about 70%. The resulting humus was rich in the main nutrients (N, P, K), and the concentrations of heavy metals in it were within the standard parameters, except for cadmium and iron, which was high.