Aerobic composting system for treating food waste at cafeteria: Wang Ulu residential college

Abstract

A study was conducted to investigate the food waste composting system in Cafeteria Wang Ulu Residential College. Food waste generated from cafeteria in Wang Ulu Residential College was evaluated using composting bin system. Aerobic composting system was applied in order to achieve the objective. The mix of food waste and sawdust was evaluated using ratio 2:1, two parts of food waste to one part of sawdust. Waste reduction, temperature, moisture content, pH value, carbon to nitrogen (C/N) ratio, nutrient content such as phosphorus (P), potassium (K), and nitrogen (N), calcium (Ca) and magnesium (Mg) were monitored during the composting process. Production of compost within three months and two weeks showed the percentage of waste reduction was 87.9%. Final temperature varies between 28oC and 30oC and moisture content dropped from the initial range of 81.7% to 22%. pH value of the compost also drop from the initial value of pH 9 to pH 7.2. The C/N ratio for mature compost was 11:1 and N content was 0.217%. P content was 0.015% while K content was 1.5%. Besides that, Ca content was 0.78% and Mg content was 0.069%. Mature compost had dark brown colour and earthy smell. All the characteristics were important parameter to determine mature compost.