Authors: Mohamed F. Hamoda
Addresses: Department of Civil Engineering, Kuwait University, P.O. Box 5969, Safat, 13060, Kuwait
Abstract: This study determined the quantities, characteristics and composting of spoiled vegetables and fruits discarded daily from supermarkets and hypermarkets in an attempt to manage such wastes for resource recovery. Data from 31 supermarkets and hypermarkets in Kuwait showed that quantities of discarded produce constitute at least 10% of displayed produce daily and are not generally affected by size of store but by attitudes of shoppers. Discarded produce contains high water content (85%) is more dense (0.65 ton/m3) and have high organic content (80%) than municipal solid waste (MSW). Carbon content of discarded fruits is 42.1% while for vegetables is 41.5%. Nitrogen content of vegetables is 3.2% and for fruits is 1.9%. Pilot plant experiments on in-vessel aerobic composting of a mixture of MSW and fruit and vegetable waste at a mass ratio of 2:1 proved effective at temperatures from 35 to 65°C and optimal at 45°C, achieving VS reduction up to 40% in 30 days. Organic reduction followed a first-order kinetic model with degradation rates in the range of 0.006 to 0.01 d−1 based on VS reduction. Statistical analysis showed process performance is dependent on operating temperature and type of waste organics.
Keywords: composting kinetics; elemental analysis; supermarket solid wastes; vegetable and fruit discards.
International Journal of Environment and Waste Management, 2017 Vol.20 No.3, pp.264 - 282
Received: 28 Dec 2016
Accepted: 21 Apr 2017
Published online: 06 Oct 2017 *