Enhanced solid waste stabilization in aerobic landfills using low aeration rates and high density compaction

Abstract

Historically, municipal solid waste landfills have been designed and operated as storage facilities with suboptimal degradation under anaerobic conditions resulting in slow waste stabilization, gaseous emissions and leachate formation. This article examines the aerobic bioreactor alternative combining the recirculation of high strength leachate [chemical oxygen demand (COD): 89,000–95,600 mg/l; biological oxygen demand (BOD): 75,700–80,000 mg/l)] with low aeration rates (0.0125–0.05 l/min.kg) at high initial waste compaction (657–875 kg/m³) to promote and control biodegradation of solid waste in laboratory-scale columns (diameter = 60 cm, height = 1 m). Low aeration rates coupled with high initial density demonstrated improved performance with increased levels of stabilization with COD and BOD attenuation reaching up to 96%, final C:N ratio of 25 and waste settlement up to 55%.