Aerobic treatment of leachate from municipal solid waste in Morocco

Solid waste disposal is one of the major environmental issues facing Morocco. More than 5 million tons of solid waste is generated across the country, with annual waste generation growth rate reaching 3%. From this waste, there is production of fresh leachate with a high level of chemical oxygen demand (COD). The authors studied the removal of pollution from municipal solid waste fresh leachate using a technique of continuous and discontinuous aeration in order to predict the efficiency of a low-cost biological treatment for this type of effluent. The physicochemical characteristics of the leachate showed that the pollution load has high levels of COD, biological oxygen demand (BOD5), phenol and surfactant. A removal of 90 and 60% of surfactant was obtained during discontinuous and continuous aeration, respectively. The phenol concentration decreased from 600 to 220 mg/l corresponding to 63% of phenol removal by aeration. This was also accompanied by a change in pH and sludge biodegradation. Discontinuous aeration for a period of 9 d achieved a removal efficiency of COD and BOD5 of 44 and 39% that corresponds to the removal of 19.92 g/l of COD and 7.05 g/l of BOD5, respectively.