Biological treatment of solid sludge from palm oil extraction for organic farming at the dawn of climate change

Abstract

Cameroon, one of Africa's leading palm oil-producing countries, is currently increasing its production rate due to growing global demand. However, this growth raises environmental concerns due to the production of enormous amounts of waste during the extraction process, including solid sludge that generates CO2 emissions responsible for global warming and climate change. Reducing the environmental impact of palm oil agro-industries through better waste management practices is essential not only for sustainable palm oil production but also for agricultural purposes. The method used in the waste management system is biostimulation coupled with bio-increase of the indigenous microorganisms. Composting parameters such as temperature, pH, electrical conductivity, water content, organic carbon content, and C/N ratio were monitored to ensure proper composting and compost maturity. Minerals of agronomic interest, such as N, P, K, and Mg, were analyzed to verify the quality of the resulting compost. The evolution of the composting parameters in all treatments showed optimal trends for the metabolic activity of microorganisms, thus allowing good degradation of organic matter. All treatments resulted in a mature final compost after 60 days, containing a considerable amount of nutrients and meeting compost quality standards. The different composts resulting from the treatment of palm oil solid sludge can therefore be used as a soil amendment to reduce the importation and use of chemical fertilizers.