Management of Fruit Wastes through Anaerobic Digestion and Utilization as Biofertilizer

One of the main environmental problems of today’s society is the continuously increasing production of organic wastes. Sustainable waste management represents a step to reduce pollution and greenhouse gas emissions and to mitigate global climate changes. India is a major producer of fruits and fruit wastes are generated at each step of the food supply chain viz. agricultural production, post-harvest handling and storage, processing and packaging, distribution and consumption. In this study an attempt has been made to adopt anaerobic digestion as a technology to manage fruit wastes. Four fruit wastes viz. Pineapple, apple, banana and orange as well as their mixtures were studied for their potentiality as substrate or cosubstrate for the production of biogas. Cow dung was used as control. Biogas produced from each of them was measured on weekly basis for a period of 9 weeks. The study revealed that the average production of biogas was highest for the cosubstrate (510 mL) followed by cow dung (480 mL). Among the individual substrates, pineapple waste performed best producing 445 mL biogas on average basis while banana waste produced the least amount of biogas (310 mL). The digested sludge from each of the substrate was also studied for their effect on the yield and yield attributes on brinjal crop. The digested sludge from the cosubstrate performed best as a potential biofertilizer by recording highest no. of fruits/plant (15), plant height (75 cm), leaf area (190 cm2) and no. of branches/ plant (20). The study indicates fruit wastes as a potential alternative source of fuel and high value fertilizer.