Biodegradation of Fruit Waste under Optimum Nutrient Conditions and Different Bacterial Inocula

Abstract

Solid waste is becoming a major problem day-by-day. Fruit waste is a significant organic fraction of municipal solid waste and has high moisture content and high volatile solids concentration or organic content. Due to this, it easily degrades in the environment and releases nuisance gases like CH₄, H₂S, CO₂, NH₃, etc. A possible method for treating fruit waste is composting. The composting rate depends on the nature of the biodegradable materials, so the main objective of this paper was to characterize mixed fruit waste and determine the biodegradable fractions of this waste and the corresponding rate constants. The mixed fruit waste samples were biodegraded using different inocula such as soil bacteria, cow dung and sludge under aerobic conditions.

Five different fruit peels samples were used in this study: Citrus limetta (Mosambi), mango, banana, pineapple, pomegranate and the same were characterized for various physico-chemical and biological parameters. Batch biodegradation studies were conducted under aerobic conditions by incubating a mixture of all five types of fruit peels in equal proportions. In the first biodegradation study of fruit waste with soil bacteria as inocula, 73.12% removal of TSS and 70.12% removal of VSS were observed in 65 days. In the second batch biodegradation study of fruit waste with cow dung as inocula, TSS removals of 75.27% and VSS removals of 82.67% were observed in 65 days. In the third batch biodegradation study of fruit waste with sludge as inocula, TSS removals of 67.78% and VSS removals of 60.17% were observed. Fruit peels waste was found to degrade rapidly (within 8 to 21 days) after which very little change in TSS or VSS concentrations were observed.