Sustainable Extraction of Micronutrient of Food Waste by Thermal Treatment under Elevating Temperature

Abstract

Abstract Food waste management by biological treatment is widely used due to the eco-friendly and more attractive than physical and chemical treatment. However, the use of biological treatment takes longer time for the food waste to degrade. To overcome this problem the pretreatment of food waste is proposed. The aim of this study is to determine the characteristic of food waste when subject to pretreatment, to determine the effect of thermal pretreatment on chemical compositions of food waste, and to determine the relationship between the effect of temperature and time on food waste carbon to nitrogen ratio, pH and micronutrient by using statistical analysis. The water bath method was carried out in this experiment. The parameter measured were Carbon to Nitrogen ratio (C;N), pH and micronutrient with the effect of temperature and time. The result of the food waste before treatment and after pretreatment was compare. The laboratory results showed that the chemical composition of the food waste was affected by the thermal pretreatment of water bath method for C:N and pH which in the range 11.18 to 25.94 and 5.32 to 5.72 respectively. The statistical analysis indicates that the interaction effect between retention time and temperature was not significant for pH, Fe, Cu and Mn except for C:N (F = 4.394, P = 0.003). Overall, the thermal pretreatment applied on the food waste revealed that temperature below 100 °C did not suitable to use as a pretreatment before the biological treatment, in order to expedite the degradation process. Instead, high temperature which above 100°C and long heating duration are beneficial for the release and reduction of organic compounds.