Effective Microorganisms in Producing Eco-Enzyme from Food Waste for Wastewater Treatment

Abstract

The problem of food wastage is becoming an increasingly worrying topic as the world is heading towards sustainability to preserve the quality and the perseverance of life on Earth. Such food waste is inclusive of fresh fruit and vegetable (FFV) which make up a substantial 60% of all food wasted around the globe. Hence the purpose of this study is to valorize the FFV waste into eco-enzymes for the purpose of wastewater treatment, as having clean water sources and cleaning greywater and blackwater before discharge back into the environment are an important factors in preserving public health worldwide. Only a total of 1% of the world's freshwater is accessible for human consumption, therefore it is important to save and recycle this precious resource. The objective of this study was to fully utilize the food waste in wastewater treatment. The production of eco-enzyme is done via the process of fermentation of FFV. In this study, eco-enzymes were generated from waste derived from vegetable and fruit. The vegetable eco-enzyme was fermented via S. cerevisiae for a total of 7 days. The fruit-produced eco-enzyme was fermented with brown sugar for three months with the native bacterial population present within the fruit as the fermentation agent. The eco-enzymes produced were used to treat the water samples collected from Menjalara Lake (3°11'42.2"N 101°37'39.7"E) and Keroh River (3°12'25.0"N 101°38'27.9"E). In addition, household rice-rinsed water was obtained from Kajang (3°07'38.0"N 101°51'83.0"E). After the fermentation, the eco-enzymes solutions were acidic with a pH range of 4.1-5.24, which could be due to the metabolization of carbohydrates into volatile and organic acids. The effectiveness of the eco-enzyme treatments was assessed via measuring Ca²⁺, Na⁺, K⁺, NO₃^- and pH. It was found that the fruit-produced eco-enzyme was effective in reducing NO₃^-, in all three water samples. But both the fruit-produced eco-enzyme and vegetable-produced eco-enzyme were not effective in reducing the concentration of Ca²⁺, Na⁺ and K⁺. Further improvements that can be done are the prolonging of treatment duration from five days to 30 days. Other than that, experimentation with different concentrations to reduce the introduction of excess metal ions into the treated water samples.