A novel food waste management framework combining optical sorting system and anaerobic digestion: a case study in Malaysia

Abstract

Food waste (FW) is a widespread problem affecting most countries in the world. Proper segregation is significant as FW will be contaminated and may not be valorised to value-added commodities once mixed with other wastes. However, public engagement and training to ensure proper segregation can be laborious and time-consuming. An uncomplicated waste segregation process with minimal behavioural change is essential to encourage the public to practise FW segregation at source. Considering the current FW practices and government policies in Malaysia, a novel management framework for FW segregation at source using an optical sorting system, followed by FW valorisation to biogas via anaerobic digestion, is proposed. A life cycle assessment study with four FW disposal and treatment scenarios is conducted. The results indicate that turning FW to electricity via anaerobic digestion is the most environmentally friendly scenario, with 4.92 × 10−4 DALY and 6.30 PDF.m2.y avoided impacts for human health and ecosystem quality, respectively. By turning 80% of daily FW to electricity, it reduces 0.4% of total carbon emissions and contributes 1.1% of total electricity consumption in Malaysia. A sustainable FW management framework is crucial to reduce reliance on landfills and promote circular economy by valorising FW to renewable energy.