Diverting food waste from landfill: a challenge for the water industry

Abstract

Food waste management is currently attracting both regulatory and public attention due to new greenhouse gas emission targets, targets relating to waste reuse, recycling and the diversion of waste from landfill, as well as other policies related to sustainability. The research presented in this thesis addressed two of the management options currently available namely the use of food waste disposal units (FWDs) and the anaerobic co-digestion of food waste with sewage sludge, because of their relevance to the water industry. The use of FWDs was studied and results demonstrated that they can bring substantial benefits to local authorities through reductions in cost from waste collection, but can also present challenges to the water industry due to the need to treat additional wastewater. Policy implications were identified, and given the prospect of FWDs application, the incorporation of anaerobic treatment processes into municipal wastewater treatment operations was investigated as a viable technology which could be implemented to give environmental and economic benefits independent of the prevailing climatic conditions. The anaerobic co-digestion of food waste with sewage sludge, well-established in other European countries but still in its infancy in the UK, was investigated as an alternative food waste management option. With sustainability becoming a driver for change in waste management practices, this option was found to have considerable potential, but significant capital investment and operational expenditure could be required to create new assets or upgrade existing ones. A multi-criteria framework was developed to support decision-making aim to select the appropriate food waste management option based on sustainability. It was concluded that diverting food waste from landfill is not only a challenge, but an opportunity that can lead to more sustainable solutions. Balancing the relationship between water, food and energy is the real means to viable solutions and the ultimate approach to deliver overall benefits.