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A food-waste initiative was conducted at two university canteens in the UK and India to examine food-waste attitudes and opportunities for food-waste reduction. Interventions were carried out to reduce food waste in both canteens. In the Indian canteen, postintervention data also included COVID-19-related changes, such as a change from self-service to table service, as well as reduced menu choices and an improved estimation of the number of students requiring meals. Surveys and focus groups were conducted with students to better understand their food-waste-related attitudes, while interviews were carried out with university staff to better understand food-waste management. The study in the UK university canteen found that introducing table cards, posters, and signs led to food-waste reductions of 13%. Meanwhile, the study in the Indian university canteen found that the interventions and COVID-19 impacts led to food-waste reductions of 50%. Concerning food-waste-related differences between the UK and India, culture and food preferences were key reasons for food waste in India, with 40.5% more participants in India stating that they wasted food because the ‘food didn’t taste good’. Students in India were more concerned about social issues and food poverty related to food waste, with around 9% more participants stating that the ‘food could be used by others’. Meanwhile, students in the UK were more bothered by the economic and environmental impacts of food waste, with around 31% more participants stating food waste is ‘a waste of money’, and is ‘bad for the environment’ when compared to India. Key opportunities for both countries included adopting food-sharing initiatives, informed menu choices, and meal planning, as well as student-led engagement projects.

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A novel, integrated system is proposed for the cultivation and co-digestion of the invasive macrophyte water hyacinth (WH) with cow manure (CM) for the production of biogas for cooking in rural India. This study investigates the pre-treatment approaches and performs a techno-economic analysis of producing biogas in fixeddome digesters as a replacement for liquefied petroleum gas (LPG). Methodologies have been developed for the cultivation of WH collected from wild plants in the Indrayani River, Pune, India. Cultivation trials were performed in 350 litre tanks using water, which was nutrient fed with CM. Cultivation trials were performed over a 3 week period, and growth rates were determined by removing and weighing the biomass at regular time intervals. Cultivation results provided typical yields and growth rates of biomass, allowing predictions to be made for cultivation scaling. Samples of cultivated WH have been co-digested with CM at a 20:80 ratio in 200 L anaerobic digesters, allowing for the prediction of bio-methane yields from fixed-dome anaerobic digesters in real world conditions, which are commonly used in the rural locations of India. A calculator has been developed, allowing us to estimate the scaling requirements for the operation of an integrated biomass cultivation and anaerobic co-digestion unit to produce an equivalent amount of biogas to replace between one and three LPG cylinders per month. A techno-economic analysis of introducing WH into fixed-dome digesters in India demonstrated that the payback periods range from 9 years to under 1 year depending on the economic strategies. To replace between one and three LPG cylinders per month using the discussed feedstock ratio, the cultivation area of WH required to produce sufficient co-feedstock ranges within 10–55 m2.

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