Food waste accounts for about 30 per cent of Hong Kong's municipal solid waste in landfills, negatively impacting environmental ecology and wasting recyclable organic materials. To address this issue, the Zeshan Foundation has funded A Plastic Ocean Foundation in collaboration with academic partner Lingnan University’s Science Unit, and strategic partner Gaw Capital People’s Place, to launch an innovative food waste processing programme in April - the Bi-Loop Nature-Based Food Waste Regeneration Pilot Programme (the programme).

This initiative will collect pre-meal food waste from four shopping malls in the North and Tuen Mun Districts and process it at a dedicated facility. The food waste will be fed to the larvae of black soldier flies, known as food waste scavengers, which will then be processed into fish feed, to nourish fish and plants. The edible fish and vegetables will be donated to charitable organisations for distribution to needy families. Additionally, the food waste processing facility and Aquaponics System will be open to schools and the catering industry at no cost to promote awareness and education.

Lingnan University will be responsible for operating the black soldier fly food waste processing facility in Tuen Mun. The facility utilises Internet of Things (IoT) technology to enhance operational efficiency. For example, when the black soldier flies’ feeding rate slows down in cold environments, the system monitors and analyses data to adjust the facility’s temperature, improving the feeding rate. The first phase of the pilot programme will last for six months, and will cover restaurants at the Wah Ming Shopping Centre, Wah Sum Shopping Centre, and Yung Shing Shopping Centre in Fanling as well as at the Tuen Mun shopping centre H.A.N.D.S. Twenty kilos of pre-meal food waste will be collected and processed a week.

The second phase, lasting ten months, will increase the weekly processing capacity to 60 kilos, amounting to approximately 3.1 tonnes (3,100 kilos) of pre-meal food waste. This phase is expected to produce at least 500 kilos of fish and crops annually for the community.

Prof Paulina Wong Pui-yun, Head and Associate Professor (Presidential Early Career Scholar) of the Science Unit at Lingnan University, explained that while the government encourages people to reduce food waste during meals, pre-meal food waste such as discarded peels, wilted vegetables, and meat trimmings have been overlooked.

"Our goal is to design a low-cost 'dual loop' system based on natural methods and the principles of sustainability and circular economy. Black soldier fly larvae have an astonishing appetite, and consume organic matter equivalent to their body weight or more each day, transforming the remaining nutritional value of food waste into high-protein and nutrient-rich products. Once dried, the larvae are processed into fish feed for aquaculture. The fish waste is decomposed by microorganisms into nutrients that can be absorbed by hydroponically grown plants, which filter the water, providing a healthy living environment for the fish, and creating a circular economy."

Mr Willy Kwong, Executive Director of the A Plastic Ocean Foundation, expressed the hope that this community-based model will set an example, and stimulate the development of sustainable waste management in Hong Kong. "Since 2021, we have collaborated with Lingnan University on the ‘Bug Wars against Food Waste Project’, collecting food waste from student hostels and canteens to feed black soldier fly larvae, and this has shown great potential in promoting environmental sustainability. Now we hope to strengthen collaboration among businesses, communities, and academia, focusing on the source of organic waste recovery, and transforming it into useful products which contribute to environmental protection, sustainable organic waste management and knowledge transfer in Hong Kong."

Ms Irene So, Executive Director of the Zeshan Foundation, said "Mainstream perceptions in developed societies are that the higher the economic growth, the better. However, the environmental, social, and economic costs of pursuing growth are often overlooked. For Hong Kong to become a sustainable and liveable place requires not only long-term, effective policy responses to urgent environmental issues, but also a change in social values and behaviours. Through this programme, we hope to inspire more stakeholders to think outside the box and apply scientific principles to achieve greater synergy in advancing Hong Kong's zero-waste strategy.”

Ms Carmen Ho, ESG Director at GAW Capital and representing People’s Place, added "We operate 29 public housing estates, and so sustainable community development is a key focus for us. This pilot programme using the black soldier fly food waste processing facility to process pre-meal waste from restaurants represents an innovative approach, and we look forward to a positive outcome. We hope to expand the programme in order to promote sustainable development and the circular economy across our properties, integrating more advanced technologies and collaborating with more community partners. We also encourage the public to respond to the initiative by reducing their food waste at home."

Lingnan University will utilise the food waste processing facility as an educational platform, hosting promotional activities at the H.A.N.D.S. during the summer holidays. The goals are to raise public awareness of the circular economy and encourage students to participate in demonstrations of food waste processing and the black soldier fly ecosystem.

In terms of research, Lingnan University will evaluate community participation strategies in the circular economy, including analysing socio-cultural and behavioural factors that influence public involvement, conducting case studies, providing data-driven policy recommendations, and researching the application of Nature-based Solutions (NbS) in urban circular economies, monitoring effectiveness, and devising similar schemes to tackle other social issues, thus promoting sustainable development within industries and communities.

About the black soldier fly
The black soldier fly originated in South America, but is now found worldwide, throughout temperate climates in the Americas, Europe, Africa, and Asia. It does not bite or sting, and feeds on almost any organic waste, making it perfect for dealing with food and agricultural waste. According to research data from Lingnan University's Bug Wars against Food Waste Project, the University has collected 400 kilos of food waste over the past two years, and after being processed by black soldier flies, this has produced organic fertiliser for the Lingnan Gardeners Project, which provides a green campus by growing vegetables and plants.

Groups interested in booking a free visit may contact Lingnan University’s Science Unit at scienceunit@ln.edu.hk or A Plastic Ocean Foundation at General@aplasticocean.foundation.