What can food waste become?

Most recycled food waste goes to the organic resources recovery centres. O·PARK1 at Siu Ho Wan, North Lantau, opened in 2018 and treats 200 tonnes of food waste a day. The waste is broken down without air in sealed tanks, producing biogas that generates electricity; the surplus goes to the grid, enough for about 3,000 households a year. What is left can be made into compost for landscaping and farming.

The second centre, O·PARK2 at Sha Ling in the North District, is designed to treat 300 tonnes a day. Since 2019 the Government has also trialled digesting food waste together with sewage sludge at Tai Po Sewage Treatment Works to produce biogas.

On farms and in neighbourhoods, food waste can be mixed with dry leaves or sawdust and composted. Over weeks to months, microbes turn it into organic matter that improves the soil. On our Farm to Table days, students start a compost pile with their lunch scraps and see food go back to the soil.

Farm to Table programme

Black soldier fly larvae feed on food waste and can break down large amounts quickly. Grown larvae can be used as feed for poultry and fish, and their droppings as fertiliser. With E Farm Biotech we set up larvae bins in secondary schools, so students can observe them and design their own experiments.

Black Soldier Fly STEAM programme

Some food waste can be reused at home. Onion skins make a natural dye that gives old clothes a new colour. Citrus peel fermented with sugar and water becomes a peel enzyme for cleaning. Both are regular activities in our workshops.

Recycling and converting food waste take energy and labour. The best option is still to waste less: buy what you need, cook what you will eat, and finish it. Then sort and recycle what is left.

How much food waste does Hong Kong produce?Back to resources