What is the use of food waste?




Can cold rice and leftover vegetables be recovered to useful stuff? Absolutely! Food waste collected can be recovered and turned to:

Animal feed (e.g. fish feed, pig feed)

Fertilizers (by way of composting and vermi-composting etc.)

Environmental-friendly cleansing products (enzyme)- they are very good natural cleansing agents

Animal feed

Fish feed


Fish feed production in Hong Kong is an unpopular industry. It requires a licence issued by Food and Environmental Hygiene Department. Currently, Kowloon Biotechnology Limited is the only company with such licence in Hong Kong. Food waste becomes fish feed granules after being dried under high temperature, crushed and all other nutrients are added.

Reference: : Kowloon Biotechnology


Pig feed


It has been more than a thousand year since food waste is used to produce pig feed. In general, feed makes up 60% of the total costs of a sizable pig feeder, which means feeding pigs with food waste helps cost reduction and reduces impacts which may be caused by a fall in the price of pigs. Some pig farmers in Taiwan feed pigs with food waste from bean dregs – not only do they contain rich nutrients but also reduce the feed cost by one-third.

There are two types of pig feed, produced from food waste by the food waste collectors in Hong Kong and they are classified as follows:

Low quality pig feed:

untreated food waste

High quality pig feed:

fermented food waste, containing rich protein, carbohydrates and enzymes

Reference: : Hong Kong Organic Waste Recycling Centre





Fertilisers are produced by composting. Under suitable environment, composting generates heat, carbon dioxide and other substances through decomposing organic substance by animals or microorganisms.

Households can recycle food waste to natural fertilisers by way of composting and vermi-composting, etc.  For details, please visit the following websites:

Composting DIY (Chinese version only)
Vermi-composting (Chinese version only)
RecycleNow website

Some countries generate energy by way of anaerobic composting, which decomposes food waste through microorganisms into sugars, acetic acid and hydrogen before turning to biogas and methane biogas.



Environmental-friendly cleansing agent (enzyme)


Food waste can be recycled to cleansing agent. This maximizes the use of food and prevents toxic substance in chemical cleansing agent from accumulating in our body in a long run. For details, please refer to the following websites:

Environmental-friendly enzyme



(2)台北市廚餘回收再利用方案評估,2005年7月,蔡坤蒼, P.16

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