Putuo throws the kitchen sink at food waste

A food disposal unit that shreds kitchen waste will support  garbage sorting and reduce the city's trash.
Jiang Xiaowei / SHINE

Kitchen waste is poured into a disposal unit. Machines have been installed in communities all over Putuo.

As the city fights on all fronts to reduce and recycle waste, the latest additions to the arsenal are powerful food disposal units being installed all over Putuo District.

Putuo’s garbage rooms are being completely renovated and 17 of them are now equipped with disposal units manned by trained operators. Further installations are underway and 30 of the machines should be grinding, chopping and pulverizing the district’s food waste by the end of the month.

The unit, installed under a sink, shreds waste into pieces under half a centimeter, small enough to pass through the plumbing system and be treated as sewage.

More than 60 percent of our daily 20,000 tons of waste is food. It ferments and it stinks. It contains large amounts of water and oil that make it difficult to process.

The city would produce an estimated 1,300 tons less garbage each day if waste disposal units were installed in just 10 percent of kitchens, as they are in the United States, Japan and some European nations.

Sewage pipes in many old residential communities could not handle shredded waste from every household, so the disposal units are in community garbage rooms, and they are doing a good job.

Almost 70 tons of waste has passed through the units since April, said Xiao Yan, an official with Putuo greenery and public sanitation bureau.

“Residents are actively separating kitchen waste from other dry waste at home and loading it into the machines with the help of the operators,” Xiao said.

In Changfu Mansions on Zhidan Road over 130 kilograms of kitchen waste is being chewed up the units daily.

However, it is essential that residents separate hard waste such as bones, bamboo and coarse-fibre vegetables like leeks that can’t be shredded, said Xiao. The operator also helps with sorting.

Sewage pipes need to be checked and cleaned frequently to ensure the scheme does not interfere with their primary objective of waste water treatment, she added.

Apart from the disposal units, garbage bins have been color coded, with colors for harmful, recyclable and other waste. About 17 tons of recyclables, such as plastic bottles were collected between April and August in Putuo.

Residents can get rewards through the city’s green account scheme for the amount and efficacy of their sorting.

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