High-tech process of garbage sorting impresses visitors

“Kitchen waste is mainly produced by catering businesses and canteens, and it contains high levels of water, oil and salt and is perishable and often odorous."

More than 20 Shanghai Daily readers attended a garbage treatment and sorting tour on Friday to learn about how kitchen waste is transferred into fertilizer and the city’s efforts to promote sorting out rubbish.

The Minhang Center of Kitchen Waste Reutilization went into trial operation last year and processes 200 tons of kitchen waste within the district every day.

At the center, readers learnt how high temperature, compound micro-organism controlled oxygen fermentation technology is used to convert urban kitchen waste into an organic fertilizer, which will nourish healthy soil and help to boost organic agriculture.

The process takes 12 hours and is largely sealed off from the outside world, emitting very little pollution while creating a valuable fertilizer through aerobic fermentation, causing “zero harm” to the environment.

“Kitchen waste is mainly produced by catering businesses and canteens, and it contains high levels of water, oil and salt and is perishable and often odorous,” said Yang Yuanhui, a senior engineer at the center.

Currently, China produces about 110,000 tons of kitchen waste daily, which is expected to rise to 120,000 tons by 2020. This staggering amount of kitchen waste can easily decay into a putrid mess, giving rise to parasites, mold, and other disease-causing microbes.

“Kitchen waste threatens people’s health, while livestock like pig and cattle will easily get infected, such as with food-and-mouth disease,” Yang said.

“Swill oil contains a large number of carcinogenic substances, while kitchen waste will also pollute air quality, soil and water,” unless appropriate measures are taken, he added.

At the Luluo Center of Environmental Protection at Daning community in Jing’an District, the second stop of the tour, readers learnt how to sort garbage. The center classifies garbage into more than just two categories of wet and dry. It sets up seven other separate bins for recyclable materials such as paper, plastic, electronics, glass and aluminum cans.

Residents are offered incentives if they throw garbage into the appropriate bins.

The center organizes online and offline activities for residents of different ages to learn about waste classification.

Readers said the trip was helpful, informative and broadened the horizon of their knowledge on garbage treatment and sorting.

“In terms of architecture, we are trying to see if there is a way to develop an infrastructure system that can be implemented through communities, and trying to figure out a way through architecture because we are running out of space for trash,” said Karen Wang, a Canadian graduate student who studies architecture.

“I am very interested in garbage reduction and environment issue,” said Liu Yinlin, another reader. “We live in the same global village and the behavior of each of us will have an influence on the environment.

“The visit is very good and helpful, and I think residents’ awareness on garbage sorting should be further raised,” she said.

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