Eco-friendly Expo turns waste into treasure

Thirdly, the city pays much attention to resource recycling. Tokyo has 21 "cleaning factories," seven ash fusibility facilities, two inflammable garbage processing centers, one faeces cleaning factory, one "big garbage breaking-up facility," and one garbage landfill.

A cleaning factory first collects garbage in its area, and then burns the flammable trash. Through burning under very high temperature, some metal and noxious gas will be disintegrated. The gas produced in the process can be used to generate electricity, and the heat can be used for warming houses.

The slag and dust after incineration will go to the ash fusibility facilities to make construction materials, iron and aluminum are to be recycled, and the toxic gas produced through burning will be detoxicated and released into the air.

Through incineration, the size of flammable garbage shrinks 95 percent. After the ash fusibility treatment, the size will further shrink 50 percent, leaving very little for landfill.

According to statistics, landfilled waste reached 2.5 million tonnes in 1989, while in 2008, the amount greatly reduced to less than half a million, and the risk of secondary pollution also considerably decreased.

Berlin, Germany

Germany started garbage classification in 1904. After more than a century, the country has formed a whole set of scientific garbage sorting and treatment in a bid to make the best use of garbage without pollution.

Germans are taught in their childhood to sort garbage into different waste bins to make garbage the collectors' job easier. The behavior has become a daily habit for every German.

Normally, every residence building has three to four trash bins to collect packaging, unrecoverable garbage, paper products and glass bottles.

In some places in Berlin, trash bins are painted into different colors to collect glass bottles by color.

At the invitation of Thomas Klockner, spokesman for Berlin Municipal Sanitation (BSR), which is in charge of all the garbage collection and treatment in Berlin, Xinhua reporters visited one of its recoverable garbage stations.

According to Klockner, the site is one of 15 recoverable garbage stations in Berlin. Besides them, BSR also has five garbage collection centers, four operating centers, one garbage distribution center, one garbage treatment center and four classification plants.

Currently, the biggest BSR plant is a garbage incineration and heating factory with eight boilers, which can process 520,000 tonnes of garbage and provide as much as 188 gwh of electricity every year, Klockner says.

BSR also collects 59,000 tonnes of good-quality organic waste annually, which can generate combustible gas equaling 77 gwh of electricity.

Electricity from the two sources alone can satisfy the needs of 100,000 families in Berlin, he said.

BSR also collects and recycles second-hand electrical appliances, furniture, metal, glass, paper and many other waste, Klockner added.

"Germany closed all garbage landfills in 2005, which has a fundamental interest to the environment," he said.

Commenting on the theme of the Shanghai Expo, namely "Better City, Better Life," he said, "This theme also applies to us, a sanitation facility in Berlin."

"The more efficiently we operate, the better life Berlin people will have," Klockner said.