A Burning Question

By LAN XINZHEN

A Burning Question

By LAN XINZHEN

Incinerating garbage might be the most suitable disposal option for Chinese cities but citizens are worried about side effects

As heaping piles of garbage grow in cities and communities across China, a divide has formed over two possible solutions to this smelly problem: Should excessive mounds of trash be burned, or should it be buried?

Already the question had triggered wide disputes, as some cities planning to build trash incinerators have met strong opposition from local residents. Since last year, more people have started to pay attention to the disposal methods to make sure trash is taken care of in a reasonable and environmentally friendly way.

On June 18, the Ministry of Environment Protection (MEP), the Ministry of Housing and Urban-Rural Development and the National Development and Reform Commission issued a draft rule on waste disposal and pollution control and invited public opinion for it.

In the draft rule, the three departments state that each local government has the right to choose disposal methods according to local conditions. Places with abundant land resources and the pollution-control ability can choose to use land fi lls. Those with land shortages can opt for clean incineration methods.

In cities where garbage is classified and recycled, biological composting can be used to dispose of the waste. This alternative cannot be applied in places where domestic garbage is not sorted.

The Central Government rule, the fi rst of its kind, serves as a guideline for major cities like Beijing, Shanghai and Guangzhou.

Dispute continues

Most cities and communities in China have adopted land fi lls to dispose of waste, and a small number have started to use biological composting. Only a very limited fraction has resorted to trash incineration. MEP figures showed in big cities, less than 1 percent of garbage is burned. There are less than 10 garbage incinerators across the country.

Since the 1990s, major cities and coastal areas prioritized the application of the trash incineration technology. But due to technological insuf fi ciencies in burning and handling smoke from the incinerators, as well as the high investment demand, local governments were hesitant to thoroughly apply the incineration technology in their areas. In some cities where land is scarce, trash burning is done in random locations with little consideration for effectiveness or the impact on the surrounding environment.As a result, Chinese citizens have a mostly negative impression on the disposal practice.

Even with organized and ef fi cient garbage incineration methods, as outlined by the joint draft rule, opinions among Chinese citizens have been mixed.

Zhao Zhangyuan, a retired research fellow from the Chinese Research Institute of Environmental Sciences, is an expert in handling garbage-related problems. He also opposes trash incineration.

Burning, Zhao said, essentially turns trash from a solid into a gas. On the surface,the quantity of solid trash is reduced, but the chemical breakdown from the burning process releases 4,000-7,000 cubic meters of gas from every ton of trash into the air. Some of the gas will deteriorate in the air, but a considerable amount of toxic gas, such as dioxin—a super-toxic carcinogen—will remain airborne.And no matter how efficient or thorough the emission-control measures are, dioxin will still be produced, eventually accumulating in the air and soil.

In Japan and Europe where incineration is widely used, residents living close to the burning facilities have developed cancer at higherthan-average rates, Zhao said.

Zhao further argued trash burning causes secondary pollution, referring to the oxysul fi de and nitrogen oxide emitted during incineration.After chemical reactions in the atmosphere,these toxic gases become sulfuric acid or nitric acid aerosol, and return to the earth in the form of acid rain. Worse still, China has yet to develop technology to deal with this secondary pollution.

But not everyone opposes the idea of burning. Nie Yongfeng, a solid waste pollution control expert and professor at Tsinghua University, stands for the application of incineration.

Nie said current trash disposal methods,including land fi ll use and composting, cannot make waste completely harmless. Landfill takes up too much space and create a powerful stench in addition to the gas methane. Methane is 21 times as powerful in terms of its greenhouse gas effect as carbon dioxide, which is produced during trash burning. By turning to land fi ll, the land required for trash disposal will only grow larger, placing an unbearable burden on rapidly developing cities.

Zhou Hongchun, a researcher on social development of the Development Research Center of the State Council, said among the three trash disposal choices, composting was the least viable solution since urban trash doesn’t contain much organic refuse. Land fi ll takes up space not readily available in developing urban centers. But incineration reduces the bulk of trash to one fi fth its original size and one 15th its original weight and is the best way for China to handle its trash problems for the time being.

No need to worry

Beijing, one of the cities planning to substantially increase trash incineration, produces 6.72 million tons of garbage each year, roughly 18,400 tons per day. Over the last fi ve years, the garbage has been growing at a rate of 8 percent annually. Currently, Beijing buries 90 percent of its trash, composts 8 percent and burns only 2 percent. The municipal government plans to increase incineration by up to about 40 percent in 10 years. In 2020, Beijing will burn 40 percent of its trash, compost 30 percent and bury 30 percent.

In order to achieve the goal, Beijing intends to build five domestic trash incinerators by 2015, by which about 11,000 tons of trash will be burned each day.

As for worries about health- and environment-related damages caused by incineration,the MEP said concerns are unnecessary.According to the draft rule on garbage disposal,newly built domestic trash incinerators must install automatic monitoring systems to check for pollutants like smoke, carbon dioxide, carbon monoxide, sulfur dioxide and nitrogen oxide produced during incineration. The data must be made available to the public at all times. He said China will adopt European standards, and facilities unable to meet those standards will be suspended from operating.

As for dioxin, the biggest concern among citizens, the MEP of fi cer said the technological barrier for controlling the toxic gas has been resolved. Information from the Beijing Environment Protection Bureau said in the future, Beijing’s dioxin emission stemming from trash incineration will reach the EU standard,meaning the density of dioxin should be less than 0.1 ng TEQ/Nm3, which is considered a harmless level for humans.

The real challenge will be supervising the facilities, since China has yet to come up with a comprehensive burning operation regulation and supervision system. At present, to seek higher economic returns, incinerators choose to use outdated methods and materials, and prolong upgrading their pollution-reducing equipment, said Wang Weiping, assistant chief engineer of the Beijing Municipal City Management Committee. Once ef fi cient regulation and supervision are introduced, Wang said, the European standard can be reached,since current trash incineration technology is more than adequate to reach that goal.