Sludge produced after wastewater treatment can be transformed into biomass gas - this new technology is known as the "sludge killer" in Xiangyang, central China's Hubei province. It entered for the first time into the market of Hefei, capital of east China's Anhui province, two years after it was applied in Xiangyang.

Reporter observed that the construction of the sludge utilization project had begun in Hefei on March 26. According to Mei Liyuan, General Manager of the Hubei Guoxintianhui Energy company, the project can treat 600 tons of sludge a day, and the biomass gas generated from the sludge can at least "feed" a thousand of taxies.

It is the first time that the technology has gone out of the market within Hubei province and entered into the national wide market.

The process is to put the sludge under high temperature for anti-virus treatment, then implant biological species inside the sludge. Biological species will "eat" the sludge, and produce methane and organic carbon soil. After purification, methane can be used as fuel for taxis, and organic carbon soil will become fertilizer.

Now Guoxintianhui base in Xiangyang can treat 300 tons of sludge per day and produce about 4,000 cubic meters of natural gas and 100 tons of organic carbon soil. Last year, it realized the sales income of more than 30 million yuan, with the net profit of 8 percent.

According to Hubei Science and Technology Department, the technology can kill all pathogens in sludge and reduce sludge by 80 percent. The organic carbon soil produced reaches the Class B of the national agricultural soil level and the methane reaches standards for natural gas vehicle.

Currently, the National Development and Reform Commission, Ministry of Environmental Protection, Ministry of Housing and Urban-Rural Development are promoting the technology across the country. More than 10 cities including Beijing, Tianjin and Shanghai are discussing the cooperation plan with Guoxintianhui.

According to the data of Ministry of Housing and Urban-Rural Development, until the end of last year, the sludge generated from national sewage process has exceeded 30 million tons a year and less than 20 percent has been retreated.