Welcome to Sludge Beach

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For Dalian city residents, Xiajiahe has long been dubbed “black sand beach." But soon, sunbathers and swimmers can expect cleaner water at the Xiajiahe Seaside Park.

Last week, China's first sludge treatment plant in Dalian, Liaoning Province began operations. The plant collects sludge from water treatment facilities, and uses it to generate gas for the municipal network. The left over liquid residue is used as fertilizer material. Until now, sludge has been dumped into rivers and bodies of water.

The plant projects that it will be able to reduce 4,000 tons of methane and 73,000 tons of wastewater every year. And the plant will produce 4,000 tons fertilizers and 40,000 tons of humic solid annually.

Wastewater sludge can be nasty material because it contains pathogens, heavy metals and carcinogenic substances. By 2010, 30 million tons of sludge will be produced per year in China, according to research conducted by China's Ministry of Environmental Protection. Western countries’ investment in sludge treatment facilities is typically greater than investment in wastewater treatment facilities.

In China, sludge treatment accounts for roughly 40 percent of the money spent on waste water, according to Professor Wang Wei of Tsinghua University Environmental Science and Engineering Program. And about half of the municipal wastewater sludge in the capital is  treated and re-used, mostly as fertilizer and the remaining half is used for landfill, said Zhou Jun, Senior Engineer of the Research and Development Division at Beijing Drainage Group.

"Although Beijing is leading China in sludge utilization, there is still much to be done,” Zhou said. The scientist pointed out that China is adopting clean technologies from Japanese, U.S and Austrian companies for drying and utilizing sludge (see Euro Tech gets $1.7M waste water contract). “There is a great need to adapt cleaner fuels and more energy efficiencies into these processes,” he added.

Like many other technology sectors in China, the opportunity for investors and equipment suppliers may be more promising in applying the current cutting edge technologies rather than developing new breakthrough technologies (see Funds flow to smart grids, carbon capture).

“In China, developers need to be aware of the different characteristics of sludge from city–to–city and across different seasons of the year," said Patrick Tam, General Partner of China Environment Fund. "The make-up of the sludge will dictate what technology solutions are suitable and what end-products are possible," he added. The large and growing volume of sludge in China could translate into new opportunities for applying cleantech to squeeze water out of sludge and use it for energy production or other purposes.

“There is very good wastewater and sludge treatment technology from Europe that can be utilized for energy or for fertilizer applications," said Tam. "However, there is a good deal of localization that must occur to best match the local project," he added.

Some companies appear to agree with that perspective. Guangzhou Yuexiu Cement Corp plans, for example, to invest 70 million RMB to build an industrial and municipal sludge treatment center at their factory site.

The process takes two steps: one is to reduce the water percentage of wet sludge from 80 percent to 30 percent by utilizing the cement kiln boiler waste heat. The next step involves the mixing of the sludge with half-dried cement material to conserve energy. They expect that every three tons of half-dried sludge can substitute 1 ton of raw coal during the burning process.

Heinz-Peter Mang, who heads the Centre for Sustainable Environmental Sanitation at the Beijing University of Science and Technology points out that sludge treatment is just beginning in China and therefore the opportunity can be great for relevant cleantech solution providers.

“In many Chinese cities and townships, it is better to speak about fecal material or septic tank content treatment rather than sewage sludge," says Mang. "Because no treatment system exists, and therefore no sludge is produced."

Mang sees main opportunities in technologies to reduce sludge volumes, as well as technologies for decontamination of sewage sludge so it can be used for a variety of applications in agriculture, bio-energy, thermal re-use (incineration, gasification) and innovative solutions for non-agricultural purposes.

In terms of business opportunities for investors and developers, Mang says service providers can establish "profit centers" in newly built waste water treatment plants. There's also opportunity in establishing for external service providers which would receive sludge from different waste water treatment plants, septic tanks etc. and then mix those waste products with other organic wastes to produce biogas, heat and power, and fertilizer, he added.

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