Image courtesy of ES&T;
While some Chinese scientists are out advocating for hybrid vehicles and solar energy, others, like Tongji University's Siqing Xia, find themselves in the unenviable position of acting as boosters for less appealing technologies, such as "toilet-to-tap" water treatment. Yet despite the challenge of having to convince China's 1.3b strong population of its merits, it is a task Xia has willingly embraced.
Tasha Eichenseher, who interviewed Xia for the latest issue of ES&T;, visited his demonstration-scale 400 L/day treatment plant, which turns one lab building's wastewater into clean water that is used for irrigation and experimental procedures. The collected water is treated in a membrane bioreactor, which uses a combination of membrane and bacterial treatment technologies to filter and clean the water.After being disinfected, the resulting gray water is either reused in the lab or for landscaping; the rest, after undergoing reverse osmosis and ion exchange treatment, becomes suitable for drinking. His small-scale treatment plant, which is cheap and easy to assemble, would be extremely useful in water-scarce regions.
Until the public is ready to embrace the technology, however, Xia will push on with his efforts to boost the technology; he hopes to have a larger demonstration-scale plant up and running by 2010 for the Shanghai World Expo. With toilet-to-tap finally making some inroads in the U.S. market, we hope it's only a matter of time until it gains heavier traction here and in other populous, resource-intensive countries.