Wei-xian Zhang, a professor of civil and environmental engineering, recently concluded a five-year research project in which he and his colleagues at Tongji University in Shanghai used two million pounds of iron to detoxify pollutants in industrial wastewater.
The project, carried out in Shanghai, was the largest in history to use iron in an environmental application. The iron, called zero valent iron (ZVI) because it is not oxidized, was obtained in the form of shavings or turnings from local metal-processing shops for less than 15 cents a pound…
The ZVI project began with small, “benchtop” experiments in the laboratory that used a total of 90 pounds of iron to treat toxins in solution. It graduated in 2005-06 to a pilot test using 2,000 pounds of iron to pretreat wastewater at a treatment plant in the Taopu Industrial District in Shanghai. Wastewater at the Taopu plant, which is generated by small chemical, materials and pharmaceutical companies, had previously been treated with microorganisms alone. ZVI augmented and improved this remediation method.
Following the pilot test, the Shanghai city government approved a grant to construct a full-scale treatment reactor in the Taopu district capable of processing almost 16 million gallons a day of wastewater. This ZVI reactor was connected to the biological treatment plant two years ago and has been in continuous use since. The system was recently certified by Shanghai’s Municipal Environmental Protection Bureau.
Read the article for an idea of the chemistry involved. Personally, I’m emailing a copy of this post to the head of the wastewater treatment plant upstream from the river bosque where we live. Every little bit helps.
Eideard 