'Green Iron': Article Summary

The article ‘Green iron’ was published on Economist.com on the 14^th of November 2008. The link to the article is: http://www.economist.com/research/articlesbysubject/displaystory.cfm?subjectid=348924&story_id=12587219

 

Iron is normally not associated with having any sort of outstanding advantages with regards to preserving the environment. However, iron shavings can now be utilized as a cheap, efficient and quick way to clean industrially polluted water, as a research project in China demonstrates. The method was applied to a wastewater facility in the Taopu district of Shanghai, where small pharmaceutical, petrochemical and textile factories contaminate the water with dyes, phosphorus and nitrogen. This method, only recently developed but based on prior information, is applied to industrial waste water since the standard water cleaning system isn’t effective if water contains toxic and non-biodegradable compounds. The idea is simple; the waste water passes through iron shavings, which are cheap and readily available (treated with a solution of copper chloride to increase their effectiveness), which attract the non-biodegradable chemicals, react with them by sharing electrons and therefore degrade them. After this, the water can be treated as normal waste water. The method has been proven to work, at least at this small of a scale, since it, for example, the removal of nitrogen went from 13% to 85%. At 20 cents a kilogram in China, with an additional 5 cents for the treatment with the copper chloride solution, the iron shavings method developed by Dr. Wei-Xian Zhang could prove to be especially useful in developing countries. Already, larger wastewater plants that apply this method are being planned in China and, hopefully, this idea will be picked up by other countries as well.