Runoff Pollution of the Road Surface Purified by Vermiculite

With the recent development of transport infrastructure construction, the ecological and environmental protection issues, caused in the construction period and the operation period of the road, especially the freeway, becomes increasingly prominent. And the runoff pollution of road surface is the one of the most serious aspects, such as the pollution by heavy metal ions and nitrogen compounds. If those problems are not effectively treated, there is a big hidden danger left behind. This paper presents a method to adsorb and purify road surface by using the vermiculite, which is huge reserves and cheap in China. A series of adsorption tests were carried out to investigate the performance of the vermiculite. It turns out that vermiculite can wipe off 50% of ammonia- nitrogen-liquor when its concentration is less then 200 mg/L. And the vermiculite can adsorb most of the metal ions, such as copper and zinc. The vermiculite can entirely wipe off copper ions and wipe off 95% of zinc ions, when the value of PH of condition is 7. The experiment results mean that there is a significant effect for having the adsorption of vermiculite to purify water, especially to purify the pollutants of the pavement runoff. Finally the paper specifically describes the methods and economics about purifying road surface by the vermiculite, especially the freeway.