Biofilters Can Reduce Herbicides in Drainage Water
March 13, 2006
U of I student Paul Davidson received top honors for research showing that a biofilter made from woodchips can significantly reduce the concentration of herbicides in water flowing through field tiles.

A biofilter provides an organic carbon source, such as woodchips, which the bacteria feed upon. This allows the bacteria population to grow. And more bacteria break down more nitrates.

Davidson wanted to know if concentrations of herbicides were also reduced with the use of a biofilter. So he placed the biofilter in a number of soil columns; and over a six-week period he applied six different combinations of three chemicals.

He found that when all three contaminants were mixed in combination and applied in the presence of only the biofilter, the nitrates showed a significant reduction in concentration.

Davidson's findings could affect the method of application for agricultural chemicals.