AMES, Iowa – Hardwood tree species have traditionally been used as a source of wood chips for bioreactors, but could conifers be used, as well?
Cesar Martinez, a senior in forestry, posed this question to Billy Beck, associate professor of natural resource ecology and management, last summer at a conference. Martinez was specifically interested in exploring eastern redcedar’s potential as a bioreactor wood chip source, since some consider the species invasive.
Wood chips from the 13 conifer species were placed in mason jars and filled with tile water to test the wood chips' ability to remove nitrate.
A bioreactor is an edge-of-field water-treatment technology used to remove nitrate nitrogen in tile water that drains from crop fields. The water is piped into a plastic-lined trench where it interacts with a high-carbon material, such as wood chips. The bioreactor environment supports microbes that transform nitrate into harmless nitrogen gas. This process results in cleaner water leaving the bioreactor before entering nearby waterways or ditches.