Water Resources Research Act Program

Details for Project ID 2014DE261B

Nutrient Removal from Stormwater, Wastewater, and Agricultural Runoff Using Scrap Iron and Biochar

Institute: Delaware
Year Established: 2014 Start Date: 2014-09-01 End Date: 2015-02-28
Total Federal Funds: $12,627 Total Non-Federal Funds: $34,829

Principal Investigators: Pei Chiu, Daniel Cha, Paul Imhoff

Abstract: Nutrient loading to natural waters is a leading cause of water quality impairment in Delaware. In particular, nitrate is one of the most prevalent groundwater contaminant in Delaware, and in the U.S. as a whole Delaware discharges approximately 2,300 tons of nitrogen and 170 tons of phosphorus every year to the Chesapeake Bay contributing to excessive algae growth, hypoxia, and significant losses of ecological habitats and economic productivity. The main sources of nutrient include fertilizer, animal manures, wastewater and biosolids, urban runoff, septic tanks, and atmospheric deposition all of which are linked directly or indirectly to growing population. Nutrient pollution is not new; the problem has been plaguing the water quality in Delaware and the rest of the Delmarva Peninsula since before the Chesapeake Bay Program was established 30 years ago to restore the Bay. It is clear that we have been producing pollution at such rates and concentrations that far exceed nature's capacity to absorb. If we stay on the current growth path, we will inevitably overtax the ecosystem, exacerbate the pollution problem, and impair the water quality further. In order to ensure sustainable growth, we need an engineering solution to help protect Delaware's water resources a technological intervention that can effectively decrease nutrient loading from multiple sources. The proposed research will evaluate the feasibility of using a combination scrap iron (zero-valent iron, or ZVI) and biochar to remove N and P simultaneously from stormwater and agricultural runoff. Specific objectives are: (1) to determine the adsorption and/or reduction rate constants for individual nutrient species by scrap iron and biochar; (2) to assess the solution conditions, such as pH, buffering capacity, dissolved oxygen, and other parameters, that influence individual nutrient removal rates and key pathways involved; (3) to evaluate the long-term performance of iron and biochar using stormwater, drainage water, and wastewater under simulated field conditions, and compare results with data from field test sites.