Capturing and Recycling Excess Nutrients from Farmland

Excess nutrient runoff from agricultural fields has been a major issue in the Midwestern U.S. for decades. This runoff results in downstream issues such as reduced water quality, higher treatment burden for water treatment plants, and eutrophic conditions like in the Gulf of Mexico’s dead zone. Agricultural best management practices such as no till farming and timing of fertilizer applications have significantly reduced the nutrient load but are a long way from meeting appropriate environmental standards.

Designer Biochar to Capture and Recycle Phosphorous from Tile Drainage Systems

To combat excess phosphorus runoff problem, Wei Zheng of ISTC along with other colleagues from the University of Illinois at Urbana-Champaign, the Metropolitan Water Reclamation District of Greater Chicago, Water Warriors, Fulton County Farm Bureau, and Illinois Farm Bureau believe that they can develop an innovative solution to keep phosphorus within the agricultural system and out of the aquatic environment. They have proposed to generate designer biochar to capture dissolved phosphorus. Biochar is a charcoal-like product produced by the pyrolysis of biomass and is composed largely of carbon. The phosphorus-captured biochars will be used as a slow-released fertilizer to mitigate the excess nutrient loads to watersheds from agricultural fields, enhance nutrient use efficiency, and improve crop yields.

This project is funded by the Illinois Nutrient Research & Education Council.

Development of a Novel Bioreactor and Biochar-Sorption-Channel (B2) Treatment System to Capture and Recover Nutrients from Tile Drainage

Principal investigator Wei Zheng and colleagues from the University of Illinois and Metropolitan Water Reclamation District of Chicago received further funding from the U.S. Environmental Protection Agency to expand the NREC project. This grant is to develop and scale up a novel bioreactor and biochar-sorption-channel (B2) system to remove both nitrogen and phosphorus. If successful, this technique will provide a cost-effective way to recycle nutrients back to farm fields.

The goal of this project is to develop and scale up an innovative B2 treatment system to effectively capture nutrients from subsurface drainage water, recycle nutrient-captured biochars as a slow-release fertilizer, and keep nutrients in the closed agricultural loop. This project will optimize the production conditions to generate the most cost-effective and efficient designer biochars to capture phosphorus and NH4-N from drainage water simultaneously. More significantly, the woodchip bioreactor/biochar-sorption-channel system will be tied into the tile drainage system to remove excess nutrients before the water is released to a nearby stream. The nutrient-captured biochars can be removed from the B2 system periodically and spread over the field as a form of slow-release phosphorus fertilizer. In addition, the team also believes that the innovative practice will reduce fertilizer expenses with the capture and reuse of excess nutrients captured on the designer biochar.

The U.S. Environmental Protection Agency is funding this three-year $1 million project. Read more about the B2 system project on ISTC’s blog and in U.S. EPA's project grant information. View the Quality Assurance Project Plan (QAPP) submitted to the U.S. EPA for the B2 system project.

woodchip bioreactor system

Bioreactor and Biochar-Sorption-Channel (B2).

Video produced by Illinois Farm Bureau at Fulton County Field Day on July 16, 2019