A novel in situ membrane technology was developed to remove nitrate (NO3-) from groundwater. Membrane-fed hydrogen gas (H2) was used as an electron donor to stimulate denitrification. A flow-through reactor fit with six hollow-fiber membranes (surface area=93cm2) was designed to simulate groundwater flowing through an aquifer with a velocity of 0.3m/day. This membrane technology supported excellent NO3- and nitrite (NO2-) removal once H2 and carbon limitations were corrected. The membrane module achieved a maximum H2 flux of 1.79×10-2mg H2/m2s, which was sufficient to completely remove 16.4mg/L NO3--N from a synthetic groundwater with no NO2- accumulation. In addition, this model in situ treatment process produced a high quality water containing <0.5mg/L total organic carbon.
Bibliographical noteFunding Information:
This work was supported in part by a United States Geological Survey Water Resources Research Institutes grant from the University of Minnesota Water Resources Center. The authors would also like to acknowledge Dr. Michael Sadowsky for his valuable comments and Dr. William Arnold for assistance with the Scientist © software.
- Groundwater remediation
- Hollow-fiber membranes