A novel in situ technology for the treatment of nitrate contaminated groundwater

A novel in situ membrane technology was developed to remove nitrate (NO 3 −) from groundwater. Membrane-fed hydrogen gas (H 2) was used as an electron donor to stimulate denitrification. A flow-through reactor fit with six hollow-fiber membranes (surface area=93 cm 2) was designed to simulate groundwater flowing through an aquifer with a velocity of 0.3 m/day. This membrane technology supported excellent NO 3 − and nitrite (NO 2 −) removal once H 2 and carbon limitations were corrected. The membrane module achieved a maximum H 2 flux of 1.79×10 −2 mg H 2/m 2 s, which was sufficient to completely remove 16.4 mg/L NO 3 −-N from a synthetic groundwater with no NO 2 − accumulation. In addition, this model in situ treatment process produced a high quality water containing