A bench-scale denitrification wall for simulating the in-situ treatment of nitrate-contaminated groundwater

In this study, a bench-scale denitrification wall has been developed to simulate the in-situ treatment of nitrate-contaminated groundwater. Nitrate spatial distribution in the vadose zone, the denitrification efficiency of denitrification wall, and the permeability of denitrification wall were investigated. It was found that the average nitrate content in middle-layer soil samples (8 cm depth) from the vadose zone was lower than that measured from the top layer (0 cm depth) and bottom layer (16 cm depth) soils, and the denitrification wall construction does not significantly influence average nitrate content of soil in the vadose zone. When nitrate loading was ≤157.68 mg N d−1 kg−1 BP-zeolite, the nitrate removal efficiency of denitrification wall exceeded 97.7%. The permeability of denitrification wall increased and remained relatively stable after 35 days of operation, and no blocking was observed during the experimental period (80 days).