In-situ zinc bioprecipitation by organic substrate injection in a high-flow, poorly reduced aquifer

Abstract We investigated if in-situ metal bioprecipitation (ISMP) is applicable to remediate a highly permeable zinc-contaminated aquifer at a metal-processing factory in Maasmechelen, Belgium. A large (more than 200 m long and 70 m wide) groundwater contamination plume has developed, with zinc concentrations in the range of 1–100 mg/L, whereas the legal Flemish clean-up standard is 0.5 mg/L. The estimated groundwater flow velocity is in the range 0.2–1 m/d. The groundwater is relatively oxidized, naturally low in DOC ( y = 2 ⋅ 1 0 7 ⋅ e − 3 , 236 x R 2 ≈ 0.7 .