Achieving 99.75% water recovery in industrial groundwater remediation: contaminant removal and feasibility of a multibarrier treatment train targeting near-zero liquid discharge

This study evaluates advanced water treatment technologies to remediate industrially contaminated groundwater under a 99.75% water recovery target for near-zero liquid discharge. Laboratory batch tests on real groundwater assessed pre-oxidation–coagulation–flocculation, activated carbon andferric hydroxide adsorption, reverse osmosis, and chemical treatments. The synergy of the selected techniques was investigated for the first time to remove specific amine-containing compounds and sulfolane. Removal rates exceeded 95% for most metals and several organics, whereas aliphaticaldehydes were found to be recalcitrant. The selected techniques were then incorporated into a multi-barrier treatment train, tested with 300 L of real groundwater under the 99.75% water recovery target. Sulfolane concentration decreased by 99.6%, amines concentrations were reduced below detection, naphthalene removal exceeded 99%, and most heavy metals were removed by >95%. Aliphaticaldehydes increased during pre-treatment and required targeted post-membrane chemical treatment to meet regulatory, while vanadium showed variable behavior. The results demonstrate that integrated treatment enables regulatory compliance and minimal liquid discharge, although persistent compounds require specific multi-barrier strategies.