A 2D tank test on remediation of nitrobenzene-contaminated aquifer using in-situ reactive zone with emulsified nanoscale zero-valent iron.

摘要: Abstract Nitrobenzene (NB) is one of the most challenging pollutants for groundwater remediation due to its great harm and recalcitrance. Emulsified nanoscale zero-valent iron (EZVI) considered as a promising agent in-situ contaminated high reactivity, good durability low cost. In this paper, 2D tank experiment was conducted evaluate effectiveness enhanced NB-contaminated with EZVI. 9 L EZVI solution injected into aquifer establish reactive zone (IRZ) before 40 d NB contamination. Results indicate that injection leads 90% reduction total NB, which mainly converted aniline (AN). concentration decreases along flow path in tank. Fe2+ generated from Fe0 oxidation. Significant acetate bicarbonate are released emulsified oil decomposition during whole operation time. Groundwater pH maintains neutral value (6.6–8.2) owing balance between organic acids OH− after Drastic decrease ORP DO indicates transformation oxidizing reducing condition, leading oxidative species (e.g. sulfate, nitrate) subsurface. Calculation equivalents suggests microbial breakdown provides more electrons than oxidation does system. Both biotic abiotic processes involved degradation NB.