Abstract: In order to observe whether an in-situ reactive zone is formed and study the remediation efficiency for high concentration of Cr(Ⅵ) pollution， the in-situ reactive zone of modified nanosale zero valent iron was created in a two-dimensional simulation trough. The results of simulated experiments showed that a large amount of sucrose-modified nano-iron slurry is injected to form an effective reaction zone in the Cr(Ⅵ) pollution halo. The recovery efficiency of the reaction zone for high concentration of Cr(Ⅵ) is the best in the first 30 minutes， and the Cr(Ⅵ) removing efficiency is 91%. The removal rate remains at 60% stably after 4 hours to 187 hours of the reaction， with a large area of effective repair area formed. The Cr(Ⅵ) in the reaction zone is reduced by Cr(Ⅲ)， and the formed Cr(Ⅲ) may naturally form a precipitate in a neutral or alkaline environment.

Key words: objective, interval particle, intervalpollution remediation, nanoscale zero valent iron, in-situ reactive zone, Cr(Ⅵ) removing, simulated remediation