The zero-valent iron (Fe0) and the activated carbon were used as reaction mediums, the reactivity characteristics and removal effect of hexavalent chromium (Cr (VI)) contaminated ground water using Fe0/AC-PRB were investigated. The results showed that AC adsorbed Cr (VI) under the pH conditions of influent, and Cr (VI) was removed. Also, the chromium could be deoxidized by zero-valent iron effectively, when simulated groundwater containing 10mg/L hexavalent chromium was continuously input. During the process, the redox products, Fe3+ and Cr3+, precipitated on the reaction media without transferring into downstream water. The pH value increased from 7.0 in influent to 8.0 in effluent, and the total iron concentration of effluent was below 0.30mg/L. Chromium was distributed mainly in the form of organic/sulphide fraction and residue fraction when the aquifer was flushed with deionized water, Moreover, bioavailable weak acid extractable fraction was not detected, indicatinga low ecological risk of chromium remained in the aquifer.
Automated Ground-Water Sampling and Analysis of Hexavalent Chromium using a “Universal” Sampling/Analytical System