The study of experiment on the interaction situation between As and Fe in groundwater under different physicochemical conditions

This article observed the change with time of existing form of arsenic and iron through changing the concentration proportion of ferric ion and ferrous ion in system to change the oxidation reduction potential, providing the theoretical basis for explaining the migration and transformation behavior of arsenic in groundwater and effective treatment of groundwater arsenic contamination. The experiment results indicate: Fe(III) do not happen obvious hydrolysis under the physicochemical conditions of system. The existing form of arsenic and iron mainly includes three forms of Fe2+ and H3AsO4, FeAsO4, Fe2+ and HAsO2. Practical proportion of each form is different according to the difference of conditions and time. The conclusion is As(V) can be reduced at Eh 250mv and pH 3.9 or Eh 350mv and pH 3.7 and reduced possibly at Eh 400mv and pH 3.1, thus causing release of arsenic into the groundwater environment to cause arsenic contamination.