Reduction effect of Vallisneria natans on different forms of arsenic in sediment-water interface

Taking the eutrophic sediment as the research object, the indoor culture experiment was carried out. From the perspective of environmental micro-interface, the effects of common submerged plant Vallisneria natans on the migration and transformation of As(Ⅲ) and As(Ⅴ) in interstitial water of sediment, the behavior of environmental micro-interface were explored, and the removal effect of Vallisneria natans on As in the sediment-water interface was accurately evaluated. The results showed that Vallisneria natans increased the penetration depth of dissolved oxygen in the sediment and decreased the pH, UV₂₅₄, dissolved As, As(Ⅴ), As(Ⅲ), dissolved Fe(Ⅱ) and dissolved Mn; three forms of As (dissolved As, As(Ⅴ) and As(Ⅲ)) were significantly correlated with dissolved Mn and UV₂₅₄, and were poorly correlated with dissolved Fe(Ⅱ); the removal effect of As(Ⅲ) (69.5%) was better than that of As(Ⅴ) (64.6%). The research can provide a scientific basis for the control of heavy metal pollution in sediments and the water ecological restoration.