Chemical Properties of the Sediment Interstitial Water at Lake Fertő/Neusiedler See

Abstract

The chemical parameters of the surface and sediment interstitial water from the 0–20 and 20–40 cm sediment layer were investigated in different reed stands of Lake Fertő/Neusiedler See. The temperature, pH, redox potential, ${\textrm{SO}}_4 ^{2 - }$, ${\textrm{NO}}_2 ^-{\textrm{-N}}$ and ${\textrm{NO}}_3 ^ -{\textrm{-N}}$ concentrations decreased, while the electrical conductivity and the concentrations of ${\textrm{Na}}^{{+}} ,{\textrm{Ca}}^{2 + } ,{\textrm{K}}^ + ,{\textrm{Mg}}^{2 + } ,{\textrm{Cl}}^ - ,{\textrm{PO}}_4 ^{3 -}{\textrm{-P}}$ and ${\textrm{S}}^{2 - }$ increased in the function of sediment depth. As comparing the vegetated and unvegetated areas of the sampling sites: ${\textrm{PO}}_{\textrm{4}} ^{3-}{\textrm{-P}},\;{\textrm{S}}^{2-}$ and ${\textrm{NO}}_2 ^-{\textrm{-N}}$ concentrations of the interstitial water were lower and the ${\textrm{SO}}_4 ^{2- }$ and ${\textrm{NO}}_3 ^ -{\textrm{-N}}$ concentrations were higher at vegetated areas, which demonstrated the effect of internal oxygen transport of the Phragmies australis rhizosphere on the chemical characteristics of interstitial water. The degraded reed stand was characterised by low redox potential and high ${\textrm{S}}^{2 - }$ concentrations. The trace element concentrations of the surface water decreased in the order ${\textrm{B}}^{3 + } > {\textrm{Fe}}^{2 + } > {\textrm{Al}}^{3 + } > {\textrm{Pb}}^{2 + } > {\textrm{Zn}}^{2 + } > {\textrm{Mn}}^{2 + }$ and increased with the depth of the sediment; their concentrations were higher in the sediment interstitial water of unvegetated than of the vegetated areas.