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Reed stands may be employed in the amelioration of water quality or even in the treatment of wastewater. In this study, the nutrient concentrations of (i) the above- and below-ground Common Reed (Phragmites australis) biomass, and (ii) surface and interstitial water were analyzed in a natural stand used in wastewater treatment. The reed stand was located in Hungarian part of Lake Fertő/Neusiedler See, by the shore near Fertőrákos Bay. The nitrate, phosphate and dissolved organic nitrogen concentrations of surface water were found to be higher on the inlet side of the reed stand compared to the outlet. The N and P concentrations in the above-ground biomass and P concentrations in the below-ground biomass increased after the introduction of pre-treated wastewater. The inter-annual differences in the characteristics of sediment interstitial water and in the nutrient content of reed tissues were assessed using statistical methods. The samples taken before and after the introduction of the pre-treated wastewater in the parcel formed different clusters. The results of the study provide further evidence that the nutrient retention capacity of natural stands of P. australis may be employed in the treatment of wastewater while protecting and preserving the valuable natural assets of the lake.

Species composition and seasonal and spatial distribution of the crustacean zooplankton groups Cladocera and Copepoda were studied in two lake-type wetlands, the Mocskos-Danube and the Riha, and the Danube River at Mohács, located in the protected side of the Béda-Karapancsa National Park in the Middle Danube River, Hungary. The investigations were carried out from April to October in 2014. A total of 23 crustacean species were found, 17 Cladocera and six Copepoda. The species richness was the lowest in the river and the highest in the isolated Riha Lake. The total abundance, especially of some cladoceran species, was the highest in the connected Mocskos-Danube Lake in the spring during the high waters. Positive correlations of zooplankton with the organic carbon, temperature and total phosphorus were found. The correlation with chlorophyll-a was negative, indicating strong grazing pressure on the phytoplankton. The bacterioplankton, which had the highest abundance in the spring, during the flood in May, had a weak negative correlation with Copepoda and positive one with the attached bacteria, and with the alien species Eurytemora velox. Cladocera negatively affected only the medium-sized free-living bacteria. The macrophyte species Ceratophyllum demersum, better developed in Riha Lake, probably as a better competitor led to N- and P- limitations for the phytoplankton and bacterioplankton, and due to the isolation from the river these plankton communities had less development in Riha Lake compared to the Mocskos-Danube and Mohács sites. [ABSTRACT FROM AUTHOR]