Halmos L., Bozsó G., Pál-Molnár E. (2015): Adsorption properties of Ni, Cu, and Zn in young alkaline lake sediments in south Hungary (Lake Fehér, Szeged). Soil & Water Res., 10: 244-251.Adsorption properties of Cu, Ni, and Zn in alkaline sediments of Lake Fehér at Szeged (Hungary) were investigated. The effects of pollution of these three chosen phytotoxic elements in sodic sediments were primarily examined. These elements are strongly adsorbed in the soils and sediments with relatively high pH values for a long time without any influence on the geochemical processes. However, the salinization (indicated by the global climate change) of soils and sediments can strongly change the original geochemical status. For the adsorption experiments, the horizons with the highest organic matter contents were selected from two profiles. The pH, electrical conductivity (EC), particle size distribution, carbonate content, quality and quantity of organic matter, and clay mineral content of the selected samples were also determined. Efficiency of the adsorption is reduced in Cu >> Zn > Ni and Cu > Ni >> Zn order based on the calculated maximum and specific adsorption values. The adsorption properties of heavy metals are dependent on the content of soil constituents. The results showed that Cu has the highest but not the same affinity to each of the sorbent materials. Ni is strongly while Zn is less bounded to the organic matter. In most cases the results showed that the most effective fixative soil constituent is carbonate, followed by clay minerals and, last, organic matter regarding to the investigated elements.

No abstract

Sodic areas can be found in every continent. The main condition of the salt accumulation in sodic soils is the near-surface groundwater. There is a serious environmental problem in the Danube-Tisza Interfluve which threatens the natural alkaline lakes and sodic areas with landscape destruction. The aim of this study is to collect information about the seasonal geochemical cycles in the sediments of Lake Fehér. Based on the results of this research, the protection of the similar alkaline wetlands could be more effective. The study area was an alkaline lake system sorrounded by sodic areas called Lake Fehér by Szeged. The investigation was carried out in three periods based on the seasonal distribution of precipitation. There were eight sampling dates on the same site during one meteorological year. For the short-term monitoring, the type of the soil, the particle content, the pH and the EC were investigated. The groundwater and precipitation data of the last century were used for the long-term observation. The results show that the precipitation decreased in the southern part of the Danube-Tisza Interfluve in the last 100 years. Along with the decreasing precipitation, the groundwater level has been sinking. Knowing the dynamics of the area, the problem could be managed; otherwise, the ecosystems of the alkaline lakes will vanish.