Anthropogenic sediments from facultative lagoons of the Konstancin - Jeziorna sewage treatment facility and their usability for soil recultivation

The sewage treatment facility of a paper mill at Konstancin-Jeziorna was opened to process industrial and domestic wastewater. After closure of that mill, the sewage treatment facility had to be rebuilt and modernized. Therefore, it was necessary to analyse the chemical and phase composition of the sediments from facultative lagoons used for biological treatment of wastewater. Eight samples of sediments were taken to identify a general phase composition by X-ray diffraction and ten to determine concentrations of selected main and trace elements with the use of ICP-AES and AMA methods.The analyses showed that the sediments consisted of over 90% of mineral fraction, mainly kaolinite, calcite, and quartz and also neomorphic smithsonite. They contained low quantities of Hg, Cd, Co and Mo, and elevated concentrations of Zn, Ba, Mn and Sr. Comparisons of the obtained mean values with admissible concentrations of metals, as defined by Regulation of the Minister of Environment of 9 September 2002, showed that the mean concentrations of As, Sn, Co, Mo and Ni (and also of Hg and Cr in the southern lagoon) met quality standards for soils in areas under protection (group A). Mean concentrations of Pb (both lagoons), Ba, Cu, Cd (northern lagoon) as well as Cr and Hg (southern lagoon) in sediments are higher. However, they still meet standards for areas usable for agricultural and other purposes (group B). The highest concentrations were recorded for Zn, Cd, Cu and Ba in samples from the southern lagoon. These continued to be lower than all the limits acceptable for industrial areas.