The total concentrations of phosphorus in solutions were determined by inductively coupled plasma – optical emission spectrometry (ICP-OES) with the aid of an Optima 3000 spectrometer (Perkin Elmer, Norwalk, USA). Ion chromatography was used to determine phosphate anions in solutions using an ICS-1000 Ion Chromatography System (Dionex, Sunnyvale, USA). The ion chromatographic determinations were carried out using a Dionex IonPac AS22 column with mobile phase containing 4.5 mM Na2CO3 and 1.4 mM NaHCO3, and suppressed conductivity detection.
MS Excel and DataFit 8.1 (Oakdale Engineering, USA) software were used for calculations and data evaluations.