Two sodalite phases (potassium sodalite (K.SD) and sodium sodalite (Na.SD)) were prepared using alkali fusion of kaolinite followed by a hydrothermal treatment step for 4 h at 90 °C. The synthetic phases were characterized as potential adsorbents for PO₄³⁻ from the aqueous solutions and real water from the Rákos stream (0.52 mg/L) taking into consideration the impact of the structural alkali ions (K⁺ and Na⁺). The synthetic Na.SD phase exhibited enhanced surface area (232.4 m²/g) and ion-exchange capacity (126.4 meq/100 g) as compared to the K.SD phase. Moreover, the Na.SD phase exhibited higher PO₄³⁻ sequestration capacity (Q_max = 261.6 mg g⁻¹ and Q_sat = 175.3 mg g⁻¹) than K.SD phase (Q_max = 201.9 mg g⁻¹ and Q_sat = 127.4 mg g⁻¹). The PO₄³⁻ sequestration processes of both Na.SD and K.SD are spontaneous, homogenous, and exothermic reactions that follow the Langmuir isotherm and pseudo-first-order kinetics. Estimation of the occupied active site density validates the enrichment of the Na.SD phase with high quantities of active sites (Nm = 86.1 mg g⁻¹) as compared to K.SD particles (Nm = 44.4 mg g⁻¹). Moreover, the sequestration and Gaussian energies validate the cooperation of physisorption and weak chemisorption processes including zeolitic ion exchange reactions. Both Na.SD and K.SD exhibit significant selectivity for PO₄³⁻ in the coexisting of other common anions (Cl⁻, SO₄²⁻, HCO₃⁻, and NO₃⁻) and strong stability properties. Their realistic application results in the complete adsorption of PO₄^3- from Rákos stream water after 20 min (Na. SD) and 60 min (K.SD).

Kutatásunkban a potenciálisan toxikus elemszennyezés által okozott környezeti kockázat becslésére alkalmazott, az EU Community Bureau of Reference (BCR) által 1993-ban ajánlott 3+1 lépéses extrakcióval végzett frakcionálás kritikai értékelésével foglalkoztunk, az elemdetektálásra korábban optimalizált multielemes ICP-OES kalibrációt alkalmazva. Munkánk fő célja a HNO3/H2O2 eleggyel végzett mikrohullámú feltárás, továbbá a királyvízzel végzett mikrohullámú feltárás és a királyvízzel visszafolyós hűtős extraktorral végzett feltárás alkalmazhatóságának összehasonlítása a reziduális és pszeudototál frakciók meghatározása során. Vizsgálataink eredményei alapján azt tapasztaltuk, hogy mind a BCR1-4 frakció összegénél, mind az összes kioldásnál a koncentrációk a visszafolyós hűtős királyvizes extrakció esetében a legnagyobbak, a mikrohullámmal támogatott királyvíz és a mikrohullámmal támogatott salétromsav/hidrogén-peroxid kivonás közel azonos hatásfokú. Tehát a salétromsav/hidrogén-peroxid mikrohullámú feltárás továbbra is alkalmazható, s különösen javasolt abban az esetben, ha a királyvíz a mátrix zavaró hatásának felerősödését okozná a mérés során.

Inland saline waters are sensitive to seasonal hydrological forcing and evaporation, yet their spatial and seasonal hydrochemical variability remains insufficiently characterized. This study investigated chemical composition and hydrochemical classification of semi-static and astatic inland saline waters in Iraq. Water samples were collected from six stations in Al-Dalmaj Marsh (ADM) and three temporary ponds in Babylon Province. pH ranged from 7.0 to 9.7, and electrical conductivity ranged from 5.7 to 471 mS cm⁻¹. Salinity in ADM ranged from 4 to 12 practical salinity units (PSU), whereas the highest reported sodium-chloride-equivalent salt concentration in the temporary ponds was 328,100 mg L⁻¹. Total dissolved solids (TDS) in the ponds reached 315,100 mg L⁻¹. Sodium dominated pond cation composition, whereas magnesium was relatively more important in ADM. Equivalent-percentage classification identified ADM and Pond 3 as saline, while Ponds 1 and 2 showed soda-saline characteristics. Mineral saturation-index (SI) calculations indicated supersaturation with respect to calcite, dolomite, and gypsum, whereas halite remained undersaturated across all sites, suggesting mineral-specific thermodynamic controls on water chemistry. Seasonal analyses showed significant changes in carbonate-related variables, total organic carbon (TOC), and phosphate; warmer periods were generally associated with higher carbonate-related values in ADM, whereas pond carbonate concentrations differed mainly between autumn and winter. Durov diagrams, Gibbs plots, Pearson correlations, and generalized additive model (GAM) results indicated that hydrological setting, evaporative concentration, Na-rich pond chemistry, chloride salinity, and carbonate-bicarbonate dynamics contributed to differentiation between marshes and ponds. TOC and nitrate were associated with carbonate variability, suggesting links with organic-matter processing and nutrient conditions rather than direct causation.