Katarzyna Szewczuk-Karpisz

The removal of hazardous ions from water is crucial for safeguarding both the environment and human health. Soil minerals, integral components of soil, play a vital role as adsorbents for various contaminants, including heavy metal ions, organic dyes, and detergents. This study investigates the interaction between boron ions and soil minerals (gibbsite, kaolinite, and montmorillonite) in the presence of polyethylenimine (PEI). The minerals underwent characterization based on specific surface area, particle size distribution, zeta potential, and the presence of functional groups. The influence of PEI addition on the stability of the soil mineral suspension was evaluated by turbidimetry. Mineral−boron and mineral−boron−PEI interactions were explored under varying conditions, including pH, initial boron concentration, and mineral quantity, with all adsorption experiments conducted over 24 hours. Using the Langmuir isotherm, the maximum adsorption capacity of the studied minerals was determined for boron both without and in the presence of PEI. For gibbsite, kaolinite and montmorillonite, it was 30.63, 24.55 and 26.62 mg g −1 , respectively, while in the presence of PEI, it increased to 33.11, 26.61 and 45.47 mg g −1 , respectively. The addition of PEI enhanced boron adsorption from aqueous solutions, increasing the removal efficiency from 65 % to about 80 %.

The studies aimed to test the adsorption capacity of two silica-enriched porous materials, synthetic Na-X zeolite and Mn-containing carbon composite, towards Pb(II) and Zn(II) ions in single and mixed systems and in the presence of diclofenac (DCF) and (or) poly(acrylic acid) (PAA). The synthetic zeolite was characterized by a well-developed surface area of 728 m2/g and a pore diameter of 1.73 nm, while the carbon composite exhibited 268 m2/g and 7.37 nm, respectively. Na-X was found to be more efficient than the carbon composite (75–212 mg/g) in adsorbing heavy metal ions in both single and bimetallic systems (322–333 mg/g). In turn, the C/Mn/SiO2 composite was more effective in removing Pb(II) ions from the systems that simultaneously contained DCF or PAA (480 and 476 mg/g, respectively). The Na-X zeolite demonstrated the greatest stability in all the systems studied. The highest stability was observed in the DCF + Pb(II) mixture, in contrast to the carbon composites where the stability was much lower. To evaluate the possibility of regeneration of the solids, HCl proved to be the best desorbent for heavy metal ions (efficiency of 99%). In general, both adsorbents offer promising potential for solving environmental problems.