In this study, individual and competitive Cu(II), Cd(II), and Pb(II) adsorptions on montmorillonite were searched by considering surface acidic functional groups of adsorbent. pH dependency of adsorptions and kinetic properties of Cu(II) adsorption was investigated. Cu(II) adsorption on montmorillonite fits pseudo-first-order reaction with the 0.008 k value. Individual and competitive heavy metal adsorptions were modeled using Langmuir, Freundlich, Temkin, and Dubinin–Astakhov isotherms. Adsorption capacities were calculated using equations of related linearized models. The adsorption capacities of individual metal adsorption, obtained from linearized models, are higher than the yielded capacities from competitive adsorption experiments. All adsorption energies calculated from linearized Dubinin–Astakhov model varied between 7 and 16 kJ/mol. The values of adsorption energies gained for metal adsorption in competition did not significantly differ from those of individual adsorption. Since montmorillonite surface behaves as a weak acid and has a strong buffer effect at pH values between 2 and 3, the pH dependency of adsorption was explained by taking into account the surface acidic properties of adsorbent and introduced preferred surface sites beyond adsorption with increasing pH. Cu(II), Cd(II), and Pb(II) existence on loaded montmorillonite was proved by the aid of SEM-EDX results.

This study investigates the mechanical, thermal, and surface characteristics of acrylonitrile–butadiene–styrene (ABS) composites reinforced with bentonite and bis(2‐ethylhexyl) phosphate (DEHPA)‐modified bentonite. The addition of bentonite significantly reduced the tensile strength and elongation at break due to the filler's inherent brittleness. Pure ABS exhibited a tensile strength of 42.2 MPa, which decreased by 16.1% with the incorporation of 20% bentonite (ABS1). Impact strength tests showed that the inclusion of bentonite lowered impact resistance, particularly in notched samples. Bentonite also increased the hardness and density, reflecting improved rigidity but reduced flexibility. Surface gloss changed from semigloss to matte, and FT‐IR spectroscopy confirmed the successful integration of bentonite. Water absorption tests revealed that DEHPA‐modified bentonite composites had higher absorption over time, highlighting the modification's effect on hydrophilicity. While bentonite improves certain properties, the balance between mechanical strength and flexibility needs to be further explored to meet the requirements of specific applications such as automotive components, electronics casings, and construction materials.