Luffa–Ni/Al layered double hydroxide bio-nanocomposite for efficient ibuprofen removal from aqueous solution: Kinetic, equilibrium, thermodynamic studies and GEP modeling

Luffa is a robust, renewable biomaterial known for its low mass, high specific strength, and non-toxicity, making it ideal for composite development. This study modified luffa to create the LF@ppy@LDH nanocomposite, combining luffa, polypyrrole, and layered double hydroxides to efficiently remove ibuprofen from water. Techniques like FE-SEM, EDX, FTIR, and XRD confirmed the modification. To optimize adsorption efficiency, factors such as contact time <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:mrow><mml:mo>(</mml:mo> <mml:mrow><mml:mi>C</mml:mi> <mml:mi>t</mml:mi> <mml:mi>i</mml:mi> <mml:mi>m</mml:mi> <mml:mi>e</mml:mi></mml:mrow> <mml:mo>)</mml:mo></mml:mrow> </mml:mrow> </mml:math> , adsorbent dosage <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo>(</mml:mo> <mml:mrow><mml:mi>A</mml:mi> <mml:mi>d</mml:mi></mml:mrow> <mml:mo>)</mml:mo></mml:mrow> </mml:math> , drug concentration <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo>(</mml:mo> <mml:mrow><mml:mi>D</mml:mi> <mml:mi>c</mml:mi></mml:mrow> <mml:mo>)</mml:mo></mml:mrow> </mml:math> , temperature ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>θ</mml:mi> <mml:mo>)</mml:mo></mml:mrow> </mml:math> , stirring rate <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo>(</mml:mo> <mml:mrow><mml:mi>S</mml:mi> <mml:mi>r</mml:mi></mml:mrow> <mml:mo>)</mml:mo></mml:mrow> </mml:math> , and pH were carefully fine-tuned to maximize efficiency. The highest ibuprofen removal occurred at pH 5, with an adsorption capacity of 44.306 mg/g at 298 K. The Temkin isotherm model, which points to chemisorption as the mechanism, accurately depicted the adsorption process with a high correlation coefficient (R² = 0.984). Moreover, the Elovich kinetic model proved to be the most precise in describing how ibuprofen adheres to the modified luffa, showing a very tight fit with the data (R² = 0.993). LF@ppy@LDH demonstrated outstanding reusability, maintaining steady adsorption over five repeated rounds. In addition, a powerful data-driven model, namely gene expression programming (GEP), was employed to provide an explicit formula relating input variables to removal efficiency, highlighting the potential of LF@ppy@LDH for water purification and environmental remediation.