Removal of pyrvinium pamoate using a licorice root extract-modified hydroxyapatite@Li-H₃BTC-MOF nanocomposite: optimization via response surface methodology

The presence of persistent pharmaceutical micropollutants like pyrvinium pamoate (PP) in aquatic environments demands eco-friendly remediation approaches. We report a bio-inspired LRE-Ca₁₀(PO₄)₆(OH)₂@Li-H₃BTC-MOFs nanocomposite synthesized via in situ hydrothermal integration of licorice root extract (LRE)-functionalized hydroxyapatite with a lithium-based metal–organic framework. Comprehensive characterization (FTIR, XRD, SEM-EDX, DLS, TGA) confirmed nanoscale (∼100 nm) morphology, structural integrity, and retention of bioactive –OH, –COO−, and PO groups. Under UV irradiation (30 W/m2) and minimal H₂O₂ (0.55 mM), PP removal was optimized via Response Surface Methodology (D-optimal design, R2 = 0.988), achieving 99.96% (SD = 2.7%) efficiency at low nanocomposite dosage (2 mg/L) and environmentally relevant PP concentration (30 mg/L). Kinetic studies revealed chemisorption-dominated removal (pseudo-second-order, R2 = 0.9997), while reusability tests confirmed >85% performance retention after five cycles. This sustainable, plant-derived nanocomposite offers a scalable solution for efficient pharmaceutical pollutant removal under practical water treatment conditions.