Bioengineering of iron oxide nanoparticles using leaves extract of Dalbergia sissoo for the removal of diclofenac and tetracycline from water: optimization by BBD approach.

Pharmaceutical compounds like tetracycline and diclofenac are causing significant environmental pollution, posing health risks and necessitating effective techniques for their elimination from water-based ecosystems. This study explores the potential of green-synthesized iron oxide nanoparticles (Fe2O3) in the adsorption of tetracycline (TC) and diclofenac (DF) and optimized the process using the Box-Behnken Design (BBD) approach. The average particle size of the synthesized Fe2O3 was found 15.71 nm. The BET results revealed that surface area, pore volume, and average pore diameter was 13.16 m2/g, 3.18 cm3/g, and 21.48 nm, respectively. At optimal conditions, TC and DF removal were 88.2-90.51%, respectively. with desirability function one. The Langmuir maximum adsorption capacity was 56.68 mg/g for TC and 62.36 mg/g for DF. The primary rate-limiting step is proposed to be chemisorption. The thermodynamics results confirm adsorption onto Fe2O3 that occurs spontaneously, endothermically, and randomly. The green Fe2O3 nanoparticles efficiently absorbed TC and DF from aqueous solutions upto five cycles, with efficiency declined from 87.9 to 67.23% and 90.01 to 65.23%, respectively, which showed economic applicability of materials. This study illustrates the efficacy of green-synthesized Fe₂O₃ nanoparticles in eliminating pharmaceutical pollutants and their significance in promoting sustainable water treatment technologies in accordance with circular economy and SDG objectives.