Simultaneous removal of bisphenol S, carbamazepine, and clonazepam from water applying composites formed by titanium oxide and coconut shell-based material: statistical and AI-based approaches for real wastewater treatment.

Abstract

The removal of contaminants of emerging concern (CECs) from water is vital due to their persistence and harmful effects on ecosystems and human health. This study developed a titanium-coconut shell based minerals (Ti-CSM) composite for the simultaneous removal of bisphenol S (BPS), carbamazepine (CBZ), and clonazepam (CZP) from water. Carbon material produced with coconut shell-a low-cost biomass-was used as support for titanium oxide in varying mass/mass Ti/biomass ratios (25:75, 50:50, and 75:25), with the Materials being calcined at 400 °C and 600 °C. The response surface methodology with central composite rotatable design (RSM-CCRD) optimized pH (5-9), adsorbate/adsorbent ratio (2.5-7.5 mg g⁻¹), and temperature (16-34 °C), while an artificial neural network (ANN) model was applied for performance prediction. The Ti-CSM 25:75 composite calcined at 600 °C achieved up to 99% removal for BPS and CZP, and 98.7% for CBZ under optimal conditions (pH 7.0, adsorbate/adsorbent ratio 2.5, and temperature 16 °C). Adsorption capacities reached 12.31 mg g⁻¹ (BPS), 8.02 mg g⁻¹ (CBZ), and 7.13 mg g⁻¹ (CZP). Kinetic studies followed a non-linear pseudo-second-order model, while Freundlich and Sips isotherms indicated monolayer adsorption. ANN model revealed higher predictive accuracy compared to RSM-CCRD (R² > 0.98 vs. R² > 0.85). Removal rates in ultrapure water exceeded 98%, while real wastewater treatment removed 89.5 ± 2.5%, 68.7 ± 1.9%, and 57.3 ± 2.0% of BPS, CBZ, and CZP, respectively. This result highlights the material's potential in treating complex matrices and lessens risks of environmental toxicity, particularly for an endocrine disruptor like BPS. By minimizing titanium use and leveraging a biomass precursor for contaminants adsorption, Ti-CSM composites offer a sustainable, efficient solution for CECs removal, showcasing the potential of biomass modification in eco-friendly water treatment.