title: Photocatalytic degradation of industrial pulp and paper mill effluent using synthesized magnetic Fe2O3-TiO2: Treatment efficiency and characterizations of reused photocatalyst.
abstract: In this work, heterogeneous photocatalysis was used to treat pulp and paper mill effluent (PPME). Magnetically retrievable Fe2O3-TiO2was fabricated by employing a solvent-free mechanochemical process under ambient conditions. Findings elucidated the successful incorporation of Fe2O3into the TiO2lattice. Fe2O3-TiO2was found to be an irregular and slightly agglomerated surface morphology. In comparison to commercial P25, Fe2O3-TiO2exhibited higher ferromagnetism and better catalyst properties with improvements in surface area (58.40 m2/g), pore volume (0.29 cm3/g), pore size (18.52 nm), and band gap (2.95 eV). Besides, reusability study revealed that Fe2O3-TiO2was chemically stable and could be reused successively (five cycles) without significant changes in its photoactivity and intrinsic properties. Additionally, this study demonstrated the potential recovery of Fe2O3-TiO2from an aqueous suspension by using an applied magnetic field or sedimentation. Interactive effects of photocatalytic conditions (initial effluent pH, Fe2O3-TiO2dosage, and air flow-rate), reaction mechanism, and the presence of chemical oxidants (H2O2, BrO3-, and HOCl) during the treatment process of PPME were also investigated. Under optimal conditions (initial effluent pH = 3.88, [Fe2O3-TiO2] = 1.3 g/L, and air flow-rate = 2.28 L/min), the treatment efficiency of Fe2O3-TiO2was 98.5% higher than the P25. Based on Langmuir-Hinshelwood kinetic model, apparent rate constants of Fe2O3-TiO2and P25 were 9.2 × 10-3and 2.7 × 10-3min-1, respectively. The present study revealed not only the potential of using magnetic Fe2O3-TiO2in PPME treatment but also demonstrated high reusability and easy separation of Fe2O3-TiO2from the wastewater.
authors.affiliation: Chemical Engineering Discipline, School of Engineering, Monash University, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia.
authors.forename: Wennie
authors.initials: W
authors.lastname: Subramonian
authors.affiliation: Chemical Engineering Discipline, School of Engineering, Monash University, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia. Electronic address: tayeong@hotmail.com.
authors.forename: Ta Yeong
authors.initials: TY
authors.lastname: Wu
authors.affiliation: Chemical Engineering Discipline, School of Engineering, Monash University, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia.
authors.forename: Siang-Piao
authors.initials: SP
authors.lastname: Chai
mesh_terms: D002384:Catalysis; D005290:Ferric Compounds / Q000737:chemistry; D006801:Humans; D007220:Industrial Waste; D010209:Paper; D010777:Photochemistry; D014025:Titanium / Q000737:chemistry; D062065:Wastewater; D018508:Water Purification / Q000379:methods*
chemical_list: D005290:Ferric Compounds; D007220:Industrial Waste; D014025:Titanium; D062065:Wastewater; C009495:titanium dioxide; C000499:ferric oxide
keywords: Coagulation-flocculation; Green synthesis; Mechanochemical milling; Photocatalysis; Response surface methodology; Wastewater treatment