Valorization of algal biomass to synthesize heterogeneous gC3N4-Biochar photocatalyst for the treatment of industrial wastewater using photocatalysis-persulfate oxidation process

Aqsa Shafique; Hafiz Muhammad Uzair Ayub; Javed Iqbal; Shanawar Hamid; Fawad Ashraf; Muhammad Saif Ur Rehman; S Boukhari; Mohamed A Habila; Alam Nawaz; Tahir Fazal

doi:10.1016/j.chemosphere.2024.141325

Valorization of algal biomass to synthesize heterogeneous gC₃N₄-Biochar photocatalyst for the treatment of industrial wastewater using photocatalysis-persulfate oxidation process

Chemosphere. 2024 Jan 29:141325. doi: 10.1016/j.chemosphere.2024.141325. Online ahead of print.

Authors

Affiliations

¹ Institute of Chemical and Environmental Engineering (ICEE), Khwaja Fareed University of Engineering and Information Technology (KFUEIT), 64200, Rahim Yar Khan, Pakistan; Department of Chemistry, The Islamia University of Bahawalpur (IUB), Rahim Yar Khan Campus, 64200, Pakistan.
² Gas Processing Center, College of Engineering, Qatar University, Doha P.O. Box 2713, Qatar.
³ Institute of Chemical and Environmental Engineering (ICEE), Khwaja Fareed University of Engineering and Information Technology (KFUEIT), 64200, Rahim Yar Khan, Pakistan. Electronic address: javed.iqbal@kfueit.edu.pk.
⁴ Department of Civil Engineering, Swedish College of Engineering and Technology, Rahim Yar Khan, 64200, Pakistan.
⁵ Department of Chemical Engineering, COMSATS University Islamabad, Lahore Campus, Lahore, 54000, Pakistan.
⁶ Office of Research, Innovation, and Commercialization (ORIC), Khwaja Fareed University of Engineering and Information Technology (KFUEIT), Rahim Yar Khan, 64200, Pakistan.
⁷ Department of Chemistry, College of Science, King Saud University, P. O. Box 2455, Riyadh, 11451, Saudi Arabia.
⁸ School of Chemical Engineering, Yeungnam University, Gyeongsan, 712-749, Republic of Korea.
⁹ Institute of Chemical and Environmental Engineering (ICEE), Khwaja Fareed University of Engineering and Information Technology (KFUEIT), 64200, Rahim Yar Khan, Pakistan; Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, 518000, China. Electronic address: tahirfazal@sustech.edu.cn.

PMID: 38296210
DOI: 10.1016/j.chemosphere.2024.141325

Abstract

Textile wastewater, heavily contaminated with organic dyes, is generating severe problems to environment and human health. The implementation of gC₃N₄ with biochar (gC₃N₄-BC) for the treatment of textile wastewater is less effective due to the limited adsorption capacity and slower degradation kinetics. To tackle these problems, peroxydisulfate (PDS) is integrated with gC₃N₄-BC photocatalyst to enhance the process efficiency and kinetics. The synthesized gC₃N₄-BC-5 composite shows higher separation of charge carriers, light absorbance, and lower energy bandgap (2.62 eV). The results of photocatalytic degradation and rate constant are enhanced up to 99.9 % and 0.041 min^-1 using gC₃N₄-BC-5 with PDS as compared to without PDS (96.8 % and 0.028 min^-1, respectively). The radicals (SO₄^-•,O₂^-•, and OH^•) are responsible to improve the degradation process efficiency and kinetics. The reusability of optimized sample indicates that gC₃N₄-BC-5 is stable and effective up to five cycles. The gC₃N₄-BC-5 composite attains highest adsorption (70.9 %) when compared to BC (62.3 %) and pure gC₃N₄ (27.1 %). The well-fitted models of adsorption (Pseudo-Second-Order and Freundlich) confirm the favorable, chemical, and multilayered adsorption process. The coupling of gC₃N₄-BC-5 with PDS is effective, efficient, and stable process to enhance the kinetics and degradation of textile wastewater.

Keywords: Adsorption; Oxidation process; Photocatalysis; Sulfate radicals; Textile wastewater; gC(3)N(4) based biochar.