Binary coagulation system (graphene oxide/chitosan) for polluted surface water treatment. (15th June 2021)

• Record Type: Journal Article
• Authors: Aboelfetoh, Eman F.; Aboubaraka, Abdelmeguid E.; Ebeid, El-Zeiny M.
• Is Part Of: Journal of environmental management. Volume 288(2021)
• Publication Date: 2021-06-15
• Subjects: Coagulant aid -- Water treatment -- Coagulation/flocculation -- Dye removal -- Adsorption -- Kinetics; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2021.112481
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: In this study, chitosan (CS) is used as a natural coagulant aid alongside graphene oxide (GO) to remove turbidity and numerous pollutants from raw and artificially contaminated surface water. The coagulation capability of the system (GO/CS) was assessed with respect to a water sample's turbidity, pH, coagulant dose, settling velocity, and temperature. The presence of CS enhanced the coagulation capacity of GO at varied pH levels and no GO residue was detected in the water after the treatment. The proposed system achieved high turbidity removal efficiency (≥98.3%) for all turbidity levels. A mixture of GO (8 mg/L) and CS (2 mg/L) was ideal to remove algae (99.5%) and bacteria (≥95.0%). Furthermore, it demonstrated a high coagulation capacity to remove dyes, direct brown-2 (DB-2), methylene blue (MB), and Pb(II) ions from artificially contaminated surface water. Interestingly, the sludge exhibited an extraordinary adsorption capacity for DB-2, MB, and Pb(II) ions. The adsorption process followed the pseudo-second-order kinetic model, and was consistent with the Langmuir model, with an adsorption capacity of up to 667.8, 400.7, and 459.1 mg/g for DB-2, MB, and Pb(II) ions, respectively. Therefore, the presented binary coagulation system is of great potential economic value for the treatment of raw surface water and wastewater. Graphical abstract: Image 1 Highlights: CS greatly improves GO's coagulation efficacy for polluted surface water treatment. Efficient removal of turbidity, algae, FCB, HB, dyes, and Pb(II) by GO/CS coagulation. CS as a coagulant aid creates huge flocks, accelerates settling, stops GO leaching. Reusability of sludge as an effective adsorbent for DB-2, MB, and Pb(II) ions. GO/CS sludge's adsorption capacity is greater than diverse reported adsorbents.