Adsorption of naphthalene polycyclic aromatic hydrocarbon from wastewater by a green magnetic composite based on chitosan and graphene oxide

Author(s)

Queiroz, Ruth Nobrega ; Carlos da Silva, Meuris Gurgel ; Mastelaro, Valmor Roberto ; Prediger, Patricia ; Adeodato Vieira, Melissa Gurgel

• Document type: Journal article
• Source: Environmental Science and Pollution Research; v. N/A, p. 19-pg., 2022-11-16.

Abstract

A green magnetic composite mCS/GO was synthesized using water hyacinth extract, as a reducing agent, and proanthocyanidin, as a crosslinking agent, for the adsorption of naphthalene from effluents. The green composite was evaluated using different characterization techniques to determine its thermal (TG/DTG), structural (BET, XPS and FTIR), crystallographic (XRD), and textural (SEM) properties in natura and post-adsorption. The results obtained through a central composite design (CCD) experiment indicated that the initial concentration of NAP and the adsorbent dosage are significant for the adsorption capacity. The adsorption assays indicated that physisorption, through pi-pi and hydrophobic interactions, were the main mechanism involved in the NAP adsorption. However, the adjustment to the PSO and Freundlich models, obtained through kinetic and equilibrium studies, indicated that chemisorption also influences the adsorptive process. The thermodynamic study indicated physisorption as the mechanism responsible for the NAP adsorption. Also, the adsorbent has high affinity for the adsorbate and the process is spontaneous and endothermic. The maximum adsorption capacity (q(max)) of the green mCS/GO was 334.37 mg g(-1) at 20 degrees C. Furthermore, the green mCS/GO was effectively regenerated with methanol and reused for five consecutive cycles, the percentage of NAP recovery went from approximately 91 to 75% after the fifth cycle. The green composite was also applied in the adsorption of NAP from river water samples, aiming to evaluate the feasibility of the method in real applications. The adsorption efficiency was approximately 70%. From what we know, this it is the first time that a green adsorbent was recycled after the polycyclic aromatic hydrocarbon (PAHs) adsorption process. (AU)

• FAPESP's process: 20/16004-9 - Development of advanced materials and artificial intelligence-based models for application for the removal and monitoring of emerging pollutants in aqueous media
• Grantee: Meuris Gurgel Carlos da Silva
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
• Grantee: Elson Longo da Silva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 19/07822-2 - Synthesis of new nanoadsorbents, their characterizations and applications in pollutant adsorption in water
• Grantee: Patricia Prediger
• Support Opportunities: Regular Research Grants