Kinetics, Isotherm, and Thermodynamic Studies of the Adsorption Mechanism of PFOS and PFOA Using Inactivated and Chemically Activated Maize Tassel

OMO-OKORO, Patricia N., Christopher J. CURTIS, Pavlína KACER, Lisa Emily MELYMUK, Opeyemi A. OYEWO and Jonathan O. OKONKWO. Kinetics, Isotherm, and Thermodynamic Studies of the Adsorption Mechanism of PFOS and PFOA Using Inactivated and Chemically Activated Maize Tassel. Water, Air and Soil Pollution. Dordrecht: Springer, 2020, vol. 231, No 9, p. 1-21. ISSN 0049-6979. Available from: https://dx.doi.org/10.1007/s11270-020-04852-z.

Basic information

• Original name: Kinetics, Isotherm, and Thermodynamic Studies of the Adsorption Mechanism of PFOS and PFOA Using Inactivated and Chemically Activated Maize Tassel
• Authors: OMO-OKORO, Patricia N. (710 South Africa), Christopher J. CURTIS (710 South Africa), Pavlína KACER (203 Czech Republic, belonging to the institution), Lisa Emily MELYMUK (124 Canada, guarantor, belonging to the institution), Opeyemi A. OYEWO (710 South Africa) and Jonathan O. OKONKWO (710 South Africa).
• Edition: Water, Air and Soil Pollution, Dordrecht, Springer, 2020, 0049-6979.

Other information

• Original language: English
• Type of outcome: Article in a journal
• Field of Study: 10503 Water resources
• Country of publisher: Switzerland
• Confidentiality degree: is not subject to a state or trade secret
• WWW: URL
• Impact factor: Impact factor: 2.520
• RIV identification code: RIV/00216224:14310/20:00117360
• Organization unit: Faculty of Science
• Doi: http://dx.doi.org/10.1007/s11270-020-04852-z
• UT WoS: 000570922700002
• Keywords in English: PFOS; PFOA; Maize tassel; Activated-maize tassel; Adsorption kinetics; Adsorption isotherm
• Tags: rivok
• Tags: International impact, Reviewed

Abstract

The extreme persistence, bioaccumulative, and toxicity tendencies of per- and polyfluoroalkyl substances (PFAS) have contributed to the ever-increasing quest for effective and low-cost technologies for removing PFAS from aqueous solutions. Therefore, in the present study, maize tassel (MT) was activated using phosphoric acid. The chemically activated maize tassel (CAMT) was thereafter applied as an adsorbent for removing perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) from aqueous media in comparison with the inactivated MT. The adsorption behaviors of PFOS and PFOA onto MT and CAMT were investigated via adsorption experiments. It was found that the isothermal data fit better with the Freundlich isotherm model than with the Langmuir isotherm model. Maximum adsorption capacities of 1552.5 mg g(-1) (3.10 mmol g(-1)) and 380.32 mg g(-1) (0.92 mmol g(-1)) were recorded for PFOS and PFOA, respectively, using CAMT, when the Freundlich model was applied. Equilibrium was attained within 60 min using both MT and CAMT. The pseudo-second-order kinetics model suited the kinetics data better. It was observed from the thermodynamic studies that the adsorption mechanism of PFOS and PFOA on MT and CAMT is spontaneous and feasible. All the values for the Gibb's free energy change (Delta G(0), kJ mol(-1)) obtained in the present study were below -20 kJ mol(-1). The adsorption of PFOS and PFOA using CAMT is exothermic in nature (enthalpy, Delta H-0 was negative) whereas the adsorption of PFOS and PFOA using MT is endothermic. The PFOS and PFOA adsorption processes using both MT and CAMT were greatly influenced by electrostatic and hydrophobic interactions.

Links

• EF16_013/0001761, research and development project: Name: RECETOX RI
• LM2015051, research and development project: Name: Centrum pro výzkum toxických látek v prostředí (Acronym: RECETOX RI)

Investor: Ministry of Education, Youth and Sports of the CR

• 734522, interní kód MU: Name: Synergising International Research Studies into the Environmental Fate and Behaviour of Toxic Organic Chemicals in the Waste Stream (Acronym: INTERWASTE)

Investor: European Union, MSCA Marie Skłodowska-Curie Actions (Excellent Science)