Enhancing the removal of organic and inorganic selenium ions using an exfoliated kaolinite/cellulose fibres nanocomposite
Introduction
Groundwater is the main freshwater supply and essential strategic reserve for several countries throughout the world (Zeeshan, Khan, Shafiq, & Sabir, 2020). The contamination of groundwater by leached elements from natural mineral, rock, and soil components during mining and agricultural activities create the primary challenge to keep water supplies at the required levels for purity and safety (Abukhadra, Bakry, Adlii, Yakout, & El-Zaidy, 2019; Abukhadra, Refay, El-Sherbeeny, Mostafa, & Elmeligy, 2019). Selenium (Se) is a commonly detected element in groundwater. Generally, it is a vital element that positively affects human and animal health when present at its recommended level. Additionally, Se is a significant industrial element in the production of particular drugs, photosensitive materials, and semiconductor products (Lounsbury et al., 2019). Notably, selenium at specific concentrations possesses toxic and carcinogenic properties (Xu et al., 2020; Zeeshan et al., 2020).
Selenium is a metalloid component and exists in four oxidation states: selenite, or Se(IV); selenate, or Se(VI); selenide, or Se(-II); and native selenium element, or Se(0), species (Cui, Li, Wang, Zheng, & Zhang, 2018; Xu et al., 2020). Selenite and selenate are the principal species in the aquatic system with toxic properties if they exist at a concentration of 50 μg/L (Xu & Huang, 2019). Such species have dangerous health effects, including (a) the irritation of eyes and skin, (b) gastrointestinal disorders, (c) the loss of nails and hair, (d) neurological damage, and (e) monstrous deformities (He, Su, Chen, & Hu, 2020).
The adsorption decontamination of Se (IV) has been endorsed as an effective technique to achieve successful removal results; however, it has been reported as an inferior technique during the decontamination of Se (VI) ions (Xu et al., 2020). Moreover, selenium as a water pollutant has been detected in organic forms as selenocysteine (C3H7NO2Se) and selenomethionine (C5H11NO2Se), relating to the metabolic activities of some microorganisms. Furthermore, organic forms of selenium as water pollutants have been categorised as toxic and dangerous compounds as compared to inorganic forms because of the high solubility properties of organic forms in lipids and their high diffusion rates during the penetration of the cell membranes that cause rapid damage to or failure of the organs (Santra & Sen, 2019).
Therefore, numerous experimental and theoretical studies have been completed to develop advanced types of simple adsorbent products that are of better affinity for the existing selenium species in both inorganic and organic forms. The commonly studied adsorbents for this target have included polyamine/magnetic graphene oxide composite (Lu, Yu, Zeng, & Liu, 2017), Ca − Al − Cl LDH (Xu, Dong, Guo, Wen, & Jie, 2019), Fe-Al-Cl-LDH/ZVI (Xu & Huang, 2019); MgO nanosheets (Cui et al., 2018), chitosan/clay composite (Bleiman & Mishael, 2010); apatite (Moore, Rigali, & Brady, 2016), iron oxy-hydroxides (Kalaitzidou, Nikoletopoulos, Tsiftsakis, Pinakidou, & Mitrakas, 2019); Fe-impregnated biochar (Hong et al., 2020); hematite (Ma, Shan, Liang, & Tong, 2018), and Mg–FeCO3 LDH/cellulose fibres (Chen & An, 2012).
Nevertheless, little research has focused on the experimental efficiency of known or new clay mineral-based adsorbents in the effective removal of selenium, especially in their advanced modified forms. Clay minerals refer to broad groups of layered silicate natural materials that exhibit noticeable ion exchange properties, significant surface areas, and valuable adsorption capacities. Moreover, such minerals are naturally available and widely distributed (Abukhadra, Bakry et al., 2019; Abukhadra, Refay et al., 2019; Dardir, Mohamed, Abukhadra, Ahmed, & Soliman, 2018). From these clay minerals, kaolinite, which has a 1:1 layered structure and a hydrous aluminium silicate composition, has been used extensively in numerous environmental and industrial applications (Shaban, Sayed, Shahien, Abukhadra, & Ahmed, 2018). The organic and inorganic modification of kaolinite shows promise in prompting the surface reactivity of its sheets as well as its surface area and directing its adsorption affinity for specific ions that support its technical value in the decontamination of different species of water pollutants (Shaban et al., 2018; Tan, Yuan, Annabi-Bergaya, Liu, & He, 2014).
Recently, exfoliation of the layered structure of common clay minerals into single sheets has been recommended as a promising modification technique, resulting in the significant enhancement of surface reactivity, surface area, and adsorption capacities of clay minerals (Abukhadra, Bakry et al., 2019; Abukhadra, Refay et al., 2019; Ma et al., 2016). While several studies have focused on the environmental and technical qualifications of exfoliated montmorillonite, unfortunately, little research has focused on the production of exfoliated kaolinite sheets. Moreover, no previous studies have demonstrated its application as an advanced adsorbent.
Notably, the combination of exfoliated kaolinite sheets and cellulose fibres as natural biopolymers of excellent technical properties are expected to result in a novel composite of promising adsorption capacity of these metal ions with enhanced affinity for both organic and inorganic forms (Abukhadra, Bakry et al., 2019; Abukhadra, Refay et al., 2019). Cellulose is a known natural biopolymer that is classified as polysaccharide polymer and plays a vital role in numerous industrial, medical, and environmental applications (Putro, Santoso, Ismadji, & Ju, 2017). Structurally, cellulose polymer chains are composed of two essential anhydroglucose rings that bind to each other by b-1,4 glycoside bonds. Additionally, these cellulose-based materials are safe, non-toxic, and highly reactive products that possess excellent adsorption properties and significant surface area (Fakhri, Tahami, & Nejad, 2017; Pooresmaeil, Javanbakht, Nia, & Namazi, 2020).
Based on these considerations, the presented manuscript involved the synthesis of exfoliated kaolinite sheets/cellulose fibres composite (EXK/CF) as a novel composite with an enhanced adsorption affinity for toxic species selenium pollutants selenite: Se (IV), Se (VI), and SeMt (C5H11NO2Se). The study involved the detection of their adsorption behaviours and optimisation for the best removal factors as well as equilibrium and thermodynamic properties.
Section snippets
Materials
The raw kaolinite was obtained from Central Metallurgical Research & Development Institute in Egypt. Cetyltrimethylammonium bromide (CTAB), high purity methanol, and analytical-grade dimethyl sulfoxide (DMSO) to be used as exfoliation reagents were obtained from Sigma-Aldrich, Egypt. Crystalline cellulose fibres were used in the preparation of the composite of exfoliated kaolinite. Sodium selenite (Na2SeO3), sodium selenate (Na2SeO4), and selenomethionine (C5H11NO2Se) were used as sources for
X-ray powder diffraction (XRD) analysis
As a raw material, kaolinite is distinguished by its essential peaks at 12.3º, 20.8°, 24.9º, and 26.6° relating to high-crystalline kaolinite of a triclinic system and corresponding to its (001), (-110), (002), and (111) crystallographic planes, showing the d-spacing value of 0.7 nm (Fig. 1A). The XRD pattern of DMSO-intercalated kaolinite reflected a reduction of several kaolinite-related peaks with a noticeable detection for two peaks only, (001) and (002), which were observed as deviated
Conclusion
The integration between the kaolinite as exfoliated sheets and the cellulose fibres resulted in an advanced hybrid structure of an enhanced surface area, surface reactivity, and multifunctional active groups. Considering the previous enhancement in the physicochemical properties of the EXK/CF composite, the hybrid structure was applied for the effective decontamination of different species of selenium as water pollutants: Se (VI), Se (IV), and SeMt. Moreover, the EXK/CF composite showed changes
CRediT authorship contribution statement
Mostafa R. Abukhadra: Conceptualization, Project administration, Visualization, Formal analysis, Writing - original draft, Writing - review & editing. Ali AlHammadi: Data curation, Formal analysis, Software, Writing - review & editing, Writing - original draft. Ahmed M. El-Sherbeeny: Project administration, Funding acquisition, Writing - review & editing, Funding acquisition, Investigation. Mohamed Abdel Salam: Conceptualization, Writing - original draft, Writing - review & editing. Mohammed A.
Acknowledgment
The authors extend their appreciation to the Deanship of Scientific Research at King Saud University for funding this work through research group number (RG-1440-047).
References (49)
- et al.
Synthesis and characterization of kaolinite nanotubes (KNTs) as a novel carrier for 5-fluorouracil of high encapsulation properties and controlled release
Inorganic Chemistry Communications
(2019) - et al.
Effective decontamination of phosphate and ammonium utilizing novel muscovite/phillipsite composite; equilibrium investigation and realistic application
Science of the Total Environment
(2019) - et al.
Facile conversion of kaolinite into clay nanotubes (KNTs) of enhanced adsorption properties for toxic heavy metals (Zn2+, Cd2+, Pb2+, and Cr6+) from water
Journal of Hazardous Materials
(2019) - et al.
Facile synthesis of bentonite/biopolymer composites as low-cost carriers for 5-fluorouracil drug; equilibrium studies and pharmacokinetic behavior
International Journal of Biological Macromolecules
(2019) - et al.
Selenium removal from drinking water by adsorption to chitosan–clay composites and oxides: batch and columns tests
Journal of Hazardous Materials
(2010) - et al.
Adsorption mechanism of selenate and selenite on the binary oxide systems
Water Research
(2009) - et al.
Kinetics and equilibrium adsorption study of selenium oxyanions onto Al/Si and Fe/Si coprecipitates
Chemosphere
(2018) - et al.
Selenium adsorption and speciation with Mg–FeCO3 layered double hydroxides loaded cellulose fiber
Talanta
(2012) - et al.
Adsorption study of selenium ions from aqueous solutions using MgO nanosheets synthesized by ultrasonic method
Journal of Hazardous Materials
(2018) - et al.
Cosmetic and pharmaceutical qualifications of Egyptian bentonite and its suitability as drug carrier for Praziquantel drug
European Journal of Pharmaceutical Sciences
(2018)
Insight into novel β-cyclodextrin-grafted-poly (N-vinylcaprolactam) nanogel structures as advanced carriers for 5-fluorouracil: Equilibrium behavior and pharmacokinetic modeling
Colloids and Surfaces A: Physicochemical and Engineering Aspects
Preparation and characterization of Fe3O4-Ag2O quantum dots decorated cellulose nanofibers as a carrier of anticancer drugs for skin cancer
Journal of Photochemistry and Photobiology B: Biology
Simultaneous speciation of inorganic selenium and tellurium in environmental water samples by polyaniline functionalized magnetic solid phase extraction coupled with ICP-MS detection
Talanta
Synthesis of Fe-impregnated biochar from food waste for Selenium (VI) removal from aqueous solution through adsorption: Process optimization and assessment
Chemosphere
Chitosan-rectorite nanospheres embedded aminated polyacrylonitrile nanofibers via shoulder-to-shoulder electrospinning and electrospraying for enhanced heavy metal removal
Applied Surface Science
Adsorption of Pb (II) on mesoporous activated carbons fabricated from water hyacinth using H3PO4 activation: adsorption capacity, kinetic and isotherm studies
Applied Surface Science
Evaluation of natural goethite on the removal of arsenate and selenite from water
Journal of Environmental Sciences
Synthesis of chitosan/MCM-48 and β-cyclodextrin/MCM-48 composites as bio-adsorbents for environmental removal of Cd2+ ions; kinetic and equilibrium studies
Reactive and Functional Polymers
Adsorption of Se (IV) and Se (VI) species by iron oxy-hydroxides: Effect of positive surface charge density
Science of the Total Environment
Removal of selenium from caustic solution by adsorption with CaAl layered double hydroxides
Hydrometallurgy
Zeolite-supported nanoscale zero-valent iron: New findings on simultaneous adsorption of Cd (II), Pb (II), and As (III) in aqueous solution and soil
Journal of Hazardous Materials
Preferential adsorption of selenium oxyanions onto {1 1 0} and {0 1 2} nano-hematite facets
Journal of colloid and Interface Science
Nanocomposite of exfoliated bentonite/g-C3N4/Ag3PO4 for enhanced visible-light photocatalytic decomposition of Rhodamine B
Chemosphere
Efficient adsorption of Selenium (IV) from water by hematite modified magnetic nanoparticles
Chemosphere
Cited by (33)
Sunlight driven photocatalytic degradation of RhB dye using composite of bismuth oxy-bromide kaolinite BiOBr@Kaol: Experimental and molecular dynamic simulation studies
2023, Journal of Photochemistry and Photobiology A: ChemistrySynergetic, steric, and energetic properties of exfoliated kaolinite and its methanol hybridized structure during the adsorption of bisphenol-A residuals from the aqueous environment
2023, Journal of Environmental Chemical EngineeringSynthesis of novel adsorbent S-SiO<inf>2</inf>@Fe<inf>3</inf>O<inf>4</inf> based on strong bonding of S-O-Se for selenium removal in water
2023, Journal of Environmental Chemical EngineeringNovel triazine-based cationic covalent organic polymers for highly efficient and selective removal of selenate from contaminated water
2022, Journal of Hazardous MaterialsCellulose composites as nanobiosorbents for ecological remediation
2022, Nano-biosorbents for Decontamination of Water, Air, and Soil PollutionModification and derivatization of cellulose-based nanobiosorbents and their utilization in environmental remediation
2022, Nano-biosorbents for Decontamination of Water, Air, and Soil Pollution