Metal/mineral-incorporating materials have received significant attention over the last decades given the outstanding adsorption behavior towards various pollutants, especially Cr(VI), in aqueous solutions. Here, the pattern of sorption of some pollutants with special focus on Cr(VI) removal over metal/mineral-incorporating materials has been compiled. Furthermore, the key influencing adsorption variables, i.e., pH, concentration at the beginning, contact time, and dosage of sorbent, were discussed while considering different material classifications. Different isothermal and kinetic models were elaborated. Langmuir and Freundlich's models are adopted as the main sorption isotherms, while the pseudo-second-order kinetic model is the most fitted heavy metal ion and Cr(VI) kinetic model in aqueous systems. The results revealed that metal/mineral-incorporating materials are quite effective for heavy metal (especially Cr(VI)) recovery from water and confirmed that these materials are affordable and reliable for contaminated water remediation. Also, several methods are available for the modification of these materials in order to increase their sorption efficiency. However, to establish the use of metal/mineral-incorporating materials for water purification compared with other established methods, more investigations are required to determine the best modification method and investigate the release of metals from these materials during sorption.

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Perspectives regarding metal/mineral-incorporating materials for water purification: with special focus on Cr(VI) removal

Nowadays, water pollution has been considered a global concern on environmental sustainability, calling for high-performance materials in effective pollution treatments. Adsorption approach has gre...

Recent trends on numerical investigations of response surface methodology for pollutants adsorption onto activated carbon materials: A review

Facile synthesis and characterization of a novel 1,2,4,5-benzene tetracarboxylic acid doped polyaniline@zinc phosphate nanocomposite for highly efficient removal of hazardous hexavalent chromium ions from water.

Hydrochar derived from Argan nut shell (ANS) was synthesized and applied to remove bisphenol A (BPA) and diuron. The results indicated that the hydrochar prepared at 200 °C (HTC@ANS-200) possessed a higher specific surface area (42 m2/g) than hydrochar (HTC@ANS-180) prepared at 180 °C (17 m2/g). The hydrochars exhibited spherical particles, which are rich in functional groups. The HTC@ANS-200 exhibited high adsorption efficiency, of about 92% of the BPA removal and 95% of diuron removal. The maximum Langmuir adsorption capacities of HTC@ANS-200 at room temperature were 1162.79 mg/for Bisphenol A and 833.33 mg/g for diuron (higher than most reported adsorbents). The adsorption process was spontaneous (− ΔG°) and exothermic (− ΔH°). Excellent reusability was reclaimed after five cycles, the removal efficiency showed a weak decrease of 4% for BPA and 1% for diuron. The analysis of Fourier transforms infrared spectrometry demonstrated that the aromatic C=C and OH played major roles in the adsorption mechanisms of BPA and diuron in this study. The high adsorption capacity was attributed to the beneficial porosity (The pore size of HTC@ANS-200 bigger than the size of BPA and diuron molecule) and surface functional groups. BPA and diuron adsorption occurred also via multiple adsorption mechanisms, including pore filling, π–π interactions, and hydrogen bonding interactions on HTC@ANS-200.

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Hydrothermal Carbonization of Argan Nut Shell: Functional Mesoporous Carbon with Excellent Performance in the Adsorption of Bisphenol A and Diuron

Facile synthesis of Silver@Eggshell nanocomposite: A heterogeneous catalyst for the removal of heavy metal ions, toxic dyes and microbial contaminants from water.

Apatitic tricalcium phosphate powder: High sorption capacity of hexavalent chromium removal

Stoichiometric hydroxyapatite (Ca10(PO)6(OH)2, HAP) foams have been produced. The porous parts were prepared from a calcined HAP powder and egg white as a bio and non-toxic pore promoter. The colloidal slurry was prepared, poured into cylindrical molds, dried, unmolded, and sintered at 1200 °C. The effects of the concentration of the solid loading, of the dispersing agent, and the foaming agent on the ceramic preparation were examined. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) were used to evaluate the composition and the structure of the sintered HAP ceramics. Scanning electron microscopy (SEM) was used for microstructural analysis. The XRD analysis of the porous parts, prepared under optimized conditions, showed the presence of crystallized HAP (JCPDS 9-432) as a single phase. SEM images showed existence of open and interconnected micro and macropores in the ceramics. The use of the egg white protein as pore former provides a total porosity of 86 vol% and a foam-structure that allows to a microporous wall.

/pdf/porous-foams-based-hydroxyapatite-prepared-by-direct-foaming-3ml5msji4q.pdf

Porous foams based hydroxyapatite prepared by direct foaming method using egg white as a pore promoter

Preparation of biphasic hydroxyapatite/ β-tricalcium phosphate foam using the replication technique

In recent years, the development of calcium phosphate/clay composites for bone tissue engineering attracted a lot of interest. In this study, novel bio-composites composed of hydroxyapatite (HAP), α and β-tricalcium phosphate (α, β-TCP) and sodium-montmorillonite (MNa) were developed. The composites were prepared by sintering at 900 °C of calcium-apatite powders in the presence of various amounts of MNa. The calcium-apatite precursors were prepared by the wet precipitation method with two desired Ca/P molar ratios (1.660 and 1.623). Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were used to characterize the prepared composites. The results showed that during the sintering process, a surface interaction apatite/MNa led to the incorporation of clay ions into the apatite structure resulting in its decomposition and formation of composite ceramics comprising HAP, β and α-TCP. The decomposition of apatite increased with increasing MNa content and with decreasing Ca/P ratio. The decomposition of stoichiometric HAP led to triphasic ceramics with substituted-HAP as the major phase while the decomposition of calcium-deficient HAP led to triphasic ceramics with substituted-α-TCP as the major phase. Combination of MNa–clay phase and substituted-α-TCP can improve both mechanical and biological properties of the prepared composites.

Development of Triphasic Hydroxyapatite/(α and β)-Tricalcium Phosphate Based Composites by Sintering Powder of Calcium-Apatite in the Presence of Montmorillonite

Abdelaziz Elouahli

Papers

Apatitic tricalcium phosphate powder: High sorption capacity of hexavalent chromium removal

Porous foams based hydroxyapatite prepared by direct foaming method using egg white as a pore promoter

Preparation of biphasic hydroxyapatite/ β-tricalcium phosphate foam using the replication technique

Development of Triphasic Hydroxyapatite/(α and β)-Tricalcium Phosphate Based Composites by Sintering Powder of Calcium-Apatite in the Presence of Montmorillonite

Characterization of β-tricalcium phosphate-clay mineral composite obtained by sintering powder of apatitic calcium phosphate and montmorillonite