Hydroxyapatite-based sorbents: elaboration, characterization and application for the removal of catechol from the aqueous phase

Abstract

Hydroxyapatite (HAP) is highly considered as good sorbent for the removal of metals from the aqueous phase. However, soluble metals co-exist with organic pollutants in wastewaters. But little work has been devoted to investigate the reactivity of HAP for the removal of organic compounds. The main objective of this work is to study the reactivity of HAP-based sorbents for the removal of catechol as a model organic pollutant from an aqueous solution. Thus, HAP sorbents were firstly synthesized using calcium carbonate and potassium dihydrogen phosphate under moderate conditions (25-80°C, atmospheric pressure). A zinc-doped HAP was also used as sorbent, which was obtained from the contact of HAP with an aqueous solution of zinc nitrate. All the sorbents were characterized by different standard physico-chemical techniques. The sorption of catechol was carried out in a batch reactor under stirring at room temperature and pressure. Zinc-doped HAP sorbent was found to be more reactive than non-doped HAP sorbents for the fixation of catechol. The highest sorption capacity was of 15 mg of C per gram of zinc-doped HAP sorbent. The results obtained suggest the reaction scheme of HAP sorbents with metals and organic pollutants when HAP sorbents were used for the treatment of complex wastewaters.

Mechanically Reinforced Catechol-Containing Hydrogels with Improved Tissue Gluing Performance

“…We applied this strategy to PEG-Dop hydrogels by mixing biocompatible HAp nanoparticles [50]. According to literature reports, the Dop end-groups in the PEG chain are expected to coordinate with the ionic surface of the HAp nanoparticles and reinforce the network [51,52,53]. In fact, tensile tests of PEG-Dop (15%)/HAp (2.5%) mixtures showed a >6-fold increase in the Young’s modulus in comparison with the PEG-Dop hydrogel without added nanoparticles (Figure 2 and Table 1).…”

Preparation of Magnetic g-C3N4/Fe3O4 Composite and Its Application in the Separation of Catechol from Water

“…Thereinto, adsorption has become a widely used method for the treatment of catechol due to its simple operation, low cost, and high efficiency. Now, many materials are used as adsorbents to remove catechol from water such as activated carbon [12,13], dolomite [14], montmorillonite [15], hydroxyapatite [16], organophilic-bentonite [17], hematite [18], goethite [19], rutile TiO 2 [20], α-alumina [21], magnetic vermiculite [22], resin [23], and waste Fe(III)/Cr(III) hydroxide [24]. These aforementioned materials were modified to increase the pore structure, specific surface area, or special functional groups, thereby enhancing their adsorption effect.…”

Sorption of divalent heavy metal ions onto functionalized biogenic hydroxyapatite with caffeic acid and 3,4-dihydroxybenzoic acid

“…Recently, the reactivity of HAP-based sorbents for the removal of catechol as a model organic pollutant from an aqueous solution was found promising, with the highest sorption capacity of 15 mg of C per gram of zinc-doped HAP sorbent. [22] Functionalization of inorganic nanoparticles (mainly wide-band-gap oxides) with small organic molecules (catechol derivatives) so far has been used to prepare inorganic-organic-hybrids with improved optical properties due to the formation of the interfacial charge transfer (ICT)…”