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

Abstract

The sorption ability of biogenic hydroxyapatite (BHAP) towards heavy metal ions (Pb, Cu, Ni, Cd, and Zn) is compared with functionalized BHAP powders with caffeic acid (CA) and 3,4dihydroxybenzoic acid (3,4-DHBA). The functionalization of the BHAP with either CA or 3,4-DHBA is indicated by the appearance of the colored powders due to the formation of the interfacial charge transfer (ICT) complexes. The detailed characterization of as-prepared and functionalized BHAP samples was performed using transmission electron microscopy, reflection spectroscopy, thermogravimetric analysis and determination of zeta potential. All three sorbents clearly displayed preferential sorption of Pb ions when the total concentration of multicomponent equimolar solutions of heavy metal ions is high. It should be emphasized that the sorption capacity of functionalized BHAP with either CA or 3,4-BHAP was found to be higher, up to 60%, compared to as-prepared BHAP without the decrease of selectivity towards Pb ions.

Removal of Ni2+ and Zn2+ from groundwater by adsorption onto fishbone and hydroxyapatite: Effect of salinity

“…16 The use of HAP has been reported to be successful for removing Zn 2+ from aqueous solutions, 17 whereas biogenic HAP could selectively remove Pb 2+ from a mixed solution of Cu 2+ , Ni 2 + , Cd 2+ , and Zn 2+ . 18 Nag et al 19 also reported that a natural hydroxyapatite obtained from fishbone (FB-HAP) effectively removed Zn 2+ up to 62.67% at the water-to-solid ratio (W/S) of 1.0 mL g -1 . Nanosized HAP also effectively removed Pb 2+ , 20 Cu 2+ , 21 Cd 2+ , 22 Fe 2+ , and Mn 2+ .…”

Removal of Ni (II) By Sol-Gel Silica Functionalized With Efficient Metal Chelating Agents

“…They show good mechanical stability and fast equilibration in metal sorption. E cient chelating agents and their metal complexes have been selected due to their analytical, industrial, biological, catalytic and other applications [29][30][31][32][33]. The synthesized materials can be utilized in biomedical and catalysis.…”