Biopolymer-Based Nanohydroxyapatite Composites for the Removal of Fluoride, Lead, Cadmium, and Arsenic from Water

Abstract

In this study, hydroxyapatite (HAP) nanocomposites were prepared with chitosan (HAP-CTS), carboxymethyl cellulose (HAP-CMC), alginate (HAP-ALG), and gelatin (HAP-GEL) using a simple wet chemical in situ precipitation method. The synthesized materials were characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, Brunauer−Emmett−Teller surface area analysis, and thermogravimetric analysis. This revealed the successful synthesis of composites with varied morphologies. The adsorption abilities of the materials toward Pb(II), Cd(II), F − , and As(V) were explored, and HAP-CTS was found to have versatile adsorption properties for all of the ions, across a wide range of concentrations and pH values, and in the presence of common ions found in groundwater. Additionally, X-ray photoelectron spectroscopy and energydispersive X-ray spectroscopy confirmed the affinity of HAP-CTS toward multi-ion mixture containing all four ions. HAP-CTS was hence engineered into a more user-friendly form, which can be used to form filters through its combination with cotton and granular activated carbon. A gravity filtration study indicates that the powder form of HAP-CTS is the best sorbent, with the highest breakthrough capacity of 3000, 3000, 2600, and 2000 mL/g for Pb(II), Cd(II), As(V), and F − , respectively. Hence, we propose that HAP-CTS could be a versatile sorbent material for use in water purification.

Structure–Activity Relationship of Lanthanide-Incorporated Nano-Hydroxyapatite for the Adsorption of Fluoride and Lead

“…The Ca/P ratios of neat HC, Pb-Ad-HC, and F-Ad-HC were estimated considering the intensities of photoelectron peaks of Ca 2p and P 2p peaks at binding energies of 347 and 133 eV, respectively. In the estimation process, photoelectron intensities were normalized by the corresponding values of photoabsorption cross sections and inelastic mean free path as given in eq . − The composition ratios were estimated to be 1.8, 1.7, and 1.8 in the cases of neat HC, Pb-Ad-HC, and F-Ad-HC, respectively. The value of 1.8 is consistent with the reported value of the Ca/P ratio of HAP, and it confirms the successful incorporation of HAP with CeO 2 in the in situ preparation without impairing the original composition of HAP .…”

Novel Acumens into Biodegradation: Impact of Nanomaterials and Their Contribution

“…In this context, combining the concept of biodegradation with nanotechnology could be identified as a more systemic and innovative approach to address the current issues with the biodegradation process [13]. Nanotechnology is an evolving branch of science that has diversified its application in many disciplines such as agriculture [14], healthcare [15], transportation [16], electronics [17], Novel Acumens into Biodegradation: Impact of Nanomaterials and Their Contribution DOI: http://dx.doi.org/10.5772/intechopen.98771 food [18], water purification [19][20][21][22][23][24][25], and security [26]. Nanotechnology involves manipulating matter in 1-100 nm nanoscale to create materials where at least one of the dimensions of the particles in the nano range [27].…”

Nanotechnological approaches as a promising way for heavy metal mitigation in an aqueous system

“…HAP's great specificity is further shown when it's used as an adsorbent. Fernando et al [128] used a simple wet chemical in situ precipitation approach to make HAP nanocomposites with CS (HAP-CTS), alginate (HAP-ALG), carboxymethyl cellulose (HAP-CMC), and gelatin (HAP-GEL). The powder form of HAP-CTS is the best sorbent, according to gravity filtration research, with breakthrough capacities of 3000, 3000, 2600, and 2000 ml g −1 for Pb (II), Cd (II), As (V), and F -, respectively.…”