Understanding the factors affecting the adsorption of Lanthanum using different adsorbents: A critical review

Bark from trees is considered a worthless raw material. However, this resource could be economically beneficial if utilized efficiently due to its rich chemical compounds. In this study, an ethanol toluene-soluble extractive, alpha-cellulose and lignin obtained from Leucaena leucocephala bark were characterized to determine their chemical functional groups. Based on FTIR spectral analysis, the results indicated that the bands of the functional groups of the extractive from the original bark remain unchanged; however, the absorbance intensity was found to be weaker in the group frequency and fingerprint regions. Removal of extractive, pectin, hemicellulose and lignin from the bark indirectly increased the strong absorbance intensity of cellulose. Broad peaks of OH stretching found in all spectra were assigned to the presence of phenolic OH and aliphatic structures for extractive and aromatic structures of lignin. It was revealed that aromatic functional groups were mainly found in the extractive, while water, carbonyl and ether were the dominant groups in cellulose, and methyl, methylene, carbonyl and carboxyl groups were enriched in lignin.

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Chemical functional groups of extractives, cellulose and lignin extracted from native Leucaena leucocephala bark

An overview on membrane strategies for rare earths extraction and separation

Biosorption-a green method for the preconcentration of rare earth elements (REEs) from waste solutions: A review

Role of Cu element in biomedical metal alloy design

Transition metal-catalyzed chemical transformation of organic electrophiles and organometallic reagents belong to the most important cross coupling reaction in organic synthesis. The biaryl ether division is not only popular in natural products and synthetic pharmaceuticals but also widely found in many pesticides, polymers, and ligands. Copper catalyst has received great attention owing to the low toxicity and low cost. However, traditional Ullmann-type couplings suffer from limited substrate scopes and harsh reaction conditions. The introduction of homogeneous copper catalyst with presence of bidentate ligands over the past two decades has totally changed this situation as these ligands enable the reaction promoted in mild condition. The reaction scope has also been greatly expanded, rendering this copper-based cross-coupling attractive for both academia and industry. In this review, we will highlight the latest progress in the development of useful homogeneous copper catalyst with presence of ligand and heterogeneous copper catalyst in Ullmann type C-O cross-coupling reaction. Additionally, the application of Ullmann type C-O cross coupling reaction will be discussed.

Recent Advancement of Ullmann Condensation Coupling Reaction in the Formation of Aryl-Oxygen (C-O) Bonding by Copper-Mediated Catalyst

Machine learning simulation of pharmaceutical solubility in supercritical carbon dioxide: Prediction and experimental validation for busulfan drug

Industrial operations, domestic and agricultural activities worldwide have had major problems with various contaminants caused by environmental pollution. Heavy metal pollution in wastewater also a prominent issue; therefore, a well built and economical treatment technology is demanded for pollution-free wastewater. The present work emphasized pure cellulose extracted from jute fiber and further modification was performed by a free radical grafting reaction, which resulted in poly(methyl acrylate) (PMA)-grafted cellulose and poly(acrylonitrile)-grafted cellulose. Subsequently, poly(hydroxamic acid) and poly(amidoxime) ligands were prepared from the PMA-grafted cellulose and PAN-grafted cellulose, respectively. An adsorption study was performed using the desired ligands with heavy metals such as copper, cobalt, chromium and nickel ions. The binding capacity (qe) with copper ions for poly(hydroxamic acid) is 352 mg g−1 whereas qe for poly(amidoxime) ligand it was exhibited as 310 mg g−1. Other metal ions (chromium, cobalt and nickel) show significance binding properties at pH 6. The Langmuir and Freundlich isotherm study was also performed. The Freundlich isotherm model showed good correlation coefficients for all metal ions, indicating that multiple-layers adsorption was occurred by the polymer ligands. The reusability was evaluated and the adsorbents can be reused for 7 cycles without significant loss of removal performance. Both ligands showed outstanding metals removal capacity from the industrial wastewater as such 98% of copper can be removed from electroplating wastewater and other metals (cobalt, chromium, nickel and lead) can also be removed up to 90%.

https://www.mdpi.com/2073-4360/12/11/2521/pdf

Polymer Ligands Derived from Jute Fiber for Heavy Metal Removal from Electroplating Wastewater.

In this study, a copolymer sawdust-graft-poly(acrylonitrile) was synthesized by free-radical initiation reaction and followed by amidoximation reaction with hydroxylamine under alkaline conditions converted into the poly(amidoxime) ligand. The functional group, compositions, and morphology of the resulting synthesized ligand and copolymer were identified by Fourier transform infrared spectroscopy, scanning electron microscopy and elemental analysis. The poly(amidoxime) ligand was utilized for heavy metal removal from aqueous solution. The synthesized polymeric ligand demonstrated a high affinity for adsorption capacity for copper and iron was 265.5 and 270.1 mg g-1, respectively. The strong adsorption capacity for lead, zinc, and cobalt were 121.2, 161.7 and 165.4 mg g-1, respectively. The adsorption data was excellently expressed by the Langmuir isotherm model (R2 >0.98) rather than Freundlich. It is suggesting that the surface of ligand is monolayer and homogeneous. The kinetic data have been determined by the first and second order. However, pseudo-second-order rate equation was well fit to the presented data. In wastewater purification process, poly(amidoxime) ligand was well removal multiple metal ions that present in the wastewater and the efficiency of removal was reached to 98.78% for copper and 99.14% iron and 90.92% for lead and 92.73% for zinc.

Synthesis of sawdust-based poly(amidoxime) ligand for heavy metals removal from wastewater

Heavy metals pollutants are nonbiodegradable and their bioaccumulation results in detrimental environmental consequences. Therefore, it is important to effectively remove toxic heavy metal waste from industrial sewage. Thus, the main goal of this research is to synthesize an ideal cellulose‐based adsorbent from palm‐based waste materials (agro waste) in order to be utilized in real‐life practical applications with low cost as such removing common toxic heavy metals from industrial effluents. A poly(methyl acrylate) grafted palm cellulose was synthesized via a free‐radical initiation process, followed by an oximation reaction to yield poly(hydroxamic acid) ligands. The adsorption capacity (qe) of poly(hydroxamic acid) ligands for metal ions such as copper (Cu2+), iron (Fe3+), and lead (Pb2+) were 325, 220, and 300 mg g−1, respectively at pH 6. In addition, the X‐ray photoelectron spectrometry results are to be proved the binding of metal ions, for instance, Cu(II) ions showed typically significant BEs of 932.7 and 952.0 eV corresponding to the Cu2p3/2 and Cu2p1/2 species. The heavy metal ions adsorption followed a pseudo‐first‐order kinetic model pathway. The adsorption capacity (qm) is also derived from the Langmuir isotherm linear plot, which does not showed good correction coefficients. However, the results were correlated to the Freundlich isotherm model, where the R2 value showed significance (>0.98), indicating that multiple layer adsorption occurs on the synthesized ligand. The synthesized polymeric ligand is an excellent adsorbent for the removal of heavy metals from the industrial wastewater. In addition, the metal analysis results showed that about 98% removal of copper and iron ions from electroplating wastewater including lead, nickel, and chromium can be removed up to 85–97%.

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Mohd Sani Sarjadi

Papers

Recent Advancement of Ullmann Condensation Coupling Reaction in the Formation of Aryl-Oxygen (C-O) Bonding by Copper-Mediated Catalyst

Machine learning simulation of pharmaceutical solubility in supercritical carbon dioxide: Prediction and experimental validation for busulfan drug

Polymer Ligands Derived from Jute Fiber for Heavy Metal Removal from Electroplating Wastewater.

Synthesis of sawdust-based poly(amidoxime) ligand for heavy metals removal from wastewater

Poly(hydroxamic acid) ligand from palm‐based waste materials for removal of heavy metals from electroplating wastewater