Selective Chelating Resin for Copper Removal and Recovery in Aqueous Acidic Solution Generated from Synthetic Copper-Citrate Complexes from Bioleaching of E-waste

This research focused on batch experiment using a new generation of chelating resins via an ion exchange process to describe the metabolic adsorption and desorption capacity onto iminodiacetic acid/Chelex 100, bis-pyridylmethyl amine/Dowex m4195, and aminomethyl phosphonic/Lewatit TP260 functional groups in bioleaching. The results showed that Dowex m4195 had the highest performance of adsorption capacity for copper removal in both H+-form and Na+-form. Results for Lewatit TP260 and Chelex 100 revealed lower adsorption performance than results for Dowex m4195. The investigation of desorption from chelating resins was carried out, and it was found that 2 M ammonium hydroxide concentration provided the best desorption capacity of about 64.86% for the H+-form Dowex m4195 followed by 52.55% with 2 M sulfuric acid. Lewatit with 2 M hydrochloric acid gave the best desorption performance in Na+-form while Chelex 100 using hydrochloric at 1 M and 2 M provided similar results in terms of the H+-form and Na+-form. As aspects of the selective chelating resins for copper (II) ions in aqueous acidic solution generated from synthetic copper-citrate complexes from bioleaching of e-waste were considered, H+-form Dowex m4195 was a good performer in adsorption using ammonium hydroxide for the desorption. However, chelating resins used were subsequently reused for more than five cycles with an acidic and basic solution. It can be concluded from these results that selective chelating resins could be used as an alternative for the treatment of copper (II) ions contained in e-waste or application to other divalent metals in wastewater for sustainable water and adsorbent reuse as circular economy.

Fabrication of A novel polyvinylpyrrolidone/abeitic acid hydrogel by gamma irradiation for the recovery of Zn, Co, Mn and Ni from aqueous acidic solution

As heavy metals are a group of pollutants that originate from industrial and nuclear facilities has become of major concern in the aquatic environment due to their toxicity to all living organisms. In this context; this study was aimed to prepare sustainable and efficient hydrogel for the removal of heavy metals such as Co, Ni, Zn and Mn from aqueous acidic solution. The polyvinylpyrrolidone (PVP)/abietic acid (AA) hydrogel were prepared by gamma irradiation at 50 kGy. The characterization of PVP/AA hydrogel were investigated by water absorbancy, gel content, scanning electron microscopy, X-ray diffraction (XRD) and Fourier transform infrared (FTIR). The characterizations indicate that bio-sorbent composite hydrogel networks provide advantageous over conventional preparation techniques. PVP/AA hydrogel was implanted for batch process with studying the effect different parameters on the sorption of the investigated metal ions such as radiation dose; pH, contact time, metal ions, V/m and temperature. The results illustrate that the highest uptake% was obtained at radiation dose 30 kGy at optimum pH = 3. The maximum adsorption capacity of PVP-AA adsorbent was reached 32, 32.5,19 and 32.5 mg.g− 1 for Zn(II), Co(III), Ni (III) and Mn(II) ions respectively. The changes in the values of free energy (ΔG) and enthalpy (ΔH) confirm the spontaneous nature of the adsorption reaction with an endothermic process. The maximum desorption of the investigated metal ions was achieved with 1 M HNO3 of (97%, 98%, 70% and 60%) and takes the order: Co > Ni > Zn > Mn. The highest separation factor for Zn/Co = 26 and Zn/Ni = 8.6 at pH = 0.75.

Achieving highly efficient and selective cesium extraction using 1,3-di-octyloxycalix[4]arene-crown-6 in n-octanol based solvent system: experimental and DFT investigation

Separation scheme was developed for selective extraction of long-lived fission product 137Cs using substituted calix crown 6 ether from aqueous acidic solution.

Towards a theoretical understanding of alkaloid-extract Cytisine derivatives of Retama monosperma (L.) Boiss. Seeds, as eco-friendly inhibitor for carbon steel corrosion in acidic 1M HCl solution

Because of their availability, lower cost, biodegradability, respect for health, environmental standards and their extremely high efficiency [Benmessaoud Left D, Zertoubi M, Irhzo A, Azzi M, Revue: Huiles et extraits de plantes comme inhibiteurs de corrosion pour différents métaux et alliages dans le milieu acide chlorhydrique, J Mater Environ Sci 4:855–866, 2013], the green corrosion inhibitors are currently the most sought after candidates. The ultimate aim of this work is to study the selectivity and reactivity of a series of three molecules, namely Cytisine, Dehydro-Cytisine and N-methyl Cytisine which are the major constituents of Retama monosperma seeds alkaloid extract (AERS) as eco-friendly inhibitors of corrosion of carbon steel in acidic medium HCl (1M), using the density functional theory (DFT) at B3LYP/aug-cc-pvdz levels. Indeed, this alkaloid extract AERS has proven experimentally its corrosion inhibitory power for carbon steel in 1 M HCl even at lower concentration (94.42% at 400[Formula: see text]mg/L). Besides, its adsorption on the steel surface in 1 M HCl solution followed Langmuir’s isotherm [El Hamdani N, Fdil R, Tourabi M, Jama C, Bentiss F, Alkaloids extract of Retama monosperma (L.) Boiss. seeds used as novel eco-friendly inhibitor for carbon steel corrosion in 1 M HCl solution: Electrochemical and surface studies, Appl Surf Sci 357:1294–1305, 2015, doi: 10.1016/j.apsusc.2015.09.159; El Hamdani N, Contribution a la valorisation des parties aériennes de Retama Monosperma, phytochimie, activités antimicrobiennes et propriétés anticorrosives, Universite Chouaib Doukkali Faculte des sciences El jadida, 2015]. Herein, the major aim of this work is to investigate the likelihood of the carbon steel corrosion being inhibited by the protonated species in the aqueous acidic solution. For this purpose, after proving that the most favorable protonation site for protonation was N9, we have evaluated the structural, global and local reactivity descriptors, partial atomic charge in terms of Natural bond orbital (NBO) of the three protonated inhibitors at the level of N9, which are the most stable in the aqueous acidic solution. NBO analysis and the thermodynamic properties such as entropy, enthalpy, heat capacity and Gibbs free energy were also done. In conclusion, it was observed that three protonated molecules showed a high propensity to adsorb to the mild steel surface with a priority of the molecule d-CytN9H+.

Quaternary ammonium based task specific ionic liquid for the efficient and selective extraction of neptunium

Liquid–liquid extraction of neptunium from aqueous acidic solution using quaternary ammonium based task specific ionic liquid (TSIL) was investigated. The extraction of Np was predominated by the ‘cation exchange’ mechanism via [NpO