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This research investigates the adsorption potential of pine cone powder (PCP) for the removal of copper ions (Cu(ii)) from aqueous solutions. The process of adsorption was reasonably fast, completed within a time of 60 min. The pseudo-second order kinetic model describes properly the Cu(ii) adsorption by PCP. The adsorbent was characterised by various instrumental techniques and batch experiments were conducted to investigate the effect of PCP dose, solution pH, particle size and initial Cu(ii) concentration on adsorption efficiency. Optimum Cu(ii) removal occurred at a slightly acidic pH, with a particle size less than 100 pm. The effective PCP dose was estimated to be 36 g L1. The increase in the initial concentration of Cu (II) was accompanied by a reduction in the rate of its reduction by almost half. The Langmuir model was the best fitting isotherm with a maximum adsorption capacity of 9.08 mg g-. The thermodynamic parameters values showed that the Cu(ii) adsorption was a spontaneous and endothermic process. The results of this research suggest that Cu(ii) could be removed through an environmentally friendly process using PCP as low-cost natural waste. [ABSTRACT FROM AUTHOR]

TiO2 porous films were prepared on ITO coated glass slides by the sol-gel dip-coating method assisted with Polyethylene glycol (PEG). The films were used as photo-anodes in the photo-assisted electrolytic removal of cuprous ions in cyanide media. These were characterized by SEM, UV-Visible spectroscopy and XRD. The PEG modified films were free of cracks and developed a porous structure after heat treatment at 500 ºC, due to the thermal decomposition of the structure associated PEG. It was demonstrated that the photo-assisted electrochemical reduction of copper is promoted by the use of modified TiO2 films as photo-anodes, thanks to the greater surface area given by the PEG decomposition. However, the film thickness was found to be a critical factor in the process, to such an extent that films composed of 5 layers were completely inefficient, meaning that despite the open porosity, multilayered films acted as a barrier within the photo-electrolytic process.

Heavy metal copper (Cu2+) ions contamination through the discharge of industrial effluent has caused serious environmental issues globally. As a result, the removal of Cu2+ ions from water bodies are of prime importance for human health and environmental protection. In the present study, the adsorption behaviour of zirconium (Zr)-based metal organic framework (MOF-801) prepared by solvothermal method in the removal of copper ion (Cu2+) from aqueous solution was studied. The results obtained from the batch mode adsorption studies revealed that at an initial Cu2+ concentration of 10 ​mg/L, contact time of 180 ​min and adsorbent dosage of 10 ​mg, the removal efficiency and equilibrium adsorption capacity of Cu2+ from the process were 97.80% and 9.78 ​mg/g, respectively. The influence of MOF-801 on the adsorption of Cu2+ ions was studied by Langmuir and Freundlich adsorption isotherm models. The graph was found to fit well with the Freundlich isotherm, and the MOF-801's maximal multilayer adsorption capacity was determined to be 16.58 ​mg/g. A kinetic study showed that Cu2+ removal was carried out in 180 ​min with a behaviour of pseudo-second-order kinetic model and in general, the majority of metal adsorption occurred within the first 30 ​min. After four cycles of adsorption-regeneration, a reusability test using adsorbent revealed a decline in adsorption removal effectiveness of less than 11%. The MOF-801 was shown to be effective in the removal of Cu2+ from wastewater treatment. [Display omitted] • Zr-based MOFs was successfully synthesized by one-pot solvothermal method for removing copper ions. • Pseudo-second-order kinetic model suitably described the kinetics of Cu adsorption. • The equilibrium data were fitted well with the Freundlich isotherm model. • Adsorption mechanism of Cu2+ ions on the Zr-based MOFs were investigated. • Adsorption efficiency by the Zr-based MOFs reached 89% after four cycles. [ABSTRACT FROM AUTHOR]

Surface modification of Fe 3 O 4 nanoparticles was performed by immobilizing silica, metformine, and amine. Mixed matrix PES nanofiltration membrane was prepared by embedding various concentrations of the modified Fe 3 O 4 based nanoparticles. The membranes were characterized in terms of morphology and performance including investigation of SEM and AFM microphotographs, water contact angle, mean pore size and porosity measurements and determination of pure water flux as well as copper ion removal. Embedding iron oxide nanoparticles resulted in a significant rise in the pure water flux as a result of changes in the mean pore radius, porosity and hydrophilicity of the membranes. Moreover, the copper removal capability of prepared membranes remarkably increased because of improved hydrophilicity and also presence of nucleophilic functional groups on nanoparticles. The membrane fabricated with 0.1 wt.% metformine-modified silica coated Fe 3 O 4 nanoparticles showed the highest copper removal (about 92%) due to high affinity in copper adsorption. Moreover, acceptable reusability was found for the membrane with the best performance after several times of usage/regeneration cycles using EDTA as eluting agent. [ABSTRACT FROM AUTHOR]

Abstract: Amine-functionalized adsorbents have attracted increasing interest in recent years for heavy metal removal. In this study, diethylenetriamine (DETA) was successfully grafted (through a relatively simple solution reaction) onto poly(glycidyl methacrylate) (PGMA) microgranules to obtain an adsorbent (PGMA-DETA) with a very high content of amine groups and the PGMA-DETA adsorbent was examined for copper ion removal in a series of batch adsorption experiments. It was found that the PGMA-DETA adsorbent achieved excellent adsorption performance in copper ion removal and the adsorption was most effective at pH>3 in the pH range of 1–5 examined. X-ray photoelectron spectroscopy (XPS) revealed that there were different types of amine sites on the surfaces of the PGMA-DETA adsorbent but copper ion adsorption was mainly through forming surface complexes with the neutral amine groups on the adsorbent, resulting in better adsorption performance at a higher solution pH value. The adsorption isotherm data best obeyed the Langmuir–Freundlich model and the adsorption capacity reached 1.5 mmol/g in the case of pH 5 studied. The adsorption process was fast (with adsorption equilibrium time less than 1–4 h) and closely followed the pseudo-second-order kinetic model. Desorption of copper ions from the PGMA-DETA adsorbent was most effectively achieved in a 0.1 M dilute nitric acid solution, with 80% of the desorption being completed within the first 1 min. Consecutive adsorption–desorption experiments showed that the PGMA-DETA adsorbent can be reused almost without any loss in the adsorption capacity. [Copyright &y& Elsevier]

Polyelectrolyte membranes (PEMs) are a novel type of material that is in high demand in health, energy and environmental sectors. If environmentally benign materials are created with biodegradable ones, PEMs can evolve into practical technology. In this work, we have fabricated environmentally safe and economic PEMs based on sulfonate grafted sodium alginate (SA) and poly(vinyl alcohol) (PVA). In the first step, 2-acrylamido-2-methyl-1-propanesulphonic acid (AMPS) and sodium 4-vinylbenzene sulfonate (SVBS) are grafted on to SA by utilizing the simple free radical polymerization technique. Graft copolymers (SA-g-AMPS and SA-g-SVBS) were characterized by 1H NMR, FTIR, XRD and DSC. In the second step, sulfonated SA was successfully blended with PVA to fabricate PEMs for the in vitro controlled release of 5-fluorouracil (anti-cancer drug) at pH 1.2 and 7.4 and to remove copper (II) ions from aqueous media. Moreover, phosphomolybdic acids (PMAs) incorporated with composite PEMs were developed to evaluate fuel cell characteristics, i.e., ion exchange capacity, oxidative stability, proton conductivity and methanol permeability. Fabricated PEMs are characterized by the FTIR, ATR-FTIR, XRD, SEM and EDAX. PMA was incorporated. PEMs demonstrated maximum encapsulation efficiency of 5FU, i.e., 78 ± 2.3%, and released the drug maximum in pH 7.4 buffer. The maximum Cu(II) removal was observed at 188.91 and 181.22 mg.g–1. PMA incorporated with PEMs exhibited significant proton conductivity (59.23 and 45.66 mS/cm) and low methanol permeability (2.19 and 2.04 × 10−6 cm2/s). [ABSTRACT FROM AUTHOR]

Fe-based amorphous alloys have been proved to exhibit excellent degradation properties for the removal of copper ions from simulated wastewater. Compared with crystalline iron, amorphous alloy has higher removal efficiency, lower reaction activation energy and high corrosion current density owing to its unique surface mobility. The copper ion can be reduced to less than 0.5 or 1 ppm at different initial concentrations. Even at a lower concentration of copper ions, it also exhibits better performance. In comparison, the concentration of the copper ion would be higher than the prescribed discharge standard if the wastewater was treated by crystalline iron. This work provides a potential application of Fe - based amorphous in the removal of heavy metal ions from wastewater. • Fe-based amorphous alloys have excellent degradation properties for the removal of copper ions from wastewater. • The higher removal efficiency and lower reaction activation energy are because of the unique surface mobility. • The copper ion can be reduced to less than 0.5 or 1 ppm at different initial concentrations. [ABSTRACT FROM AUTHOR]