Adsorption studies for removal of trace copper metal ions from aqueous samples using magnetic nanoparticles

Fe3O4 magnetic nanoparticles (MNPs) synthesized in-housed using co-precipitation method was assessed for the treatment of synthetic aqueous solutions contaminated by Cu(II) ions. Experimental results showed that at 25ºC, the optimum value for Cu(II) removal was pH 6.0 and an adsorbent dose of 60.0 mg. The adsorption capacity of Fe3O4 nanoparticles for Cu(II) is 16.28 mg g-1. Adsorption kinetic rates were found to be fast; total equilibrium was achieved after 180 min. Kinetic experimental data fitted very well the pseudo-second order equation and the value of adsorption rate constants was calculated to be 0.0006 and 0.0013 g mg-1 min at 5 and 40 mg L-1 initial Cu(II) concentrations, respectively. The equilibrium isotherms were evaluated in terms of maximum adsorption capacity and adsorption affinity by the application of Langmuir and Freundlich equations. Results indicate that the Langmuir model fits adsorption isotherm data better than the Freundlich model

New application of magnetic nanoparticles for adsorption of nickel(II) metal ions from aqueous solution by batch method

Ni(II) is toxic for living organism at trace levels. Currently the Environmental Protection Agency (EPA) standard for Ni(II) in drinking water is 0.04 mg/L [1]. The adsorption of metal ions using magnetic nanoparticles is preferred due to their lower costs, have high adsorption capacities, durability and high efficiency, especially for metal ions with trace and ultra-trace concentration level [2]. In this study, an in-house synthesized Fe3O4 MNPs adsorbent was evaluated for its feasibility in the adsorption of Ni(II) metal ions from aqueous solutions. Adsorption experiments were investigated by kinetic and isotherm adsorption models

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Novel synthesis and characterization of magnesium-doped CoFe2O4 nanoparticles –SiO2 –3-aminopropylethoxysilane– gallic acid magnetic nanocomposite for effective removal of cationic dyes

Magnesium-doped CoFe2O4 nanoparticles (MgCF)@SiO2-NH-COOH were prepared through a step-wise procedure for the removal of two cationic dyes from real wastewater. MgCF was successfully synthesized through the co-precipitation technique. Subsequently, these nanoparticles were coated within a silica (SiO2) shell and functionalized with amino groups utilizing 3-Aminopropylethoxysilane (APTES). To assess its adsorption capabilities, the nanocomposite underwent further modification with Gallic acid (GA). MgCF@SiO2-NH-COOH has a well-developed pore structure with a BET surface area of 31.655m2/g, which also has a crystalline structure. Adsorption tests revealed the excellent performance of MgCF@SiO2-NH-COOH in removing Methylene Blue (MB) and Rhodamine B (RhB) dyes. Kinetic studies demonstrated that the adsorption of MB and RhB followed the Boyd kinetic model. The Langmuir isotherm model provided the best fit for the experimental data, with a maximum adsorption capacity of 103 mg/g and 89 mg/g for MB and RhB, respectively. Moreover, recycling tests established the high stability and reusability of MgCF-SiO2-APTES-GA nanocomposites, with consistent adsorption performance over at least five cycles. At the first stage, the adsorption was 98.6 % for MB and 95.3 % for RhB, and after five regenerations, the adsorption was 82.5 % for MB and 79.6 % for RhB. This research offers a cost-effective compound that addresses pressing environmental concerns related to the removal of organic dyes from wastewater

Adsorption studies of nickel(II) metal ions uptake using Fe3O4 magnetic nanoadsorbent

In the present study, Fe3O4 magnetic nanoparticles (MNPs) synthesized in-housed using co-precipitation method was applied for the treatment of aqueous solutions contaminated by Ni(II) ions. Experimental results indicated that at 25ºC, the optimum pH value for Ni(II) removal was pH 6.0 and an adsorbent dose of 60.0 mg. The adsorption capacity of Fe3O4 nanoparticles for Ni(II) is 20.54 mg g−1. Adsorption kinetic rates were found to be fast; total equilibrium was achieved after 180 min. Kinetic experimental data fitted very well the pseudo-second order equation and the value of adsorption rate constants was calculated to be 0.004 and 0.0008 g mg−1 min at 5 and 40 mg L−1 initial Ni(II) concentrations, respectively. The equilibrium isotherms were evaluated in terms of maximum adsorption capacity and adsorption affinity by the application of Langmuir and Freundlich equations. The maximum monolayer capacity obtained from the Langmuir isotherm was 24.57 mg g−1 for Ni(II). Results indicate that the Langmuir model fits adsorption isotherm data better than the Freundlich mode

New chrysin-functionalized silica-core shell magnetic nanoparticles for the magnetic solid phase extraction of copper ions from water samples

This study describes the synthesis, characterization and application of a new chrysin-based silica core-shell magnetic nanoparticles (Fe3O4@SiO2-N-chrysin) as an adsorbent for the preconcentration of Cu(II) from aqueous environment. The morphology, thermal stability and magnetic property of Fe3O4@SiO2-N-chrysin were analyzed using FTIR, FESEM, TEM, XRD, thermal analysis and VSM. The extraction efficiency of Fe3O4@SiO2-N-chrysin was analyzed using the batch wise method with flame atomic absorption spectrometry. Parameters such as the pH, the sample volume, the adsorption-desorption time, the concentration of the desorption solvent, the desorption volume, the interference effects and the regeneration of the adsorbent were optimized. It was determined that Cu(II) adsorption is highly pH-dependent, and a high recovery (98%) was achieved at a pH 6. The limit of detection (S/N=3), the limit of quantification (S/N=10), the preconcentration factor and the relative standard deviation for Cu(II) extraction were 0.3 ng mL-1, 1 ng mL-1, 100 and 1.9% (concentration=30 ng mL-1, n=7), respectively. Excellent relative recoveries of 97-104% (%RSD<3.12) were achieved from samples from a spiked river, a lake and tap water. The MSPE method was also validated using certified reference materials SLRS-5 with good recovery (92.53%)

Application of solid-phase extraction for trace elements in environmental and biological samples: a review

The progress of novel sorbents and their function in preconcentration techniques for determination of trace elements is a topic of great importance. This review discusses numerous analytical approaches including the preparation and practice of unique modification of solid-phase materials. The performance and main features of ion-imprinting polymers, carbon nanotubes, biosorbents, and nanoparticles are described, covering the period 2007-2012. The perspective and future developments in the use of these materials are illustrated