Removal of cadmium from aqueous solutions using inorganic porous nanocomposites

Ianăși, Cătălin; Picioruş, Mirela; Nicola, Roxana; Ciopec, Mihaela; Negrea, Adina; Nižňanský, Daniel; Len, Adél; Almásy, László; Putz, Ana-Maria

doi:10.1007/s11814-019-0262-6

Cited by 24 publications

(14 citation statements)

References 56 publications

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“…Even in an acid solution with a relatively low initial pH of 2.5, the removal efficiency still reached up to 99.67%. The obtained result was inconsistent with most of the previous research, which had indicated that initial solution pH significantly affected removal efficiency of heavy metals [ 36 ].…”

Section: Resultscontrasting

confidence: 91%

Highly Efficient Cd2+ Removal Using Tobermorite with pH Self-Adjustment Ability from Aqueous Solution

et al. 2023

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Cadmium (Cd), as a type of heavy metal, can increase the incidence of many diseases, even in low concentrations. In this study, tobermorite was hydrothermally synthesized and then applied to adsorb Cd2+ from an aqueous solution. The physicochemical characteristics of the synthesized tobermorite were detected, and the results indicated that the well-crystallized tobermorite had a lot of mesopores and a large specific surface area of 140.92 m2/g. It acquired a pH self-adjustment ability via spontaneously releasing Ca2+ and OH- into the aqueous solution. The effects of different factors on Cd2+ removal were investigated. For Cd2+, the removal efficiency could reach 99.71% and the maximum adsorption capacity was 39.18 mg/g using tobermorite. The adsorption data was best fitted with the pseudo-second-order kinetic and Langmuir isotherm models. In addition, there was no strict limit on the solution pH in Cd2+ adsorption because the tobermorite could adjust the solution pH to an alkaline atmosphere spontaneously. The efficient removal of Cd2+ using tobermorite was a result of surface complexation and ion exchange.

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Section: Resultscontrasting

confidence: 91%

Highly Efficient Cd2+ Removal Using Tobermorite with pH Self-Adjustment Ability from Aqueous Solution

et al. 2023

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“…Peaks observed at 38, 53 and 70 degrees are specific for NaF phase (reference code 00-001-1184). Peaks located at 32, 38, 45, 52, 63 are specific to the maghemite phase [ 39 ]. From comparisons with the literature [ 39 ], it can be observed that the specific peaks for the maghemite are slightly shifted to smaller angles.…”

Section: Resultsmentioning

confidence: 99%

“…Peaks located at 32, 38, 45, 52, 63 are specific to the maghemite phase [ 39 ]. From comparisons with the literature [ 39 ], it can be observed that the specific peaks for the maghemite are slightly shifted to smaller angles. In order calculate the crystallite size was used the Scherrer equation, and for new synthesized SiO 2 /Fe(acac) 3 /NaF compound was founded that the mean crystallite size is 36 nm.…”

Section: Resultsmentioning

confidence: 99%

Silica- Iron Oxide Nanocomposite Enhanced with Porogen Agent Used for Arsenic Removal

et al. 2022

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This study aims to remove arsenic from an aqueous medium by adsorption on a nanocomposite material obtained by the sol–gel method starting from matrices of silica, iron oxide and NaF (SiO2/Fe(acac)3/NaF). Initially, the study focused on the synthesis and characterization of the material by physico–chemical methods such as: X-ray diffraction, FT-IR spectroscopy, Raman spectroscopy, atomic force microscopy, and magnetization. Textural properties were obtained using nitrogen adsorption/desorption measurements. The zero load point, pHpZc, was also determined by the method of bringing the studied system into equilibrium. In addition, this study also provides a comprehensive discussion of the mechanism of arsenic adsorption by conducting kinetic, thermodynamic and equilibrium studies. Studies have been performed to determine the effects of adsorbent dose, pH and initial concentration of arsenic solution, material/arsenic contact time and temperature on adsorption capacity and material efficiency. Three theoretical adsorption isotherms were used, namely Langmuir, Freundlich and Sips, to describe the experimental results. The Sips isotherm was found to best describe the experimental data obtained, the maximum adsorption capacity being ~575 µg As(III)/g. The adsorption process was best described by pseudo-second order kinetics. Studies have been performed at different pH values to establish not only the optimal pH at which the adsorption capacity is maximum, but also which is the predominantly adsorbed species. The effect of pH and desorption studies have shown that ion exchange and the physiosorption mechanism are implicated in the adsorption process. From a thermodynamic point of view, parameters such as ΔG°, ΔH° and ΔS° were evaluated to establish the mechanism of the adsorption process. Desorption studies have been performed to determine the efficiency of the material and it has been shown that the material can be used successfully to treat a real-world example of deep water with a high arsenic content.

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“…There are a number of applications in which nanocomposites based on iron and silica oxides can be used with great success, namely: in the remediation of the polluted environment by acting as adsorbents [ 10 , 11 ], or catalyzers [ 12 , 13 ], sensors [ 14 ] and especially in medical field [ 15 , 16 ].…”

Section: Introductionmentioning

confidence: 99%

Antimicrobial Perspectives of Active SiO2FexOy/ZnO Composites

et al. 2022

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The antibacterial activity of zinc oxide particles has received significant interest worldwide, especially through the implementation of technology to synthesize particles in the nanometer range. This study aimed to determine the antimicrobial efficacy of silica-based iron oxide matrix (SiO2FexOy) synthesized with various amounts of ZnO (SiO2FexOyZnO) against various pathogens. It is observed that, with the addition of ZnO to the system, the average size of the porosity of the material increases, showing increasingly effective antibacterial properties. Zinc-iron-silica oxide matrix composites were synthesized using the sol–gel method. The synthesized materials were investigated physicochemically to highlight their structural properties, through scanning electron microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), and Fourier-transform infrared spectroscopy (FT-IR). At the same time, surface area, pore size and total pore volume were determined for materials synthesized using the Brunauer–Emmett–Teller (BET) method. Although the material with 0.0001 g ZnO (600 m2/g) has the highest specific surface area, the best antimicrobial activity was obtained for the material with 1.0 g ZnO, when the average pore volume is the largest (~8 nm) for a specific surface of 306 m2/g. This indicates that the main role in the antibacterial effect has reactive oxygen species (ROS) generated by the ZnO that are located in the pores of the composite materials. The point of zero charge (pHpZc) is a very important parameter for the characterization of materials that indicate the acid-base behaviour. The pHpZc value varies between 4.9 and 6.3 and is influenced by the amount of ZnO with which the iron-silica oxide matrix is doped. From the antimicrobial studies carried out, it was found that for S. aureus the total antibacterial effect was obtained at the amount of 1.0 g ZnO. For Gram-negative bacteria, a total antibacterial effect was observed in S. flexneri (for the material with 0.1 g ZnO), followed by E. coli (for 1.0 g ZnO). For P. aeruginosa, the maximum inhibition rate obtained for the material with 1.0 g ZnO was approximately 49%.

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Removal of cadmium from aqueous solutions using inorganic porous nanocomposites

Cited by 24 publications

References 56 publications

Highly Efficient Cd2+ Removal Using Tobermorite with pH Self-Adjustment Ability from Aqueous Solution

Highly Efficient Cd2+ Removal Using Tobermorite with pH Self-Adjustment Ability from Aqueous Solution

Silica- Iron Oxide Nanocomposite Enhanced with Porogen Agent Used for Arsenic Removal

Antimicrobial Perspectives of Active SiO2FexOy/ZnO Composites

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