Predicting heavy metals' adsorption edges and adsorption isotherms on MnO2 with the parameters determined from Langmuir kinetics

“…After processing the adsorption data, it was found that MPS adsorption to the drugs belonged to the single‐molecule layer adsorption, which conformed to the Langmuir adsorption model [33,34]. The formula is as follows:

\frac{C_{e}}{q_{e}} = \frac{1}{q_{0} b} + \frac{C_{e}}{q_{0}}

where q e (mmol/g) and q 0 (mmol/g) are the equilibrium and maximum adsorption capacity, C e (mmol/L) is equilibrium adsorption concentration, and b (L/mmol) is the adsorption equilibrium constant, which is equivalent to the selectivity coefficient of adsorption equilibrium, reflecting the intensity of the interaction between MPS and the drug.…”

Section: Resultsmentioning

confidence: 89%

Preparation of highly responsive monodisperse magnetic porous silica microspheres for the enrichment of cephalosporins in wastewater

Ruiting

Chang

Chen

2020

J of Separation Science

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Highly responsive monodisperse microsized magnetic silica microspheres were synthesized through the electrostatic self-assembly method. Monodisperse composite silica microspheres were prepared by depositing tetraethyl orthosilicate prepolymer on the glycidyl methacrylate-co-ethylene glycol dimethacrylate microspheres. After calcination, the organic moiety was removed and macroporous microspheres were left on the silica particles. To increase the selectivity, magnetic porous silica was bonded with different alkyl functional groups. The morphology, particle size distribution, magnetic properties, and functional groups of magnetic porous silica microspheres were characterized by scanning electron microscopy, coulter counter, vibrating sample magnetometry, X-ray diffraction, and elemental analysis, respectively. Extraction parameters, including pH, the salt concentration of the adsorbed solution, adsorption time, elution solvent, and time, were systematically investigated. The developed magnetic solid-phase extraction method, combined with high-performance liquid chromatography, presented reasonable linearity (0.5-10 µg/mL), low limit of detection (45.0-108.0 ng/mL), and high selectivity for cefadroxil, cefquinome, and cefradine. It was operated in three kinds of cephalosporins detection from wastewater with the relative recovery rates in the range of 86.5-97.0%. These results indicated that the synthesized magnetic microsphere is a promising adsorbent for the enrichment of cephalosporins.

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“…The adsorption capability of roxarsone and As(V) increased from 10% to 78% and from 10% to 65% as the pH rose from 3.0 to 9.0, respectively (Figure S9). The zeta potential of MnO 2 decreased from near zero (the pH zpc of MnO 2 ∼ 3.0) to −30 mV with increasing pH from 3.0 to 9.0; thus, the MnO 2 that formed in the process can be destabilized under acidic conditions, resulting in poor adsorption.…”

Section: Results and Discussionmentioning

confidence: 98%

Complete Removal of Organoarsenic by the UV/Permanganate Process via HO^• Oxidation and in Situ-Formed Manganese Dioxide Adsorption

et al. 2021

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The UV/permanganate process is an innovative advanced oxidation process (AOP) that generates oxidative species, such as hydroxyl radicals (HO • ) and reactive manganese species (RMnS), and adsorptive species of in situ formed MnO 2 . The cooperation of oxidation and adsorption has the potential to remove organic metals from water. Herein, the removal of organoarsenic compounds of roxarsone and p-arsanilic acid by UV/permanganate was investigated. The pseudo-first-order reaction rate (k ox ′) of roxarsone was 0.0375 min −1 at a permanganate dose of 100 μM and pH 7.0 in the UV/ permanganate process, which was mainly attributable to HO • . The transformation of roxarsone was initiated with a HO • attack on the C−As bond, releasing As(V), which was then removed from the aqueous phase by MnO 2 adsorption. Additionally, hydroxylated products were generated by HO • oxidation and subsequently oxidized into nitro-1,4-benzoquinone and ring cleavage products. Under neutral conditions, the removal rate of total arsenic reached 73% at 20 min, 50% of roxarsone was transferred to As(V) via oxidation, and the in situ formed MnO 2 could remove 78% of the remaining roxarsone and 70% of As(V) via adsorption. With an increase in the pH from 3.0 to 9.0, the k ox ′ of oxidation decreased by 68%, whereas the removal rate of total arsenic increased from just 20% to 73%. This is the first study to use the UV/permanganate process to completely remove organic heavy metals with the combination of oxidative and adsorptive species, which demonstrates that this process is promising in water treatment.

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Predicting heavy metals' adsorption edges and adsorption isotherms on MnO2 with the parameters determined from Langmuir kinetics

Cited by 22 publications

References 30 publications

Adsorptive removal of antibiotics from water using peanut shells from agricultural waste

Adsorptive removal of antibiotics from water using peanut shells from agricultural waste

Preparation of highly responsive monodisperse magnetic porous silica microspheres for the enrichment of cephalosporins in wastewater

Complete Removal of Organoarsenic by the UV/Permanganate Process via HO^• Oxidation and in Situ-Formed Manganese Dioxide Adsorption

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Predicting heavy metals' adsorption edges and adsorption isotherms on MnO2 with the parameters determined from Langmuir kinetics

Cited by 22 publications

References 30 publications

Adsorptive removal of antibiotics from water using peanut shells from agricultural waste

Adsorptive removal of antibiotics from water using peanut shells from agricultural waste

Preparation of highly responsive monodisperse magnetic porous silica microspheres for the enrichment of cephalosporins in wastewater

Complete Removal of Organoarsenic by the UV/Permanganate Process via HO• Oxidation and in Situ-Formed Manganese Dioxide Adsorption

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Complete Removal of Organoarsenic by the UV/Permanganate Process via HO^• Oxidation and in Situ-Formed Manganese Dioxide Adsorption