The effect of pH and ionic strength on the adsorption of glyphosate onto ferrihydrite

Pereira, Rodrigo C.; Anizelli, Pedro R.; Mauro, Eduardo Di; Valezi, Daniel F.; Costa, Antônio Carlos Saraiva da; Zaia, Cássia Thaïs Bussamra Vieira; Zaia, Dimas Augusto Morozin

doi:10.1186/s12932-019-0063-1

Cited by 84 publications

(44 citation statements)

References 59 publications

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“…The pH is one of the main parameters that control the removal of compounds present in aqueous solutions using solid adsorbents. According to several authors, pH can change the availability and characteristics of the pollutants in solution and it can modify the chemical state of the functional groups that are responsible for adsorption [47][48][49].…”

Section: Influence Of Ph and Contact Timementioning

confidence: 99%

Adsorptive Behavior of an Activated Carbon for Bisphenol A Removal in Single and Binary (Bisphenol A—Heavy Metal) Solutions

Martín-Lara

Calero

Ronda

et al. 2020

Water

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Bisphenol A (BPA) is an extensively produced and consumed chemical in the world. Due to its widespread use, contamination by this pollutant has increased in recent years, reaching a critical environmental point. This work investigates the feasibility of bisphenol A adsorption from industrial wastewater solutions, testing the reduction of bisphenol A in synthetic solutions by a commercial activated carbon, AC-40, in batch mode. Besides, mixtures of bisphenol A and different heavy metal cations were also studied. So far, no works have reported a complete study about bisphenol A removal by this activated carbon including the use of this material to remove BPA in the presence of metal cations. First, adsorption experiments were performed in batch changing pH, dose of adsorbent, initial bisphenol A concentration and contact time. Results showed greater retention of bisphenol A by increasing the acidity of the medium. Further, the percentage of bisphenol A adsorbed increased with increasing contact time. The selected conditions for the rest of the experiments were pH 5 and a contact time of 48 h. In addition, an increase in retention of bisphenol A when the dose of adsorbent increased was observed. Then, specific experiments were carried out to define the kinetics and the adsorption isotherm. Equilibrium data were adequately fitted to a Langmuir isotherm and the kinetics data fitted well to the pseudo-second-order model. The maximum adsorption capacity provided by Langmuir model was 94.34 mg/g. Finally, the effect of the presence of other heavy metals in water solution on the adsorption of bisphenol A was analyzed. Binary tests revealed competition between the adsorbates and a significant selectivity toward bisphenol A. Finally, the study of the adsorption performance in three consecutive adsorption–desorption cycles showed efficiencies higher than 90% in all cycles, indicating that the activated carbon has good reusability.

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Section: Influence Of Ph and Contact Timementioning

confidence: 99%

Adsorptive Behavior of an Activated Carbon for Bisphenol A Removal in Single and Binary (Bisphenol A—Heavy Metal) Solutions

Martín-Lara

Calero

Ronda

et al. 2020

Water

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“…2020, 4, x 6 of 12 carry an overall negative charge. The point of zero charge (pHpzc) of FHY is reported between 7.5 and 8.2 [44][45][46], and thus in our experiment, the synthesized FHY nanoparticles carry a positive charge. We postulate that ionic bonds between the carboxyl groups on the MWCNT and the hydroxyl groups on FHY underlie the attachment of FHY and MWCNT in the hybrid composites.…”

Section: Surface Area (Bet) and Specific Capacitance (Cv) Analysis Of The Fhy/mwcnt Compositesmentioning

confidence: 53%

Synthesis and Optimization of Multiwalled Carbon Nanotubes–Ferrihydrite Hybrid Composite

2020

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Carbon nanotubes (CNT) are a family of carbon nanomaterials that have uses in many technological and medical applications due to their unique properties. However, compared to other nanomaterials, CNT have a significantly lower specific surface areas (SSA), which is a critical limitation for applications. To overcome this limitation, here, we report a new protocol to synthesize a hybrid material composed of varying ratios of multiwalled carbon nanotubes (MWCNT) and ferrihydrite (FHY). Furthermore, through a series of physical and electrochemical characterization tests, we determined that 36% FHY and 64% MWCNT is the optimum ratio for a composite that maximizes both SSA and specific capacitance. The calculated SSA of the composite was 190 m2·g−1, 2.9 times higher than that of MWCNT alone. Moreover, the composite retained valuable electrochemical properties of CNT with an estimated specific capacitance of 100 F·g−1. This composite is a promising multifunctional nanomaterial for environmental and technological applications requiring electrochemical reactivity and high specific areas such as environmental biosensors, and capacitive deionization for wastewater remediation, and water softening.

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“…1). The surface area, pore volume and pore size for the ferrihydrite samples (Fh-6, Fh-SW, Fh-SW-NH 4 SCN-2) are close to the values obtained by other studies (Schultz et al ., 1987; Stanjek and Weidler, 1992; Cornell and Schwertmann, 2003; Pereira et al ., 2019). As the Fh-DW-NH 4 SCN-1 and Fh-DW-NH 4 SCN-2 samples presented much lower crystallinity than the Fh-SW-NH 4 SCN-1 sample (Fig.…”

Section: Resultsmentioning

confidence: 99%

Study of the formation of ferrihydrite under prebiotic chemistry conditions: artificial seawater 4.0 Gy and ammonium thiocyanate

Zaia

Coutinho

Mosca

et al. 2020

International Journal of Astrobiology

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Among the several steps involved in molecular evolution, molecular preconcentration is the first and most important. If the molecules are not preconcentrated the other steps of molecular evolution cannot occur. There are several ways to preconcentrate molecules: sorption, wetting/drying cycles, freezing/sublimation and sorption/precipitation with minerals. In the present work, the effect of NH4SCN and artificial seawater 4.0 Gy on the synthesis of ferrihydrite was studied. It should be noted that thiocyanate could play the same role as that of CN− in the Strecker reaction. Unlike today's seawater that has high Na+ and Cl− concentrations, the seawater used in this work has high Mg2+, Ca2+ and SO42− concentrations. Two results stand out, first SCN− and NH4+ were preconcentrated by sorption/precipitation in some syntheses and second, in some experiments, a mixture of goethite, hematite and magnetite was obtained. The sorption/precipitation of SCN− is always associated with the synthesis of goethite. This could be an indication that SCN− interacts with Fe3+ through the sulphur group of SCN−. In addition, the synthesis of magnetite could be an indication that the SCN− ion oxidized, forming thiocyanogen-(SCN)2 or trithiocyanate ion-(SCN)−3 and that Fe3+ reduced to Fe2+. Besides the sorption/precipitation of SCN− and NH4+, Fourier-transform infrared spectroscopy also showed that sorption/precipitation of SO42− and CO32− occurred. Ferrihydrite synthesized with artificial seawater presented the highest surface area and pore size. The pHpzc values of the samples were in the range of pHpzc described in the literature. The X-ray photoelectron spectroscopy (XPS) measurements performed show proportions of iron present in different oxidation states, however, the electronic similarities observed in the mixtures of iron oxides and oxy-hydroxides make it difficult to quantify them. Direct comparison between XPS spectra of the Fe2p and O 1s core-levels reveal no significant differences from the effect of artificial seawater 4.0 Gy on the synthesis of ferrihydrite.

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The effect of pH and ionic strength on the adsorption of glyphosate onto ferrihydrite

Cited by 84 publications

References 59 publications

Adsorptive Behavior of an Activated Carbon for Bisphenol A Removal in Single and Binary (Bisphenol A—Heavy Metal) Solutions

Adsorptive Behavior of an Activated Carbon for Bisphenol A Removal in Single and Binary (Bisphenol A—Heavy Metal) Solutions

Synthesis and Optimization of Multiwalled Carbon Nanotubes–Ferrihydrite Hybrid Composite

Study of the formation of ferrihydrite under prebiotic chemistry conditions: artificial seawater 4.0 Gy and ammonium thiocyanate

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