chromium and manganese in water samples via solid-phase extraction. This study revealed

Overview

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Key numbers

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• broad reflection in the 2θ-range of 20–30 originates from the glass substrate of the gold
• the 2θ-range2θ-range of 20–30° originates from the glass substrate of the gold
• studied in the pH range 3–9 starting with sorption time of 12 h. The amount of gold in the
• metal cations in the pH range 3–9. The results presented in Figure S5 show that quantitative
• approximately 65% and 10%, respectively. The remarcable decrease in Cr(III) and Mn(II)
• range of 3–9. It is seen that the degree of sorption of both Cr(VI) and Mn(VII) is negligible
• Figure 6. Degree of sorption (DS, %) of (a) Cr(III) in the presence of Cr(VI) and (b) Mn(II) in the
• Figure 6. Degree of sorption (DS , %) of (a) Cr(III) in the presence of Cr(VI) and (b) Mn(II) in the
• times was studied in the range 1–16toh.optimize
• 12 14 16at 18an initial concentration of 1 mg/L
• concentration of Cr(III) ions or Mn(II) ions (0.5–10 mg/L) on the sorption capacity of the
• increases reaching 75% when using
• nitric acid, with the maximum value reaching 75% when at room temperature, regardless
• where C0 (mg/L) is the initial concentration of sorbate in the liquid phase.
• The final calculated adsorption isotherm parameters are summarized in Table 1, with
• comparing the correlation coefficient (R2 ) values. As shown in Table 1, the Langmuir model
• Table 1. Langmuir, Freundlich, and DKR isotherm parameters obtained by linear fitting of
• within the range of 0 < RL < 1, indicating that the adsorption of Cr(III) and Mn(II) onto
• sponse (52), which contain three and four adjustable parameters, respectively. All models
• Table 2. Fitted kinetic parameters of the pseudo-first-order, pseudo-second-order, sigmoidal model
• separation of chromium and manganese species. As shown in Table S1, sorption onto the
• as the sample volume increases, the sorption efficiency decreases, dropping to 64% for
• Cr(III) and 57% for Mn(II) at a volume of 50 mL. To evaluate the membrane’s applicability
• The results showed recoveries of Cr(VI) ranging from 95% to 98%, confirming the mem-
• 95%, demonstrating the method’s suitability for simultaneous Cr and Mn speciation. Fur-
• Constituents. The results shown in Table 4 are in very good agreement with certified values,
• Table 4. Analysis of SLRS-6: River Water Certified Reference Material.
• Certified value, µg/L 0.252 ± 0.012 2.12 ± 0.10
• tap water from the drinking water treatment plant Bistritsa spiked with 0.5 µg/L Cr(VI) and
• 0.2 µg/L Mn(VII) and wastewater from the urban wastewater treatment plant Kubratovo
• spiked with 50 µg/L Cr(VI) and 100 µg/L Mn(VII), according to the developed analytical
• Cr(III) and Mn(II) varied in the range 3–9% and for Cr(VI) and Mn(VII) in the range 4–10%.
• Table 5. Analytical figures of merit.
• in Table 4, indicating very good membrane performance, most probably because for each
• Cr(VI) in surface waters with a total chromium content above 5 µg/L. The results obtained
• speciation procedures using different sorbent materials is presented in Table S2 (22,60–73).
• (37%, Merck, Darmstadt, Germany), absolute ethanol (EtOH, 99.8%, Sigma-Aldrich,
• on an Evolution 300 spectrometer (Thermo Scientific, Waltham, MA, USA) in the range
• concentrations of Cr(III) ions (from 0.5 to 10 mg/L) were added to one tested membrane
• AuNP hybrid hydrogel membrane in contact with 5 mL 1 mg/L Cr(III) or Mn(II) standard
• a temperature of 25 ± 1 ◦ C. The sorption time was varied in the range of 1–16 h and
• chromium concentration in the solution (Ci , mg/L) at t = 0 and the residual chromium

Methods (brief)

• chromium and manganese in water samples via solid-phase extraction. This study revealed
• chromium and manganese in drinking water and wastewater samples.
• of chromium and manganese in water samples using selective solid-phase extraction. The
• appearanceofofaasingle,
• synthesized starch-coated gold nanoparticles as a polycrystalline sample.
• as a polycrystalline sample.
• using scanning electron microscopy, a membrane sample
• electron microscopy, a membrane sample was immersed was immersed in a nitrogen
• brane’s volume. We believe that the observed folding is an artifact of the sample preparation
• artifact of the sample preparation and is not an inherent structural feature of the
• and Mn(II)/Mn(VII) in various water samples. Initially, experiments were conducted to
• determine the maximum sample volume that allows for the quantitative and selective
• nanocomposite membrane remains quantitative at a sample volume of 20 mL. However,
• as the sample volume increases, the sorption efficiency decreases, dropping to 64% for
• ples from the municipal water supply in Sofia and wastewater samples from the Kubratovo
• recovery (added/found) method. Water samples were spiked with Cr(III)/Cr(VI) and
• Sample Cr(III) Cr(VI) Mn (II) Mn(VII)
• Analytical figures of merit were defined after the analysis of five parallel samples of

Implications

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Wiki pages this source may touch

• Fish — marine, non-predatory (sardines, anchovies, salmon, cod)
• Mercury
• Cadmium
• Arsenic
• Chromium

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