A novel ANN approach for modeling of alternating pulse current electrocoagulation-flotation (APC-ECF) process: Humic acid removal from aqueous media

Adsorption of 2-chlorophenol onto octyl-modified ordered mesoporous silica material from an aqueous solution was investigated systematically using batch experiments in this study. Hexagonal mesoporous silica (HMS) owning double pore paths and OD-HMS were synthesized by using cheap sodium silicate and a non-ion surfactant C16PyCl under room temperature here and characterized by X-ray diffraction (XRD), N2 adsorption–desorption measurement, and Fourier Transform-Infrared (FT-IR). Results indicate that 2-chlorophenol adsorption is initially rapid and the adsorption process reaches a steady state after 5 min. The adsorption isotherms are well described by the Langmuir and the Freundlich models, the former being found to provide a better fit with the experimental data. The effects of temperature, pH, ionic strength, and humic acid on the adsorption are also examined. According to the experimental results, the amount of 2-chlorophenol adsorbed decreases with increases of temperature from 288 to 308 K, and pH from 2.0 to 11.0, the amount of 2-chlorophenol adsorbed increases with an increase of ionic strength from 0.001 to 0.1 mol/L. However, the amount of 2-chlorophenol adsorbed onto octyl-modified ordered mesoporous silica material shows notable difference in the presence of humic acid. The desorption process shows a reversibility of 2-chlorophenol adsorption onto octyl-modified ordered mesoporous silica material. Thermodynamic parameters such as Gibbs free energy are calculated from the experimental data at different temperatures. Based on the results, It was found that octyl-modified ordered mesoporous silica shows significant adsorption for 2-chlorophenol. This might be due to hydrophobic interaction among the octyl functional groups and 2-chlorophenol.

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Review: Low Cost, Environmentally Friendly Humic Acid Coated Magnetite Nanoparticles (HA-MNP) and Its Application for the Remediation of Phosphate from Aqueous Media

Journal of Encapsulation and Adsorption Sciences ◽

10.4236/jeas.2018.84013 ◽

2018 ◽

Vol 08 (04) ◽

pp. 256-279 ◽

Cited By ~ 1

Author(s):

Tadewos Damena ◽

Tajeldin Alansi

Keyword(s):

Humic Acid ◽

Magnetite Nanoparticles ◽

Low Cost ◽

Aqueous Media ◽

Environmentally Friendly

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Cupric ion binding by coal humic acids at pH's 1–3

Canadian Journal of Chemistry ◽

10.1139/v77-452 ◽

1977 ◽

Vol 55 (18) ◽

pp. 3248-3254 ◽

Cited By ~ 6

Author(s):

John B. Green ◽

Stanley E. Manahan

Keyword(s):

Humic Acid ◽

Ion Exchange ◽

Humic Acids ◽

Aqueous Media ◽

Surface Adsorption ◽

Ion Binding ◽

Cupric Ion ◽

Floc Structure ◽

Intermolecular Bonding ◽

High Concentrations

The extent and mechanism of cupric ion binding by humic acid (HA) at low pH's where the material was insoluble in aqueous media was investigated. It was shown that significant amounts of Cu(II) were bound by HA even at pH's as low as 1.35. Two major types of HA—Cu2+ binding were observed. Binding which was accompanied by exchange of H+ was more prevalent at high pH's and [Cu2+]. Nonexchange bonding occurred at all pH's, but assumed greater importance at low pH's. Since the pattern of Cu(II) uptake could not be interpreted in terms of basic ion exchange or surface adsorption theory, a new model was proposed which qualitatively explained the dependence of Cu(II) on pH and [Cu2+]. The model assumed that the intermolecular bonding in flocculated HA was determined by the relative amounts of H+ and Cu2+ available for forming bridging bonds between the HA molecules. The model suggested that at high concentrations of Cu(II) and/or high pH's, the floc structure was such that the formation of copper bridge bonds was maximized.

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Removal of humic acid from aqueous media using magnetite nanoparticles

10.5004/dwt.2021.26552 ◽

2021 ◽

Vol 210 ◽

pp. 273-280

Author(s):

Behzad Shahmoradi ◽

Kitirote Wantala ◽

H. Jari ◽

Yahya Zandsalimi ◽

S. Mohammadloo ◽

...

Keyword(s):

Humic Acid ◽

Magnetite Nanoparticles ◽

Aqueous Media

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Fabrication of nano zero valent iron/biopolymer composite with antibacterial properties for simultaneous removal of nitrate and humic acid: Kinetics and isotherm studies

10.21203/rs.3.rs-324935/v1 ◽

2021 ◽

Author(s):

Nazanin Zahra Pourbaghaei ◽

Mansoor Anbia ◽

Fatemeh Rahimi

Keyword(s):

Humic Acid ◽

Aqueous Solutions ◽

Desirability Function ◽

Aqueous Media ◽

Antibacterial Properties ◽

Freundlich Isotherm ◽

Zerovalent Iron ◽

Simultaneous Removal ◽

High Antibacterial Activity ◽

Isotherm Adsorption

Abstract This investigation compared the adsorption behavior of humic acid (HA) on cellulose, chitosan and nano zerovalent iron/chitosan (nZVI/chitosan). Results show that nZVI/chitosan is very effective in the adsorption of HA from aqueous media. The feasibility of using nZVI/chitosan as an adsorbent for the simultaneous removal of nitrate and HA from aqueous media was also studied. Structural analyses of the samples were identified by TEM, FT-IR, EDX, XRD and N2 isotherms. The effects of pH, amount of composite, nitrate concentration, HA concentration and contact time and their interactions on responses were explored by central composite design (CCD) and response surface methodology (RSM). The optimal conditions of pH (5.5), adsorbent amount (0.098 g), reaction time (27 min) and initial concentrations (110 mg/L for nitrate and 30 mg/L for HA) were obtained from desirability function. The adsorption properties of the resulting nanocomposite toward nitrate and HA were investigated through kinetic and isotherm adsorption studies. The adsorption kinetics was found to fit the pseudo-second order model. The results obtained indicate that nitrate uptake fitted well with the Langmuir model while the Freundlich isotherm was the best model for describing the multilayer uptake of HA from aqueous solutions. Moreover, nZVI/chitosan nanocomposite illustrates a very high antibacterial activity against pathogen bacteria strains such as Staphylococcus aureus ATCC 25935, ATCC 25923, and Pseudomonas aeruginosa ATCC 27853. The findings reported in this investigation highlight the potential of using nZVI/chitosan as a promising adsorbent for the simultaneous removal of nitrate and HA from aqueous solutions.

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