Methylene blue removal from aqueous media using tassel adsorbent

Marofi, Safar; Zare, Mohamad Ali; Krimi, Yaghoub

doi:10.2166/wst.2017.347

Cited by 4 publications

(3 citation statements)

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“…The values of n in the range of 1-10 represent good adsorption. In this study, the values of n indicated favorable adsorption (n = 1.96) and a more heterogeneous feature (Marofi et al 2017).…”

Section: Freundlich Isotherm Modelmentioning

confidence: 47%

Fabricating pentaazatetraethylene modified sulfonated polyacrylamide for dye adsorption from aqueous media: isotherms and kinetics models

Karimi,

Marofi,

Zare

2024

Environ Sci Pollut Res

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In this study, pentaazatetraethylene modified sulfonated polyacrylamide (PAm-SO3-N5) was synthesized and used as a novel efficient adsorbent to remove Calmagite from aqueous media. To this end, a central composite design (CCD) was applied to reduce the number of reaction variables (i.e., adsorbent concentration, temperature, initial concentration, and pH) on Calmagite removal.The results showed that calmagite was entirely adsorbed by the PAm-SO3-N5 within 30 min. In addition, a pseudo-second-order (PSO) model was prepared as the optimum formula to fit the kinetics information. The modeling results revealed that film diffusion and adsorption are ratelimiting stages to remove the dyes. Using a Langmuir isotherm to fit the equilibrium data, the highest equilibrium adsorption was calculated to be 1,732.5 mg/g. In the present study, the ΔH value indicates that the adsorption is of chemical type. Also, the negative sign of ΔS° shows that PAm-SO3-N5 removes Calmagite during a relatively stable process with randomness in the system.The increase in ΔG° values with increasing temperature indicates a descending trend in the feasibility degree of Calmagite adsorption. Eventually, recycling the adsorbent for 7 cycles to adsorb calmagite dye showed no remarkable activity loss.

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Section: Freundlich Isotherm Modelmentioning

confidence: 47%

Fabricating pentaazatetraethylene modified sulfonated polyacrylamide for dye adsorption from aqueous media: isotherms and kinetics models

Karimi,

Marofi,

Zare

2024

Environ Sci Pollut Res

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“…In previous studies, [66–74] the reuse of synthesized materials has been investigated and it has been shown that synthesized compounds also can be recycled.…”

Section: Resultsmentioning

confidence: 99%

“…Decreasing the efficiency by increasing the number of steps can be related to the saturation of adsorbent sites or damage to sites active in the adsorbent. [64,65] In previous studies, [66][67][68][69][70][71][72][73][74] the reuse of synthesized materials has been investigated and it has been shown that synthesized compounds also can be recycled.…”

Section: Adsorbents Recyclementioning

confidence: 99%

Crystal violet removal from aqueous media using Tragopogon dubius adsorbent

Yaghoub Krimi,

Marofi,

Zare

2024

ChemistrySelect

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In this study, Tragopogon dubius was used using a specific condition of adsorption to remove a cationic harmful dye (crystal violet : CV) in aqueous liquid media. Removing time, rate of adsorbent, pH of the media, initial concentration of the harmful dye, and absorbent particle size were studied to reach an optimum adsorption condition. Before and after the biosorption process of CV, the SEM micrographs and EDX spectra were obtained for Tragopogon dubius. The maximum removal efficiency of CV (90–93 %) has happened at pH=7.0, contact time of 120 min, adsorbent dose of 0.2 g/L (with particle size of 0.074 mm), temperature of 25 ○C, and pollutant rate of 50.0 mg/L. The adsorption rate of Tragopogon dubius was calculated using equilibrium models. It was also increased by water washing (30 min). The results showed that 50 % of the dye was absorbed when the adsorption time reached 50 min. Maximum adsorption (212.9 mg/g) occurred after 120 min of removing time. The results revealed the best accordance of the Tragopogon dubius adsorption with the Freundlich model (R2=0.96). A kinetic agreement was also observed between the dye adsorption and the Pseudo‐second order model. The negative value of ΔS° (−53.51 J/K mol) indicates that Tragopogon dubius removes CV during a relatively stable process with randomness in the system. The negative values of ΔG° at different temperatures indicate that the nature of CV adsorption was spontaneous.

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