Guava (Psidium guajava) leaf powder: Novel adsorbent for removal of methylene blue from aqueous solutions

Venkatachalam, P.; Vikram, Sahi Shivendra; Srivastava, S.N.

doi:10.1016/j.jhazmat.2007.06.107

Cited by 294 publications

(124 citation statements)

References 30 publications

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“…e maximum adsorption capacity obtained for ZnCl 2 -modified CGAC was higher than the corresponding values assumed by others for polyethylene glycol/chitosan and polyvinyl alcohol/chitosan (11.44 mgN·g −1 and 7.91 mgN·g −1 ) [21]. In addition, the constant 1/n in the range of 0-1 showed the favorable conditions for adsorption [38].…”

Section: Adsorption Isothermsmentioning

confidence: 52%

Adsorption of Nitrate onto ZnCl₂‐Modified Coconut Granular Activated Carbon: Kinetics, Characteristics, and Adsorption Dynamics

Liu

Wang

2018

Advances in Materials Science and Engineering

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Coconut granular activated carbon (CGAC) was modified by impregnating with ZnCl 2 solution to remove nitrate from aqueous solutions. Sorption isotherm and kinetic studies were carried out in a series of batch experiments. Nitrate adsorption of both ZnCl 2 -modified CGAC and CGAC fitted the Langmuir and Freundlich models. Batch adsorption isotherms indicated that the maximum adsorption capacities of ZnCl 2 -modified CGAC and CGAC were calculated as 14.01 mgN·g −1 and 0.28 mgN·g −1 , respectively. e kinetic data obtained from batch experiments were well described by pseudo-second-order model. e column study was used to analyze the dynamic adsorption process. e highest bed adsorption capacity of 1.76 mgN·g −1 was obtained by 50 mgN·L −1 inlet nitrate concentration, 20 g adsorbents, and 10 ml·min −1 flow rate. e dynamic adsorption data were fitted well to the omas and Yoon-Nelson models with coefficients of correlation R 2 > 0.834 at different conditions. Surface characteristics and pore structures of CGAC and ZnCl 2 -modified CGAC were performed by SEM and EDAX and BET and indicated that ZnCl 2 had adhered to the surface of GAC after modified. Zeta potential, Raman spectra, and FTIR suggested the electrostatic attraction between the nitrate ions and positive charge. e results revealed that the mechanism of adsorption nitrate mainly depended on electrostatic attraction almost without any chemical interactions.

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Section: Adsorption Isothermsmentioning

confidence: 52%

Adsorption of Nitrate onto ZnCl₂‐Modified Coconut Granular Activated Carbon: Kinetics, Characteristics, and Adsorption Dynamics

Liu

Wang

2018

Advances in Materials Science and Engineering

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“…Furthermore, with increasing the flow rate, the value of qo decreased but the value of KTH increased. This is due to that at higher flow rate there is a deficient residence time of the solution inside the column and migration on of the solute into the pores of both adsorbents which leads to lower adsorption capacity and thus the solute leaves the column before equilibrium occurs [32]. Accordingly, with lower flow rate, lower initial dye concentration and higher bed depth would increase the adsorption of CR on both adsorbents column.…”

Section: Thomas Modelmentioning

confidence: 99%

Fixed-Bed Column Studies for the Removal of Congo Red Using <i>Simmondsia chinesis</i> (Jojoba) and Coated with Chitosan

et al. 2018

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“…This decrease in unit adsorption as the adsorbent dose increases was due to a large number of adsorption sites remaining unsaturated during the adsorption process. Several studies have also shown that unit adsorption capacity decreased as adsorbent dosage increased [22][23][24]. This study found that the adsorption percentage and adsorption density (q e, exp. )…”

Section: Resultsmentioning

confidence: 63%

Adsorption Kinetics of Lead and Zinc Ions by Coffee Residues

Wu¹,

Kuo²,

Guan³

2015

Pol. J. Environ. Stud.

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IntroductionMining, electroplating, and metal processing are the main sources of heavy metal contamination. Metals such as lead, arsenic, chromium, mercury, copper, and zinc have been characterized as hazardous heavy metals. Due to their hazardous effects, persistency, and tendency to accumulate, effective removal of heavy metal ions from wastewater is an important issue.Various agricultural by-products have been used to remove heavy metals from solutions. Using waste materials as low-cost adsorbents is attractive as it reduces costs for their disposal. Several studies have employed low-cost adsorbents such as orange peels [1] [2] were reported for adsorption onto coffee residues. However, only pseudo first-and second-order models were tested for adsorption kinetics in these investigations. Generally, an adsorption process can be characterized as three stages:(i) external diffusion or boundary-layer diffusion, (ii) intraparticle mass diffusion, (iii) adsorption on interior sites.Pol. J. Environ. Stud. Vol. 24, No. 2 (2015), [761][762][763][764][765][766][767] Original Research AbstractUntreated coffee residues (UCRs) were used to remove heavy metal ions from aqueous solutions. The effects of solution pH, heavy metal ions, and UCR concentrations on heavy metal ion removal by UCRs were determined. The removal percentage for heavy metal ions increased as pH and UCR doses increased; conversely, it decreased as the concentration of heavy metal ions increased. This study employed the pseudo firstand second-order kinetics models, the intraparticle diffusion model, and the Bangham model to simulate adsorption kinetics of Pb 2+ and Zn 2+ onto UCRs. Simulation results indicate that adsorption kinetics fit well with the pseudo second-order model. After reaction for 180 min at [adsorbate] = 20 mg/L, [UCRs] = 2 g/L, and pH 5, the adsorption percentage of Pb 2+ and Zn 2+ was 96% and 44%, respectively; moreover, the adsorption density of Pb 2+ and Zn 2+ onto UCRs was 9.7 and 4.4 mg/g (4.7×10 -2 and 6.8×10 -2 mmol/g), respectively. The adsorption of Pb 2+ and Zn 2+ onto UCRs is controlled mainly by surface diffusion.

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Guava (Psidium guajava) leaf powder: Novel adsorbent for removal of methylene blue from aqueous solutions

Cited by 294 publications

References 30 publications

Adsorption of Nitrate onto ZnCl₂‐Modified Coconut Granular Activated Carbon: Kinetics, Characteristics, and Adsorption Dynamics

Adsorption of Nitrate onto ZnCl₂‐Modified Coconut Granular Activated Carbon: Kinetics, Characteristics, and Adsorption Dynamics

Fixed-Bed Column Studies for the Removal of Congo Red Using <i>Simmondsia chinesis</i> (Jojoba) and Coated with Chitosan

Adsorption Kinetics of Lead and Zinc Ions by Coffee Residues

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Guava (Psidium guajava) leaf powder: Novel adsorbent for removal of methylene blue from aqueous solutions

Cited by 294 publications

References 30 publications

Adsorption of Nitrate onto ZnCl2‐Modified Coconut Granular Activated Carbon: Kinetics, Characteristics, and Adsorption Dynamics

Adsorption of Nitrate onto ZnCl2‐Modified Coconut Granular Activated Carbon: Kinetics, Characteristics, and Adsorption Dynamics

Fixed-Bed Column Studies for the Removal of Congo Red Using <i>Simmondsia chinesis</i> (Jojoba) and Coated with Chitosan

Adsorption Kinetics of Lead and Zinc Ions by Coffee Residues

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Product

Resources

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Adsorption of Nitrate onto ZnCl₂‐Modified Coconut Granular Activated Carbon: Kinetics, Characteristics, and Adsorption Dynamics

Adsorption of Nitrate onto ZnCl₂‐Modified Coconut Granular Activated Carbon: Kinetics, Characteristics, and Adsorption Dynamics