Simulation of saxitoxins adsorption in full-scale GAC filter using HSDM

Neto, José Capelo; Buarque, Neuma Maria Silva

doi:10.1016/j.watres.2015.10.048

Cited by 20 publications

(9 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mass transfer of solute from the bulk solution either through external film mass transfer, internal mass transfer or adsorption may be involved in the mass transfer rate controlling step. 11,30 The homogeneous surface diffusion model (HSDM) is an inparticle diffusion model which considers only surface diffusion and liquid film mass transfer but ignores pore diffusion. 31 Weber and Mathews developed a solid-phase HSDM using a finitedifference solution method for any arbitrary isotherm in a batchadsorption system, 32 and this model has been applied successfully to describe adsorption dynamics for powdered activated C applications.…”

Section: Hdsm Analysismentioning

confidence: 99%

“…For example, the slow internal diffusion rates of granular adsorbents seriously limit their overall kinetics due to their small pore sizes, 9 the stacking of active sites can result in serious loss of performance, 10 and some nano-adsorbents are difficult to separate. 11 In summary, it remains imperative to develop adsorbents with high adsorption performance and ease of operation, in order to maintain costeffectiveness and lower environmental impact.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Cu(II) and Cd(II) capture using novel thermosensitive hydrogel microspheres: adsorption behavior study and mechanism investigation

Tang

Huang

Tun

et al. 2021

J of Chemical Tech & Biotech

View full text Add to dashboard Cite

BACKGROUND: At present, various kinds of hydrogel adsorbents are applied to the treatment of heavy metal ions in wastewater. In this work, we focused on the adsorption of cadmium [Cd(II)] and copper [Cu(II)] onto microspheres of a novel thermosensitive hydrogel (NH 2 -SA/PNIPA, aminated sodium alginate/poly-N-isopropyl acrylamide), studied the effect of temperature on the phase transition of the hydrogel in detail, and discussed the influence on the adsorption behavior of metal ions in the hydrogel. RESULTS:The NH 2 -SA/PNIPA exhibited a higher adsorption efficiency under the conditions of interfering monovalent cationic and neutral pH. The adsorption capacities based on the Langmuir model were 57.2 mg g -1 for Cu(II) and 100.5 mg g -1 for Cd(II) at 20°C, respectively. Higher temperature facilitated the adsorption process and also led to the volume shrinkage and hydrophobicity of NH 2 -SA/PNIPA. The metal ions had different hydration and hence different adsorption capacities, of 56.7 mg g -1 for Cu(II) and 88.6 mg g -1 for Cd(II) at 40°C. The results of diffusion behavior analysis showed that the diffusion coefficients were ≈1 × 10 −11 m 2 s -1 . The adsorption performance of NH 2 -SA/PNIPA hardly decreased even after five cycles. In addition, the adsorption process was controlled mainly by the complexation reaction. CONCLUSION:The novel hydrogel microspheres overcame the deficiency of conventional adsorbents and possessed high diffusibility. This work provides a theoretical basis and empirical evidence for enhancement of adsorbents for removing heavy metals in wastewater.

show abstract

Section: Hdsm Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Cu(II) and Cd(II) capture using novel thermosensitive hydrogel microspheres: adsorption behavior study and mechanism investigation

Tang

Huang

Tun

et al. 2021

J of Chemical Tech & Biotech

View full text Add to dashboard Cite

show abstract

“…The adsorption behavior of dc-STX and STX onto commercial coconut shell-based GAC was studied by Capelo-Neto et al [70]. Their kinetic study was conducted with an initial concentration of 7 and 60 µg/L for dc-STX and STX, respectively.…”

Section: Coconut Shellmentioning

confidence: 99%

“…In comparison, adsorption of dc-STX was less than that of STX, due to its lower initial concentration. In a similar study, conducted by Capelo-Neta and Silva Buarque [70], four different coconut shell-based GACs, with the same surface charge but different BET surface areas and pore sizes, were tested. Those GACs with a greater percentage of mesopores showed the highest STX removal.…”

Section: Coconut Shellmentioning

confidence: 99%

Recent Advancements in the Removal of Cyanotoxins from Water Using Conventional and Modified Adsorbents—A Contemporary Review

Abbas

Kajjumba

Ejjada

et al. 2020

Water

View full text Add to dashboard Cite

The prevalence of cyanobacteria is increasing in freshwaters due to climate change, eutrophication, and their ability to adapt and thrive in changing environmental conditions. In response to various environmental pressures, they produce toxins known as cyanotoxins, which impair water quality significantly. Prolonged human exposure to cyanotoxins, such as microcystins, cylindrospermopsin, saxitoxins, and anatoxin through drinking water can cause severe health effects. Conventional water treatment processes are not effective in removing these cyanotoxins in water and advanced water treatment processes are often used instead. Among the advanced water treatment methods, adsorption is advantageous compared to other methods because of its affordability and design simplicity for cyanotoxins removal. This article provides a current review of recent developments in cyanotoxin removal using both conventional and modified adsorbents. Given the different cyanotoxins removal capacities and cost of conventional and modified adsorbents, a future outlook, as well as suggestions are provided to achieve optimal cyanotoxin removal through adsorption.

show abstract

“…To optimize the industrial design and maintenance, numerical modeling is a useful tool to predict the MP removal efficiency. Among all the descriptive models, the homogeneous surface diffusion model (HSDM) is commonly used in number of studies to simulate adsorption processes at different scales (Bakir et al, 2014;Capelo-Neto and Buarque, 2016;Hand et al, 1997;Kim et al, 2016;Schideman et al, 2006aSchideman et al, , 2006bZhang et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Upscaling fixed bed adsorption behaviors towards emerging micropollutants in treated natural waters with aging activated carbon: Model development and validation

Cimetière

Heim

et al. 2019

Water Research

View full text Add to dashboard Cite

A scale-up procedure was assessed in this study to predict the fixed bed adsorption behaviors with aging granular activated carbon (GAC) for various micropollutants (pesticides, pharmaceuticals). Two assumptions of this upscaling methodology (i.e., involving equal adsorption capacities and surface diffusivities between the batch test and the fixed bed) were studied for the first time to investigate the aging effect on the adsorption capacity and kinetics of carbon at full scale. This study was conducted in natural waters (the Seine River) treated by Veolia Eau d'Ile de France in Choisy-Le-Roi, a division of Syndicat des Eaux d'Ile de France, aiming to monitor real industrial conditions. The isotherms showed that the adsorption capacity for most compounds was significantly affected by aging. For the mass transfer coefficients (i.e., as determined by the homogeneous surface diffusion model (HSDM)), different patterns of adsorbate/adsorbent behaviors were observed, suggesting different competition mechanisms. The model predictions (i.e., HSDM) performed with all parameters obtained during the batch tests tended to overestimate the full-scale pilot adsorption performance. This overestimation could be compensated for by applying a scaling factor. Finally, an empirical pseudo-first order function was used to model the impact of the GAC service time on the characteristic adsorption parameters. Thus, our scale-up procedure may enable the prediction of long-term fixed bed adsorption behaviors and increase the model efficiency for practical implementation.

show abstract

Simulation of saxitoxins adsorption in full-scale GAC filter using HSDM

Cited by 20 publications

References 53 publications

Cu(II) and Cd(II) capture using novel thermosensitive hydrogel microspheres: adsorption behavior study and mechanism investigation

Cu(II) and Cd(II) capture using novel thermosensitive hydrogel microspheres: adsorption behavior study and mechanism investigation

Recent Advancements in the Removal of Cyanotoxins from Water Using Conventional and Modified Adsorbents—A Contemporary Review

Upscaling fixed bed adsorption behaviors towards emerging micropollutants in treated natural waters with aging activated carbon: Model development and validation

Contact Info

Product

Resources

About