Adsorption of p-Cresol by Mesoporous Activated Carbon. II. Mechanism studies and data modeling

2017 ◽  
Vol 68 (3) ◽  
pp. 496-499
Author(s):  
Mihaela Neagu ◽  
Daniela Roxana Popovici ◽  
Loredana Elena Vijan ◽  
Catalina Calin

In this work, the adsorption mechanism of p-cresol from aqueous solution onto mesoporous activated carbon was investigated. The mechanism of the adsorption process was determined from Weber-Morris and Boyd models. By graphical and statistical analysis was demonstrated that both film-diffusion and intra-particle diffusion are concurrent in adsorption mechanism. The adsorption mechanism of p-cresol onto mesoporous activated carbon was sustained by FTIR analysis, Boehm titration and the point of zero charge of the GAC.

2012 ◽  
Vol 550-553 ◽  
pp. 2190-2193
Author(s):  
Xiao Yan Tan ◽  
Fang Zhao ◽  
Rui Zhi Wen ◽  
Yu Dai

Commercially available coal-based activated carbon was treated with different concentration of nitric acid. The resultant samples were used to adsorb lead from aqueous solution. N2 adsorption, Boehm titration, point of zero charge (pHPZC) and X-ray photoelectron spectroscopy (XPS) were used to characterize the samples. Acidic pH is favorable for Pb(Ⅱ) adsorption. The acidic groups increase significantly with the increment of the concentration of nitric acid during the treatment. The carboxylic groups of surface carbon play an important role in the adsorption process.


2016 ◽  
Vol 7 (3) ◽  
pp. 280-287 ◽  
Author(s):  
S. Salvestrini ◽  
P. Vanore ◽  
A. Bogush ◽  
S. Mayadevi ◽  
L. C. Campos

In this work, the ability of granular activated carbon (GAC) to sorb metaldehyde was evaluated. The kinetic data could be described by an intra-particle diffusion model, which indicated that the porosity of the sorbent strongly influenced the rate of sorption. The analysis of the equilibrium sorption data revealed that ionic strength and temperature did not play any significant role in the metaldehyde uptake. The sorption isotherms were successfully predicted by the Freundlich model. The GAC used in this paper exhibited a higher affinity and sorption capacity for metaldehyde with respect to other GACs studied in previous works, probably as a result of its higher specific surface area and high point of zero charge.


2021 ◽  
pp. 2150075
Author(s):  
YA GAO ◽  
DI SUN ◽  
CHENGLIANG HAN ◽  
JUNJUN HUANG

In this work, comprehensive utilization of phosphogypsum was developed. Methylene blue (MB) in aqueous solution was adsorbed by waste phosphogypsum (PG), and then the MB-adsorbed PG was used to the fabrication of PG bricks. The adsorption mechanism and the strength of PG bricks also have been studied. The dye maximum capacity of PG monolayer adsorption was found to be 0.2[Formula: see text]mg/g. The kinetic behavior is more accordant with the intra-particle diffusion equation. The MB-adsorbed PG could be effectively used as a raw material for building material. The mechanical properties of PG bricks were little different from the one of the water-washed PG bricks. The 2h-flexural and compressing strengths were about 2.8[Formula: see text]MPa and 6[Formula: see text]MPa, the dry-flexural and compressing strengths were about 5[Formula: see text]MPa and 20[Formula: see text]MPa.


Author(s):  
Xiulei Fan ◽  
Zheng Qian ◽  
Jiaqiang Liu ◽  
Nan Geng ◽  
Jun Hou ◽  
...  

Abstract Application of sewage sludge biochar as an adsorbent for antibiotics treatment has obtained special attention owning to their low cost and surface functionality. Three metal ions were selected to modify sewage sludge biochar through the pyrolysis with the metal loaded method. Fe loaded sewage sludge biochar (BC-Fe), Al loaded sewage sludge biochar (BC-Al) and Mn loaded sewage sludge biochar (BC-Mn) were characterized and used to explore the performance of adsorbing tetracycline (TC), sulfamethoxazole (SMZ) and amoxicillin (AMC). BC-Fe, BC-Al and BC-Mn possessed rougher surfaces, larger specific surface area and better pore structure. Intra-particle diffusion and Langmuir models were more suitable to describe the adsorption process. The maximum adsorption amount of TC, SMZ and AMC could reach 123.35, 99.01 and 109.89 mg/g by BC-Fe. Furthermore, the main mechanism of antibiotics adsorption by metal loaded sewage sludge biochars might be pores filling, Van der Waals forces and H-bonding. The study can not only solve the problems associated with the pollution of antibiotics from wastewater, but also reduced the treatment press of sewage sludge effectively.


2012 ◽  
Vol 1373 ◽  
Author(s):  
Teresa Ramírez-Rodríguez ◽  
Fray de Landa Castillo-Alvarado

ABSTRACTThe intra-particle diffusion model (IPD), proposed by Weber and Morris has been applied to the analysis of the kinetics of adsorption on activated carbon fibers with phosphate groups in the removal of cadmium ions in aqueous media. It is evident that the removal of cadmium ion kinetic model of pseudo-second order provides a better fit than the model of pseudo-first order and the intra-particle diffusion model provides the best to the sample compared activating solution: grams fibers of 1:3.


2016 ◽  
Vol 81 (10) ◽  
pp. 1199-1213 ◽  
Author(s):  
Khaled Taleb ◽  
Jelena Rusmirovic ◽  
Milica Rancic ◽  
Jasmina Nikolic ◽  
Sasa Drmanic ◽  
...  

A novel adsorbents NC-PEG, obtained by the modification of nanocellulose (NC) with PEG-6-arm amino polyethylene glycol (PEG-NH2) via maleic anhydride (MA) linker, was used for the removal of Cd2+ and Ni2+ from water. Subsequent precipitation of goethite (FO) on NC-PEG produced NC-PEG/FO adsorbent which was used for As(V) and As(III) removal. In a batch test, the influence of pH, contact time, initial ion concentration and temperature on adsorption efficiency were studied. The maximum adsorption capacities found for Cd2+ and Ni2+, obtained by the use of Langmuir model, were 37.9 and 32.4 mg g?1 at 25 ?C, respectively. Also, high As(V) and As(III) removal capacity of 26.0 and 23.6 mg g-1 were obtained. Thermodynamic parameters indicate endothermic, feasible and spontaneous nature of adsorption process. Kinetic study, i.e. fitting by Weber-Morris model predicted intra-particle diffusion as a rate-controlling step. Multi-cycle reusability of both NC-PEG and NC-PEG/FO, significantly affects the affordability of techno-economic indicators for consideration of their possible application.


2012 ◽  
Vol 9 (1) ◽  
pp. 63-74 ◽  
Author(s):  
M. Ghaedi ◽  
S. J. Hossaini ◽  
S. Ramezani

Platinum nanoparticles loaded on activated carbon as novel adsorbent was successfully applied for efficient removal of congo red. The influences of effective parameters including contact time, pH and temperature, amount of adsorbents and concentration of initial dye on the efficiency of removal of congo red from aqueous solution were investigated. Adsorption experiments indicate that the extent of adsorption is strongly dependent on pH of solution. Thermodynamic parameters like Free energy of adsorption, enthalpy and entropy changes were calculated to know the nature of adsorption. The calculated values of free energy of adsorption (negative value) indicate that the adsorption process is spontaneous. The estimated values of enthalpy and entropy both show the positive sign, which indicate that the adsorption process is endothermic and the dye molecules are organized on the adsorbent surface in more randomly fashion than in solution. Fitting experimental data to different kinetic models including first order, pseudo second order and Elovich and intra-particle diffusion models shows that the rate of dye adsorption follows pseudo second order model and involvement of intera- particle diffusion mechanism.


Author(s):  
Chukwunonso Chukwuzuloke Okoye ◽  
Okechukwu Dominic Onukwuli ◽  
Chinenye Faith Okey- Onyesolu ◽  
Ifeoma Amaoge Obiora- Okafo

Remediation of crystal violet (CV) dye aqueous solution was attempted using acid activated raphia hookeri seeds (AARHS) as adsorbent. Adsorption equilibrium and kinetics of CV dye uptake onto AARHS were examined in series of experimental runs, and effects of contact time and initial CV dye concentrations were investigated at different solution temperatures (303 K, 313 K and 323 K). Equilibrium and kinetic data modeling of the adsorption process was performed using selected theoretical methods. Four different forms of Langmuir (type I, II, III and IV) and Freundlich isotherms were considered for fitting the equilibrium data while zero order, first order, pseudo-first order (PFO), second order, types I, II, III and IV pseudo-second order (PSO) and intra-particle diffusion models were selected to describe the kinetics of the adsorption process. Error functions including coefficient of determination (R2), root mean square error (RMSE), chi square (χ2) and average relative error (ARE) were employed to reveal model of best fit. Results obtained from error value computations show that the equilibrium data best followed Freundlich isotherm, which indicates multilayer adsorption of CV dye onto AARHS. The calculated Freundlich’s adsorption intensity values at different temperatures reveal the favourability of the adsorption process. PSO type I, II and IV best fitted the kinetic data compared to other investigated models. Intra-particle diffusion plots depict that the adsorption process of CV dye onto AARHS is a two-step process and also, intra-particle diffusion is not the only rate-limiting step.


Author(s):  
Andressa Jenifer Rubio ◽  
Rosângela Bergamasco ◽  
Natália Ueda Yamaguchi

With the increasing use of several pesticides in agriculture, including the Glyphosate which is the herbicide most widely consumed worldwide, there is a need for the development of diversified and effective water treatment, since glyphosate consumption can cause serious health problems on animals, humans and plants. As an alternative treatment, the removal of glyphosate from the water can be obtained with the use of activated carbon, and further to leverage its results, may be used the impregnation of silver and copper on the activated carbon, since the activated carbon in the purest form it is marketed often not sufficiently effective for removing some pollutants. Therefore, this study aimed at the removal of glyphosate by an adsorption process using activated carbon impregnated with 0.5% silver and 0.5% copper with the aim of increasing the adsorption efficiency when compared to activated carbon. It was observed that the removal of glyphosate is improved when using the impregnated metal compounds, being 66.1% with the adsorbent GAC / AgCu and only 21.1% with GAC. It is still needed profound research related to characterization and adsorption experiments to better explain the adsorption mechanism that occurs in this process. However, it can be concluded that the granular activated carbon soaked with 0.5% silver and copper developed in the present work may be named as a possible technology for improving the quality of water intended for human consumption for removal of the glyphosate herbicide.


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