Kinetics and isotherm studies for the adsorption of phenol using low cost micro porous ZnCl2 activated coir pith carbonA paper submitted to the Journal of Environmental Engineering and Science.

2009 ◽  
Vol 36 (1) ◽  
pp. 148-159 ◽  
Author(s):  
R. Subha ◽  
C. Namasivayam
Keyword(s):  
Adsorption Process ◽  
Physical Adsorption ◽  
Low Cost ◽  
Ph Effect ◽  
Synthetic Wastewater ◽  
Isotherm Models ◽  
Langmuir Adsorption ◽  
Coir Pith ◽  
Endothermic Process ◽  
Efficient Adsorbent

In the present study, the potential of ZnCl2 activated coir pith carbon for adsorption of phenol from aqueous solution was investigated. Batch kinetics and isotherm studies were carried out to evaluate the effects of contact time, initial concentration, adsorbent dose, pH, and temperature. Adsorption kinetics was tested for first order, second order, and Bangham’s model and rate constants of kinetic models were evaluated. Equilibrium isotherms for the adsorption of phenol were analysed by Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherm models. The Langmuir adsorption capacity, Q0, was found to be 92.58 mg g–1 of the adsorbent. pH effect showed that physical adsorption might be involved in the adsorption process. Thermodynamic studies revealed that the adsorption of phenol by activated carbon was an endothermic process. The negative value of ΔG0 indicated the spontaneity of the adsorption process. Removal of phenol from synthetic wastewater was also tested. This study showed that ZnCl2 activated coir pith carbon could be used as an efficient adsorbent material for the removal of phenol from water.

scholarly journals Removal of Cadmium(II) from Water using Modified Citrus limettioides Peels: Thermodynamic and Isotherm Studies

2019 ◽  
Vol 32 (1) ◽  
pp. 73-78
Author(s):  
P. Janaki ◽  
R. Sudha ◽  
T.S. Sribharathi ◽  
P. Anitha ◽  
K. Poornima ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Low Cost ◽  
Raw Material ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Adsorption Method ◽  
Chemically Modified ◽  
Adsorption Performance ◽  
Monolayer Adsorption ◽  
Isotherm Equations

The adsorption performance of sulphuric acid treated low cost adsorbent synthesized by using Citrus limettioides peel as an effective raw material for the removal of cadmium(II) from water. The batch adsorption method was carried out to optimize some parameters like contact time, pH and adsorbent dose. The nonlinear isotherm equations were used to calculate the different isotherm constant of five isotherm models namely Freundlich, Langmuir, Dubinin-Radushkevich, Redlich-Peterson and Sips. The Langmuir monolayer adsorption capacity of chemically modified Citrus limettioides peel was found to be 287.60 mg g-1. The negative values of ΔGº and ΔHº showed that the adsorption process is spontaneous and exothermic.

Removal of VOCs Using Sludge-Based Adsorbents

2012 ◽  
Vol 599 ◽  
pp. 305-308 ◽  
Author(s):  
Ping Fang ◽  
Chao Ping Cen ◽  
Hong Tao Zhang ◽  
Zi Jun Tang ◽  
Ding Sheng Chen ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Physical Adsorption ◽  
Low Cost ◽  
Fixed Bed ◽  
Cost Effective ◽  
Langmuir Adsorption Isotherm ◽  
Fixed Bed Reactor ◽  
Dynamic Adsorption ◽  
Langmuir Adsorption ◽  
Isotherm Equations

Efficient and cost-effective sludge-based adsorbents were developed and the adsorption of VOCs on the sludge-based adsorbents was studied in a fixed bed reactor. The results indicate that the adsorption of VOCs on sludge-based adsorbents is typical physical adsorption, the dynamic adsorption capacity of VOCs on adsorbents sharply increases as the VOCs concentration is increased at first, then increasing gradually, at last retains stable with the change of VOCs concentration. The dynamic adsorption capacity of sludge-based adsorbents for VOCs is O-Xylene > Butylcetate > Toluene > Ethylacetate > Benzene > Propanone > n-Hexane, the maximum dynamic adsorption capacity is 0.247, 0.225, 0.192, 0.186, 0.180, 0.176, 0.133g/g, respectively. Meanwhile the adsorption of VOCs on sludge-based adsorbents corresponds to the Langmuir adsorption isotherm equations. The sludge-based adsorbent is a low-cost alternative to activated carbon for VOCs treatment, and this technology is a promising method for the VOCs removal.

scholarly journals Equilibrium, Kinetics, and Thermodynamics of the Removal of Nickel(II) from Aqueous Solution Using Cow Hooves

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
I. Osasona ◽  
O. O. Ajayi ◽  
A. O. Adebayo
Keyword(s):  
Aqueous Solution ◽  
Contact Time ◽  
Room Temperature ◽  
Physical Adsorption ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Equilibrium Studies ◽  
Equilibrium Data

The feasibility of using powdered cow hooves (CH) for removing Ni2+ from aqueous solution was investigated through batch studies. The study was conducted to determine the effect of pH, adsorbent dosage, contact time, adsorbent particle size, and temperature on the adsorption capacity of CH. Equilibrium studies were conducted using initial concentration of Ni2+ ranging from 15 to 100 mgL−1 at 208, 308, and 318 K, respectively. The results of our investigation at room temperature indicated that maximum adsorption of Ni2+ occurred at pH 7 and contact time of 20 minutes. The thermodynamics of the adsorption of Ni2+ onto CH showed that the process was spontaneous and endothermic. Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherm models were used to quantitatively analysed the equilibrium data. The equilibrium data were best fitted by Freundlich isotherm model, while the adsorption kinetics was well described by pseudo-second-order kinetic equation. The mean adsorption energy obtained from the D-R isotherm revealed that the adsorption process was dominated by physical adsorption. Powdered cow hooves could be utilized as a low-cost adsorbent at room temperature under the conditions of pH 7 and a contact time of 20 minutes for the removal of Ni(II) from aqueous solution.

scholarly journals Super and Selective Adsorption of Cationic Dyes onto Carboxylate-Modified Passion Fruit Peel Biosorbent

2021 ◽  
Vol 9 ◽  
Author(s):  
Kaiwei Chen ◽  
Linlin Du ◽  
Peng Gao ◽  
Junli Zheng ◽  
Yuanli Liu ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Selective Adsorption ◽  
Low Cost ◽  
Methyl Violet ◽  
Passion Fruit ◽  
Cationic Dyes ◽  
Polluted Water ◽  
Isotherm Models ◽  
Fruit Peel ◽  
Environmental Friendliness

The carboxylate-functionalized passion fruit peel (PFPCS) was an efficient and rapid biosorbent for wastewater treatment. The PFPCS exhibited excellent selectivity to the cationic dyes, where the maximum adsorption capacities for methylene blue (MB) and methyl violet (MV) were 1,775.76 mg g−1 and 3,756.33 mg g−1, respectively. And the adsorption process of MB and MV on PFPCS reached equilibrium within 20 min. Moreover, the adsorption conditions and mechanisms were investigated. The adsorption process was in good agreement with the pseudo-second-order and Langmuir isotherm models. The adsorption mechanism was also proposed to be electrostatic interaction and hydrogen bond. After six cycles of desorption-adsorption, the removal efficient of MB and MV could be kept above 95%. Thus, PFPCS was considered as a highly efficient absorbent for removing cationic dyes from polluted water due to excellent adsorption characteristics, low cost and environmental friendliness.

scholarly journals The efficiency of nano-TiO2 and γ-Al2O3 in copper removal from aqueous solution by characterization and adsorption study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fatemeh Ezati ◽  
Ebrahim Sepehr ◽  
Fatemeh Ahmadi
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Ph Value ◽  
Physical Adsorption ◽  
Geochemical Modeling ◽  
Low Cost ◽  
Background Electrolyte ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Equilibrium Data

AbstractWater pollution is a major global challenge given the increasing growth in the industry and the human population. The present study aims to investigate the efficiency of TiO2 and γ-Al2O3 nanoadsorbents for removal of copper (Cu(II)) from aqueous solution as influenced by different chemical factors including pH, initial concentration, background electrolyte and, ionic strength. The batch adsorption experiment was performed according to standard experimental methods. Various isotherm models (Freundlich, Langmuir, Temkin, and Dubinin–Radushkevich) were fitted to the equilibrium data. According to geochemical modeling data, adsorption was a predominant mechanism for Cu(II) removal from aqueous solution. Calculated isotherm equations parameters were evidence of the physical adsorption mechanism of Cu(II) onto the surface of the nanoparticles. The Freundlich adsorption isotherm model could well fit the experimental equilibrium data at different pH values. The maximum monolayer adsorption capacity of TiO2 and γ-Al2O3 nanosorbents were found to 9288 and 3607 mg kg−1 at the highest pH value (pH 8) and the highest initial Cu(II) concentration (80 mg L−1) respectively. Copper )Cu(II) (removal efficiency with TiO2 and γ-Al2O3 nanoparticles increased by increasing pH. Copper )Cu(II) (adsorption deceased by increasing ionic strength. The maximum Cu(II) adsorption (4510 mg kg−1) with TiO2 nanoparticles was found at 0.01 M ionic strength in the presence of NaCl. Thermodynamic calculations show the adsorption of Cu(II) ions onto the nanoparticles was spontaneous in nature. Titanium oxide (TiO2) nanosorbents could, therefore, serve as an efficient and low-cost nanomaterial for the remediation of Cu(II) ions polluted aqueous solutions.

scholarly journals Selection of the Activated Carbon Type for the Treatment of Landfill Leachate by Fenton-Adsorption Process

Molecules ◽  
2020 ◽  
Vol 25 (13) ◽  
pp. 3023
Author(s):  
Liliana San-Pedro ◽  
Roger Méndez-Novelo ◽  
Emanuel Hernández-Núñez ◽  
Manuel Flota-Bañuelos ◽  
Jorge Medina ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Adsorption Process ◽  
Physical Adsorption ◽  
Oxygen Demand ◽  
Isotherm Models ◽  
Adsorptive Capacity ◽  
Fenton Process ◽  
Landfill Leachates ◽  
Selection Of ◽  
Adsorption Stage

Sanitary landfill leachates usually have characteristics that depend on the region where they are generated and according to the age of the landfill, which is why a unique treatment for their sanitation has not been found. However, the adsorption preceded by the Fenton process has been proven to be highly efficient at removing contaminants. In this study, the adsorptive capacity of two types of activated carbon, granular and powdered, was analyzed to determine which was more efficient in the adsorption stage in the Fenton-adsorption process. Likewise, its behavior was analyzed using three isotherm models (Langmuir, Freundlich and Temkin), testing the raw leachate and the Fenton-treated one with both carbons. The adsorption that is carried out on the carbons is better adjusted to the Freundlich and Temkin models. It concludes that multilayers, through the physical adsorption, carry out the adsorption of pollutants on the surface of the carbons. The results show that, statistically, granular activated carbon is more efficient at removing chemical oxygen demand (COD), and powdered activated carbon removes color better. Finally, an adsorption column was designed for the Fenton-adsorption process that was able to remove 21.68 kgCOD/kg carbon. Removal efficiencies for color and COD were >99%.

Adsorptive removal of phosphate from aqueous solutions using lead–zinc tailings

2013 ◽  
Vol 67 (5) ◽  
pp. 983-988 ◽  
Author(s):  
Shuncai Wang ◽  
Rongzhuo Yuan ◽  
Xueyong Yu ◽  
Chaojie Mao
Keyword(s):  
Laboratory Experiments ◽  
Low Cost ◽  
Ph Effect ◽  
Cost Effective ◽  
Phosphate Removal ◽  
Phosphate Adsorption ◽  
Isotherm Models ◽  
Effective Removal ◽  
Elovich Equation ◽  
Lead Zinc

This study explored the feasibility of utilizing lead–zinc tailings for phosphate removal in laboratory experiments. The adsorption isotherm, kinetics and pH effect were examined in batch experiments. The Freundlich and Langmuir isotherm models were used for data fitting. The adsorption kinetics can be best described by the simple Elovich equation. The phosphate adsorption tends to decrease with the increase of pH, from 0.37 mg P/g at pH 2.05 to 0.12 mg P/g at pH 7.01, and tends to increase from 0.12 mg P/g at pH 7.01 to 0.64 mg P/g at pH 12.52. The actual phosphate removal on the tailings could be a consequence of adsorption and precipitation reactions with Fe, Al and Ca. Due to their low cost, this type of tailings has the potential to be utilized for cost-effective removal of phosphate from wastewater.

scholarly journals Sorption of Bivalent Ions by Cymbopogon citratus: Characterisation and Investigation of Biosorptive Capacity and Mechanism

2018 ◽  
Vol 4 (3) ◽  
pp. 297-302
Author(s):  
S. Jayashree ◽  
Jeyavathana Samuel ◽  
R. Vashantha
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Adsorption Process ◽  
Low Cost ◽  
Kinetic Studies ◽  
Solution Temperature ◽  
Isotherm Models ◽  
Physical Parameters ◽  
Cymbopogon Citratus ◽  
Equilibrium Data

The main objective of this study was to investigate the removal of cadmium(II) ions from aqueous solution using raw Cymbopogon citratus as an adsorbent. It was characterized by FT-IR, XRD, SEM-EDAX and its physical parameters were analyzed. Different factors such as pH, contact time, initial concentration and temperature were studied. Maximum adsorption was taken place at the optimum pH of 6 and the equilibrium data were analyzed by Langmuir, Freundlich and Temkin Isotherm models. Among those isotherm models Langmuir and Temkin were fitted well with good correlation coefficient (R2). The negative values of ΔG⁰ for all temperature shows the adsorption process for cadmium(II) ion was spontaneous in nature and feasible. The negative value of enthalpy change ΔH⁰ shows the adsorption process is exothermic and the positive value of ΔS⁰ indicates the disorderness or randomness process of adsorption. The positive value of Ea indicates the higher solution temperature favors the adsorption of metal ion onto RCC. The experimental data were analyzed by kinetic studies such as pseudo-first order, pseudo-second order and intra-particle diffusion models. Desorption was also studied and the recovery of the adsorbent was found to be 10%. Thus on the basis of these investigations the present study concludes that the raw Cymbopogon citratus (RCC) was found to be highly effective, nontoxic, environmental friendly and low cost adsorbent for the removal of toxic Cd(II) ions from aqueous solution.

scholarly journals Removal of sodium salicylate from aqueous solution using spruce wood sawdust as an eco-friendly adsorbent

2020 ◽  
Vol 10 (4) ◽  
pp. 335-345
Author(s):  
Nouh Aarab ◽  
Abdelilah Essekri ◽  
Mohamed Ait Haki ◽  
Hassan Kabli ◽  
Habiba Eljazouli ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Sodium Salicylate ◽  
Low Cost ◽  
Cost Effective ◽  
Isotherm Models ◽  
Noticeable Effect ◽  
Wood Sawdust ◽  
Spruce Wood ◽  
Initial Ph ◽  
Solid Liquid

This study reports the application of Spruce wood sawdust as a low-cost and eco-friendly adsorbent for the removal of sodium salicylate from aqueous solutions. The effects of physicochemical parameters on the sodium salicylate adsorption process such as initial pH, temperature, solid/liquid ratio, initial concentration, contact time, and ionic strength were investigated. The optimum adsorption conditions were found as: equilibrium time = 3h, adsorbent dosage = 0.5 g/L, pH= 6.5, initial sodium salicylate concentration = 10 mg/L and temperature = 25°C. The kinetic study shows that the pseudo-second-order model is suitable to describe the adsorption process. The adsorption isotherm models (Langmuir, Freundlich, Temkin and generalized) were tested to understand the adsorption mechanism of sodium salicylate onto wood sawdust surface. The adsorption of sodium salicylate follows the Langmuir isotherm model. The maximum monolayer uptake capacity was found to be 99.01 mg/g. In addition, the temperature seems to have no noticeable effect on the adsorption of sodium salicylate. Finally, the thermodynamic parameters indicate that the adsorption is spontaneous (ΔG°˂ 0) and exothermic (ΔH°=-5.081 kJ/mol) in nature. Overall, Spruce wood sawdust can be used as a cost-effective and eco-friendly adsorbent for wastewater treatment applications.

Biosorption of Cu2+ from Aqueous Solutions Using NaOH-Modified Fir Sawdust

2013 ◽  
Vol 726-731 ◽  
pp. 1827-1832
Author(s):  
Hong Mei Deng ◽  
Yong Heng Chen ◽  
Cui Qin Wu ◽  
Xue Xia Huang ◽  
Tao Liu
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Process ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
Factors Affecting ◽  
Langmuir Adsorption ◽  
Adsorption Processes ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Agricultural Material

Fir sawdust, a low-cost residual agricultural material, was used as adsorbent for the removal of Cu2+from aqueous solutions. Factors affecting the adsorption behavior of Cu2+, such as pH, initial metal concentration, contact time and temperature, have been carried out. The Cu2+removal was pH-dependent, reaching a maximum at pH 5. The adsorption capacity of the fir sawdust from Langmuir adsorption isotherm was 38.6 mg/g at 25°C. The adsorption process followed pseudo-second-order kinetics. The equilibrium data fitted very well to the Freundlich isotherm. The negative ΔGovalues at various temperatures confirm that the adsorption processes are spontaneous.

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