Phenol Adsorption Capacity Research Articles

Adsorption of phenol and methylene blue from aqueous solutions by pyrolytic tire char: Equilibrium and kinetic studies

Acid-treated pyrolytic tire char (PTC) was studied as an adsorbent for the removal of phenol and methylene blue (MB) dye from aqueous solutions. PTC was derived via pyrolysis of used rubber tires at 450°C in oxygen-free atmosphere. Textural characteristics and surface chemical nature of the adsorbent were examined through a battery of techniques such as X-ray diffraction, porosimetry, Boehm titration, and point of zero charge determination. The adsorption characteristics of phenol and MB dye were evaluated on the basis of equilibrium and kinetic studies. The adsorption kinetic data fitted better to pseudo-second kinetic model. Equilibrium isotherms were analyzed by Langmuir, Freundlich, Dubinin–Radushkevich, Temkin and Frumkin models. Langmuir and Freundlich isotherm models were found to fit the adsorption data of phenol and MB, respectively. The maximum adsorption capacities of phenol and MB on PTC were found to be 51.92 and 65.81mgg−1, respectively. In the case of phenol, the adsorption mechanisms can be attributed to π–π electron donor/acceptor interaction, hydrogen bonding of phenol with surface groups of PTC. On the other hand, electrostatic attraction between the carboxylic groups of PTC surface and cationic dye is responsible for the adsorption of MB. The effect of temperature on the organics’ adsorption was studied and the thermodynamic parameters (ΔH, ΔS and ΔG) were determined for each of the studied systems. The adsorption for both pollutants was found to be thermodynamically spontaneous (ΔG<0), although it was exothermic (ΔH<0) for phenol vs endothermic (ΔH>0) for MB.

Characterization of Adsorption Capacity of Phenol Using Groundnut Husk-based Activated Carbon

Equilibrium adsorption studies of phenol onto activated carbon prepared from groundnut husk was investigated for effectiveness. Groundnut husk s w ere washed, dried at temperatures between 110 ° C and 160 o C, pulverized and finally activated at 200 ° C for 3 hours. Optimum conditions of carbon dosage, pH, contact time and influence of concentration of phenol on carbon were investigated. Several analyses of isotherm data were tested by fitting them into different isotherm (Temkin, Langmuir, Dubinin - Kaganer - Rushkevich and Freundlich) models. The results of the optimization studies indicated an optimum adsorption of phenol with carbon dosage of 2.2 g; pH = 5 and contact time = 5 hours. Temkin, Dubinin - Kaganer - Rushkev ich and Freundlich had high correlation coefficients in the range of 0.853 – 0.9501. The experimental data fitted adequately into these models but not into the Langmuir isotherm model with extremely low regression coefficient of 0.0038. The high correlatio n coefficient s connoted strong interactions between the adsorbate and the adsorbent and a good interpretation of the adsorption behaviour of phenol. However, the Temkin and Dubinin - Kaganer - Rushkevich models showed indications of chemisorptions with high h eat of adsorption of 1531.39 J mol - 1

Phenol adsorption from aqueous solutions by functionalized multiwalled carbon nanotubes with a pyrazoline derivative in the presence of ultrasound

MWCNT-Py indicated a high adsorption capacity for phenol in comparison with MWCNT-COOH.

3D BiOI–GO composite with enhanced photocatalytic performance for phenol degradation under visible-light

Coupling semiconductors with graphene-based materials could enable better photocatalytic performance as compared to that of pristine semiconductors. In this work, a three-dimensional BiOI–GO composite was fabricated by a simple self-assembly approach. The resultant BiOI–GO composite showed a higher photocatalytic activity than that of pure BiOI and P25 towards the degradation of phenol under visible-light irradiation, which could be attributed to the more effective separation of photogenerated electrons and holes between BiOI and GO, and the better adsorption capacity of phenol.

Fabrication of ZIF-8@super-macroporous poly(glycidyl methacrylate) microspheres

ZIF-8@super-macroporous poly(glycidyl methacrylate) (SM-PGMA) microspheres were synthesized. The SM-PGMA microsphere was a novel material with high surface areas and large pore size. Here, ZIF-8 was loaded effectively both on the surface and inside of the macro-pores of microspheres by a facile way. The ZIF-8@SM-PGMA microspheres were characterized by SEM, TEM, XRD and FTIR. Additionally, they were used as an adsorbent material for the adsorption of phenol from aqueous solutions. The results indicated that the ZIF-8@SM-PGMA microspheres possessed apparently higher adsorption capacity for phenol than that of SM-PGMA microspheres. The ZIF-8@SM-PGMA microspheres obtained in this study have great potential for adsorption, separation, catalysis etc.

Adsorption and desorption of phenol onto barley husk-activated carbon in an airlift reactor

Batch studies of phenol adsorption onto barley husk-activated carbon (BHAC) were performed at different BHAC doses, solution pH, temperatures, stirring speeds, BHAC particle sizes and initial phenol concentrations. The maximum phenol adsorption capacity onto BHAC was 98.83 mg g−1 at 25°C and pH 7, similar to commercial activated carbon. The external mass transfer was minimised at stirring speeds greater than 400 min−1, and the adsorption kinetics were affected by both the initial phenol concentration and the temperature. Ethanol/water solutions at 10% V/V were the most effective regenerating agent, with a desorption capacity of 47.79 mg g−1, after five adsorption–desorption cycles. The breakthrough data for phenol adsorption using an airlift reactor were obtained at different air flow rates, initial phenol concentrations, BHAC doses and influent flow rates. Experimental data confirmed that the time to achieve the breakthrough point increases when the air flow rate or the BHAC dosage increases, as a result of more turbulent flow or greater available surface area, respectively. Additionally, the breakthrough point decreases when the initial phenol concentration or inlet flow rate increases, due to the rapid exhaustion of adsorption sites. These promising results demonstrate the feasibility of adsorption in continuous operation in an airlift reactor.

In-situ improved phenol adsorption at ions-enrichment interface of porous adsorbent for simultaneous removal of copper ions and phenol

The carboxylic acid functionalized poly (glycidyl methacrylate) (PGMA) porous material was prepared and developed as porous adsorbent for simultaneous removal of copper ions and phenol in aqueous solution. The adsorption capacities of Cu2+ and phenol were 37.5 and 36.2mg/g in their mixed solution, separately. Compared with their adsorption capacities in individual pure solution, it was found that there was no obvious difference on the adsorption behavior of copper ions in mixed solution. What’s exciting result was that the adsorption capacity of phenol in mixed solution was improved dramatically. According to the effect of pH value and the relative content of copper ions on the adsorption capacity, the adsorption mechanism of phenol at the presence of copper ions was investigated. Furthermore, the oxygen and copper elemental before and after adsorption in pure and mixed solution were analyzed by X-ray photoelectron spectroscopy in detail. It could be deduced that copper ions in mixed solution were firstly absorbed at the interface of porous monolith and then the ions-enrichment interface layer was benefit for the phenol adsorption. In addition, the adsorption isotherms and kinetics of phenol adsorption were studied, and it was further indicated that the copper ions played important role in improving phenol adsorption capacity.

Phenol removal from aqueous solution by adsorption onto solidified landfilled sewage sludge and its modified sludges

This study addresses the removal of phenol from aqueous solutions using solidified landfilled sewage sludge and its modified sludges as adsorbents. After the sludge was characterized using instrumental techniques, adsorption studies were performed in a batch system, and the effects of various experimental parameters were evaluated upon phenol adsorption. The characterization results revealed that more irregular pores, higher surface roughness, and a greater content of oxygen-containing functional groups formed in adsorbents derived from ZnCl2 or ZnCl2 and H2SO4 activation. Batch experiments revealed that pH had the weakest effect on phenol adsorption, regardless of the adsorbent type. With increasing adsorbent dosage, the phenol adsorption capacity decreased, and the phenol adsorption rate gradually increased. The maximum adsorption capacity occurred within 120 min, and a first-order kinetic model best described the adsorption. The equilibrium data fitted both the Langmuir and Freundlich isotherm models well, whereas a much higher adsorption capacity and better adsorption strength were observed for phenol adsorption onto adsorbents derived from ZnCl2 or ZnCl2 and H2SO4 activation. The results demonstrated that the solidified landfilled sewage sludge previously modified by activator treatment had a heterogeneous surface and was an effective adsorbent for phenol removal from aqueous solution.

Comparative Study of Phenol Adsorption from Aqueous Solution onto Four Kinds of Absorbents

The absorbents including MnO2, fly ash, NaY zeolite and activated carbon powder were used to study the adsorption capacity of phenol. The effect of contact time and dosage of absorbents on the removal efficiency were investigated. The experimental results suggested that activated carbon powder is most effective absorbent, following as fly ash, MnO2 and NaY zeolite which the removal efficiency could reached 98.41%,77.65%, 60.19% and 24.13% at 90min respectively. The data indicated that the activated carbon powder was favorable for adsorption while NaY zeolite was unfit for absorbent of phenol from aqueous solution due to lower removal.

Application of fractional factorial and Doehlert designs for optimizing the preparation of activated carbons from Argan shells

A high quality activated carbon has been obtained, by physical activation with steam, from a Moroccan agricultural by-product (Argan shells) and their characteristics were investigated. In order to optimize experimental conditions of the preparation, a combination of a fractional factorial design and a Doehlert design was applied. In the first step of this work, a two-level fractional factorial design 2(5–1) was used to study effects and first order interactions of various factors such as atmosphere in carbonization step, carbonization time at 400°C, activation temperature, activation time and steam flow. The results reveal that the most influential factors on the yield and the methylene blue adsorption are activation temperature, activation time, steam flow and the presence of a significant interaction between activation temperature and activation time in both cases. In the second step, activation temperature and activation time were optimized using Response Surface Methodology with a Doehlert design, and Desirability function. The optimal conditions for the preparation of activated carbon have been identified to be an activation temperature of 880°C, an activation time of 96min and steam flow fixed at this positive level of 0.2cm3min−1. The characteristics of prepared activated carbon obtained at the optimal conditions were determined using adsorption capacity of methylene blue, iodine and phenol, BET surface area, pHpzc, and surface functions based on Boehm method. Those characteristics (MB adsorption: 608.9mgg−1, iodine adsorption: 1026.4mgg−1, phenol adsorption: 633.3mgg−1, BET surface area: 1292m2g−1) were shown greater than those of a commercial activated carbon used in water treatment and those reported by other researchers studying activated carbon preparation from various solid wastes by steam activation method.On the other hand, this work showed that Argan shells are a good precursor for the production of activated carbon, by steam physical activation, with high performance to be used in water treatment applications.

Study of Phenol and Nicotine Adsorption on Nitrogen-Modified Mesoporous Carbons

In this work, a mesoporous carbon material was modified by nitrogen atom by two different ways. The X-ray photoelectron spectroscopy (XPS) results show that the N atoms at the surface mainly exist in pyridine- and pyridone-like forms (around 80 % in atom ratio). The adsorption capacity of phenol and nicotine on mesoporous carbon and two N-containing mesoporous carbons was studied through adsorption isotherms. The adsorption isotherms were interpreted by three models (Freundlich, Langmuir, and Sips equations). Heat-flow microcalorimetry in liquid phase was used to determine the bonding strength between the organic pollutants and the surface of the adsorbents. In addition, the possibility of regeneration of adsorbents was investigated by temperature-programmed desorption (TPD) technique. The obtained values of differential heats and isotherms showed the heterogeneous properties of the mesoporous carbon materials. Comparing the different results obtained from the experiments, the surface area is a key factor for the adsorption of phenol and nicotine in water. The introduction of N improved the adsorption of phenol but did not affect the adsorption of nicotine.

Synthesis and characterization of polyaniline Zr(IV) molybdophosphate for the adsorption of phenol from aqueous solution

In the present investigation, a composite cation exchange material has been synthesized by the sol–gel method and used as an adsorbent for the removal of phenol from aqueous solutions. Scanning electron microscope, Fourier transform infrared spectroscopy, X-ray diffraction and transmission electron microscopy studies were performed to characterize the polyaniline Zr(IV) molybdophosphate (PZMP) particles. The average size of the PZMP was in the nano-range. Batch adsorption studies were carried out to study the effect of various parameters like effect of pH, initial concentration, contact time and temperature. Increase in the initial phenol concentration with time could effectively increase the phenol adsorption capacity. Adsorption data of phenol agreed well with Langmuir, Freundlich, Temkin and Dubinin–Redushkeuich (D–R) isotherms at different temperatures. The maximum phenol adsorption capacity was obtained as 25.144 mg/g for 50 mg/L initial phenol concentrations. Thermodynamic parameters showed that adsorption of phenol were endothermic, spontaneous and thermodynamically favorable. The kinetic data followed pseudo-second order kinetic model.

Simultaneous adsorption of phenol and Cu2+ from aqueous solution by activated carbon/chitosan composite

A multifunction adsorbent was synthesized by incorporating AC into CTS, and the ratio of AC to CTS was 1/1. The resultant was called activated carbon (AC)/chitosan (CTS) composite. The simultaneous adsorption of phenol and Cu2+ from aqueous solution onto AC/CTS composite was investigated by a batch procedure. The adsorption processes for both Cu2+ and phenol obeyed the pseudo second-order kinetic model. Phenol was prone to be adsorbed more quickly as compared with Cu2+ when they coexisted in solution. The adsorption behavior of both phenol and Cu2+ followed the Langmuir isotherm. The maximum adsorption capacities of phenol and Cu2+ were 34.19 mg/g and 74.35 mg/g at 293 K, respectively. No obvious competitive adsorption existed between phenol and Cu2+.

Adsorption of Phenol and p-Nitrophenol from Aqueous Solutions on Metal–Organic Frameworks: Effect of Hydrogen Bonding

Three metal–organic frameworks (MOFs), MIL-100(Fe, Cr) and NH2-MIL-101(Al), were prepared, and their adsorption equilibria for phenol and p-nitrophenol (PNP) from water were investigated. All three MOFs show similar and limited adsorption capacities for phenol, but NH2-MIL-101(Al) reveals exceptional adsorption capacity for PNP, greatly exceeding those of MIL-100(Fe, Cr). MIL-100(Fe, Cr) possess similar adsorption affinity for phenol and PNP, which suggests that the effect of metal ions and the coordinatively unsaturated sites in MOFs show negligible effect for phenol and PNP adsorption from water. NH2-MIL-101(Al) exhibits superior adsorption capacity for PNP and uniquely higher adsorption selectivity for PNP over phenol than a benchmark activated carbon. The remarkable adsorption affinity is attributed to the hydrogen bonding between PNP and the amino groups in NH2-MIL-101(Al). Phenol and PNP displayed a fast adsorption kinetics on NH2-MIL-101(Al) and followed a pseudo-second-order kinetic model. This wo...

Absorption of Phenol on Nitrogen-Enriched Activated Carbon from Wood Fiberboard Waste with Chemical Activation by Potassium Carbonate

Preparation of nitrogen-enriched activated carbons from wood fiberboard waste was studied. Activated carbons were obtained with an impregnation ratio (gram chemical agent/gram wood fiberboard waste) of 3 with 50 % potassium carbonate solution in 800°C activation temperature carbonized for 1h. Optimum adsorption conditions were determined as a function of effects of contact time, pH, and dosage of activated carbon and temperature of solution for phenol adsorption. Adsorption equilibrium was achieved with in 120 min at the given phenol concentration of 250 mg/L. When 0.3 g of the carbon absorbent and 100 mL of phenol solution at 250 mg/L were used, maximum adsorption capacity of phenol on activated carbon can reach 208 mg/g. In the adsorption isotherm .the Langmuir model fit better than the Freundlich model in phenol adsorption. The kinetics of phenol adsorption followed nicely the pseudosecond-order rate expression.

Highly efficient adsorption of chlorophenols onto chemically modified chitosan

A novel chemically modified chitosan CS-SA-CD with phenol and β-cyclodextrin groups was prepared. The adsorptions of phenol, 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2,4-dichlorophenol (DCP) and 2,4,6-trichlorophenol (TCP) on the functional chitosan from aqueous solution were investigated. CS-SA-CD exhibited excellent adsorption ability for chlorophenols especially for DCP and TCP. The maximum adsorption capacities of phenol, 2-CP, 4-CP, DCP and TCP on CS-SA-CD were 59.74, 70.52, 96.43, 315.46 and 375.94mg/g, respectively. The scanning electron microscope and Brunauer–Emmett–Teller analyses revealed that the introduction of phenol group changed the surface morphology and surface properties of chitosan. The modified chitosan CS-SA-CD possesses larger surface areas (4.72m2/g), pore volume (7.29×10−3mL/g) and average pore diameter (59.99Å) as compared to those of chitosan 3.27m2/g, 2.00×10−3mL/g and 15.95Å, respectively. The enhanced adsorption of chlorophenols was also attributed to the interaction of hydrogen bond between Cl atom and OH group. The adsorption of chlorophenols on CS-SA-CD followed the pseudo-second-order kinetic model. Adsorbent could be regenerated easily and the regenerated CS-SA-CD remained 80–91% adsorption efficiency.

Phenol adsorption by modified clay from Northeastern Brazil

AbstractThis research had as objective the use of an adsorbent organoclay to remove the phenol compound, found on a large scale in aqueous effluents of petrochemical industries. The particular clay studied, called ‘Chocolate,’ originated in the Northeast Region of Brazil, from Campina Grande, Paraíba. Initially the clay sample was treated with sodium carbonate in an aqueous suspension, according to an experimental design (with the variables, sodium concentration, contact time and system temperature). The sodium‐containing clay was then treated with a quaternary ammonium salt solution. The adsorption capacity of phenol in this organoclay was estimated using the Langmuir–Freundlich Equation. The adsorptive efficiency, for the best conditions, was approximately 80% of phenol removed from the aqueous phase. The experimental data was fitted to a pseudo‐second‐order kinetic model. X‐ray diffraction results showed that the basal spacing of natural Chocolate clay and organophilic Chocolate clay were 1.549 and 2.092 nm, respectively. The maximum adsorption capacity, with experiments at pH 8.3, at room temperature (27°C), was equal to 12.287 mg g−1.

Development of olivestones-activated carbons by physical, chemical and physicochemical methods for phenol removal: a comparative study

ABSTRACTOlive stones, an agricultural waste, have successively undergone a chemical activation by ZnCl2 (coals CZ), a physical activation by CO2 (coals CP) and a combined activation by ZnCl2 followed by CO2 (coals CC) in order to compare the efficiency of these activating agents in the production of activated carbons for their applications in polluted water treatment. The obtained results show that the larger the ratio of ZnCl2 to olive stones (coals CZ and CC), and the duration of preservation of CO2 (coals CP), the more developed the porous texture. These results are confirmed by immersion calorimetry in cyclohexane and tri-2,4-xilyl phosphate. The adsorption of phenol in aqueous solution on all activated carbons at 25°C was investigated. The adsorption kinetics data were well described by the pseudo-second-order model, and all phenol adsorption isotherms on various activated carbons perfectly fit the Langmuir equation. Furthermore, the phenol adsorption capacities of activated carbons obtained by physi...

A Facile Removal of Phenol in Wastewater Using Crosslinked β‐Cyclodextrin Particles with Ultrasonic Treatment

AbstractA crosslinked β‐cyclodextrin polymer (β‐CD‐MDI), synthesized by the modification of β‐cyclodextrin (β‐CD) with crosslinking reagent diphenyl methane diisocyanate (MDI), was prepared and used as an adsorbent in the treatment of phenol wastewater ultrasonic aided. An infrared spectroscopy test was conducted to characterize β‐CD‐MDI. The adsorption capacity of phenol in wastewater was determined by assessing the corresponding parameters, such as the amount of adsorbent β‐CD‐MDI, the initial concentration of phenol, the influence of pH and ultrasonic intensity. The adsorption efficiency of β‐CD‐MDI is up to 87.3% with an amount of crosslinked polymer of 40 g/L, an initial phenol concentration of 100 mg/L and a wastewater pH of 6. The application of ultrasound can facilitate the purification of wastewater and reduce the adsorption time remarkably.

Adsorbed solution theory based modeling of binary adsorption of nitrobenzene, aniline and phenol onto granulated activated carbon

The modeling study on simultaneous adsorption of three binary systems (nitrobenzene–aniline (NI–AN), nitrobenzene–phenol (NI–PH) and phenol–aniline (PH–AN)) onto granular activated carbon (GAC) in aqueous solution were performed at 30°C by conducting batch experiments. The single solute equilibrium adsorption data of nitrobenzene (NI), aniline (AN) and phenol (PH) were fitted with Langmuir, Freundlich and Redlich–Peterson model. The Redlich–Peterson and Freundlich model gave better fitting as compared to Langmuir model for individual adsorption. The binary adsorption data were examined and compared by using ideal adsorbed solution theory (IAST) and real adsorbed solution theory (RAST) models. IAST model didn’t provide an acceptable prediction of binary data except for low liquid concentration levels, as it undervalued AN and PH adsorption capacity and overvalued NI adsorption capacity. This is due to the non-ideality of binary mixtures at high concentration levels in the solution. The RAST model gave an excellent prediction of binary adsorption experimental data, thus it can be used as a reliable model for the design of industrial adsorption equipment.