Phenol Uptake Research Articles

Adsorption of phenol from aqueous solutions using activated carbon prepared from crofton weed

Abstract Activated carbon derived from crofton weed (ACCW) was evaluated for its ability to remove phenol from an aqueous solution. The kinetics study, adsorption isotherm, pH effect, and thermodynamic study were examined in batch experiments. Adsorption data for phenol uptake by ACCW were analyzed according to Langmuir, Freundlich and Temkin adsorption models. Thermodynamic parameters for the adsorption system were determined at 293 K, 313 K and 333 K (ΔH° = −22.92 kJ mol−1; ΔG° = −2.87 to −5.28 kJ mol−1 and ΔS° = −60.20 J/K·mol). ΔG° v alues obtained were negative, indicated that the adsorption of the phenol on the surface of ACCW was a spontaneous adsorption process. The kinetics process can be described by a pseudosecond-order rate equation very well. These results show that the ACCW could be considered as a potential adsorbent for phenol in aqueous solutions.

The acceleration of sludge granulation using the chlamydospores of Phanerochaete sp. HSD

In the present paper, a novel method to accelerate sludge granulation is presented. Inoculation with chlamydospores of Phanerochaete sp. HSD accelerated sludge granulation during the treatment process of phenol wastewater, and the sludge granulation rate reached 66 ± 2% on day 7, 32 days earlier than that of the control inoculated with activated sludge only. Aerobic granule in R1 (AG R1) showed an annual ring-like multilayer structure and a primary core also existed in the nuclear area of the granule. The mechanism of rapid granulation revealed that the chlamydospore could survive in phenol wastewater and form the primary matrix on which aerobic granule was developed layer by layer. In addition, AG R1 developed in a phenol uptake system to counteract the adverse effects of phenol inhibition. Higher tolerance toward wastewater with high phenol strength was exhibited, and the maximum specific phenol degradation rate reached 1.54 g phenol g −1 VSS day −1.

Adsorption of phenol onto activated carbon from seaweed: Determination of the optimal experimental parameters using factorial design

Brown seaweed biomass was used as a precursor for the preparation of activated carbon employing zinc chloride activation. The activated carbon was characterized and employed as an adsorbent for the removal of phenol from aqueous solution. In order to reduce the number of experiments to achieve better phenol removal efficiency, two independent sets of full 2 3 factorial design experiments were carried out. The results showed that all the factors were significant, besides several interactions among the factors were also significant. Using this statistical tool, the best conditions for phenol removal by the seaweed based activated carbon was established as pH 3.0; initial concentration of phenol 150 mg/L; adsorbent dosage 10 g/L; time 4 h; experimental temperature 50 °C and an agitation speed of 75 strokes/min. The maximum phenol uptake under these experimental conditions was 98.31%.

Evaluation of Activated Carbon from Fluted Pumpkin Stem Waste for Phenol and Chlorophenol Adsorption in a Fixed –Bed Micro-Column

Fluted pumpkin stem waste, which is both a waste and pollutant, was chemically modified with ortho-phosphoric acid and used to adsorb phenol and chlorophenol in fixed bed micro column It was found thatthe carbon bed sorption capacity for phenol and chlorophenol (77.20 and 80.0 mg/g) were higher than the equilibrium sorption studies. The critical bed depth increased with increasing phenol and chlorophenolconcentrations. An increase in phenol and chlorophenol concentration from 100 to 200mg/l increased the rate constant, critical bed depth (Do) and bed sorption capacity, for phenol 77.20 to 160.00mg/g and chlorophenol80.00 to 173.20mg/g. The breakthrough time, exhaustion time, uptake capacity decreased as the flow rate increased. Chlorophenol and phenol uptake capacity increased with increase in bed height. Experimental data for the change in concentration were correlated using the bed depth service time (BDST) model. In all parameters determined chlorophenol had better adsorption than phenol. Fluted pumpkin is the largest consumed vegetable in the West African sub region and therefore, creates one of the major agro waste problems in Nigeria. Preliminary investigations showed that several tons of these waste are produced daily in market places around the country but scarcely useful and therefore create environmental nuisance. The results obtained could be useful for the application of agricultural wastes for phenol and chlorophenol removal from industrial wastewater. @ JASEM

Remediation of phenol-contaminated water by adsorption using poly(methyl methacrylate) (PMMA)

Recently polymeric adsorbents have been emerging as highly effective alternatives to activated carbons for pollutant removal from industrial effluents. Poly(methyl methacrylate) (PMMA), polymerized using the atom transfer radical polymerization (ATRP) technique has been investigated for its feasibility to remove phenol from aqueous solution. Adsorption equilibrium and kinetic investigations were undertaken to evaluate the effect of contact time, initial concentration (10–90 mg/L), and temperature (25–55 °C). Phenol uptake was found to increase with increase in initial concentration and agitation time. The adsorption kinetics were found to follow the pseudo-second-order kinetic model. The intraparticle diffusion analysis indicated that film diffusion may be the rate controlling step in the removal process. Experimental equilibrium data were fitted to five different isotherm models namely Langmuir, Freundlich, Dubinin–Radushkevich, Temkin and Redlich–Peterson by non-linear least square regression and their goodness-of-fit evaluated in terms of mean relative error (MRE) and standard error of estimate (SEE). The adsorption equilibrium data were best represented by Freundlich and Redlich–Peterson isotherms. Thermodynamic parameters such as Δ G° and Δ H° indicated that the sorption process is exothermic and spontaneous in nature and that higher ambient temperature results in more favourable adsorption.

Extracting organic contaminants from water using the metal–organic framework CrIII(OH)·{O2C–C6H4–CO2}

The water-stable metal-organic framework MIL-53(Cr) is able to adsorb phenol and p-cresol from contaminated water as well as the monomeric sugar D-(-)-fructose. Based on the isotherm for phenol uptake from the liquid phase, it is proposed that the framework breathes to maximize the uptake.

Adsorption of Phenol on Different Activated Carbons Prepared from Date Pits

The potential use of different activated carbons (ACs) prepared from dates pits and phosphoric acid for the removal of phenol from aqueous solutions was investigated. Date pits were converted into five different types of activated carbons by air and phosphoric acid activation. The specific surface area (BET) of the prepared ACs varied from 794 m2/g, for the phosphoric acid:date pit ratio of 5:1, to 1707 m2/g for a ratio of 2:1. Batch adsorption experiments revealed that the adsorption of phenol varied among all of the prepared ACs, where the 2:1 AC showed the highest uptake. Equilibrium pH studies showed that the phenol removal was pH dependent and the maximum phenol uptake occurred at an equilibrium pH of 3.0. Dynamics studies indicated that the initial uptake of phenol on 2:1 AC at pH 4 was rapid, where 80% of the maximum uptake was achieved during the first 30 minutes; both surface adsorption and intraparticle diffusion were involved in the adsorption process and the data followed the pseudo second-order reaction. The equilibrium adsorption data of phenol on 2:1 AC at solution pH 3 was best described by the Redlich-Peterson, Sips, and Langmuir models.

Adsorptive Removal of Phenol by Coffee Residue Activated Carbon and Commercial Activated Carbon: Equilibrium, Kinetics, and Thermodynamics

Carbons were prepared from coffee residue using chemical activation with ZnCl2. Among five carbons prepared by varying the activating agent ratio (mass of ZnCl2/mass of coffee residue) from 0 % to 100 %, the one with an activation ratio equal to 25 % (AC 25 %) was the most effective sorbent showing the maximum phenol uptake (68 %). Consequently, all the adsorption experiments were achieved with the carbon having an activation ratio equal to 25 %. A comparative study of prepared activated carbon (AC 25 %) and a commercial activated carbon (CAC) was undertaken to determine their capacities for phenol removal. For each adsorbent−phenol system, a pseudosecond-order kinetic model described the adsorption kinetics accurately at all concentrations and temperatures for the two systems. The thermodynamics of the phenol−CAC and phenol−AC 25 % systems indicate an exothermic process. Phenol adsorption isotherms onto the prepared and commercial activated carbons have been studied. They display two plateaus. The degree of coverage of the surface of two carbons by the phenol molecules was calculated, and it was revealed that the second plateau, appearing at high concentrations, is assigned to the desorption of water molecules fixed on the surface oxygen groups of the activated carbons and the occupation of these sites by phenol molecules in excess in the treated solutions. The Langmuir, Freundlich, and Elovich models were tested.

Adaptation of bagasse fly ash, a sugar industry solid waste into zeolitic material for the uptake of phenol

AbstractBagasse fly ash (BFA), a sugar industry waste was converted into zeolitic material (ZBFA) by alkaline hydrothermal treatment. The virgin BFA and synthesized ZBFA were characterized by various instrumental techniques viz. XRF, FTIR, PXRD. Zeolitazation achieved showed that zeolite‐P was the dominant constituent of ZBFA. The physico‐chemical properties of BFA and ZBFA were compared. Morphology of the sorbents was examined by SEM. The kinetic and thermodynamic data of sorbents were evaluated by Coats and Redfern method using Thermal Analysis (TGA, DTG, and DTA) data. The point of zero charge value of the sorbents determined by mass titration method showed higher value for ZBFA (pH 8.62) as compared with BFA (pH 5.80). The specific surface area of ZBFA increased to 505 m2/g (BFA = 440 m2/g). Sorption capacities of BFA and ZBFA were examined by sorption of phenol at various operational parameters. The equilibrium data were analyzed by various adsorption isotherms viz. Langmuir, Freundlich, Temkin, and D‐R. Langmuir isotherm best fits the experimental data for ZBFA (qm = 35.43 mg/g) and BFA (qm = 16.33 mg/g). The isotherms study indicates that the sorption capacity of synthetic zeolitic (ZBFA) products is significantly increased after alkaline hydrothermal treatment. © 2010 American Institute of Chemical Engineers Environ Prog, 2011

Production and characterization of activated carbon derived from brewer’s yeast

Activated carbon (AC) was produced from brewer’s yeast with K2CO3 activation. The effects of K2CO3/yeast ratio and activation temperature on the yield and adsorption properties of the AC were investigated. The results indicate that the optimum conditions were as follows: ratio of K2CO3/yeast=2 and activation temperature 800 °C. The AC produced under the optimum conditions has BET surface area of 1,603 m2/g, pore volume of 1.43 cm2/g and average pore diameter of 3.5 nm. Adsorption of phenol onto the AC was determined by batch test at solution pH of 7. The effects of contact time and initial phenol concentration were investigated. The adsorption process was found to follow pseudo-second-order kinetics. The rate of phenol adsorption onto the AC produced was rapid with the adsorption equilibrium reached within 5 min. The experimental data fitted well with the Langmuir isotherm model. The maximum phenol uptake by the AC was estimated to be 513.5 mg/g.

Removal of phenol from petroleum refinery wastewater through adsorption on date-pit activated carbon

Experiments were carried out to evaluate the batch adsorption of phenol from petroleum refinery wastewater on a locally prepared date-pit activated carbon (DP-AC). Adsorption equilibrium and kinetics data were determined for the uptake of phenol from real refinery wastewater and from synthetically prepared aqueous phenol solution. The data were fitted to several adsorption isotherm and kinetics models. Sips as well as Langmuir models gave the best fit for equilibrium isotherms, whereas the kinetics data were best fitted by the pseudo-second order model. The enthalpy of adsorption showed an exothermic nature of the adsorption process. Several chemical and thermal techniques were tested for the regeneration of saturated activated carbon; using ethanol was found to be the most effective with more than 86% regeneration efficiency after four regeneration cycles.

Uptake and transformation of phenols by duckweed (Lemna gibba)

Uptake and transformation of phenol and its five derivatives each labeled with 14C were examined in duckweed (Lemna gibba). A kinetic analysis on uptake and metabolic transformation was conducted using the assumed compartments. Positive correlation was observed between log P and the logarithm value of relative uptake rate constant with respect to phenol, and an even higher correlation was obtained against the physico-chemical index, EffTox, where the undissociated fraction of phenol was incorporated. No significant correlation was observed between any of the electronic parameters of the phenol derivatives and the transformation rate. These analyses showed that the uptake of phenols by duckweed is mainly controlled by the hydrophobic profile of the undissociated form. For the metabolic profile, the glycoside conjugate was detected as a typical major metabolite for all phenols and the glutathione conjugate as a unique metabolite for 4-chlorophenol.

Removal of Toxic Pollutants from Aqueous Solutions by Adsorption onto Organo-kaolin

In this study, the adsorption of toxic pollutants onto cetyltrimethylammonium kaolin (CTAB-Kaolin) is investigated. The organo-kaolin is synthesized by exchanging cetyltrimethylammonium cations (CTAB) with inorganic ions on the surface of kaolin. The chemical analysis, the structural and textural properties of kaolin and CTAB-kaolin were investigated using elemental analysis, FTIR, SEM and adsorption of nitrogen at <TEX>$-196^{\circ}C$</TEX>. The kinetic adsorption and adsorption capacity of the organo-kaolin towards o-xylene, phenol and Cu(II) ion from aqueous solution was investigated. The kinetic adsorption data of o-xylene, phenol and Cu(II) are in agreement with a second order model. The equilibrium adsorption data were found to fit Langmuir equation. The uptake of o-xylene and phenol from their aqueous solution by kaolin, CTAB-kaolin and activated carbon proceed via physisorption. The removal of Cu(II) ion from water depends on the surface properties of the adsorbent. Onto kaolin, the Cu(II) ions are adsorbed through cation exchange with <TEX>$Na^+$</TEX>. For CTAB-kaolin, Cu(II) ions are mainly adsorbed via electrostatic attraction with the counter ions in the electric double layer (<TEX>$Br^-$</TEX>), via ion pairing, Cu(II) ions removal by the activated carbon is probably related to the carbon-oxygen groups particularly those of acid type. The adsorption capacities of CTAB-kaolin for the investigated adsorbates are considerably higher compared with those of unmodified kaolin. However, the adsorption capacities of the activated carbons are by far higher than those determined for CTAB-kaolin.

Adsorption of phenol by activated carbon: Influence of activation methods and solution pH

Cherry stone based activated carbon derived from a canning industry was evaluated for its ability to remove phenol from an aqueous solution in a batch process. A comparative adsorption on the uptake of phenol by using commercial activated carbon (Chemviron CPG-LF), and two non-functional commercial polymeric adsorbents (MN-200 and XAD-2) containing a styrene–divinylbenzene macroporous hyperreticulated network have been also examined. Equilibrium studies were conducted in 25 mg L −1 initial phenol concentrations, 6.5–9 solution pH and at temperature of 30 °C. The experimental data were analyzed by the Langmuir and Freundlich isotherm models. Besides, the cherry stone based activated carbons were carried out by using zinc chloride and KOH activation agents at different chemical ratios (activating agent/precursor), to develop carbons with well-developed porosity. The cherry stone activated carbon prepared using KOH as a chemical agent showed a high surface area. According to the results, activated carbons had excellent adsorptive characteristics in comparison with polymeric sorbents and commercial activated carbon for the phenol removal from the aqueous solutions.

Removal kinetics and mechanism for phenol uptake by surfactant-modified alumina

The present work has been devoted to study the kinetics and the mechanism of the phenol removal from water by surfactant-modified alumina (SMA). Sodium dodecyl sulfate (SDS), an anionic surfactant (AS) was used for the surface modification of neutral alumina. Micelle-like structures are formed on the surface of alumina, which was used for the removal of phenol from aquatic environment through the process, called adsolubilization. The SMA was found to be very efficient showing >90% phenol removal from a 50 mg/L phenol bearing solution with only 12 g/L of adsorbent dose. The kinetic study was conducted and the experimental data were analysed by different kinetic models viz., first order, second order, pseudo-first and pseudo-second order models. The details of rate-limiting step were studied. Isotherm study was conducted to find the maximum adsorption capacity and different isotherm models were analysed. The experiments were conducted with both phenol-spiked distilled water and synthetically prepared wastew...

Sorption/desorption studies on some natural minerals for the removal of toxic organic pollutants from aqueous solution

This work explored the sorption potential of Kyanite and Pyrolusite for the removal of phenol, chlorophenol (CP) and β-Naphthol (BN). Uptake of phenol and CP was negligible on Kyanite and Pyrolusite. BN was significantly sorbed on these two sorbents. Maximum uptakes of BN on Kyanite and Pyrolusite were observed in acidic medium. Langmuir and Freundlich isotherms confirm favorable sorption of BN on Kyanite and Pyrolusite with high sorption efficiency in acidic medium. The kinetics studies indicate that Pseudo-second-order models are better obeyed than Pseudo-first-order model. The intraparticle diffusion models show the lines were not passing through the origin. Statistical data analysis also verifies the applicability of Pseudo-second-order model. Desorption studies were carried out by a batch process. 100% BN was recovered from Pyrolusite when hexane and hexane:propanol mixture (99:1) was used as eluent.

Enhanced adsorption of phenol from water by a novel polar post-crosslinked polymeric adsorbent

A novel post-crosslinked polymeric adsorbent PDM-2 was prepared by Friedel-Crafts reaction of pendant vinyl groups without external crosslinking agent. Both the specific surface area and the pore volume of starting copolymer PDM-1 increased significantly after post-crosslinking. Batch adsorption runs of phenol from aqueous solution onto PDM-1 and PDM-2 were investigated. Commercial macroporous resins XAD-4 and AB-8 were chosen as the comparison. Experimental results showed that isotherms of phenol adsorption onto these four polymeric adsorbents could be represented by Freundlich model reasonably. PDM-2 exhibited higher adsorption capacity of phenol than other three adsorbents, which resulted from synergistic effect of larger specific surface area and polar groups on the network. The adsorption process for phenol was proved to be exothermic and spontaneous in nature. Thermodynamic parameters such as Gibb's free energy (Δ G), change in enthalpy (Δ H) and change in entropy (Δ S) were calculated. Kinetics studies indicated that phenol uptake onto PDM-1 and PDM-2 followed the pseudo-second order model and the intraparticle diffusion process was a rate-controlling step. Column adsorption runs demonstrated that nearly 100% regeneration efficiency for PDM-2 by 3 BV industrial alcohol and the adsorbate phenol can be easily recovered by further distilling. Continuous column adsorption–regeneration cycles indicated negligible capacity loss of PDM-2 during operation.

Performance comparison of constructed wetlands with gravel- and rice husk-based media for phenol and nitrogen removal

This study aims to compare the performance of planted and unplanted constructed wetlands with gravel- and raw rice husk-based media for phenol and nitrogen removal. Four laboratory-scale horizontal subsurface-flow constructed wetland units, two of which planted with cattail ( Typha latifolia) were operated outdoors. The units were operated at a nominal hydraulic retention time of 7 days and fed with domestic wastewater spiked with phenol concentration at 300 mg/L for 74 days and then at 500 mg/L for 198 days. The results show that planted wetland units performed better than the unplanted ones in the removal and mineralization of phenol. This was explained by the creation of more micro-aerobic zones in the root zone of the wetland plants which allow a faster rate of phenol biodegradation, and the phenol uptake by plants. The better performance of the rice husk-based planted wetland compared to that of the gravel-based planted wetland in phenol removal could be explained by the observation that more rhizomes were established in the rice husk-based wetland unit thus creating more micro-aerobic zones for phenol degradation. The role of rice husk as an adsorbent in phenol removal was considered not of importance.

Biosorption of phenol and 2-chlorophenol by Funaliatrogii pellets

The removal of phenol (Ph) and 2-chlorophenol (2-CPh) from aqueous solution by native and heat inactivated fungus Funalia trogii pellets were investigated. The effects of contact time, solid/liquid ratio, optimum pH and temperature on the phenols removal capacity by the pellets were established. The removal efficiency of phenols increased significantly with increasing biomass dose. The optimum pH was detected to be 8.0. The second-order equations are described and evaluated on the basis of a comparative estimation of the corresponding coefficients. The phenol removal equilibrium isotherm was modeled by the Langmuir equations. The enthalpy change values were obtained between −7.62 and −10.64 kJ/mol. This indicated that the uptake of phenols either on native or heat inactivated fungal pellets was based on a physical adsorption process.

Improved phenol adsorption on carbons after mild temperature steam reactivation

The purpose of this work is to explore steam reactivation at moderate temperatures of activated carbon exhausted with phenol, a highly toxic compound frequently present in industrial wastewater. The spent carbon was treated with steam at various temperatures (450, 600 and 850 °C) and times (from 5 to 60 min). Promising results were obtained by applying moderate temperatures and times. Whereas at low temperatures the complete regeneration of the carbon is not accomplished, an almost quantitative desorption of the pollutant was achieved at 600 °C after exposure times below 30 min, with minimal damages in the porous network of the carbon. Further reutilization of the regenerated carbon resulted in a superior performance towards phenol uptake. The regeneration efficiency at 850 °C strongly depends on the time of reactivation, with an enhanced phenol uptake when short treatment times are applied. Prolonged duration of the regeneration treatment reduced phenol adsorption capacities, due to overreactivation of the carbon in the steam atmosphere, and to the blockage of the porous carbon network.