Maximum Phenol Removal Research Articles

Effect of Solvent and pH on the Extraction of Carbolic Acid from Aqueous Solution by TOMAC

Studies on the extraction of carbolic acid (phenol) at different pHs by trioctyl methylammonium chloride (TOMAC) diluted in octane, decan, octan-1-ol, and decan-1-ol are reported. Experimental results of batch extraction experiments are calculated and reported for distribution coefficients (KD), loading factors (Z), and extraction efficiency (E). All measurements were carried out at 298.15 K. The maximum removal of phenol was observed to be 88.679% at pH = 5 for octan-1-ol. The results of the liquid–liquid equilibrium measurements were correlated with a linear solvation energy relationship (LSER) model, which takes into account physical interactions. The remaining parameters were fitted to the experimental results. Experimental results for the liquid–liquid equilibrium were compared to the model. The LSER model was applied to correlate experimental values.

Optimization of the preparation of activated carbon from steam activated cornstraw black liquor for phenol removal

AbstractThe activated carbon (AC) was produced from steam activation of cornstraw black liquor. Response surface methodology (RSM) and the central composite design (CCD) were employed for determining optimal adsorbents with maximum phenol removal capacity. The operational parameters such as activation temperature (°C), duration (min) and steam velocity (SV) (L min−1) were chosen as independent variables in CCD. The statistical analysis indicates that the effects of activation temperature, duration, steam flow rate and combined effect of activation temperature and duration are all significant to the phenol removal capacity. The optimal condition for achieving the maximum phenol adsorption capacity is obtained as the followings: carbonization temperature (850 °C), duration (2.1 h) and SV (38 L h−1) with phenol removal capacity reaching 130 mg/g. The BET specific surface area of AC prepared at optimal conditions could reach 800 m2/g. © 2016 Curtin University of Technology and John Wiley & Sons, Ltd.

Removal of phenol at high concentrations using UV/Persulfate from saline wastewater

This study investigated the degradation of phenol at high concentrations from saline wastewater using UV/Persulfate (UV/PS) in a bench scale reactor. The effect of operational variables such as PS concentration (50, 80, 100, 150, and 200 mM), solution pH (3, 7, and 10), initial phenol concentration (200, 450, 1,000, 1,500, and 2,000 mg/L), and NaCl concentration (30,000, 50,000, and 70,000 mg/L) were surveyed. The results revealed that maximum removal of phenol (91%) was obtained after 60 min of reaction at PS molar concentration of 150 mM. Also, changes in pH values had no significant effect on removal efficiency and had slightly greater removal at acidic pH, so pH 3 was selected as optimum. Phenol removal efficiency was increased from 91 to 93% with an increase in the NaCl concentration from 30,000 to 70,000 mg/L, respectively. In addition, phenol removal percentages decrease with an increase in the initial phenol concentration. Efficiency of PS and UV photolysis were 30 and 21%, respectively. The results showed that UV/PS process could be optimally used to remove phenol from saline wastewater and could be effective, economically and environmentally.

Evaluation of micro- and nano-carbon-based adsorbents for the removal of phenol from aqueous solutions

This work reports on the adsorption efficiency of two classes of adsorbents: nano-adsorbents including carbon nanotubes (CNTs) and carbon nanofibers (CNFs); and micro-adsorbents including activated carbon (AC) and fly ash (FA). The materials were characterized by thermogravimetric analysis, transmission electron microscopy, Brunauer–Emmett–Teller (BET) specific surface area, zeta potential, field emission scanning electron microscopy, and UV spectroscopy. The adsorption experimental conditions such as pH of the solution, agitation speed, contact time, initial concentration of phenol, and adsorbent dosage were optimized for their influence on the phenol. The removal efficiency of the studied adsorbents has the following order: AC > CNTs > FA > CNFs. The capacity obtained from Langmuir isotherm was found to be 1.348, 1.098, 1.007, and 0.842 mg/g of AC, CNTs, FA, and CNFs, respectively, at 2 hours of contact time, pH 7, an adsorbent dosage of 50 mg, and a speed of 150 rpm. The higher adsorption of phenol on AC can be attributed to its high surface area and its dispersion in water. The optimum values of these variables for maximum removal of phenol were also determined. The experimental data were fitted well to Langmuir than Freundlich isotherm models.

Sorption of phenol from waters on activated carbon impregnated with iron oxide, aluminum oxide and titanium oxide

The efficiency of Fe2O3, Al2O3 and TiO2 nanoparticles-loaded activated carbon (AC) for the adsorption of phenol from waters, was investigated. The raw and doped ACs were characterized by using Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, Thermogravimetric analysis and Brunauer–Emmett–Teller surface analysis. Batch adsorption experiments were performed to evaluate the effects of solution pH, agitation speed, contact time, adsorbent dosage and ionic strength on the phenol removal efficiency. Activated carbon impregnated with Fe2O3, Al2O3 and TiO2 showed higher adsorption capacity compared to raw AC. The maximum removal of phenol was achieved by iron oxide, aluminum Oxide and titanium oxide doped AC under the optimum conditions of 200mg dosage, at pH7, 150rpm agitation speed, 2ppm initial phenol concentration and contact time of 2h. While for raw AC, the maximum removal was achieved for an adsorbent dosage of 300mg under the same treatment conditions. The Langmuir isotherm model best fitted the data of the adsorption of phenol using AC, AC–TiO2, AC–Fe2O3 and AC–Al2O3, with correlation coefficient of 0.971, 0.96, 0.976 and 0.972. Surface characterization of both the impregnated AC showed an improvement in its surface area of the doped AC. The adsorption capacities, as determined by the Langmuir isotherm model were 1.5106, 3.1530, 3.2875 and 3.5461mg/g for raw AC, AC–TiO2, AC–Fe2O3 and AC–Al2O3.

Evaluation of bench-scale solar photocatalytic reactors for degradation of phenolic wastewaters

Four bench-scale solar photocatalytic reactors were fabricated viz. solar photocatalytic single-baffle reactor (SPSBR), solar photocatalytic multiple-baffles reactor (SPMBR), solar photocatalytic cascade reactor (SPCR) and solar photocatalytic pond reactor (SPPR) of 5-L capacity. Evaluation of the reactors performance was carried out by varying the volume of wastewaters in the range of 1–5 L and the recycle flow rates in the range of 250–750 mL/min for the degradation of phenolic wastewaters. The single-baffle reactor gives the maximum phenol removal efficiency irrespective of all volume of wastewater. The phenol removal efficiency increases when the recycle flow rate is increased from 250 to 500 mL/min and then decreased for the recycle flow rate of 750 mL/min. The single-baffle reactor showed the maximum phenol removal efficiency with recycle flow rate of 500 mL/min. For untreated pulp and paper mill wastewater of 200 mg/L phenol concentration, the BOD5/COD ratio is 0.02, while solar photocatalytic treatment of 4 h enhanced the biodegradability values to 0.80.

Simultaneous Continuous Removal of Cr(VI) and Phenol from Binary Synthetic Simulated Waste Water in Tea Waste Packed Bed Column: Kinetic Modeling

In this study, simultaneous co-adsorption of Cr(VI) and phenol was carried out in a continuous packed-bed reactor packed with tea waste biomass. The experiments were carried out using binary synthetic simulated solution containing 100 mg/L of Cr(VI) and 50 mg/L of phenol. The binary synthetic solution was passed through the packed-bed reactor at different flow rates (5.46, 8.19, and 16.3 mL/min) and bed height (36, 54, 72, and 93 cm). The pH of the binary synthetic solution was 5 as the maximum simultaneous percentage removal of Cr(VI) and phenol was obtained at this pH reported in our previous study.[1] The effects of flow rate and bed depth onto the simultaneous percentage removal of Cr(VI) and phenol were investigated. According to the average percentage error (ϵ%) and average relative error (ARE %) calculated for various kinetic models reveal that Yoon–Nelson model for Cr(VI) and Thomas model for phenol best describes the experimental data. The maximum adsorption capacity of tea waste biomass in a packed-bed reactor for Cr(VI) and phenol was 57.04 and 27.96 mg/g, respectively. The packed bed of the column was regenerated using 2 N NaOH.

DEGRADATION OF PHENOL USING SEQUENTIAL BATCH REACTOR

The paper presents the experimental study on the use of Sequential Batch Reactor (SBR) for the degradation of phenol in the synthetic wastewater. SBR was used as a biological treatment for the reduction of COD, which is based on suspended growth system. The garden soil with cow dung was used as the seeding material in SBR, the micro-organisms that are present help in degradation of phenol as well as reducing the COD concentration. The parameters varied in the study were initial concentration of phenol in the synthetic wastewater, aeration rate and hydraulic retention time. The degradation study shows that the maximum phenol removal efficiency is 97% for 200 ppm of initial phenol concentration under 40 ml/min of aeration rate. The COD removal efficiency of 92.3% is achieved for 250 ppm of concentration of phenol. The variation in the aeration rate was found to be very effective in increasing the efficiency of SBR. For 600 ml/min of aeration, the removal efficiency of phenol and COD are respectively, 98% and 75%. But for the aeration rate of 200 ml/min the removal efficiency of COD is as high as 81.25%. Hence, with the increase in the aeration rate, there is an increase in the degradation rate of phenol and decrease in COD reduction. This study demonstrates the utilization of SBR in degrading high concentration of phenol.

Adsorptive Removal of Phenol from Aqueous Solution Using Activated Carbon Prepared from Babul Sawdust

AbstractStudy on the adsorption of phenol onto activated carbon prepared from Babul (Acacia nilotica) sawdust (BAC), a waste from sawmill, is presented in this paper. The effect of various parameters such as adsorbent dose (m), initial pH (pH0), contact time (t), initial concentration (Co), and temperature (T) on adsorption capacity of BAC was tested using batch adsorption experiments. The kinetic study was performed by using different kinetic models, viz pseudo first, pseudo second order, and intraparticle diffusion. Langmuir, Freundlich, Redlich-Peterson, and Temkin isotherm equations were used to find the suitable and well-describing experimental isotherm data. The adsorption of phenol onto BAC follows the pseudo second order kinetic model, and equilibrium adsorption data follow the Redlich-Peterson and Freundlich isotherm equation. The maximum removal of phenol was found to be about 83% for the initial concentration of 50 mg/L and about 50% for the higher initial concentration of 500 mg/L at 10 kg/...

Efficiency of Carbohydrate Additives on the Stability of Horseradish Peroxidase (HRP): HRP‐Catalyzed Removal of Phenol and Malachite Green Decolorization from Wastewater

AbstractThe present study was undertaken to develop a cost effective stabilized horseradish peroxidase (HRP) for removal of phenol and decolorization of malachite green from synthetic wastewater. As revealed by enzyme stabilization assays, guar gum and galactose improved the stability of HRP successfully in solution state as compared as other additives such as pectin, carrageenan, or starch, respectively. In order to enhance the stability of HRP, combination of galactose and guar gum were effectively optimized together along with pH by constructing an appropriate response surface methodology (RSM). The RSM results suggest 18.25% of galactose and 0.35% of guar gum for maximum stabilization of HRP at 60°C, pH 7.4. In this study, optimization of removal of phenol and decolorization of malachite green using stabilized HRP was successfully carried out. Various process parameters such as aqueous phase of pH (7.4), concentration of enzyme (1.8 U/mL), phenol concentration (0.1 mM), and reaction time of 180 min were optimized effectively to achieve maximum removal of phenol from synthetic waste water. Dye decolorization studies indicated that stabilized HRP (1.2 U/mL) required lower concentration than the native enzyme (2 U/mL) to obtain similar decolorization efficiency. In addition, stabilized enzyme successfully decolorized the dye at 60°C, pH 7.2.

Adsorption of phenol onto garlic peel: optimization, kinetics, isotherm, and thermodynamic studies

In the present study, optimization of phenol adsorption onto garlic peel (GP) was conducted with process parameters such as initial pH, adsorbent dosage, agitation speed, and contact time. The percentage removal of phenol was optimized based on these process parameters. Response surface methodology was used for optimization as it has many advantages over classical optimization methods. A Box–Behnken experimental design was employed. The optimum conditions for maximum removal of phenol from an aqueous solution of 50 mg L−1 were found as follows: pH: 2, adsorbent dosage: 2.1g L−1, contact time: 7 h, and agitation speed: 135 rpm. At these optimized conditions, batch adsorption experiments were conducted to study the effects of initial concentration and temperature on phenol removal. Thermodynamic parameters such as ΔG∘,ΔH∘ and ΔS∘ were also evaluated. From the results, the sorption process was found to be spontaneous and exothermic. The equilibrium experimental data were analyzed with several isotherm models. The adsorption kinetics for phenol removal by GP follows the pseudo-second-order kinetic model. The results from the study demonstrated that more than 80% phenol removal is possible at the above-mentioned optimum conditions.

Application of dried anaerobic digested sewage sludge as phenol biosorbent

Untreated anaerobically digested sewage sludge was used for the first time as a biosorbent for removing phenol from aqueous solution. Results showed that adsorption capacity was influenced by the pH of the aqueous solution with an observed maximum phenol removal at pH around 6–8. The adsorption equilibrium of phenolic compounds was obtained after almost two hours with an adsorption of approximately 90% of the phenolic compounds. A sorbent concentration of 1.8 g/L was found to insure the best removal percentage and the best sorbent capacity. Both Langmuir and Freundlich models have provided reasonable fittings for the data of phenol adsorption. The experimental data fitted the pseudo-second-order kinetic model and the intraparticle diffusion model. The values of change in Gibbs free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) were calculated. The thermodynamic study of adsorption process showed that the process was exothermic in nature.

Dephenolization, dearomatization and detoxification of olive mill wastewater with sonication combined with additives and radical scavengers

In this study, the effects of some additives [manganese (III) oxide (Mn3O4), Cu+2, Fe0 and potassium iodate (KIO3)] and some radical scavengers [sodium carbonate (Na2CO3), perfluorohexane (C6F14) and t-butyl alcohol (C4H10O)] on the sonication of olive mill effluent wastewater (OMW) were investigated since the wastewaters of this industry are removed with low efficiencies. The maximum total phenol and total aromatic amines (TAAs) removal efficiencies were 88% and 79%, respectively, at 60°C with only 150min sonication. The maximum phenol removal was found as 98% with 19mgL−1 perfluorohexane and 5mgL−1 Fe0 while the maximum TAAs removal was 99% with 16mgL−1 KIO3. Catechol, tyrosol, quercetin, caffeic acid, 4-methyl catechol, 2-phenylphenol (2-PHE) and 3-phenyl phenol (3-PHE) were detected as phenol intermediates while trimethlyaniline, aniline, o-toluidine, o-anisidine, dimethylaniline, ethylbenzene and durene were identified as TAAs in the OMW. The maximum acute toxicity removals were 96% and 99% in Vibrio fischeri and Daphnia magna, respectively. Total phenol, TAAs and the toxicity in an OMW were removed efficiently and cost-effectively through sonication.

Modeling and optimization of photocatalytic/photoassisted-electro-Fenton like degradation of phenol using a neural network coupled with genetic algorithm

Oxidation of phenol in aqueous media using supported TiO2 nanoparticles coupled with photoelectro-Fenton-like process using Mn2+ cations as catalyst of electro-Fenton reaction was studied. The influence of the basic operational parameters such as initial pH of the solution, applied current, initial Mn2+ concentration, initial phenol concentration and kind of ultraviolet (UV) light on the oxidizing efficiency of phenol was studied. An artificial neural network (ANN) model was coupled with genetic algorithm to predict phenol oxidizing efficiency and to find an optimal condition for maximum phenol removal. The findings indicated that ANN provided reasonable predictive performance (R2=0.949).

Optimization of Removal of Phenol from Aqueous Solution by Ionic Liquid‐Based Emulsion Liquid Membrane Using Response Surface Methodology

AbstractResponse surface methodology was employed to optimize the removal of phenol from aqueous solution by ionic liquid (1‐butyl‐3‐methylimidazolium hexafluorophosphate dissolved in tributyl phosphate) based emulsion liquid membrane. A “minimum run resolution V” central composite design with six variables (surfactant concentration, internal phase concentration, emulsification time, internal to membrane phase ratio, stirring speed and external phase pH) was applied to optimize the process. The optimized conditions for maximum removal of phenol were a surfactant concentration – 4.95% (v/v), internal agent concentration – 0.298 N, emulsification time – 4.07 min, internal to membrane phase ratio – 0.93, stirring speed – 247 rpm and external phase pH – 5.91 respectively. The results showed good fits with the proposed statistical model for removal of phenol (R2 = 0.9833).

Biological treatment of phenolic wastewater in an anaerobic continuous stirred tank reactor

In the present study, an anaerobic continuous stirred tank reactor (ACSTR) with consortium of mixed culture was operated continuously for a period of 110 days. The experiments were performed with three different hydraulic retention times and by varying initial phenol concentrations between 100 to 1000 mg/L. A maximum phenol removal was observed at a hydraulic retention time (HRT) of 4 days, with an organic loading rate (OLR) of 170.86 mg/L.d. At this condition, phenol removal rate of 89% was achieved. In addition, the chemical oxygen demand (COD) removal corresponds to phenol removal. Additional operating parameters such as pH, MLSS and biogas production rate of the effluents were also measured. The present study provides valuable information to design an anaerobic ACSTR reactor for the biodegradation of phenolic wastewater.

The potential of different bio adsorbents for removing phenol from its aqueous solution

The use of natural resources for the removal of phenol and phenolic compounds is being looked upon by researchers in preference to other prevailing methods. In the present study, different biosorbents, brown algae (Padina pavonia), fresh water macrophyta (Ceratophyllum demersum), and black tea residue, were tested as adsorbent for the removal of phenol from aqueous solutions. The optimum conditions for maximum adsorption in terms of concentration of the adsorbate and pH were identified. The results show that the initial concentration increases as the removal of phenol increases in C. demersum; in the case of the other two adsorbents, the initial concentration increases as the removal of phenol decreases, especially for an initial concentration lower than 100 and 1,000μg/L for P. pavonia and black tea residue, respectively. Maximum percentage removal of phenol by each adsorbent is 77, 50.8, and 29% for C. demersum, P. pavonia, and black tea residue, respectively. Also, the biosorption capacity was strongly influenced by the pH of the aqueous solution with an observed maximum phenol removal at pH of around 6-10. The first biosorbent (black tea residue) displays the maximum adsorption capacity at a pH of 10 with a percentage sorption capacity of 84%; P. pavonia revealed a greater adsorption percentage at pH 10, reaching 30%, while for C. demersum, the removal of phenol increases with the increase in initial pH up to 6.0 and decreases drastically with further increase in initial pH. The Freundlich, Langmuir, and Brauner-Emmet-Teller adsorption models were applied to describe the equilibrium isotherms. The results reveal that the equilibrium data for all phenol adsorbents fitted the Freundlich model which seemed to be the best-fitting model for the experimental results with similar values of coefficient of determination.

Biodegradation of phenol from a synthetic aqueous system using acclimatized activated sludge

Phenol is one of the aromatic hydrocarbons. Phenol and its derivatives are highly toxic. These pollutants can be observed in the effluents of many industries. This research investigates the removal of phenol by the use of activated sludge in a batch system. The effects of influencing factors on biodegradation efficiency have been evaluated. The main factors considered in this study were the volume of acclimatized activated sludge inoculation, pH, temperature, and initial concentration of phenol. The inoculation volumes of 1, 3, and 5 mL of acclimatized activated sludge were taken into account. Different pH values of 3, 5, 7, 9, and 11 were examined. The experiments were conducted for temperatures of 25, 30, 35, and 40 °C and initial phenol concentrations of 400, 800, 1,000, and 1,500 ppm. The results show that the acclimatized activated sludge has a high capacity for the removal of phenol. From a 100-mL aqueous solution was removed 1,500 ppm of phenol after 80 h. Furthermore, maximum phenol removal was observed for an inoculation volume of 5 mL for three different phenol concentrations of 100, 400, and 800 ppm. The best pH was 7 for the biodegradation process, and the optimum temperature was 30 °C. It was further found that an increase in the phenol concentration increased its removal time. Moreover, the activated sludge could effectively remove about 99.9 % of phenol from a synthetic aqueous solution in a batch system.

Ozonation of acidic phenol wastewater with O3/Fe(II) in a rotating packed bed reactor: Optimization by response surface methodology

The relatively low gas–liquid mass transfer efficiency and the low activity of ozone in acidic solution limit the application of ozonation. In this work, ferrous-catalyzed homogeneous ozonation (FCHO) was adopted to treat acidic phenol wastewater in a rotating packed bed (RPB), and the operating conditions in this process were optimized by using a response surface method (RSM). The variables investigated included the rotation speed (300–1500rpm), liquid flow rate (10–30L/h), ferrous ion concentration (0–0.8mM) and inlet ozone concentration (30–70mg/L). Experiments were carried out on the basis of a central composite design approach. It was found that ferrous ion could effectively enhance the ozonation of phenol and the rotation speed affected both phenol degradation degree and ozonation efficiency greatly. Quadratic models were developed with phenol degradation degree and ozonation efficiency as the responses, and the model predictions were confirmed to fit well with the experimental data with a deviation less than 11%. The BOD/COD values increased from 0.2 to 0.56 at the maximum phenol removal rate in the validation experiment. It is concluded that the quadratic model is an effective tool to optimize the FCHO process of phenol in the RPB.

Removal of phenol from aqueous solution using carbonized Terminalia chebula-activated carbon: process parametric optimization using conventional method and Taguchi’s experimental design, adsorption kinetic, equilibrium and thermodynamic study

In the present paper, the phenol removal from wastewater was investigated using agri-based adsorbent: Terminalia chebula-activated carbon (TCAC) produced by carbonization of Terminalia chebula (TC) in air-controlled atmosphere at 600 °C for 4 h. The surface area of TCAC was measured as 364 m2/g using BET method. The surface characteristic of TCAC was analyzed based on the value of point of zero charge. The effect of parameters such as TCAC dosage, pH, initial concentration of phenol, time of contact and temperature on the sorption of phenol by TCAC was investigated using conventional method and Taguchi experimental design. The total adsorption capacity of phenol was obtained as 36.77 mg/g using Langmuir model at the temperature of 30 °C at pH = 5.5. The maximum removal of phenol (294.86 mg/g) was obtained using Taguchi’s method. The equilibrium study of phenol on TCAC showed that experimental data fitted well to R–P model. The results also showed that kinetic data were followed more closely the pseudo-first-order model. The results of thermodynamic study showed that the adsorption of phenol on TCAC was spontaneous and an exothermic in nature.