Article pubs.acs.org/est
Adsorption and Desorption of Mixtures of Organic Vapors on Beaded Activated Carbon Haiyan Wang,† Masoud Jahandar Lashaki,† Mohammadreza Fayaz,† Zaher Hashisho,†,* John H. Philips,‡ James E. Anderson,§ and Mark Nichols§ †
Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB T6G 2W2, Canada Ford Motor Company, Environmental Quality Office, Dearborn, Michigan 48126, United States § Ford Motor Company, Research and Advanced Engineering, Dearborn, Michigan 48121, United States ‡
S Supporting Information *
ABSTRACT: In this study, adsorption and desorption of mixtures of organic compounds commonly emitted from automotive painting operations were experimentally studied. A mixture of two alkanes and a mixture of eight organic compounds were adsorbed onto beaded activated carbon (BAC) and then thermally desorbed under nitrogen. Following both adsorption and regeneration, samples of the BAC were chemically extracted. Gas chromatography−mass spectrometry (GC-MS) was used to quantify the compounds in the adsorption and desorption gas streams and in the BAC extracts. In general, for both adsorbate mixtures, competitive adsorption resulted in displacing low boiling point compounds by high boiling point compounds during adsorption. In addition to boiling point, adsorbate structure and functionality affected adsorption dynamics. High boiling point compounds such as n-decane and 2,2-dimethylpropylbenzene were not completely desorbed after three hours regeneration at 288 °C indicating that these two compounds contributed to heel accumulation on the BAC. Additional compounds not present in the mixtures were detected in the extract of regenerated BAC possibly due to decomposition or other reactions during regeneration. Closure analysis based on breakthrough curves, solvent extraction of BAC and mass balance on the reactor provided consistent results of the amount of adsorbates on the BAC after adsorption and/or regeneration.
Received: Revised: Accepted: Published: © 2012 American Chemical Society
8341
April 2, 2012 June 26, 2012 June 28, 2012 June 28, 2012 dx.doi.org/10.1021/es3013062 | Environ. Sci. Technol. 2012, 46, 8341−8350
Environmental Science & Technology
■
Article
0.84 mm). The BET surface area, total pore volume, and micropore volume of the BAC were 1307 m2/g, 0.55 cm3/g, and 0.47 cm3/g, respectively. These properties were determined by a micropore surface analysis system (IQ2MP, Quantachrome) with nitrogen testing gas at 77 K. Before use, the virgin BAC was dried in a laboratory oven at 150 °C for 24 h and then cooled to ambient temperature in a desiccator. Organic Mixtures. Two mixtures were used as adsorbates for multicomponent adsorption: “alkane mixture” and “key mixture”. The alkane mixture was used to verify the analysis methods used. The key mixture consisted of eight chemicals representing different functional groups commonly used in paint solvents.1,41 These groups included aliphatic hydrocarbons, aromatic hydrocarbons and oxygenated compounds (alcohol, ketone, ester, glycol ether). The mixtures were prepared with equal molar amounts of each component. The density of each mixture was determined from the mass of a known volume (5.00 mL). The composition of the mixtures and the physical properties of the chemicals are summarized in Table 1. Extraction Solvent. BAC was extracted after adsorption and after regeneration using 3% dimethyl sulfoxide (DMSO) (99% purity, Fisher Scientific) in carbon disulfide (CS2) (99% purity, Fisher Scientific). This solvent mixture has been shown to be able to extract many commonly used automotive paint VOCs from activated carbon.42 Adsorption and Desorption Experiments. The experimental setup used in this study was described in detail by Jahandar Lashaki et al.43 and is briefly described here. A stainless steel tube (0.75 in. outer diameter, 6 in. long) was used as an adsorption-regeneration reactor and contained 6.96−7.22 g of dry virgin BAC. Glass wool was used at the bottom and top of the reactor as a support for the BAC bed. A syringe pump (kd Scientific, KDS-220) was used to inject each mixture into a 10 standard liters per minute (SLPM) dry air stream at room temperature. The air flow rate was controlled with a 0−20 SLPM mass flow controller (Alicat Scientific). A photoionization detector (PID) (Minirae 2000, Rae Systems) was used to intermittently monitor the total VOC concentration at the reactor effluent during adsorption. Before each adsorption test, the generated adsorbate gas stream was monitored with the PID and was used as a reference for effluent monitor. After generating a steady concentration stream, the gas stream was directed into the reactor to start the adsorption cycle. The adsorption cycle continued until the BAC was fully saturated as indicated by stable effluent concentrations, equal to the influent concentrations (500 ppmv), measured by the PID. Saturation typically occurred after 5 and 6.5 h for the alkane and key mixtures, respectively. During desorption, the reactor was heated from room temperature to a set-point of 288 °C using heating tape (Omega), insulation tape, and data acquisition and control (DAC) system (National Instruments, Compact DAQ).The DAC system recorded the temperature measured with a 1/16 in. outer diameter type K thermocouple (Omega) inserted at the middle and center of the reactor, and controlled the heating to maintain the 288 °C set-point temperature. A mass flow controller (Alicat Scientific) was used to provide 1 SLPM of nitrogen (99.998% purity) to purge oxygen out of the reactor and carry away desorbed compounds during regeneration. Typically, the temperature of the BAC bed reached 189 °C, 283 °C and 288 °C after 15 min, 30 min, and 40 min, respectively. After three hours, heating was stopped and the reactor was allowed to cool down for 50 min
INTRODUCTION Large amounts of organic solvents are used in automotive painting booths. On average, more than 6 kg of volatile organic compounds (VOCs) are used as paint solvents per vehicle in typical automotive plants with solvent based coatings in North America.1 These compounds can be photochemically reactive and can negatively affect local air quality.2 Adsorption onto activated carbon has been successfully applied for controlling emissions of VOCs and other organic compounds.3−10 The adsorption and regeneration of single organic compounds on activated carbon has been extensively studied.11−15 Previous research showed that the adsorption and regeneration processes on activated carbon are influenced by the characteristics of the adsorbent (specific surface area, pore size distribution, and surface functional groups) as well as of the adsorbate (polarity, boiling point, molecular weight, and molecular size).16−19 For instance, previous studies16,20 reported that activated carbon with narrower pore size distribution or small pore width was more effective in reducing oligomerization of adsorbate than activated carbon with wider pore size distribution or large pore width due to comparable pore size of activated carbon with molecular size of adsorbate. Mesopores have a significant role in the adsorption of bulky adsorbates on activated carbon, whereas micropores are typically used to capture small adsorbates.21 Adsorbates with high boiling points,22 high molecular weight,19 and large molecular size21 are susceptible to irreversible adsorption onto activated carbon. The adsorption and regeneration conditions (temperature and gas characteristics) can also affect chemisorption of adsorbates on activated carbon.17,23−26 Previous studies investigated multicomponent adsorption of organic compounds from water27−31 and air.19,32−37 Most of the adsorption and desorption experiments and models investigated binary32,35,36,38 or ternary33,37 mixtures. Few studies modeled the adsorption of more than three components from water.39,40 Limited information is available on mixture of more than three compounds. In particular, there is no information about multicomponent adsorption of painting emissions on activated carbon. These emissions typically consist of a complex mixture (more than three adsorbates) of high and low molecular weight compounds with different rates of evaporation to achieve a high quality finish, including aromatic hydrocarbons, esters, ketones, alcohols, and glycol ethers.1,41 The objective of this study is an improved understanding of multicomponent adsorption and desorption on activated carbon using relevant organic compounds typically present in automotive painting operations. For this purpose, adsorption and regeneration experiments were completed using a benchscale adsorption-regeneration system with mixtures of organic vapors as adsorbates and beaded activated carbon (BAC) as adsorbent. The BAC was extracted after adsorption and regeneration to study the partitioning of adsorbates onto BAC. Gas chromatography-mass spectrometry (GC-MS) was used to characterize the composition of the adsorption and desorption gas streams and of the BAC extract. Extraction and GC-MS analysis of the gas streams and extracts were used to understand the behavior of the organic compounds during adsorption and desorption.
■
EXPERIMENTAL (MATERIALS AND METHODS) Activated Carbon. The BAC adsorbent (Kureha America Inc.) has a mean diameter of 0.71 mm with a narrow particle size distribution (99.5% of the beads have diameter between 0.60 and 8342
dx.doi.org/10.1021/es3013062 | Environ. Sci. Technol. 2012, 46, 8341−8350
Environmental Science & Technology
Article
Table 1. Composition of Alkane Mixture and Key Mixturea
a
The order of chemicals follows GC retention time.
GC-MS analysis of the solvent extract of BAC after adsorption and regeneration was completed in triplicate with a relative standard deviation of n-butyl acetate (29 ppmv) ≫ 2-heptanone (10 ppmv) > 2-butoxyethanol (4 ppmv) > n-decane (3 ppmv) > 1,2,4-trimethylbenzene ≃ Indane ≃ 2,2-dimethylpropylbenzene (1−2 ppmv). The order of breakthrough of the tested adsorbates is generally consistent with the order of increasing boiling point except for 1,2,4-trimethylbenzene which has a boiling point (170 °C) comparable to 2-butoxyethanol (171 °C) and n-decane (174 °C). This deviation could be attributed to the difference in structure and functionality of 1,2,4-trimethylbenzene which is a bulky aromatic compound compared to the straight chain n-decane and 2-butoxyethanol. In fact the kinetic diameter of 1,2,4trimethylbenzene is 7.4 Å45 which is larger than the kinetic diameter of n-decane (4.3 Å)46 or 2-butoxyethanol which have straight chain structure. This makes the diffusion of 1,2,4trimethylbenzene out of the micropores of the BAC slower hence its breakthrough curve is shallower compared to that of n-decane
indicating that the BAC adsorbed n-decane preferentially over n-heptane, likely because of n-decane’s greater molecular weight, longer carbon chain length, and as a result, higher boiling point (Table 1). The amount of n-heptane and n-decane adsorbed on virgin BAC was calculated based on the breakthrough curve characteristics (difference between the influent and effluent n-heptane and n-decane concentrations, gas flow rate, and adsorption time), (Figure 1-b). Accordingly, the total amount adsorbed on the BAC was 37.5% of virgin BAC weight, consisting of 0.4% n-heptane and 37.1% n-decane. At the end of the adsorption cycle, a sample of the saturated BAC was extracted with 3% DMSO in CS2. Based on the GC-MS analysis of the extract, the total adsorbed amount was 41.0% of virgin BAC weight. This was somewhat higher than the estimates from the breakthrough curve (37.5%) and from the mass balance on the reactor (36.3%) (Figure 1-b). The majority (99.0%) of the extracted mass was n-decane, consistent with the earlier observation that n-decane had out-competed n-heptane during adsorption. The discrepancy in the amount of n-heptane and n-decane adsorbed between the various methods could be due to uncertainty in the gas and liquid phase GC-MS analyses and in the weighing of the BAC. The BAC saturated with the alkane mixture (as described above) was then regenerated at 288 °C. The composition of the desorption stream varied with the regeneration time which lasted for three hours (Figure 2-a). Toward the beginning of
Figure 2. (a) Effluent concentrations in the desorption stream during regeneration of BAC saturated with the alkane mixture. (b) Amounts of alkanes remaining on regenerated BAC (heel) based on solvent extraction of regenerated BAC previously saturated with the alkane mixture (eq 1) and mass balance on the reactor (eq 4). 8345
dx.doi.org/10.1021/es3013062 | Environ. Sci. Technol. 2012, 46, 8341−8350
Environmental Science & Technology
Article
Figure 3. (a) Effluent concentrations during adsorption of the key mixture on BAC, in the order of GC retention time. The boiling points are shown along with the name of chemicals. Total adsorbates concentrations measured with a PID (total by PID) and by GC-MS (total by GC-MS) in the effluent gas are also shown. Total and individual adsorbates concentration at the influent gas is shown for reference. (b) Amounts adsorbed on BAC based on breakthrough curves (eq 3), solvent extraction of the saturated BAC (eq 1), and mass balance on the reactor (eq 2).
adsorption, though to a lesser extent, include adsorbate structure (size and functionality). In general, higher boiling point compounds are preferentially adsorbed and displace lower boiling point compounds. However, for adsorbates with similar boiling point, the effect of the adsorbate size and functionality becomes more apparent. These results are consistent with previous reports that competitive adsorption and breakthrough of binary and tertiary organic mixtures on granular activated carbon and zeolite are determined by thermodynamic properties of the individual organic compounds, including boiling point,49 heat of vaporization,50 and saturation vapor pressure.34 At the beginning of the adsorption period, all the key mixture components including both high boiling point compounds (e.g., indan and 2,2-dimethylpropylbenzene) and low boiling
and 2-butoxyethanol. In addition, the electron donating methyl groups on 1,2,4-trimethylbenzene results in stronger interaction with the carbon structure.47,48 Following breakthrough, the effluent concentration of the lower boiling point species (n-butanol, n-butyl acetate, 2-heptanone, and 2-butoxyethanol) rapidly increased to beyond their influent concentrations (62.5 ppmv), generally consistent in the order of increasing boiling point. After that, their concentrations began to decrease until they dropped to their influent concentration. For high boiling point compounds (n-decane, 1,2,4-trimethylbenzene, indan and 2,2-dimethylpropylbenzene), the effluent concentration continuously increased up to their influent concentration until the end of adsorption. The boiling point is the main factor affecting the adsorption of the tested adsorbates. Other factors that may affect 8346
dx.doi.org/10.1021/es3013062 | Environ. Sci. Technol. 2012, 46, 8341−8350
Environmental Science & Technology
Article
Figure 4. (a) Concentrations of the organic species in the desorption gas during regeneration of BAC previously saturated with the key mixture. (b) Amounts of Key mixture remaining on regenerated BAC based on solvent extraction of regenerated BAC (eq 1) and mass balance on the reactor (eq 4). Compounds identified by GC-MS in the extraction of regenerated BAC, including compounds that were not present in the key mixture but were present at a level ≥0.002% by BAC weight, are also depicted.
point compounds (e.g., n-butanol and n-butyl acetate) were able to freely occupy the abundant active sites on the BAC. However, after breakthrough occurred, far fewer adsorption sites remained available, and the low boiling point compounds were desorbed as they were displaced by the high boiling point compounds which have stronger adsorbate−adsorbent interaction. After breakthrough, the concentration of the low boiling point compounds such as n-butanol and n-butyl acetate, increased beyond their influent concentrations because they were displaced by heavier compounds. As more of the adsorbed light compounds were displaced, their concentrations decreased and ultimately approached their influent values. Compounds with high boiling points needed longer adsorption times for the effluent concentrations to reach their influent ones, showing their preferential adsorption. For instance, the effluent concentration
of 2,2-dimethylpropylbenzene only approached its influent amount after 335 min because it preferentially adsorbed onto the BAC and displaced the more volatile compounds. Figure 3-b shows the individual chemical and total amounts adsorbed based on the adsorption breakthrough curves, chemical extraction of saturated BAC with CS2-DMSO, and mass balance on the reactor during adsorption. The total amount adsorbed calculated from the adsorption breakthrough curves (i.e., based on the difference between the influent and effluent concentration of the adsorbates) was 50.5% and modestly greater than the amount determined based on extraction of the saturated BAC (40.7%) and by mass balance on the reactor (42.4%). The discrepancy among these three estimates may be due to chemisorption of some of the adsorbates that cannot be chemically extracted from the BAC, uncertainty in the 8347
dx.doi.org/10.1021/es3013062 | Environ. Sci. Technol. 2012, 46, 8341−8350
Environmental Science & Technology
Article
competitive adsorption of organic compounds on activated carbon. In general, high boiling point compounds displaced low boiling points compounds. For adsorbate with similar boiling points, the structure and functionality of the adsorbate also affected adsorption dynamics. High boiling point compounds might contribute to heel accumulation on the activated carbon since they are more difficult to desorb.
measurements of some of the compounds in the gas and liquid phase, and the limited number of samples collected during gas phase analysis of the effluent gas stream. For example, in the latter case, missing a spike between data points in effluent gas analyses would have resulted in an overestimation of the adsorbed amount. The extraction results were qualitatively consistent with the analyses of the effluent stream during adsorption in that the extracted amounts of each component generally increased with the boiling point and molecular weight and follow the replacement order during adsorption. 1,2,4trimethylbenzene deviated from this rule because of its structure (large kinetic diameter) and/or functionality (three electron donating methyl groups) which resulted in its slower diffusion and stronger interaction with the adsorbent as explained before. After the 390 min adsorption period with the key mixture, the BAC was regenerated for 180 min. Figure 4-a depicts the composition of the resulting desorption stream. The concentrations of lighter compounds such as n-butanol and n-butyl acetate were negligible since they were displaced by heavier compounds during adsorption and only small amounts were retained at the end of adsorption (Figure 3-b). At the beginning of regeneration (e.g., after 15 min.), the concentrations of most compounds were above the limit of quantification. With time, the effluent concentrations of each dropped into the quantifiable range and eventually asymptotically approached zero. The order generally followed their boiling points. At the end of the 3 h regeneration period, n-decane and 2,2-dimethylpropylbenzene were still detected indicating that some amount of these compounds were still present on the BAC. These two compounds have relatively high molecular weight compared to other chemicals (Table 1), indicating the heavy compounds need more energy to desorb from activated carbon. The total heel after regeneration was 1.09% by weight of virgin BAC based on mass balance on the reactor. Speciation results for compounds in the chemical extract of BAC after regeneration are depicted in Figure 4-b. Based on GCMS analysis of the regenerated BAC extract, compounds present in the key mixture contributed 1.34% by weight of BAC to the nonthermally desorbed heel, including 2,2-dimethylpropylbenzene (1.04%) and n-decane (0.30%), while none of the other compounds were detected. These results are consistent with those obtained from analysis of the desorption stream which showed that 2,2-dimethylpropylbenzene and n-decane were still desorbing at the end of the regeneration process and contributed to the heel (Figure 4-a). Additional compounds not present in the key mixture were also detected in the regenerated BAC extract (Supporting Information Figure S-2). These additional compounds contributed an additional 0.14% by weight of BAC and were detected only in the regenerated BAC extract. The origin of these compounds is not known, but may have been formed due to thermal decomposition or other reactions of the key mixture compounds during the regeneration period.51 These additional compounds were not detected with GC-MS analysis of the liquid (neat components) or gas (adsorption gas stream) key mixture nor in the desorption gas stream. For instance, 2,2,4,4,5,5,7,7octamethyloctane coeluted with 5-t-butyl-cycloheptene which is an impurity in 2,2- dimethylpropylbenzene. It is possible that this extra compound originated from the breakdown of 5-t-butylcycloheptene during regeneration (Supporting Information Figure S-2). The results from this study shows that the boiling point of the adsorbate was the main factor affecting adsorption dynamics in
■
ASSOCIATED CONTENT
S Supporting Information *
Additional information including Figures S-1 and S-2. This material is available free of charge via the Internet at http://pubs. acs.org.
■
AUTHOR INFORMATION
Corresponding Author
*Phone: +1-780-492-0247; fax: +1-780-492-0249; e-mail:
[email protected]. Notes
The authors declare no competing financial interest.
■
ACKNOWLEDGMENTS We acknowledge financial support for this research from Ford Motor Company and the Natural Science and Engineering Research Council (NSERC) of Canada. We also acknowledge the support of infrastructure and instruments grants from Canada Foundation for Innovation (CFI), NSERC, and Alberta Advanced Education and Technology. Disclaimer: While this article is believed to contain correct information, Ford Motor Company (Ford) does not expressly or impliedly warrant, nor assume any responsibility, for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe the rights of third parties. Reference to any commercial product or process does not constitute its endorsement. This article does not provide financial, safety, medical, consumer product, or public policy advice or recommendation. Readers should independently replicate all experiments, calculations, and results. The views and opinions expressed are of the authors and do not necessarily reflect those of Ford. This disclaimer may not be removed, altered, superseded or modified without prior Ford permission.
■
REFERENCES
(1) Kim, B. R. VOC emissions from automotive painting and their control: A review. Environ. Eng. Res. 2011, 16 (1), 1−9. (2) Sexton, K.; Westberg, H. Ambient hydrocarbon and ozone measurements downwind of a large automotive painting plant. Environ. Sci. Technol. 1980, 14 (3), 329−332. (3) Chiang, Y.; Lee, C.; Su, W. Adsorption behaviors of activated carbons for the exhaust from spray painting booths in vehicle surface coating. Toxicol. Environ. Chem. 2006, 88 (3), 453−467. (4) Carter, E. M.; Katz, L. E.; Speitel, G. E., Jr.; Ramirez, D. Gas-phase formaldehyde adsorption isotherm studies on activated carbon: Correlations of adsorption capacity to surface functional group density. Environ. Sci. Technol. 2011, 45 (15), 6498−6503. (5) De Nevers, N. Air Pollution Control Engineering; McGraw-Hill: New York, 1995. (6) Parmele, C.; Kovalcson, T. Adsorption: Carbon. In Odor and VOC Control Handbook; Rafson, H. J., Eds.; McGraw-Hill: New York, 1998; pp 866−893. (7) Ryu, Y.; Lee, H.; Yoo, H.; Lee, C. Adsorption equilibria of toluene and gasoline vapors on activated carbon. J. Chem. Eng. Data 2002, 47, 1222−1225.
8348
dx.doi.org/10.1021/es3013062 | Environ. Sci. Technol. 2012, 46, 8341−8350
Environmental Science & Technology
Article
(8) Adsorption by Carbons; Bottani, E. J. Tascón, J. M.D., Eds.; Elsevier Ltd: Oxford, U.K., 2008. (9) Golovoy, A.; Braslaw, J. Adsorption of automotive paint solvents activated carbon: II. Adsorption kinetics of single vapors. Environ. Prog. 1982, 1 (2), 89−94. (10) SenGupta, U. Granular activated carbon thermal regeneration process for control of VOC emissions from surface coating operations. Proceedings of the 81th APCA Annual Meeting, Paper 88/84.4, Dallas, TX, July, 1988. (11) Popescu, M.; Joly, J. P.; Carré, J.; Danatoiu, C. Dynamical adsorption and temperature-programmed desorption of VOCs (toluene, butyl acetate and butanol) on activated carbons. Carbon 2003, 41 (4), 739−748. (12) Aktas, O.; Cecen, F. Effect of type of carbon activation on adsorption and its reversibility. J. Chem. Technol. Biotechnol. 2006, 81, 94−101. (13) Kim, K. J.; Kang, C. S.; You, Y. J.; Chung, M. C.; Jeong, S. W.; Jeong, W. J.; Woo, M. W.; Ahn, H. G. Adsorption-desorption characteristics of modified activated carbons for volatile organic compounds. Stud. Surf. Sci. Catal. 2006, 159, 457−460. (14) Prakash, J.; Nirmalakhandan, N.; Speece, R. E. Prediction of activated carbon adsorption isotherms for organic vapors. Environ. Sci. Technol. 1994, 28 (8), 1403−1409. (15) Hashisho, Z.; Rood, M. Microwave-swing adsorption to capture and recover vapors from air streams with activated carbon fiber cloth. Environ. Sci. Technol. 2005, 39 (17), 6851−6859. (16) Lu, Q. L.; Sorial, G. A. The role of adsorbent pore size distribution in multicomponent adsorption on activated carbon. Carbon 2004, 42 (15), 3133−3142. (17) Henning, K. D.; Bongartz, W.; Degel, J. Adsorptive recovery of problematic solvents. The Meeting of the Nineteenth Biennial Conference on Carbon; Pennsylvania State University, 1989. (18) Rudling, J.; Bjö rkholm, E. Irreversibility effects in liquid desorption of organic solvents from activated carbon. J. Chromatogr., A 1987, 392, 239−248. (19) Guideline Series, Control of Volatile Organic Compound Emissions from Reactor Processes and Distillation Operations Processes in the Synthetic Organic Chemical Manufacturing Industry; United States Environmental Protection Agency: Research Triangle Park, North Caroline, 1993. (20) Lu, Q.; Sorial, G. A. Adsorption of phenolics on activated carbonImpact of pore size and molecular oxygen. Chemosphere 2004, 55, 671− 679. (21) Tanthapanichakoon, W.; Ariyadejwanich, P.; Japthong, P.; Nakagawa, K.; Mukai, S. R.; Tamon, H. Adsorption-desorption characteristics of phenol and reactive dyes from aqueous solution on mesoporous activated carbon prepared from waste tires. Water Res. 2005, 39, 1347−1353. (22) McGinness, M. A. Novel new approach to VOC and HAP emission control. In Proceedings from the Twenty-second National Industrial Energy Technology Conference, Houston, TX, 2000. (23) Schnelle, K. B.; Brown, C. A. Air Pollution Control Technology Handbook; CRC Press: New York, USA, 2002. (24) Á lvarez, P. M.; Beltrán, F. J.; Gómez-Serrano, V.; Jaramillo, J.; Rodriguez, E. M. Comparison between thermal and ozone regenerations of spent activated carbon exhausted with phenol. Water Res. 2004, 38 (8), 2155−2165. (25) Magne, P.; Walker, P. L., Jr Phenol adsorption on activated carbons: Application to the regeneration of activated carbons polluted with phenol. Carbon 1986, 24 (2), 101−107. (26) De Jonge, R. J.; Breure, A. M.; Van Andel, J. G. Reversibility of adsorption of aromatic compounds onto powdered activated carbon (PAC). Water Res. 1996, 30 (4), 883−892. (27) Sulaymon, A. H.; Ahmed, K. W. Competitive adsorption of furfural and phenolic compounds onto activated carbon in fixed bed column. Environ. Sci. Technol. 2008, 42 (2), 392−397. (28) Hand, D. W.; Loper, W. S.; Ari, M.; Crittenden, J. C. Prediction of multicomponent adsorption equilibria using ideal adsorbed solution theory. Environ. Sci. Technol. 1985, 19 (11), 1037−1043.
(29) Lu, Q.; Sorial, G. A. A comparative study of multicomponent adsorption of phenolic compounds on. GAC and ACFs. J. Hazard. Mater. 2009, 167, 89−96. (30) Li, P.; Xiu, G.; Jiang, L. Competitive adsorption of phenolic compounds onto activated carbon fibers in fixed bed. J. Environ. Eng. August, 2001, 730−734. (31) O’Connor, T. P.; Mueller, J. A.; Mahony, J. D.; DiToro, D. M. A correction factor for predicting the multicomponent adsorption of air stripper offgas. Water Environ. Res. 1996, 68 (1), 66−69. (32) Lordgooei, M; Kim, M. Modeling volatile organic compound sorption in activated carbon. II: Multicomponent equilibrium. J. Environ. Eng. 2004, 130, 223−230. (33) Chenu, M.; Bouzaza, A.; Wolbert, D.; Laplanche, A. Adsorption of volatile organic compounds (VOC) mixtures onto activated carbon. Experimental study and simulation of multicomponent adsorption. Environ. Technol. 1998, 19, 1029−1038. (34) Aizpuru, A.; Malhautier, L.; Roux, J. C.; Fanlo, J. L. Biofiltration of a mixture of volatile organic compounds on granular activated carbon. Biotechnol. Bioeng. 2003, 83, 479−488. (35) Braslaw, J.; Golovoy, A.; Beckwith, E. C. Adsorption of automotive paint solvents on activated carbon: III. Equilibrium adsorption of binary mixtures. Chem. Eng. Commun. 1987, 51, 321−331. (36) Fletcher, A. J.; Benham, M. J.; Thomas, K. M. Multicomponent vapor sorption on active carbon by combined microgravimetry and dynamic sampling mass spectrometry. J. Phys. Chem. B 2002, 106, 7474−7482. (37) Gironia, F.; Piemontea, V. VOCs removal from dilute vapour streams by adsorption onto activated carbon. Chem. Eng. J. 2011, 172, 671−677. (38) Cal, M. P.; Rood, M. J.; Larson, S. M. Removal of VOCs from humidified gas streams using activated carbon cloth. Gas Sep. Purif. 1996, 10 (2), 117−121. (39) Kuennen, R. W.; Van Dyke, K.; Crittenden, J. C.; Hand, D. W. Predicting the multicomponent removal of surrogate compounds by a fixed-bed adsorber. J. Am. Water Works Assoc. 1989, 81 (12), 46−58. (40) Crittenden, J. C.; Luft, P.; Hand, D. W.; Oravitz, J. L.; Loper, S. W.; Arl, M. Prediction of multicomponent adsorption equilibria using ideal adsorbed solution theory. Environ. Sci. Technol. 1985, 19 (11), 1037−1043. (41) Golovoy, A.; Braslaw, J. Adsorption of automotive paint solvents on activated carbon: Equilibrium adsorption of single Vapors. J. Air Pollut. Control Assoc. 1981, 31 (8), 861−865. (42) Lopes, D. P. DMSO/CS2Mixture: A solvent system for desorption of polar and nonpolar paint solvents from activated charcoal. Am. Ind. Hyg. Assoc. J. 1997, 58, 603−607. (43) Jahandar Lashaki, M.; Fayaz, M.; Wang, H.; Hashisho, Z.; Philips, J. H.; Anderson, J. E.; Nichols, M. Effect of adsorption and regeneration temperature on irreversible adsorption of organic vapors on beaded activated carbon. Environ. Sci. Technol. 2012, 46 (7), 4083−4090. (44) RAE Systems Inc. http://www.raesystems.com/sites/default/ files/downloads/FeedsEnclosure-TN-106_Correction_Factors.pdf (accessed July 10, 2012). (45) Corma, A.; Corell, C.; Pitrez-Pariente, J.; Guil, J. M.; Guil-Lopez, R.; Nicolopoulos, S.; Gonzalez Calbet, J.; Vallet-Regit, M. Adsorption and catalytic properties of MCM-22: The influence of zeolite structure. Zeolites 1996, 16, 7−14. (46) Breck, D. W. Zeolites Molecular Sieves: Structure, Chemistry and Use; Wiley: New York, NY, 1974. (47) Grant, T. M.; King, C. J. Mechanism of irreversible adsorption of phenolic compounds by activated carbons. Ind. Eng. Chem. Res. 1990, 29 (2), 264−271. (48) Osei-Twum, E. Y.; Abuzaid, N. S.; Nahkla, G. Carbon-catalyzed oxidative coupling of phenolic compounds. Bull. Environ. Contam. Toxicol. 1996, 56 (4), 513−519. (49) Clausse, B.; Garrot, B.; Cornier, C.; Paulin, C.; Simonot-Grange, M. H.; Boutros, F. Adsorption of chlorinated volatile organic compounds on hydrophobic faujasite: Correlation between the thermodynamic and kinetic properties and the prediction of air cleaning. Microporous Mesoporous Mater. 1998, 25 (1−3), 169−177. 8349
dx.doi.org/10.1021/es3013062 | Environ. Sci. Technol. 2012, 46, 8341−8350
Environmental Science & Technology
Article
(50) O’Connor, T. P.; Mueller, J. A.; Mahony, J. D.; DiToro, D. M. A correction factor for predicting the multicomponent adsorption of air stripper offgas. Water Environ. Res. 1996, 68 (1), 66−69. (51) Anderson, J. E.; Gilland, R. D.; Adams, J. A.; Saloka, G. S.; Dearth, M. A.; Novak, R. F.; Kim, B. R.; Wherrett, M. R.; Davies, K. L.; Hula, A. C.; Edgeworth, R. K.; Ryan, P. A.; Cowles, H. Recovering VOCs from paint spraybooth air using an activated-carbon fluidized-bed adsorber for subsequent power generation. In 99th Air & Waste Management Association Annual Conference; New Orleans, LA, 2006.
8350
dx.doi.org/10.1021/es3013062 | Environ. Sci. Technol. 2012, 46, 8341−8350
