Types Of Activated Carbon Research Articles

Active Carbon for Coal Mine Methane Separation by Pressure Swing Adsorption

Five types of active carbon’s adsorption isotherm of nitrogen at 77K were measured, and their adsorption characteristic were analysed. The results show AC1, AC2 and AC3 have a lot of micropores for they have high nitrogen adsorbance in low pressure at 77K. The HK model was employed to analysis the pore size distribution of the adsorbance. AC1 has most developed microspore structure, its surface area reached 1706㎡/g, and its pore size mainly concentrated at 4.6 angstroms. Then the five adsorbents’ adsorption isotherm on methane, oxygen and nitrogen at 298K, 308K and 318K were measured. Methane’s adsorption capacity on active carbon is much higher than nitrogen and oxygen, and the adsorbance of nitrogen and oxygen have little difference, so the coal mine methane could be regarded as the binary of methane and nitrogen on methane separation by adsorption method. AC1 has the highest methane adsorbance and equilibrium selectivity factor of methane to nitrogen. Then the adsorption heat was studied, the results show that the isosteric heat of methane on AC1 decreased from 20.6kJ/mol to 19.55kJ/mol when the adsorbance of methane increases from 0.4 mol/kg to 1.2mol/kg, and methane’s adsorption heat is higher than nitrogen.

A Comparative Study on the Removability of Different Ozone-Produced Oxidants by Activated Carbon Filtration

A comparative study about the removability of four potentially harmful ozone-produced oxidants (free bromine, bromamines, free chlorine and chloramines) by activated carbon filtration was performed under identical conditions in small-scale filter experiments. Removability was high and similar among the oxidants with the exception of chloramines which showed the least removability. Results proved activated carbon filtration to be very efficient in removing the dominating brominated oxides formed during the ozonation of natural and most artificial seawaters. In contrast, removability of chloramines, sometimes present in ozonated bromide-free artificial saltwater, was shown to be significantly lower. To improve removal of persistent chloramines by activated carbon filtration, a comparative evaluation of 3 different activated carbon types was conducted. Granulated activated carbon on coal basis was suggested to be the most cost-effective carbon for removing chloramines as it possessed highest removal capacity, while being the cheapest of the carbons tested.

Necessity of Development on New Types of Activated Carbons for Advanced Drinking Water Purification Technology

최근 국내의 산업화 및 공업화가 가속됨에 따라 주요 상수 원의 수질이 급속히 나빠지면서 강 하류지역의 수질이 3급수 이하로 떨어져 일반적인 정수방법으로는 오염물질의 제거가 어렵고, 1989년 이후 중금속, trihalomethanes (THM), 페놀, 벤 젠 등 각종 수돗물 유기물질 오염사고가 다발하면서 낙동강을 원수로 하는 정수장에서 우선적으로 고도정수시설을 도입하게 되었다 [1]. 기존의 정수처리 시설은 응집침전, 여과, 염소처리 로 구성되어 있으며, 이를 청정한 원수의 처리를 목적으로 하 는 ‘재래식 정수처리 공정(conventional water treatment system; CWTS)’이라고 한다 [1]. 그러나 상수원으로 사용하고 있는 주 요하천이나 호수가 각종 생활용수, 공업폐수, 농업용수 등으로 질소, 인 성분이 과다하게 증가되어 부영양화를 가속시키고 있 으며, 각종 난분해성 물질이나 중금속 성분, 발암성물질 및 농 약, 비료성분은 미량으로도 인체에 치명적인 결과를 주기 때 문에 기존의 재래식 정수처리 공정만으로는 한계가 있으며, 고 도정수처리 시스템의 도입이 필수 불가결한 문제로 대두되고 있다 [2-4].

Adsorption modeling of Cr, Cd and Cu on activated carbon of different origins by using fractional factorial design

The metallic ion removals have been studied by several researchers in the recent years. Activated carbons have been often used in metallic ions adsorption processes due their large available surface area, besides being cheap and environmentally friendly material with good cost–benefit for the industries. The present work evaluated the simultaneous adsorption of the metallic ions Cd(II), Cu(II) and Cr(VI) on activated carbons from different origins (vegetal and mineral) by using a fractional factorial design 25−1. The main and interactive factors studied were the initial concentration of metallic ions, pH, temperature, type of activated carbon and contact time. The resulting models were different for each ion. The main influent factors were the initial concentration of metal, pH and activated carbon type. The Cr(VI) adsorption was better than Cu(II) and Cd(II) at pH 2. In this condition, the vegetal activated carbon from coconut shell (DEN), Elais guineensis, was better than mineral bituminous activated carbon (MBE) for Cr(VI) adsorption. At pH 4, Cu(II) was removed in bigger quantities, especially by MBE. Cu(II) was the main metallic ion removed at pH 4. The removal of Cd(II) was efficient only at pH 4 and the mineral bituminous activated carbon showed the best performance. The variance analysis (ANOVA) was applied in the fractional factorial design and the statistic data showed adequate models.

Effect of Granular Activated Carbon on the Enhancement of Cometabolic Biodegradation of Phenol and 4-Chlorophenol

Enhancement of the cometabolic biotransformation of 4-chlorophenol (4-cp) and phenol were studied using chemically and thermally granular activated carbons (GACs). It was found that both chemically activated and thermally activated GAC effectively adsorb phenol and 4-cp. More than 80% adsorped substrates were later desorpted, showing a reversible sorption behaviour in the GAC. For each activated carbon type, 4-cp was preferentially adsorbed over phenol and the desorption efficiencies of both phenol and 4-cp were found to increase linearly with the initial mass of adsorbate in the adsorbent. The biodegradation of 500 mg/L phenol by Pseudomonas putida took 24 h while the biodegradation of 4-cp took 32 h. Inhibitions during the cometabolic biodegradation of 4-cp and phenol were alleviated by the addition of the GACs. The system with chemically-activated coconut type GAC had better system stability over thermally-activated peat type GAC. The results show that GAC can be regenerated by the cells enhancement of the cometabolic biotransformation of 4-cp and phenol can be accomplished using chemically-activated coconut type GAC.

Experimental Adsorption Isotherm of Methane onto Activated Carbon at Sub- and Supercritical Temperatures

This paper presents the experimentally measured adsorption isotherm data for methane onto the pitch-based activated carbon type Maxsorb III for temperatures ranging from (120 to 220) K and pressures up to 1.4 MPa. These data are useful to study adsorbed natural gas (ANG) storage systems when the low temperature natural gas regasified from the liquid phase is considered to charge in the storage chamber. Adsorption parameters were evaluated from the isotherm data using the Tóth and Dubinin−Astakhov models. The isosteric heat of adsorption, which is concentration- and temperature-dependent, is extracted from the data. The Henry’s law coefficients for the methane/Maxsorb III pairs are evaluated at various temperatures.

ChemInform Abstract: Catalytic Properties of Mo(CO)6-Supported on Activated Carbon for Ethene Homologation.

Abstract Several types of active carbons were used to support Mo(CO) 6 and the resultant Mo(CO) 6 /carbon was used for the homologation of ethene to yield propene as well as the metathesis of propene. Effects of pretreatment of carbon and evacuation temperature of Mo (CO) 6 /carbon on the catalytic activities were examined. Treatment of carbon with acids, such as hydrochloric and nitric, as well as air oxidation resulted in a pronounced enhancement in the catalytic activity regardless of the carbon sources. Supported Mo (CO) 6 decomposed thermally in such a way that all carbonyl ligands were lost in rapid succession without yielding intermediate subcarbonyl species. The effect of the oxidation was interpreted in terms of the contribution of surface oxygenated compounds to control the oxidation states of decomposed Mo(CO) 6 .

Influence of adsorption on phenol transport through soil–bentonite vertical barriers amended with activated carbon

The potential for enhanced containment of phenol by soil–bentonite (SB) vertical barriers amended with activated carbon (AC) was investigated. Results of batch equilibrium adsorption tests on model SB backfills amended with 0–10 wt.% granular AC (GAC) or powdered AC (PAC) illustrate that the backfills exhibited nonlinear adsorption behavior that was described well by both the Freundlich and Tóth adsorption models. The AC amended backfills exhibited enhanced phenol adsorption relative to unamended backfill due to hydrophobic partitioning to the AC. Adsorption capacity increased with increasing AC content but was insensitive to AC type (GAC versus PAC). Results of numerical transport simulations based on the measured adsorption behavior show that the Tóth model yielded similar or lower phenol breakthrough times than the Freundlich model for the range of source concentrations ( C o ) considered in the simulations (0.1–10 mg/L). Breakthrough time decreased with increasing C o but increased with increasing AC content. Predicted breakthrough times for an SB vertical barrier amended with 2–10 wt.% AC increased by several orders of magnitude relative to the theoretical case of a nonreactive (non-adsorbing) barrier. The findings suggest that AC may be a highly effective adsorption amendment for sustaining the containment performance of SB vertical barriers.

Preparation of Supported Pd Catalysts: From the Pd Precursor Solution to the Deposited Pd2+ Phase

The preparation by the deposition-precipitation method (using Na(2)PdCl(4) as a palladium precursor and Na(2)CO(3) as a basic agent) of Pd catalysts supported on gamma-Al(2)O(3) and on two different types of active carbons has been followed by several techniques (UV-vis, EXAFS, XRPD, and TPR). This work consists of four successive parts: the investigation of (i) the palladium precursor liquid solution (in the absence of substrate), (ii) the solid precipitated phase (in the absence of substrate), (iii) the precipitated Pd(2+)-phase on the supports as a function of Pd loading from 0.5 to 5.0 wt % (i.e., the final catalyst for debenzylation reactions), and (iv) the Pd(0)-phase formed upon reduction in H(2) atmosphere at 393 K. A time/pH-dependent UV-vis experiment indicates that Pd(2+) is present in the mother solution mainly as PdCl(2)(H(2)O)(2)] and [PdCl(H(2)O)(3)](+). Upon progressive addition of NaOH (3.0 < pH < approximately 3.8), the concentration of the two complexes is almost constant and then they rapidly disappear because of the precipitation of an amorphous aggregation of Pd(2+)-polynuclearhydroxo complexes. This phase represents a model material for the active supported phase. Thermal treatments at increasing temperature of this phase cause progressive water loss and resulted in a progressive increase in crystallinity typical of a defective PdO-like phase. The EXAFS spectrum of the final catalysts has been found to be intermediate between that of the unsupported amorphous Pd(2+)-polynuclearhydroxo complexes and that of the PdO-like phase. Independent of the support, EXAFS was not able to evidence any fraction of reduced metallic Pd, meaning that all Pd is in the 2+ oxidation state within the sensitivity of the technique (a few percent). Analogously, independent of the support, XRPD was not able to detect the presence of any crystalline supported phase. The Pd local environment of the as-precipitated samples changes slightly as a function of Pd loading from 0.5 to 2.0 wt %: at higher loadings, no further modification has been observed. After reduction in an H(2) atmosphere, two trends have been observed: (i) the dispersion of Pd nanoparticles tends to decrease with increasing Pd concentration, less significantly on Al(2)O(3)-supported samples and more significantly on carbon-supported ones and (ii) the dispersion depends on the carrier following the sequence Al(2)O(3) >> Cp > Cw according to the increasing palladium-support interaction strength.

Prediction of Activated Carbon Injection Performance for Mercury Capture in a Full-Scale Coal-Fired Boiler

Activated carbon injection (ACI) is an effective mercury control technology demonstrated in both short-term and long-term full-scale tests. The effectiveness of mercury capture by activated carbon depends on the mercury speciation, total mercury concentration, flue gas composition, method of capture, and activated carbon properties, such as pore size, type of carbon impregnation, and surface area, etc. It is also desired that an ACI system be designed to produce good mixing between the activated carbon and the flue gas. In recent years, General Electric Energy has conducted both short-term and long-term tests in large-scale coal-fired boilers for ACI mercury capture demonstration. The programs consisted of (1) combustion optimization to improve natural mercury capture by fly ash, (2) computational fluid dynamics (CFD) modeling of activated carbon injection to design ACI lances, (3) a short-term test to select the activated carbon type, and (4) a long-term test to evaluate the mercury capture performance. This paper presents the CFD modeling for an ACI demonstration in Sundance Station Unit 5. The CFD model developed describes the film mass transport, pore diffusion, and carbon surface adsorption and desorption phenomena for the prediction of the mercury capture rate. The model was applied to evaluate the lance design and to calculate the mercury capture rate. The test data were also presented for comparison with the model results.

Influences of pH, temperature and activated carbon properties on the interaction ozone/activated carbon for a wastewater treatment process

The influence of experimental parameters ( T, pH) and activated carbon (AC) properties on the intensity and the nature (molecular or radical) of the ozone (O 3) /AC interaction was studied to optimize an O 3/AC wastewater treatment process. This interaction was investigated by studying the dissolved O 3 decomposition kinetics in the presence of two commercial AC (Pica 150 and Picaflo), whose chemical and structural properties were previously determined by using different analyses (Boehm method, nitrogen adsorption at 77 K). The kinetic study showed that a first order model is the most suitable to describe O 3 decomposition in water ( r 2 > 0.981). Moreover, the influence of the experimental parameters was demonstrated. An increase in temperature limits the O 3/AC interaction by favouring ozone self decomposition in water. An increase in pH leads to deprotonated surface groups (when pH > pH PZC) which favour radical mechanisms but limits the interaction by electrostatic repulsion. Further, the contribution of the radical mechanism in ozone decomposition was evaluated by adding terbutyl alcohol (tBuOH) as radical scavenger. This contribution varied with the pH and the nature of the AC: it operates from 7% (pH = 3) to 76% (pH = 7) for Pica 150 and from 10% (pH = 3) to 86% (pH = 7) for Picaflo. The comparison of kinetic rate constants obtained in the presence of both types of AC revealed the importance of the chemical and structural properties of AC, especially the number of acid functions.

Removal of sulfur compounds in FCC raw C4 using activated carbon impregnated with CuCl and PdCl2

Fluid catalytic cracking (FCC) is one of the most important refinery processes for economical efficiency that produces commercial fuels with acceptable concentrations of sulfur. Several activated carbon (AC) based adsorbents were studied to develop a more efficient adsorbent for removal of mercaptanes and sulfides during the FCC C4 refinery process. The adsorbents were prepared by impregnating AC with CuCl and PdCl2. To evaluate the degree of metal halide impregnation into the AC support, each adsorbent was characterized by N2 adsorption, elemental analysis (EA) and XRF. Three types of ACs were used to investigate the effect of the structural properties such as surface area, total pore volume and pore size distribution. From this analysis, an AC micro pore size of 0.7 nm was found to be the most effective support material for FCC C4 removal of sulfur compounds. The experimental adsorption isotherms were compared with Langmuir and Freundlich models and were found to fit the Freundlich model much better than the Langmuir model. The sulfur removal performance of the prepared adsorbents was tested using the breakthrough experiments. The sulfur adsorption capacities of adsorbents decreased in the following order: AC impregnated PdCl2, AC impregnated CuCl and non-impregnated AC (NIAC). The saturated adsorbents were regenerated by toluene treatment and reactivated at 130 °C under a vacuum.

Optimization of Enzyme Assisted Processes for Extracting and Hydrolysing Corn Proteins Aiming Phenylalanine Removal

Two enzyme assisted processes were studied in this work, protein extraction and hydrolysis, aiming phenylalanine (Phe) removal from corn. For protein extraction, a protease of Bacillus liccheniformis was used and the effect of temperature (55 and 60°C) and time (1, 5, 15 and 24 h) was evaluated. For Phe removal, a pancreatin was used for hydrolyzing corn proteins and the activated carbon (AC) was the adsorbent support. In this case, the influence of several parameters was estimated, such as protein extract concentration, E:S ratio, use of freezedrying, protein: AC ratio and way of using AC. The efficiency of Phe removal was evaluated by second derivative spectrophotometry, measuring the Phe content in the corn flour as well as in the hydrolysates after AC treatment. The results showed that the time and the temperature influenced the protein extraction yield and the best results were obtained at 55°C, after 5 h, 15 h and 24 h of reaction, having reached an average extraction yield of 85.3%. The removal of Phe, changed from 68.63 to 97.55%, and its final concentration from 18.80 to 240.75 mg/100 g hydrolysate. The condition that produced the highest Phe removal was the one using a protein extract concentration = 1%, E:S = 1 or 2%, pH 9, temperature = 25°C, protein: C = 1:88.5, using three types of AC and freezedrying (hydrolysates H1 and H2). However, this condition presents some disadvantages such as the use of freezedrying, which highly raises the process cost, and a non-controlled and non-repeatable reaction. Among the samples with no freezedrying stage and more controllable reaction (H9 and H10), H10 is the best one, since it showed smaller Phe content (149.27 mg/100 g) using three types of AC, which is advantageous from the technical point of view. The reduction of the protein: AC ratio, for these two hydrolysates (H9 and H10) was not beneficial for Phe removal, leading to higher Phe content.

Competitive adsorption and desorption of a bi-solute mixture: effect of activated carbon type

This study aims to clarify the effects of carbon activation type and physical form on the extent of adsorption capacity and desorption capacity of a bi-solute mixture of phenol and 2-chlorophenol (2-CP). For this purpose, two different PACs; thermally activated Norit SA4 and chemically activated Norit CA1, and their granular countertypes with similar physical characteristics, thermally activated Norit PKDA and chemically activated Norit CAgran, were used. The thermally activated carbons were better adsorbers for phenol and 2-CP compared with chemically activated carbons, but adsorption was more reversible in the latter case. 2-CP was adsorbed preferentially by each type of activated carbon, but adsorption of phenol was strongly suppressed in the presence of 2-CP. The simplified ideal adsorbed solution (SIAS) model underestimated the 2-CP loadings and overestimated the phenol loadings. However, the improved and modified forms of the SIAS model could better predict the competitive adsorption. The type of carbon activation was decisive in the application of these models. For each activated carbon type, phenol was desorbed more readily in the bi-solute case, but desorption of 2-CP was less compared with single-solute. This was attributed to higher energies of 2-CP adsorption.

Adsorption of phenol onto activated carbons having different textural and surface properties

Adsorption of phenol in aqueous phase onto activated carbons (ACs) having different textural and surface properties has been considered. Six types of ACs were used: three were commercial, and three were obtained from Kraft lignin chemically activated with sodium hydroxide, potassium hydroxide or ortho-phosphoric acid. The apparent surface areas of the commercial ACs varied from 620 to 1320 m 2/g, while ACs made from lignin presented surface areas as high as 1300 m 2/g and 2900 m 2/g when prepared with H 3PO 4 and alkaline hydroxides, respectively; moreover, the highest proportion of microporosity was found for ACs derived from lignin. A kinetic study was carried out, showing that the phenol adsorption data may be correctly adjusted, for all the ACs tested, by an equation corresponding to a pseudo second-order chemical reaction. Freundlich, Langmuir and Tempkin equations were tested for modelling the adsorption isotherms at equilibrium, and it was concluded that Langmuir model fitted adequately the experimental data. However, Tempkin model fitted even better the adsorption data obtained with ACs derived from lignin activated with alkaline hydroxides, which are characterized by the highest number of surface groups. Remarkably high phenol adsorption capacities were found for the ACs prepared by activation of Kraft lignin with NaOH and KOH: 238 and 213 mg/g of AC, respectively. Finally, the adsorption of phenol was found to depend not only on the micropore volume, but also on the total amount of carbonyl and basic groups and on the ratio of acid to basic groups.

Monochloramine destruction by GAC—effect of activated carbon type and source water characteristics

This research evaluated the effect of granular activated carbon (GAC) type and source water characteristics on steady‐state monochloramine reduction in fixed‐bed reactors (FBRs) under drinking water treatment conditions. Five commercially available GACs and two background waters were used to study monochloramine reduction in laboratory‐scale column studies. Steady‐state monochloramine destruction increased with decreasing water pH (over the range likely in chloramination, i.e., pH 7–9) regardless of GAC type or source water. A previously developed finite element model was verified experimentally for monochloramine influent concentrations of interest in drinking water (2 mg/L as Cl2). Simulation of steady‐state process performance with GAC particle sizes used in practice was performed using the model after it was calibrated to results from the monochloramine FBR studies. These steady‐state simulations indicate that with at least one of the GACs tested, &lt; 8 min of empty bed contact time (EBCT) was required to meet the monochloramine standard for kidney dialysis water (0.1 mg/L as Cl2). Despite a required EBCT as long as 20 min, use of more‐traditional GACs may also be feasible for kidney dialysis, provided that benefits gained by steady‐state operation (i.e., never having to replace the filter media) outweigh filter size and portability considerations.

Adsorption reversibility and bioregeneration of activated carbon in the treatment of phenol

This study aims to clarify the effect of adsorbability, desorbability, biodegradability and activated carbon type on the extent of bioregeneration in the treatment of phenol. For this purpose, four different activated carbon types; one thermally activated and one chemically activated powdered carbon (PAC), and their granular countertypes (GAC) with similar physical characteristics were used. Adsorption isotherms showed that the thermally activated carbons, either in powdered or granular form, were better adsorbers for phenol than the chemically activated ones. However, adsorption was more irreversible in the case of thermally activated carbons. Bioregeneration of chemically activated carbons were found to be higher in accordance with their higher reversibility of adsorption showing that bioregeneration was controlled by the reversibility of adsorption. Bioregeneration efficiencies for the thermally activated carbons were much higher than their efficiencies of total desorbability. This indicated that some exoenzymatic reactions might have occurred so that phenol was bioregenerated more than expected.

Bioregeneration of activated carbon: A review

Bioregeneration is defined as the renewal of the adsorptive capacity of activated carbon by microorganisms for further adsorption. Bioregeneration of activated carbon increases the service-life of activated carbons. It is traditionally believed that bioregeneration occurs as a result of a concentration gradient between the carbon and the bulk liquid. Therefore, bioregeneration can only occur for compounds that readily desorb. Some researchers suggest that also exo-enzymes act in bioregeneration. Bioregeneration has been demontrated in offline systems, which involve desorption and biological removal of adsorbed organic matter in a closed-loop recirculating batch system. It has also been shown that bioregeneration of carbon occurs during the time course of wastewater treatment processes that are based on biological activated carbons (BACs). However, most of the studies aiming at quantifying bioregeneration were performed using offline systems because of difficulties encountered in quantifying bioregeneration during BAC treatments of wastewater. Bioregeneration is dependent on several factors including biodegradability, adsorbability and desorbability of sorbate, characteristics of activated carbon and process configuration, and it can be optimized by varying the operational conditions. In this review, we are addressing the enhancement of biological treatment by activated carbon, the definition and mechanisms of biological regeneration, the relationship between adsorption reversibility and bioregeneration, the factors affecting bioregeneration, the methods for determination and quantification of bioregeneration and the mathematical models of bioregeneration. Future research is still required to determine the optimum conditions for an increased bioregeneration. Particularly, factors such as the activated carbon type, nature of the microbial community and optimum process configuration need further investigation. The validity and efficiency of exo-enzymatic activities on bioregeneration should still be investigated.

Removal of an Endocrine Disrupting Chemical (17α-ethinyloestradiol) from Wastewater Effluent by Activated Carbon Adsorption: Effects of Activated Carbon Type and Competitive Adsorption

Granular activated carbon has been extensively used for the adsorption of organic micropollutants for potable water production. In this study the removal of an endocrine disrupting chemical from wastewater final effluent by three types of granular activated carbon (wood, coconut and coal based) has been investigated in batch adsorption experiments and correlated with the removal of chemical oxygen demand (COD), total organic carbon (TOC) and ultraviolet absorbance (UV). The results obtained demonstrated 17α-ethinyloestradiol (EE2) removals of 98.6%, 99.3%, and 96.4% were achieved by the coal based (ACo), coconut based (ACn) and wood based (AWd) carbons respectively at the lowest dose of carbon (0.1gl−1). The other adsorbates investigated all exhibited good removal. At an equilibrium concentration of 7mgl−1 the COD adsorption capacities were 3.16mg g−1, 4.8 mg g−1 and 7.1 mg g−1 for the wood, coconut and coal based carbons respectively. Overall, the order of removal efficiency of EE2 and the other adsorbates for the three activated carbons was ACn > ACo > AWd. The adsorption capacities of the carbons were found to be reduced by the effects of other competing adsorbates in the wastewater effluent.

Adsorption, desorption and bioregeneration in the treatment of 2-chlorophenol with activated carbon

This study aims to clarify the effect of activated carbon type on the extent of adsorbability, desorbability, and bioregenerability in the treatment of 2-chlorophenol. Four different activated carbon types; thermally activated and chemically activated powdered carbons (PAC), and their granular countertypes (GAC) with similar physical characteristics were used. Thermally activated carbons adsorbed 2-chlorophenol much better than chemically activated ones. However, adsorption was more reversible in the case of chemically activated ones. The use of powdered and granular activated carbon countertypes resulted in comparable adsorption and desorption characteristics. For each activated carbon type, 2-chlorophenol exhibited higher adsorbability and lower desorbability than phenol. Biodegradation of 2-chlorophenol took place very slowly when it was used as the sole carbon source in acclimated and non-acclimated activated sludges. Bioregeneration occurred only via desorption due to an initial concentration gradient and no further desorption took place due to low biodegradability. Bioregeneration of activated carbon loaded with 2-chlorophenol was not a suitable option when 2-chlorophenol was the only carbon source. It is suggested to remove 2-chlorophenol via adsorption onto activated carbon rather than applying biological treatment. Also in such cases, the use of thermally activated carbons with higher adsorption and lower desorption capacities is recommended rather than chemically activated carbons.