Concentration Of Acid Groups Research Articles

Insight into the interaction mechanism of iron ions with soil humic acids. The effect of the pH and chemical properties of humic acids.

The main aim of this work was to study the mechanisms of interaction between iron(II) ions and humic acids as a function of pH, iron concentration and various humic acids chemical properties, including the degree of humification, elemental composition, aromaticity and content of acidic functional groups. The results indicated that iron was bound by humic acids at pH 7 in amounts ∼2 times higher than at pH 5 (averaged capacities: 117 and 57 cmol/kg, respectively). Iron binding at pH 7 increased with increasing the total carboxylic and phenolic groups content and the degree of humification of humic acids (R-coefficients: 0.99 and 0.95, respectively). The stability of humic acid-iron complexes at pH 7 were only slightly lower than at pH 5 due to iron hydroxides formed at pH > 5 (averaged stability constants: 5.18 and 5.26, respectively). Iron coordination mode varied depending on pH: at pH 5, the bidentate (chelate) mode dominated, whereas at pH 7 the bridging mode appeared prevalent. The total amount of bound iron was much smaller than the content of the carboxylic and phenolic groups in humic acids, on average by ∼80 (pH 7) and ∼90.1% (pH 5) indicating the occurrence of steric effects in humic acid structure i.e. the reduction of the complexation capacity of free functional groups by adjacent groups occupied by iron and/or the formation of intramolecular aggregates with iron hindering the access of further metal ions. At pH 5 the complexes were soluble in the iron concentration range positively correlated to carboxylic and phenolic groups content, showing the protective nature of negatively charged functional groups on the stability of the solution. At this pH, the destabilization of the system was governed by the neutralization of humic acid charged structures by metal cations and the compression of the double electric layer. At pH 7 the stability of the humic acid-iron solution was largely determined by the form of iron, mainly by the precipitation of metal hydroxides acting as a flocculant destabilizing the solution by co-precipitation of humic acid-iron complexes.

Changes in the physicochemical characteristics of peanut straw biochar after freeze-thaw and dry-wet aging treatments of the biomass

Effects of aging after pyrolysis were tested relative to the physicochemical characteristics of peanut straw biochar. Biochar was prepared at pyrolysis temperatures of 350 °C, 500 °C, and 650 °C; then, it was freeze-thawed and dry-wet aged. The physicochemical characteristics of the fresh and aged biochar were analyzed. The results showed that the pyrolysis temperature, ambient temperature, and humidity affected the physicochemical characteristics of the biochar. With the increase of pyrolysis temperature, the yield and surface acidic functional groups of the fresh biochar decreased, whereas the ash content, C content, pH, specific surface area, and mesoporous volume of the fresh biochar increased. The aging treatment increased the acidic functional groups content in the biochar and reduced the aromatic functional groups content, which decreased the pH value of the biochar. The aging treatment increased the specific surface area and pore volume of the biochar, and the effect of freeze-thaw aging was greater than that of dry-wet aging. The aging treatment also destroyed the complete shape of the fresh biochar, and reduced its stability. After the aging treatment, the C content of the biochar decreased, whereas the O content increased, due to oxidation of the biochar.

Nitrate sorption to biochar following chemical oxidation

Biochar amendments can reduce nitrate (NO3) leaching in agricultural soil. It has been hypothesized that functional groups on the biochar surface from oxidation can increase NO3 sorption. This study evaluates the effect of chemical oxidation of biochar on NO3 sorption characteristics. Eight biochars, made from wood and corn cobs, underwent sodium hypochlorite (NaClO) and hydrogen peroxide (H2O2) oxidation and then assessed for NO3 sorption capacity using batch isotherm methods. The unoxidized and oxidized biochar produced at low temperatures (400 °C) had no significant NO3 sorption. Oxidized biochars produced at higher temperatures (600 °C and 700 °C) had calculated maximum NO3 sorption capacities (Smax) ranging from 0.50 to 3.97 mg NO3-N g-1. Biochar oxidations with 50 mmol NaClO g-1 (N50) in combination with an acid wash (AW) had the largest estimated sorption capacities of 3.68, 3.97, and 1.46 mg NO3-N g-1 for CTN50,AW, BW3N50,AW, and CC3N50,AW, respectively. Sorption capacity of wood-based biochars was higher than corn cob biochars due to increased oxidation as measured by total acid group content (TAGC). Wood biochar Smax values were correlated with ΔTAGC (R2 = 0.86), with a slope of 1.2 μmol NO3-N μmol TAGC-1 suggesting that cationic bridging of NO3 to oxidized sites is the primary mechanism for NO3 sorption.

Experimental and mathematical model evaluation of asphaltene fractionation based on adsorption in porous media: Part 1. calcite reservoir rock

This study investigates the properties of asphaltene fractions in porous media and their role in reducing permeability and porosity. Based on the classification of a whole asphaltene deposited in porous media, the fractions can be defined as bulk, hard (h)-adsorbed, normal (n)-adsorbed, and irreversible (i)-adsorbed, which effects on porosity and permeability reduction in the reservoir rock. According to laboratory results for five types of calcite cores with porosity and permeability close to each other, the highest reduction in porosity (55%) and permeability (76%) is related to bulk asphaltene fractions. The n-adsorbed and h-adsorbed asphaltenes have approximately equal influence in reducing the porosity and permeability values in the reservoir rock. The i-adsorbed asphaltene, which has the highest adsorption on the rock surface, has the lowest porosity and permeability decrease due to lower amounts of asphaltene deposits in porous media. The amounts of hydrogen (H), nitrogen (N), sulfur (S), and oxygen (O) are higher in adsorbed fractions of asphaltene. In the case of h-adsorbed asphaltene, H has the highest value in the asphaltene fractions (7.13 wt%). Compared with adsorbed asphaltene fractions, N values are higher in n-adsorbed (1.89 wt%) than h-adsorbed (1.41 wt%) fractions. This suggests that the S element plays a more significant role in the adsorption of asphaltene to the calcite surface. Based on the results, asphaltene compounds that adhere to the rock surface contain lighter carbon compounds than whole asphaltene. This means that the peak of the carbon compounds of h-adsorbed asphaltene in each rock sample is C17. Fourier-transform infrared spectroscopy (FTIR) results show that the highest concentrations of carbonyl, carboxylic acid or derivative groups are found in h-adsorbed and n-adsorbed asphaltenes, respectively. A new experimental model of asphaltene deposition has been presented based on the deposition analysis of each asphaltene fraction in a porous medium under dynamic conditions, which results in a high correlation coefficient for each of the asphaltene classifications in the porosity and permeability reduction model. The reason for the high accuracy and uniqueness of the model is the use of parameters such as the velocity of fluid flow in the pores and the amount of volume injected in the reservoir rock sample, as well as the asphaltene fractions and their polarization ratio.

The concentration and origins of carboxylic acid groups in oil paint.

Although the concentration of carboxylic acid (COOH) groups is crucial to understand oil paint chemistry, analytical challenges hindered COOH quantification in complex polymerised oil samples thus far. The concentration of COOH groups is important in understanding oil paint degradation because it drives the breakdown of reactive inorganic pigments to dissolve in the oil network and form metal carboxylates. The metal ions in such an ionomeric polymer network can exchange with saturated fatty acids to form crystalline metal soaps (metal complexes of saturated fatty acids), leading to serious problems in many paintings worldwide. We developed two methods based on ATR-FTIR spectroscopy to accurately estimate the COOH concentration in artificially aged oil paint models. Using tailored model systems composed of linseed oil, ZnO and inert filler pigments, these dried oil paints were found to contain one COOH group per triacylglycerol unit. Model systems based on a mixture of long chain alcohols showed that the calculated COOH concentration originates from side chain autoxidation at low relative humidity (RH). The influence of increasing RH and ZnO concentration on COOH formation was studied and high relative humidity conditions were shown to promote the formation of COOH groups. No significant ester hydrolysis was found under the conditions studied. Our results show the potential of quantitative analysis of oil paint model systems for aiding careful (re)evaluation of conservation strategies.

Extraction and characterization of acid-soluble collagen and pepsin-soluble collagen from the dry scales of the striped snakehead (Channa striatus)

Characteristics of collagen are influenced by the source of raw materials and extraction methods used. The aim of this research was to characterize the acid- and pepsin-soluble collagens from the dry scales of the striped snakehead (Channa striatus). Collagen was extracted using to methods including 0.5 M acetic acid and 0.1% pepsin. The yield of acid soluble collagen (KLA-SH) and pepsin soluble collagen (KLP-SH) were 0.98% and 1.94%, respectively. KLA-SH and KLP-SH contained glycine as the major amino acid and had high imino acid group content i.e 226 and 230 residues/1.000 residues, respectively. FTIR spectra of KLA-SH and KLP-SH showed that of the structure of collagen could be maintained in the form of triple helix structure. KLA-SH and KLP-SH consisted of α1- and α2-chain, β-chain, and γ-chain and is suggested as type I collagen.

Sulfonation of dialdehyde cellulose extracted from sugarcane bagasse for synergistically enhanced water solubility

Sulfonated cellulose (SC) was successfully derived from microcrystalline cellulose (MCC) extracted from sugarcane bagasse, which is a type of agricultural waste. The obtained MCC was first modified by oxidation using sodium periodate in order to cleave the carbon-carbon bonds at the C2 and C3 of the pyranose ring to form 2,3-dialdehyde cellulose. These activated aldehyde groups significantly facilitated the sulfonation carried out using potassium metabisulfite. The sulfonic acid group contents, surface morphology, and water solubility of the obtained products were characterized by titration, field-emission scanning electron microscopy, UV–vis spectroscopy, and zeta potential. High sulfonic acid group content was achieved for the obtained SC samples (i.e., 305–689 μmol/g). The increase in the sulfonic acid group content resulted in the gradual change in the surface morphology and water solubility of the SC samples. The obtained results imply that sugarcane bagasse is a promising raw material for the production of SC with good water solubility.

Papermaking potential of Pennisetum hybridum fiber after fertilizing treatment with municipal sewage sludge

This study uses municipal sewage sludge (MSS) as a fertilizer for cultivating Pennisetum hybridum (hybrid Giant Napier grass). The effects of the MSS treatment on the chemical composition of Pennisetum hybridum and on the properties of paper made from its pulp were investigated. The study found that the holocellulose content of Pennisetum hybridum exceeded 72% and the fiber length reached 0.83 mm for one-year-old MSS treated plants. The tensile index of paper made from Napier grass fiber increased by 194% after beating. SEM observation revealed that the Pennisetum hybridum fiber bonded more tightly after beating. The content of carboxylic acid groups was similar in the fibers of 3-month-old and 1-year-old hybrid Giant Napier plants, and higher than that for 1.5-year-old plants. The present research demonstrates that Pennisetum hybridum fiber is suitable for pulping and paper-making after fertilizing treatment of the plants with MSS, which provides new ways for MSS utilization.

Rapid and energy-saving preparation of ramie fiber in TEMPO-mediated selective oxidation system

Although oxidation systems were many and varied, alkali peroxide oxidation system was the only one used for ramie degumming in previous studies. In the work reported here, the possibility of ramie degumming in TEMPO-mediated selective oxidation system was studied. Results revealed that ramie fiber can be extracted by using TEMPO-mediated oxidation treatment (NaClO 2 mmol/g; 15 min; 20 ∼ 25 °C) followed by a low concentration NaOH scouring (2.5%, 100 °C, 60 min) and a reducing process. Fiber degummed in TEMPO-mediated selective oxidation system showed better tensile properties and lower acid group contents compared with that in alkali peroxide oxidation system. The required time for TEMPO-mediated selective oxidation degumming was about 125 min, which was 55 min shorter than hydrogen peroxide system. Moreover, the COD value of wastewater in TEMPO-mediated selective oxidation degumming was 28% lower than that in alkali peroxide oxidation degumming.

Effect of carboxylic group on the compatibility with retarder and the retarding side effect of the fluid loss control additive used in oil well cement.

The retarding side effect and the compatibility with other additives are the main problems that limit the field application of the synthesized fluid loss control additive (FLCA). The effect of the type and content of carboxylic acid groups on the retarding side effect of FLCA and the compatibility between FLCA and the retarder AMPS-IA synthesized using 2-acrylamido-2-methyl propane sulfonic acid (AMPS) and itaconic acid (IA) was studied in this paper. The type and content of carboxylic acid group have a great influence on the fluid loss control ability, the compatibility with retarder and the retarding side effect of FLCA. FLCA containing IA or maleic acid (MA) shows better compatibility with retarder than FLCA containing acrylic acid, but the retarding side effect of FLCA containing MA is weaker than that of FLCA containing IA. Thus, MA is the most suitable monomer for synthesizing FLCA having good compatibility with retarder AMPS-IA.

Quantifying Carboxylic Acid Concentration in Model Polyamide Desalination Membranes via Fourier Transform Infrared Spectroscopy.

Carboxylic acid groups impart hydrophilicity and ionizable moieties to polyamide membranes for desalination, hence influencing water and ion transport through the material. Model polyamide films were synthesized via molecular layer-by-layer deposition on planar substrates to study the formation process of these materials and overcome the chemical and topological inhomogeneity inherent to conventional interfacially polymerized polyamide membranes. The carboxylic acid content in these model films was characterized using Fourier transform infrared (FTIR) spectroscopy by quantifying the C=O band at 1718 cm-1. The concentration of carboxylic acid groups decreased as the thickness of the membrane increased, suggestive of an increase in crosslink density as the polyamide network develops. For the thinnest molecular layer-by-layer (mLbL) samples, the carboxylic acid concentration for films on gold was 0.35 mmol g-1, whereas analogous films on silicon had an acid content of 0.56 mmol g-1, indicating a clear influence of the substrate on the initial network formation. As the thickness of the membrane increased, the influence of the substrate and initial layer growth became less significant as the carboxylic acid concentration on both substrates reached a value of 0.12 mmol g-1. We demonstrate that FTIR spectroscopy is a practical and accessible way to quantify the carboxylic acid content in these types of extremely thin polyamide membranes to help quantify network formation in these materials.

A comprehensive study of asphaltene fractionation based on adsorption onto calcite, dolomite and sandstone

In this study, based on a new procedure, asphaltene fractions of Sarvak oil samples were determined based on their adhesion to calcite, dolomite, and sandstone surfaces and their properties were evaluated. In irreversibly adsorbed asphaltenes, the highest concentrations of elements were 4.23 wt.% nitrogen (N) on the calcite surface, 7.12 wt.% sulfur (S) on dolomite surface, and 6.18 wt.% S and oxygen (O) on the sandstone surface. The dispersion of asphaltene fraction constituents on the surface, is approximately the same across the calcite sample, but in the dolomite sample, the highest adsorption of S correlates to the presence of magnesium (Mg). However, in sandstone samples, the highest S adsorption is achieved by potassium (K). The most dispersion of O occurs at the surface of the sandstone samples; according to matching through EDS mapping, due to the presence of silicon (Si), O has considerable dispersion. Asphaltene fractions also make lighter carbon compounds. It is important to note that in all samples, C17 is the highest peak seen in irreversibly adsorbed asphaltenes. In addition, the zeta potential is negatively affected by increasing the adsorption properties of asphaltene fractions; this depends on the concentration of asphaltene elements adhering to the surface. The O–H polar peak in the irreversibly absorbed asphaltene/sandstone sample is higher due to the presence of O, compared to the other samples. In all three mineral samples, bulk asphaltene and adsorbed fractions have roughly the same values for alkyl groups. The concentration of carbonyl, carboxylic acid, or derivative groups in adsorbed fractions in calcite and sandstone samples show a higher intensity.

Tuning the Gas Selectivity of Tröger's Base Polyimide Membranes by Using Carboxylic Acid and Tertiary Base Interactions.

Polyimide-based materials provide attractive chemistries for the development of gas-separation membranes. Modification of inter- and intra-chain interactions is a route to improve the separation performance. In this work, copolyimides with Tröger's base (TB) monomers are designed and synthesized. In particular, a series of copolyimides is synthesized with different contents of carboxylic acid groups (0-50 wt %) to alter the inter- and intra-chain interactions and enhance the basicity of the TB-polyimides. A detailed thermal and structural analysis is provided for the new copolyimides. Gas permeation data reveal a tunable trend in separation performance with increasing carboxylic acid group content. Importantly, this is one of the few examples of copolyimide membranes materials that show enhanced plasticization resistance to high-pressure gas feeds through physical cross-linking.

Effect of sulfonation treatment concentration on the properties of mulberry chemi-mechanical pulp

Sulfonation chemimechanical pulping (SCMP) of mulberry stalk was studied with different treatment concentrations. The resulting mulberry SCMP pulp contained different content of sulfonic acid groups depending on the concentrations. The brightness, tensile index, and folding resistance of mulberry SCMP pulp increased with the increasing concentration of sulfonation treatment, but the thickness decreased with increasing concentration. There was either a linear or a non-linear relationship between the content of sulfonic groups and the pulp physical properties. The mass average length of mulberry SCMP pulp was 0.66 mm, the fiber width was 16.4 μm, and the content of fine fibers was 20.6%.The mulberry extract and lignin dissolved, and part of soluble lignin may have been deposited on fiber surface in the process of SCMP pretreatment. There were almost no changes to the cellulose crystalline structure.

Heavy crude oil upgrading using nanoparticles by applying electromagnetic technique

The upgrading of heavy oil is one of the most important processes in heavy oil recovery due to the low quality of these types of oil. In this study, the effects of nanomaterials of Fe, titanium oxide (TO) and super activated carbon (CA) as catalysts in the process of upgrading heavy oil from the Azadegan Oilfield in Southwest Iran using microwave (MW) radiation are investigated. Samples of heavy oil are exposed for 2, 4, 6, 8 and 10 min to MW radiation with 4 wt% of each nanoparticle in each step. The results of the experiments show that Fe and TO nanoparticles have no significant effect on MW absorption in the initial 2 and 4 min intervals, while the CA nanoparticle, due to its higher potential for absorbing these waves, causes the temperature of the heavy oil sample to rise from the earliest time intervals. The presence of nanoparticles in heavy oil leads to a greater reduction in viscosity at initial and even longer intervals. In fact, these nanoparticles, by absorbing MWs over longer periods of time, cause cracking of heavier compounds the effect of which exceeds that of the loss of lighter compounds from the heavy oil. The CA catalyst has the highest viscosity reduction during the 6-min period and viscosity varies from 882.37 mPa.s to 791.19 mPa.s. The results of the analysis of carbon compounds (C), hydrogen (H), sulfur (S) and nitrogen (N) indicate that the presence of nanoparticles results in a further reduction of S and N in heavy oil than with MW radiation alone. The highest CA desulfurization over a period of 8 min is a reduction by 30.5%, while the highest H/C ratio occurs in the presence of this nanoparticle at 6 min. On the other hand, the lowest amount of N in the heavy oil sample is observed in the presence of the Fe nanoparticle with a decrease of 0.65 wt% at 10 min. According to Fourier transform infrared (FTIR) spectra, the presence of nanoparticles along with MW radiation reduces the concentration of OH, S-H, alkyl groups, carbonyl, carboxylic acid or derivative groups and aromatic compounds in heavy oil. These changes are more evident with CA and Fe nanoparticles. In terms of deasphalting heavy oil, the Fe nanoparticle has the greatest effectiveness with the asphaltene content reduced from 12.75 wt% to 9.13 wt% in 4 min. However, other nanoparticles reduced asphaltene components compared to MW radiation alone and promoted the process of reducing asphaltene content over longer periods. From the results of this study, it can be concluded that the use of nanoparticles with a higher potential for MW absorption can be more suitable options for the process of upgrading heavy oils. Moreover, the optimal duration of MW radiation in the presence of nanoparticles is one of the key parameters that varies greatly depending on the type of catalyst and the type of heavy oil.

Effect of Chemical Oxidation on the Adsorption Properties of Cationic Dye on Activated Carbons Prepared from Locally Atropa belladonna

This study investigates the influence of wet chemical oxidation using nitric acid and ammonium persulfate on the surface nature and the adsorption properties of activated carbon prepared from sulfuric acid activation of locally Atropa belladonna plant at 200oC. The surface properties of produced carbons (AC-S, AC-S/N and AC-S/A, respectively) were demonstrated by FTIR, potentiometric titration and N2 adsorption. The adsorption properties of these carbons were estimated using methyl green (MG) dye as a cationic dye. The effect of variables including pH, initial dye concentration and contact time on the adsorption properties of these carbons was studied. Acidic carbon adsorbents were obtained with large content of acidic surface functional groups in the sequence order AC-S<AC-S/N<AC-S/A as confirmed by FTIR and potentiometric plots. It was assessed that a large number of basic functional groups were generated after oxidation with ammonium persulfate (AC-S/N) and hence led to a decrease in its adsorption capacity towards MG dye. High adsorption capacities were found to be 100, 200 and 125 mg/g from MG dye onto AC-S, AC-S/N and AC-S/A, respectively. The adsorption results show that the adsorption was pH dependent with a high adsorption at pH of 6 which is obviously pH of dye solution. The equilibrium adsorption data were analyzed by Langmuir, Freundlich and FlorryHuggins isotherm models. Pseudo-second-order kinetic model and Langmuir isotherm model showed better fit to the adsorption of MG dye onto the prepared carbons. Overall, this study reveals that the obtained carbons from Atropa belladonna are effective adsorbents in removing dyes from wastewater sources. Finally, the results also suggest that oxidation treatment with nitric acid is more efficient than ammonium persulfate to produce high acidic carbon adsorbents.

Adsorption of lead(II), cadmium(II) and dysprosium(III) from aqueous solutions using mesoporous silica modified with phosphonic acid groups

The mesoporous silica samples with different concentrations of phosphonic acid groups on the surface were obtained by direct template synthesis. The block-copolymer Pluronic P123 was used as a template, and sodium meta-silicate with diethylphosphatoethyltriethoxysilane as precursors. According to the SAXS diffractograms, mesoporous silica samples have a p6mm hexagonal symmetry. In addition, we used sol–gel method to synthesize xerogel with the same groups for comparison. All samples possess high values of specific surface area 615–730 m2/g and sorption pore volume. FTIR and potentiometric titration methods were used to investigate the surface layer of these samples. Sorption properties of the samples with phosphonic acid groups were studied in respect to a row of metal cations, among which we focused on lead(II), cadmium(II), and dysprosium(III) cations.

Effects of Activated Carbon Surface Property on Structure and Activity of Ru/AC Catalysts

The activated carbon (AC) was modified by supercritical (SC) methanol, HNO3 oxidation, or HNO3 oxidation plus SC methanol, respectively. Then, the original and the modified AC were used as supports for Ru/AC catalysts prepared via the impregnation method. The results showed that the SC methanol modification decreased the content of surface acidic groups of AC. While HNO3 oxidation displayed the opposite behavior. Furthermore, the dispersion of ruthenium and the activity of catalysts were highly dependent on the content of surface acidic groups, and the SC methanol modified sample exhibited the highest activity for hydrogenation of glucose.

Bioactive potential and structural characterization of sulfated polysaccharides from Bullet tuna (Auxis Rochei) by-products

The present study deals with the isolation of sulfated polysaccharides (Ps) from the Bullet tuna by-products (head, skin and bones). Results of chemical characterization revealed that Ps-bones showed the highest total sugar, uronic acid and sulfate group contents. Tuna extracted-Ps contained a mixture of neutral sugars, with high amounts of glucuronic and galacturonic acids and presented different molecular weights. The presence of sulfate groups in different Ps was confirmed by FTIR analysis. Interestingly, Ps-bones showed the highest antioxidant activity among all the extracted Ps. Moreover, results revealed that all polysaccharides displayed varying degrees of antibacterial activity. Ps-bones exhibited high and wide spectrum of activities, inhibiting the growth of all bacteria tested. Ps-bones incorporated during fillet cooking offered an excellent protection of fish fillet by avoiding pH change, color loss, lipid oxidation and spoilage. Overall, the results demonstrated that Ps could be potentially used as natural antioxidant and antibacterial agents.

Removal of Chloramphenicol from Aqueous Solution Using Low-Cost Activated Carbon Prepared from Typha orientalis

Low-cost and efficient activated carbon (AC) was prepared from Typha orientalis via phosphoric acid activation for chloramphenicol (CAP) removal. The adsorption capacity and mechanisms of CAP on AC were investigated. The physicochemical properties of AC were characterized by an N2 adsorption/desorption isotherm, elemental analysis, Boehm’s titration and X-ray photoelectron spectroscopy (XPS). The effects of experimental parameters were investigated to study the adsorption behaviors of CAP on AC, including contact time, initial concentration, ionic strength, and initial pH. AC had a micro-mesoporous structure with a relatively large surface area (794.8 m2/g). The respective contents of acidic and basic functional groups on AC were 2.078 and 0.995 mmol/g. The adsorption kinetic that was well described by a pseudo-second-order rate model implied a chemical controlling step. The adsorption isotherm was well fitted with the Freundlich isotherm model, and the maximum CAP adsorption capacity was 0.424 mmol/g. The ionic strength and pH had minimal effects on CAP adsorption. The dominant CAP adsorption mechanisms on AC were evaluated and attributed to π-π electron-donor-acceptor (EDA) interaction, hydrophobic interaction, in conjunction with hydrogen-bonding interaction. Additionally, AC exhibited an efficient adsorption performance of CAP in a realistic water environment.