Efficient adsorption of benzoic acid from aqueous solution by nitrogen-containing activated carbon

Abstract Adsorption is an efficient treatment process to remove benzoic acid from aqueous solution. In this study, nitrogen-containing surface groups were introduced onto activated carbon (AC) surface by modification with ammonium hydroxide, ammonium carbonate, melamine or urea. The nitrogen-containing AC samples were characterized using N2 adsorption-desorption, Boehm titration, determination of the pH of the point of zero charge (pHpzc) and X-ray photoelectron spectroscopy. The adsorption of benzoic acid from aqueous solution by nitrogen-containing AC has been studied. The Langmuir model fitted the experimental data of equilibrium isotherms better than the Freundlich model. At initial solution pH 2.1, the adsorption capacity was closely related with the amount of pyridinic and pyrrolic N on the AC surface, which indicated these two nitrogen-containing groups played an important part in the adsorption process. The enhancement of adsorption capacity was due to the strengthened π–π dispersion force between benzoic acid and the AC basal plane. Since the surface charge of AC as well as the existence form of benzoic acid varied with solution pH value, the adsorption capacity was found to be highest at pH 3.8 and dropped sharply at higher or lower pH values.

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Adsorption of hexavalent chromium by polyacrylonitrile-based porous carbon from aqueous solution

Royal Society Open Science ◽

10.1098/rsos.171662 ◽

2018 ◽

Vol 5 (1) ◽

pp. 171662 ◽

Cited By ~ 14

Author(s):

Bin Feng ◽

Wenzhong Shen ◽

Liyi Shi ◽

Shijie Qu

Keyword(s):

Aqueous Solution ◽

Adsorption Capacity ◽

Porous Carbon ◽

Photoelectron Spectroscopy ◽

Ph Value ◽

Functional Materials ◽

High Specific Surface Area ◽

Maximum Adsorption Capacity ◽

Elementary Analysis ◽

Initial Adsorption

Owing to the unique microporous structure and high specific surface area, porous carbon could act as a good carrier for functional materials. In this paper, polyacrylonitrile (PAN)-based porous carbon materials (PPC-0.6-600, PPC-0.8-600, PPC-0.6-800 and PPC-0.8-800) were prepared by heating KOH at 600°C and 800 o C for the removal of Cr(VI) from aqueous solution. The adsorbent was characterized by the techniques of Fourier transform infrared spectroscopy (FT-IR), elementary analysis, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and N 2 adsorption techniques. The results showed that the adsorption capacity increased with decreasing pH value of the initial solution. The adsorption capacity of Cr(VI) on PPC-0.8-800 was much greater than that on other materials, and maximum adsorption capacity were calculated to be 374.90 mg g −1 . Moreover, PPC-0.8-800 had superior recyclability for the removal of Cr(VI) from wastewater, about 82% of its initial adsorption capacity was retained even after five cycles. The result of kinetic simulation showed that the adsorption of Cr(VI) on the PAN-based porous carbon could be described by pseudo-second-order kinetics. The adsorption process was the ionic interaction between protonated amine groups of PPC and HCrO 4 - ions.

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Metal Adsorbent Prepared from Coir Pith as Agricultural Waste: Adsorption of Zn(II) and Pb(II) from Aqueous Solution

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.545.101 ◽

2013 ◽

Vol 545 ◽

pp. 101-108 ◽

Cited By ~ 1

Author(s):

Kitirote Wantala ◽

Nusavadee Pojananukij ◽

Pongsert Sriprom ◽

Tinnakorn Kumsaen ◽

Arthit Neramittagapong ◽

...

Keyword(s):

Aqueous Solution ◽

Adsorption Capacity ◽

Calcination Temperature ◽

Ph Value ◽

Agricultural Waste ◽

Initial Solution ◽

Order Kinetic ◽

Solution Ph ◽

Freundlich Isotherms ◽

Coir Pith

Adsorption of Zn(II) and Pb(II) from aqueous solution were studied by using modified coir pith as an adsorbent. The extended adsorption conditions were investigated as a function of calcination temperature, contact time, adsorbent size, initial pH of solution and initial Zn(II) and Pb(II) concentrations. The adsorption capacity increased rapidly in first 5 minute and reached equilibrium in 120 minutes for Zn(II) and 10 minutes for Pb(II). In case of Zn(II); the results showed that the calcination temperature of modified coir pith above 600oC gave the higher adsorption capacity. The sizes of modified coir pith have no effect on the adsorption capacity. The adsorption capacity increased with increasing initial solution pH value. In case of Pb(II); the calcination temperature of modified coir pith showed no effect on the adsorption capacity. The sizes of modified coir pith showed a little effect on the adsorption capacity. The adsorption capacity increased with increasing of initial solution pH value up to pH of 3 and then stable. The results also corresponded with the Langmuir and Freundlich isotherms and pseudo second order kinetic adsorption models. The modified coir pith gave a higher Zn(II) and Pb(II) adsorption capacity of 29.33 mg Zn(II)/g adsorbent and 36.50 mg Pb(II)/g adsorbent, respectively.

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Mass-transfer processes in the adsorption of crystal violet by activated carbon derived from pomegranate peels: Kinetics and thermodynamic studies

Journal of Engineered Fibers and Fabrics ◽

10.1177/1558925020919847 ◽

2020 ◽

Vol 15 ◽

pp. 155892502091984

Author(s):

Moussa Abbas ◽

Zahia Harrache ◽

Mohamed Trari

Keyword(s):

Activated Carbon ◽

Adsorption Capacity ◽

Crystal Violet ◽

Agitation Speed ◽

Second Order ◽

Point Of Zero Charge ◽

Order Kinetic ◽

Solution Ph ◽

Pseudo Second Order ◽

Adsorbent Dose

This study investigates the potential use of activated carbon, prepared from pomegranate peels, as an adsorbent activated using H3PO4 and its ability to remove crystal violet from an aqueous solution. The adsorbent was characterized by the Brunauer–Emmett–Teller method (specific surface area: 51.0674 m2 g−1) and point of zero charge (pHPZC = 5.2). However, some examined factors were found to have significant impacts on the adsorption capacity of activated carbon derived from pomegranate peels such as the initial dye concentration (5–15 mg L−1), solution pH (2–14), adsorbent dose (1–8 g L−1), agitation speed (100–700 r/min), and temperature (298–338 K). The best adsorption capacity was found at pH 11 with an adsorbent dose of 1 g L−1, an agitation speed at 400 r/min, and a contact time of 45 min. The adsorption mechanism of crystal violet onto activated carbon derived from pomegranate peels was studied using the pseudo-first-order, pseudo-second-order, Elovich, and Webber–Morris diffusion models. The adsorption kinetics were found to rather follow a pseudo-second order kinetic model with a determination coefficient ( R2) of 0.999. The equilibrium adsorption data for crystal violet adsorbed onto activated carbon derived from pomegranate peels were analyzed by the Langmuir, Freundlich, Elovich, and Temkin models. The results indicate that the Langmuir model provides the best correlation with qmax capacities of 23.26 and 76.92 mg g−1 at 27°C and 32°C, respectively. The adsorption isotherms at different temperatures have been used for the determination of thermodynamic parameters like the free energy, enthalpy, and entropy to predict the nature of adsorption process. The negative values Δ G0 (−5.221 to −1.571 kJ mol−1) and Δ H0 (−86.141 kJ mol−1) indicate that the overall adsorption is spontaneous and exothermic with a physisorption process. The adsorbent derived from pomegranate peels was found to be very effective and suitable for the removal of reactive dyes from aqueous solutions, due to its availability, low-cost preparation, and good adsorption capacity.

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Study of phosphate removal from aqueous solution by zinc oxide

Journal of Water and Health ◽

10.2166/wh.2015.210 ◽

2015 ◽

Vol 13 (3) ◽

pp. 704-713 ◽

Cited By ~ 5

Author(s):

Zhen Luo ◽

Suiyi Zhu ◽

Zhongmou Liu ◽

Jiancong Liu ◽

Mingxin Huo ◽

...

Keyword(s):

Aqueous Solution ◽

Zinc Oxide ◽

Adsorption Capacity ◽

Adsorption Process ◽

Chloride Ions ◽

Phosphate Removal ◽

Point Of Zero Charge ◽

Phosphate Adsorption ◽

Solution Ph ◽

Base Interaction

Zinc oxide (ZnO) was synthesized and used to investigate the mechanism of phosphate removal from aqueous solution. ZnO particles were characterized by X-ray diffraction, scanning electron microscope and Fourier transform infrared spectroscopy before and after adsorption. Batch experiments were carried out to investigate the kinetics, isotherms, effects of initial pH and co-existing anions. The adsorption process was rapid and equilibrium was almost reached within 150 min. The adsorption kinetics were described well by a pseudo-second-order equation, and the maximum phosphate adsorption capacity was 163.4 mg/g at 298 K and pH ∼6.2 ± 0.1. Thermodynamic analysis indicated the phosphate adsorption onto ZnO was endothermic and spontaneous. The point of zero charge of ZnO was around 8.4 according to the pH-drift method. Phosphate adsorption capacity reduced with the increasing initial solution pH values. The ligand exchange and Lewis acid-base interaction dominated the adsorption process in the lower and the higher pH range, respectively. Nitrate, sulfate and chloride ions had a negligible effect on phosphate removal, while carbonate displayed significant inhibition behavior.

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Effect of Treatment on the Adsorption Capacity of Activated Carbon

Adsorption Science & Technology ◽

10.1260/02636170260555822 ◽

2002 ◽

Vol 20 (9) ◽

pp. 917-925 ◽

Cited By ~ 5

Author(s):

Sirous Nouri

Keyword(s):

Adsorption Capacity ◽

Activated Carbons ◽

Ph Value ◽

Carbon Surface ◽

Point Of Zero Charge ◽

Molecular Forms ◽

Model Parameters ◽

Ionic Form ◽

Solution Ph ◽

Adsorption Affinity

The adsorption of p-cresol by three activated carbons, one untreated S.E.I. and the other two treated S.E.I., was carried out under controlled conditions. Such treatment led to a change in the point of zero charge (PZC) and the adsorption capacity (Qmax) of the carbon concerned. The adsorption capacity and affinity (K1) of each carbon was determined using the Langmuir homogeneous and binary models to compare the effects of different treatments on these and relative parameters. The variation of the model parameters with the solution pH was also studied. The fitted parameters obtained from both models showed the pH value had the most significant effect on the adsorption capacity (Qmax) and the adsorption affinity (K1) of a given carbon, with both quantities showing a decrease with increasing pH. It was found that the uptake of the molecular forms of the aromatic solute was dependent on the PZC of the carbons. Treatment with H2 increased the PZC whilst treatment with H2SO4 led to a decrease in this factor. At higher pH (when the solute was in an ionic form), it was found that electrostatic forces played a significant role on the extent of adsorption. Under these conditions, the adsorption of the solute depended on the concentration of its anionic form. It was shown that the effect of pH must be considered from the viewpoint of its combined effect on the carbon surface and on the solute molecules.

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Removing Cd(II) from Aqueous Solution by Inverse Opal Hybrid SiO2

NANO ◽

10.1142/s1793292020500472 ◽

2020 ◽

Vol 15 (04) ◽

pp. 2050047

Author(s):

Yanhong Wang ◽

Xiuli Wang ◽

Cuihong Wu ◽

Xiaomei Wang ◽

Xu Zhang

Keyword(s):

Aqueous Solution ◽

Adsorption Capacity ◽

Ph Value ◽

Pore Wall ◽

Ionic Concentration ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Inverse Opal ◽

Solution Ph ◽

Adsorption Desorption

A hybrid adsorbent with inverse opal (IO) structure was prepared for removing Cd(II) from aqueous solution. The functional polymeric chains were grafted from the pore wall of IO silica to prepare the porous hybrid material by surface-initiated atom-transfer radical polymerization. Furthermore, the amidation reaction was carried out to obtain diethylenetriamine-modified hybrid adsorbent (IO SiO2-g-PAA-DETA). Batch adsorption of removing Cd(II) onto IO SiO2-g-PAA-DETA was studied as the effect of solution pH, adsorbent doses, contact time, ionic concentration, and temperature. When the grafted amount was 73%, the maximum adsorption capacity was obtained. The optimum adsorbent dose and pH value for adsorbing Cd(II) were found to be 5[Formula: see text]g/L and 0.5[Formula: see text]g/L, respectively. The adsorption capacity was almost unaffected by Na[Formula: see text] at low concentrations. The adsorption data was depicted by the corresponding models and the results displayed that adsorbing Cd(II) on IO SiO2-g-PAA-DETA followed the Freundlich and pseudo-first-order model. In addition, after six adsorption–desorption cycles, IO adsorbent could remain above 80% of the first adsorption ability while it was washed using 0.025[Formula: see text]M EDTA.

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Modified Activated Carbon for Copper Ion Removal from Aqueous Solution

Processes ◽

10.3390/pr10010150 ◽

2022 ◽

Vol 10 (1) ◽

pp. 150

Author(s):

Wei-Sheng Chen ◽

Yun-Chung Chen ◽

Cheng-Han Lee

Keyword(s):

Aqueous Solution ◽

Activated Carbon ◽

Adsorption Capacity ◽

Copper Ions ◽

Copper Ion ◽

Base Material ◽

Column Experiment ◽

Iminodiacetic Acid ◽

Point Of Zero Charge ◽

Batch Sorption

Because of increasing environmental awareness, it is becoming more important to remove harmful elements from water solutions. This study used activated carbon (AC) derived from waste wood-based panels as the base material, oxidized with nitric acid (OAC), and grafted with iminodiacetic acid (IDA-OAC) to improve the adsorption capacity and affinity for metals. The characterization of AC, OAC, and IDA-OAC was conducted via FTIR, SEM, N2 adsorption and desorption analysis, elemental analysis, Boehm titration, and point of zero charge (PZC). The instrument studies proved the modified increasing of the functional groups of the adsorbents. Moreover, batch and column experiments were conducted to evaluate the ability of the three adsorbents to remove copper ions from aqueous solution. In batch sorption, IDA-OAC had the highest adsorption capacity (84.51 mg/g) compared to OAC (54.74 mg/g) and AC (24.86 mg/g) at pH 5. The breakthrough point (Ct/Ci = 0.05) of copper ions for IDA-OAC occurred much later than AC in the column experiment (AC = 19 BV, IDA-OAC = 52 BV). The Langmuir isotherm and pseudo-second-model kinetics modeling could better fit with the data obtained from the batch sorption of AC, OAC, and IDA-OAC. The significant capacity and reusability of IDA-OAC displayed high applicability for water treatment.

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Adsorption of Pb2+ ions from aqueous solutions by gelatin/activated carbon composite bead form

Adsorption Science & Technology ◽

10.1177/0263617417693006 ◽

2017 ◽

Vol 36 (1-2) ◽

pp. 355-371 ◽

Cited By ~ 6

Author(s):

Fareeda Hayeeye ◽

Qiming J Yu ◽

Memoon Sattar ◽

Watchanida Chinpa ◽

Orawan Sirichote

Keyword(s):

Activated Carbon ◽

Aqueous Solutions ◽

Adsorption Capacity ◽

Ph Value ◽

Carbon Composite ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Solution Ph ◽

Experimental Conditions ◽

Composite Bead

Gelatin and activated carbon materials have been combined together to obtain a gelatin/activated carbon composite bead form which is ecofriendly, nontoxic, biocompatible, and inexpensive material. In this paper, gelatin/activated carbon adsorption for Pb2+ ions from aqueous solutions was studied experimentally under various conditions. The experimental conditions such as contact time, solution pH, and gelatin/activated carbon dosage were examined and evaluated by using batch adsorption experiments. The maximum adsorption capacity of gelatin/activated carbon for Pb2+ ions was obtained to be 370.37 mg g−1. This maximum capacity was comparable with that of commercial ion exchange resins and it was much higher than those of natural zeolites. The uptake process for Pb2+ ions was found to be relatively fast with 92.15% of the adsorption completed in about 5 min in batch conditions. The adsorption capacity was also strongly solution pH dependent. Adsorption was observed at pH value as low as 2.0 and maximum adsorption was achieved at a pH of approximately 5. The results indicated that the gelatin/activated carbon was effective to be used as an adsorbent for Pb2+ ions removal in wastewater treatment.

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Mercury (II) adsorption from aqueous solution using nitrogen and sulfur co-doped activated carbon

Water Science & Technology ◽

10.2166/wst.2018.117 ◽

2018 ◽

Vol 2017 (1) ◽

pp. 310-318 ◽

Cited By ~ 7

Author(s):

Hangdao Qin ◽

Rong Xiao ◽

Lei Guo ◽

Jianling Meng ◽

Jing Chen

Keyword(s):

Activated Carbon ◽

Adsorption Capacity ◽

Photoelectron Spectroscopy ◽

Point Of Zero Charge ◽

Adsorption Behaviors ◽

Pseudo Second Order ◽

Adsorption Desorption ◽

Initial Cycle ◽

Co Doped

Abstract Activated carbon (AC) was modified with urea, thioglycolic acid and thiourea to obtain nitrogen doped activated carbon (ACN), sulfur doped activated carbon (ACS) and nitrogen and sulfur co-doped activated carbon (ACNS), respectively. The AC samples were characterized by elemental analysis, N2 adsorption-desorption, determination of the pH of the point of zero charge (pHpzc) and X-ray photoelectron spectroscopy, and tested for adsorption behaviors of Hg(II) ions. The experimental data of equilibrium isotherms fitted well with the Langmuir model. ACNS showed the highest adsorption capacity of 511.78 mg/g, increasing more than 2.5 times compared to the original ACA. The adsorption process followed pseudo-second-order kinetics. The thermodynamic parameters of ΔH°, ΔS°, and ΔG° at 30 °C were −20.57 kJ/mol, −0.032 kJ/mol K and −10.87 kJ/mol, respectively. It was concluded that the Hg(II) ions' adsorption on ACNS was exothermic, spontaneous and physiosorptive in nature. Finally, the adsorption capacity of ACNS reduced by just 8.13% even after the sixth cycle compared to the initial cycle.

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High Cr(VI) Adsorption Performance of Coal-Based Activated Carbon in Aqueous Solution

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.798-799.1123 ◽

2013 ◽

Vol 798-799 ◽

pp. 1123-1127

Author(s):

Hua Lei Zhou ◽

Qiong Qiong Zhu ◽

Dong Hua Huang

Keyword(s):

Aqueous Solution ◽

Activated Carbon ◽

Pore Structure ◽

Ph Value ◽

High Surface ◽

High Surface Area ◽

Koh Activation ◽

Transmission Electron ◽

Mesoporous Adsorbent ◽

Initial Ph

The activated carbon with high surface area was prepared by KOH activation from anthracite and used as adsorbent for removal of Cr (VI) from aqueous solution. The pore structure and surface properties were characterized by N2 adsorption at 77K, transmission electron microscope (TEM) and Fourier transform infrared spectroscopy ( FTIR). Effect of pH and isotherms at different temperature were investigated. Results show that the prepared carbon is a microporous-and mesoporous-adsorbent with developed pore structure and abundant surface oxygen-containing groups. PH value of the solution plays key function on the adsorption. The chemical adsorption dominates the adsorption process. The activated carbon exhibits much higher Cr adsorption capacity than the commercial activated carbon at initial pH of ~3. The equilibrium adsorption data are fitted by both Freundlich model and Langmuir model well.

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