Removal of the Endocrine Disrupting Chemical Bisphenol A from Water by Activated Carbon

2013 ◽  
Vol 671-674 ◽  
pp. 2726-2731 ◽  
Author(s):  
Xiao Dong Wang ◽  
Yu Feng Xiao
Keyword(s):  
Activated Carbon ◽  
Photoelectron Spectroscopy ◽  
Ph Value ◽  
Micropore Volume ◽  
Absorption Capacity ◽  
Carbon Surface ◽  
Adsorption Model ◽  
Endocrine Disrupting Chemical ◽  
First Order Kinetics ◽  
Negative Effect

Physical properties including surface area, average porediameter, and micropore volume and chemical structure of the activated carbon was characterized by N2 adsorption experiment and X-ray photoelectron spectroscopy (XPS). The high O content of carbon surface lead a negative effect to absorption capacity and low pH value, low temperature lead a positive effect to adsorption. The effect of humus in water to the removal was also studied and EDCs-humus bi-component adsorption model was established, it was found that there is strong competition between EDCs and humus. Due to this competition adsorption capacity of BPA greatly decreased especially when BPA concentration is very low. The adsorption kinetics test results indicated that the adsorption of BPA followed the first-order kinetics and the smaller diameter GAC could increase adsorption velocity.

Removal of the Endocrine Disrupting Chemicals Nonylphenol from Water by Activated Carbon

2012 ◽  
Vol 178-181 ◽  
pp. 520-525
Author(s):  
Xiao Dong Wang ◽  
Yu Feng Xiao
Keyword(s):  
Activated Carbon ◽  
Photoelectron Spectroscopy ◽  
Pore Volume ◽  
Ph Value ◽  
Absorption Capacity ◽  
Carbon Surface ◽  
Drinking Water Source ◽  
Adsorption Model ◽  
Average Pore ◽  
Endocrine Disrupting

Nonylphenol(NP) have endocrine disrupting effects and exist generally in drinking water source. Physical properties including surface area, average pore-diameter, and micro-pore volume and chemical structure of the activated carbon was characterized by N2 adsorption experiment and X-ray photoelectron spectroscopy (XPS). Pore volume could be the most important for adsorption. The high O content of carbon surface lead a negative effect to absorption capacity and low pH value, low temperature lead a positive effect to adsorption. The effect of humus in water to the removal was also studied and EDCs-humus bi-component adsorption model was established, it was found that there is strong competition between EDCs and humus. Due to the competition adsorption capacity of NP greatly decreased especially when the concentration of NP is very low. The adsorption kinetics test results indicated that the adsorption of NP followed the first-order kinetics and the smaller diameter GAC could increase adsorption velocity.

scholarly journals The Effect of Sulphur Dioxide Exposure under Controlled Environmental Conditions on the Challenge Performance of Copper and Chromate Impregnated Active Carbon against Hydrogen Cyanide

1997 ◽  
Vol 15 (7) ◽  
pp. 531-540 ◽  
Author(s):  
P.J.C. Anstice ◽  
J.F. Alder
Keyword(s):  
Activated Carbon ◽  
Numerical Analysis ◽  
Flow Rate ◽  
Active Carbon ◽  
Environmental Conditions ◽  
Sulphur Dioxide ◽  
Hydrogen Cyanide ◽  
Carbon Surface ◽  
Adsorption Model ◽  
Active Centres

An ASC/T (Cu2+, Cr6+, Ag and triethylenediamine impregnated) Whetlerite activated carbon sample was exposed to a flow rate of 1 l/min, 0.746 mg/l SO2 in 80% RH air at 22°C for up to 510 min. Samples were subsequently challenged with 2 mg/l HCN in an identical diluent gas stream. Increasing SO2 exposure resulted in accelerated HCN and (CN)2 bed penetration. The basic shapes of the breakthrough profiles were however essentially unchanged. This observation is in accordance with numerical analysis of these results using Hinshelwood's adsorption model, which suggested that the adsorption rate constant was not significantly affected by SO2 but rather the pollutant exposure resulted in the number of active centres on the carbon surface being reduced and the effective bed depth of the sample being shortened. This loss in active centres was thought most likely to result from the reduction of Cr6+ to Cr3+.

scholarly journals Single and competitive adsorption of Cd(II) and Pb(II) from aqueous solution by activated carbon prepared with Salix matsudana Kiodz

2016 ◽  
Vol 74 (12) ◽  
pp. 2751-2761 ◽  
Author(s):  
Yan Shu ◽  
Kelin Li ◽  
Jinfeng Song ◽  
Bing Li ◽  
Chunfang Tang
Keyword(s):  
Activated Carbon ◽  
Ph Value ◽  
Total Pore Volume ◽  
Maximum Adsorption Capacity ◽  
Single Element ◽  
Acid Activation ◽  
Adsorption Model ◽  
Adsorption Selectivity ◽  
Average Pore ◽  
Salix Matsudana

In this study, Salix matsudana activated carbon (SAC) was prepared by phosphoric acid activation, and the adsorption characteristics of Cd(II) and Pb(II) on SAC in single- and double-component solutions were investigated. In both systems, the adsorption capacities of both ions on SAC increased with the increasing initial pH value and temperature in the solutions, and the adsorption equilibrium was approached at 10 min. The adsorption process was spontaneous, endothermic, and depicted well by the pseudo-second-order adsorption model, and the equilibrium adsorption fitted reasonably well with the Langmuir isotherm. The maximum adsorption capacity (Qm) of Cd(II) and Pb(II) was 58.48 and 59.01 mg/g, respectively, in the single-element systems. However, it reduced to 25.32 and 31.09 mg/g, respectively, in the double-element system. The physicochemical property analysis showed that the specific surface area, total pore volume, and average pore diameter of SAC was 435.65 m2/g, 35.68 mL/g, and 3.86 nm, respectively. The SAC contained groups of -OH, C = O, and P = O. Results suggest that SAC had a good performance for the adsorption of Cd(II) and Pb(II) from solution, and the adsorption selectivity sequence was Pb(II) > Cd(II).

Modeling of heavy metals removal from aqueous solution using activated carbon produced from cotton stalk

2013 ◽  
Vol 67 (7) ◽  
pp. 1612-1619 ◽  
Author(s):  
Mohamed El Zayat ◽  
Edward Smith
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Activated Carbon ◽  
Metal Removal ◽  
Ph Value ◽  
Equilibrium Constants ◽  
Surface Complexation ◽  
Fixed Bed ◽  
Breakthrough Curves ◽  
Carbon Surface

Activated carbon produced from cotton stalks was examined for the removal of heavy metal contaminants. Adsorption studies in completely mixed batch reactors were used to generate equilibrium pH adsorption edges. Continuous flow experiments using the activated carbon in fixed beds were conducted to determine heavy metal breakthrough versus bed volumes treated. At given pH value in the range 5–7, the adsorption capacity was similar for copper and lead and clearly greater than for cadmium. A surface titration experiment indicated negative surface charge of the activated carbon at pH > 6, meaning that electrostatic attraction of the divalent heavy metals can occur below the pH required for precipitation. Substantive metal removal below the pH of zero charge might be due to surface complexation. Accordingly, a surface complexation model approach that utilizes an electrostatic term in the double-layer description was used to estimate equilibrium constants for the protolysis interactions of the activated carbon surface as well as equilibria between background ions used to establish ionic strength and the sorbent surface. Pb(II) adsorption edges were best modeled using inner-layer surface complexation of Pb2+, while Cd(II) and Cu(II) data were best fit by outer-layer complexes with Me2+. The full set of equilibrium constants were used as input in a dual-rate dynamic model to simulate the breakthrough curves of the target metals (Pb, Cu and Cd) from fixed bed experiments and to estimate external (or film) diffusion and internal (surface) diffusion coefficients.

scholarly journals Adsorptive and Electrochemical Properties of Carbon Nanotubes, Activated Carbon, and Graphene Oxide with Relatively Similar Specific Surface Area

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 496
Author(s):  
Krzysztof Kuśmierek ◽  
Andrzej Świątkowski ◽  
Katarzyna Skrzypczyńska ◽  
Lidia Dąbek
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Materials ◽  
Organochlorine Compound ◽  
Carbon Surface ◽  
Negative Effect

Three carbon materials with a highly diversified structure and at the same time much less different porosity were selected for the study: single-walled carbon nanotubes, heat-treated activated carbon, and reduced graphene oxide. These materials were used for the adsorption of 2,4-D herbicide from aqueous solutions and in its electroanalytical determination. Both the detection of this type of contamination and its removal from the water are important environmental issues. It is important to identify which properties of carbon materials play a significant role. The specific surface area is the major factor. On the other hand, the presence of oxygen bound to the carbon surface in the case of contact with an organochlorine compound had a negative effect. The observed regularities concerned both adsorption and electroanalysis with the use of the carbon materials applied.

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

2018 ◽  
Vol 2017 (3) ◽  
pp. 686-694 ◽  
Author(s):  
Hangdao Qin ◽  
Rong Xiao ◽  
Renhui Zhang ◽  
Jing Chen
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Benzoic Acid ◽  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Ph Value ◽  
Point Of Zero Charge ◽  
Dispersion Force ◽  
Solution Ph ◽  
Efficient Treatment

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.

Treatment of Simulated Wastewater Containing Chlorobenzene by Iron-Carbon Micro-Electrolysis Packing

2010 ◽  
Vol 113-116 ◽  
pp. 176-180 ◽  
Author(s):  
Meng Li ◽  
Dong Lei Zou ◽  
Hao Chen Zou ◽  
Dong Yan Fan
Keyword(s):  
Activated Carbon ◽  
Ph Value ◽  
Raw Materials ◽  
Removal Rate ◽  
Reaction Rates ◽  
First Order ◽  
First Order Kinetics ◽  
Low Degree ◽  
Simulated Wastewater ◽  
Pseudo First Order

Using iron filings, activated carbon power and clay as raw materials, the granular iron-carbon micro-electrolysis packing was made by the method of calcination. The influence of initial chlorobenzene (CB) concentration, pH value and reaction temperature on the removal rate of simulated wastewater containing CB were investigated. The results showed that the reaction followed the pseudo-first-order kinetics model and the rate constants varied at a relatively low degree at various pH. Temperature is an important parameter and an increase in temperature could significantly raise the reaction rates. The column packed with packing was designed to remove CB in wastewater. After running for 70 days, the packing still had good performance and there was no obvious decrease on the removal rate.

scholarly journals Synergy Effect of Nitrogen and Molybdenum on Activated Carbon Matrix for Selective Adsorptive Desulfurization: Insights into Surface Chemistry Modification

2021 ◽  
Author(s):  
Musa O Azeez ◽  
Abdulkadir Tanimu ◽  
Khalid Alhooshani ◽  
Saheed A. Ganiyu
Keyword(s):  
Activated Carbon ◽  
Surface Chemistry ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Photoelectron Spectroscopy ◽  
Pore Volume ◽  
Carbon Surface ◽  
Synergy Effect ◽  
Adsorptive Desulfurization ◽  
X Ray

Abstract This study reports the synthesis of mesoporous metal-modified nitrogen doped activated carbon (AC-N-Mo) from date seeds by ZnCl2 activation and its applicability for selective adsorptive desulfurization of dibenzothiophene (DBT). The AC-N-Mo exhibits higher adsorption capacity for DBT at 100 mg-S/L with the maximum value of 99.7% corresponding to 19.94 mg-S/g at room temperature than the unmodified carbon with 17.96 mg-S/g despite its highest surface area and pore volume of 1027 m2g− 1 and 0.55 cm3g− 1 respectively. The adsorption capacity breakthrough follows the order AC-N-Mo > AC-Mo > AC > AC-N. AC-N-Mo also displayed excellent selectivity in the presence of aromatics (toluene, naphthalene and 1-methylisoquinoline). The enhancement in the DBT uptake capacities of AC-N-Mo is attributed to synergy effect of nitrogen heteroatom that aid well dispersion of molybdenum nanoparticles on carbon surface thereby improving its surface chemistry and promising textural characteristics. The kinetic studies showed that the DBT adsorption proceeds via pseudo-second order kinetics while the isotherm revealed that both Freundlich and Langmuir fit the data but Freundlich fit the data more accurately for the best performing adsorbent. The physico-chemical properties (surface area, pore volume, carbon content, particle size etc.) of as-prepared adsorbents namely; AC, AC-N, AC-N-Mo and AC-Mo were characterized by N2- physisorption, X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Spectroscopy/Energy Dispersive Spectroscopy (SEM/EDS), Raman Spectroscopy (RS), Fourier Transform Infrared Spectroscopy (FTIR) and Ammonia-Temperature-Programmed Desorption (NH3-TPD).

scholarly journals The influence of active carbon contaminants on the ozonation mechanism interpretation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lilla Fijołek ◽  
Joanna Świetlik ◽  
Marcin Frankowski
Keyword(s):  
Activated Carbon ◽  
Active Carbon ◽  
Alkali Metals ◽  
Activated Carbons ◽  
Carbon Surface ◽  
Bulk Solution ◽  
Ozone Decomposition ◽  
Reaction Products ◽  
Treatment Technology ◽  
Carbon Impurities

AbstractIn water treatment technology, activated carbons are used primarily as sorbents to remove organic impurities, mainly natural organic matter, but also as catalysts in the ozonation process. Commercially available activated carbons are usually contaminated with mineral substances, classified into two main groups: alkali metals (Ca, Na, K, Li, Mg) and multivalent metals (Al, Fe, Ti, Si). The presence of impurities on the carbon surface significantly affects the pHpzc values determined for raw and ozonated carbon as well as their acidity and alkalinity. The scale of the observed changes strongly depends on the pH of the ozonated system, which is related to the diffusion of impurities from the carbon to the solution. In an acidic environment (pH 2.5 in this work), the ozone molecule is relatively stable, yet active carbon causes its decomposition. This is the first report that indirectly indicates that contaminants on the surface of activated carbon (multivalent elements) contribute to the breakdown of ozone towards radicals, while the process of ozone decomposition by purified carbons does not follow the radical path in bulk solution. Carbon impurities also change the distribution of the reaction products formed by organic pollutants ozonation, which additionally confirms the radical process. The study showed that the use of unpurified activated carbon in the ozonation of succinic acid (SA) leads to the formation of a relatively large amount of oxalic acid (OA), which is a product of radical SA degradation. On the other hand, in solutions with purified carbon, the amount of OA generated is negligible.

scholarly journals Study on Chromaticity Removal from Mineral Processing Wastewater with Salicylic Hydroxamic Acid by Granular Activated Carbon Catalyzed Ozonation

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 359
Author(s):  
Liping Zhang ◽  
Shengnian Wu ◽  
Nan Zhang ◽  
Ruihan Yao ◽  
Eryong Wu
Keyword(s):  
Activated Carbon ◽  
Reaction Time ◽  
Hydroxamic Acid ◽  
Ph Value ◽  
Oxygen Demand ◽  
Granular Activated Carbon ◽  
Mineral Processing ◽  
Ultraviolet Absorption Spectrum ◽  
Experimental Conditions ◽  
Removal Ratio

Salicylic hydroxamic acid is a novel flotation reagent used in mineral processing. However, it impacts the flotation wastewater leaving behind high chromaticity which limits its reuse and affects discharge for mining enterprises. This study researched ozonation catalyzed by the granular activated carbon (GAC) method to treat the chromaticity of the simulated mineral processing wastewater with salicylic hydroxamic acid. The effects of pH value, ozone (O3) concentration, GAC dosage, and reaction time on chromaticity and chemical oxygen demand (CODCr) removal were discussed. The results of individual ozonation experiments showed that the chromaticity removal ratio reached 79% and the effluent chromaticity exceeded the requirement of reuse and discharge when the optimal experimental conditions were pH value 3, ozone concentration 6 mg/L, and reaction time 40 min. The orthogonal experimental results of catalytic ozonation with GAC on chromaticity removal explained that the chromaticity removal ratio could reach 96.36% and the chromaticity of effluent was only 20 when the optimal level of experimental parameters was pH value 2.87, O3 concentration 6 mg/L, GAC dosage 0.06 g/L, reaction time 60 min respectively. The degradation pathway of salicylic hydroxamic acid by ozonation was also considered based on an analysis with ultraviolet absorption spectrum and high-performance liquid chromatography (HPLC).

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