The role of water and surface acidity on the reactive adsorption of ammonia on modified activated carbons

The surface areas of non-activated, activated and modified activated carbons were determined from the adsorption of nitrogen at −196°C and of carbon dioxide at 25°C. The base neutralization capacities were determined from the adsorption of NaOH, Na2CO3, NaHCO3 and NH4OH. The amount of oxygen combined to the carbon surface was estimated by measuring the pressure of CO and CO2 obtained on outgassing the carbon sample in the temperature range 300–1000°C. The surface area of activated carbon is not a determining factor in its ammonia adsorption. The surface acidity of the active carbon is a good measure of its capacity for ammonia removal. Ammonia adsorption increases appreciably upon surface oxidation of carbons with oxidizing gases and solutions. The acidic groups on the surface of carbons differ in their strength. Only a fraction of the surface covered by the carbon–oxygen groups is responsible for the capacity of the carbon towards ammonia. Most of the adsorbed ammonia is recovered upon treatment with dilute hydrochloric acid leaving the surface free for successive ammonia adsorption cycles.

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Role of Aluminum Oxycations in Retention of Ammonia on Modified Activated Carbons

The Journal of Physical Chemistry C ◽

10.1021/jp074118e ◽

2007 ◽

Vol 111 (44) ◽

pp. 16445-16452 ◽

Cited By ~ 26

Author(s):

Camille Petit ◽

Teresa J. Bandosz

Keyword(s):

Activated Carbons ◽

Modified Activated Carbons

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Methane Recovery from Coal Bed Gas Using Modified Activated Carbons: A Combined Method for Assessing the Role of Functional Groups

Energy & Fuels ◽

10.1021/acs.energyfuels.5b01706 ◽

2015 ◽

Vol 29 (10) ◽

pp. 6858-6865 ◽

Cited By ~ 8

Author(s):

Ziyi Li ◽

Yingshu Liu ◽

Chuanzhao Zhang ◽

Xiong Yang ◽

Jianliang Ren ◽

...

Keyword(s):

Functional Groups ◽

Activated Carbons ◽

Coal Bed ◽

Combined Method ◽

Methane Recovery ◽

Modified Activated Carbons

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Promoting role of sulfur groups in selective catalytic reduction of NO with NH3 over H2SO4 modified activated carbons

Korean Journal of Chemical Engineering ◽

10.1007/s11814-015-0076-0 ◽

2015 ◽

Vol 32 (11) ◽

pp. 2257-2263 ◽

Cited By ~ 5

Author(s):

Qianqian Guo ◽

Wen Jing ◽

Shangzeng Cheng ◽

Zhanggen Huang ◽

Dekui Sun ◽

...

Keyword(s):

Selective Catalytic Reduction ◽

Activated Carbons ◽

Catalytic Reduction ◽

Reduction Of No ◽

Modified Activated Carbons

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Modified activated carbons for esterification of acetic acid with ethanol

Diamond and Related Materials ◽

10.1016/j.diamond.2019.107608 ◽

2020 ◽

Vol 101 ◽

pp. 107608 ◽

Cited By ~ 1

Author(s):

Beata Krzyżyńska ◽

Anna Malaika ◽

Karolina Ptaszyńska ◽

Agnieszka Tolińska ◽

Piotr Kirszensztejn ◽

...

Keyword(s):

Acetic Acid ◽

Activated Carbons ◽

Modified Activated Carbons

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Oxytetracycline Adsorption from Aqueous Solutions on Commercial and High-Temperature Modified Activated Carbons

Energies ◽

10.3390/en14123481 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3481

Author(s):

Joanna Lach ◽

Agnieszka Ociepa-Kubicka ◽

Maciej Mrowiec

Keyword(s):

Activated Carbon ◽

Aqueous Solutions ◽

Activated Carbons ◽

Electricity Consumption ◽

Solution Ph ◽

Carbon Modification ◽

Modification Method ◽

Flow Through ◽

Proposed Modification ◽

Modified Activated Carbons

The aim of the work was to evaluate the possibility of using commercial and modified activated carbons for the removal of oxytetracycline from aqueous solutions. The kinetics and statics of adsorption as well as the effect of the activated carbon dose and solution pH on the efficiency of the oxytetracycline adsorption were analyzed. Based on the study of oxytetracycline adsorption isotherms, the activated carbons were ranked in the following order: F-300 > WG-12 > Picabiol > ROW08 > WACC 8 × 30 > F-100 > WAZ 0.6–2.4. The most effective activated carbons were characterized by large specific surfaces. The best matching results were obtained for: Redlich–Peterson, Thot and Jovanovic models, and lower for the most frequently used Freundlich and Langmuir models. The adsorption proceeded better from solutions with pH = 6 than with pH = 3 and 10. Two ways of modifying activated carbon were also assessed. A proprietary method of activated carbon modification was proposed. It uses the heating of activated carbon as a result of current flow through its bed. Both carbons modified at 400 °C in the rotary kiln and on the proprietary SEOW (Joule-heat) modification stand enabled to obtain adsorbents with higher and comparable monolayer capacities. The advantage of the proposed modification method is low electricity consumption.

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