Heteroatom-doped porous carbons with enhanced carbon dioxide uptake and excellent methylene blue adsorption capacities

Bamboo is found worldwide but is especially concentrated in tropical and subtropical areas with the major producing nations being China, Indonesia and Thailand with an annual production of 12 million tonnes. It has found uses in many applications such as: furniture, flooring, roofing, fencing, interior design and scaffolding in the construction industry. In this study, discarded waste bamboo furniture was used in the ground form as the raw material feedstock for the production of a series of biochars and activated carbons. The biochars were produced at different temperatures, namely, 723, 823, 923, 1,023, 1,123 and 1223 K, in a muffle furnace inerted with nitrogen and for different pyrolysis times. The product chars yields were 20–30% by weight of the raw material, surface areas were 100–350 m2/g. Other tests include elemental analysis, helium displacement density, pH, ICP-AES on a leachate sample. Four of the different temperature samples of biochar were used to adsorb the basic dye methylene blue and were shown to possess high adsorption capacities. Then, the same bamboo raw material powder was treated with acid and pyrolysed/activated in a nitrogen atmosphere at the same range of temperatures to produce activated carbons; these were characterized using similar test methods to the biochars. The yields are in the range 20–40% by weight of the raw material feedstock and the BET surface areas are in the range 200–600 m2/g. Three of the different temperature activated carbons were used to adsorb methylene blue and the results were compared with the biochar results. All the adsorption experimental isotherm results were analyzed using conventional isotherm equations. The benefits and cost implications of both biochar and activated carbon routes are discussed. The methylene blue adsorption capacities are extremely attractive in the range 0.42–1.12 mmol/g (150–300 mg/g char product) and extend to over 2.35 mmol/g (700 mg/g) for the bamboo derived activated carbons. The micropore and mesopore volumes have been determined under the various char and activated carbon experimental conditions and coupled with the surface areas; these results have been used to explain the trends in the methylene blue adsorption capacities.

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Materials for methylene blue adsorption

Research Society and Development ◽

10.33448/rsd-v10i9.18114 ◽

2021 ◽

Vol 10 (9) ◽

pp. e37410918114

Author(s):

Ronald Vieira Garcia ◽

Magno de Lima Silva ◽

Victor Emanuel de Morais Oliveira ◽

Vitória Catarina Cardoso Martins ◽

Josiney Farias de Araújo ◽

...

Keyword(s):

Methylene Blue ◽

Activated Carbon ◽

Coconut Shell ◽

Surface Phenomenon ◽

Blue Dye ◽

Molecular Formula ◽

Methylene Blue Adsorption ◽

Adsorption Capacities ◽

Pineapple Peel ◽

Adsorbent Materials

Adsorption is a surface phenomenon, in which the adsorbate is adhered to an adsorbent material and have been study for the removal of textile dyes, which have high toxicity to the aquatic environment. One of the dyes that stands out is methylene blue, which is organic, basic, aromatic, heterocyclic and molecular formula (C16H18ClN3S). In this study, we aim was to carry out a bibliography review in national and international scientific journals with articles published in the period from 2005 to 2019, of the adsorbent materials for the adsorption of the methylene blue dye. The materials reported are: mango seed powder, wheat husks, activated carbon obtained from rattan sawdust, activated carbon prepared from coconut shell, garlic shell, NaOH modified pummell shell, activated carbon (coconut shell and modified with NaOH), activated carbon (pea peel), HCl modified watermelon peel, potato peel, ZnCl2 activated cashew nut peel, mesoporous carbon obtained from fish scales, pineapple peel and bamboo. Our review indicate that the adsorbent materials found in the literature for methylene blue adsorption have high adsorption capacities. The adsorption capacities are high and depend on several parameters, which influence the adsorption (pH of the medium, mass and particle size of the adsorbent material, concentration of adsorbate (methylene blue), temperature and time of contact of the adsorbate with the adsorbent.

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The use of insoluble matter of Moroccan oil shale for removal of dyes from aqueous solution

10.31221/osf.io/x4v9p ◽

2019 ◽

Author(s):

Chem Int

Keyword(s):

Methylene Blue ◽

Oil Shale ◽

Heating Temperature ◽

Blue Dye ◽

Adsorption Capacities ◽

Experimental Parameters ◽

Initial Ph ◽

New Material ◽

Activating Agent ◽

Moderate Cost

The study aims to use an adsorbent natural based of Moroccan oil shale of Timahdit area (Y layer) in a physical-chemical adsorption process for treating industrial discharges colorful. The used adsorbent is the insoluble party of the sub-critical extraction of decarbonized oil shale of Timahdit. The tests performed on the methylene blue (MB), showed a strong elimination in the first 10 minutes. The influences of various experimental parameters were studied: mass ratio of adsorbent, time and temperature of thermal treatment, contact time, pH of MB and heating temperature of solution on the parameters of material were studied. The experimental results have shown that the adsorption of methylene blue dye by the adsorbent is more than 90% at initial pH a range 6-7 at room temperature for 30 minutes. The process is simple and the adsorbent produced is a new material with interesting adsorption capacities of moderate cost which does not require an activating agent and can be used as industrial adsorbent for the decontamination of effluents containing organic pollutants.

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