Synergistic and competitive adsorption of organic dyes on multiwalled carbon nanotubes

Abstract

h i g h l i g h t s" Adsorption of methylene blue and acid red 183 on a MWCNT in single and binary dye systems was investigated. " MWCNT shows higher adsorption capacity to methylene blue in both systems. " A synergistic effect for basic and acid dyes occurs in a binary dye system. t r a c tA multiwalled carbon nanotube (MWCNT) was used as an adsorbent for removal of a cationic dye (methylene blue, MB) and acid dye (acid red 183, AR183) from aqueous solution in single and binary dye systems. Characterization of the MWCNT and MWCNT-dye systems were performed using several techniques such as Fourier transform infrared spectroscopy (FTIR), thermogravimetric-differential thermal analysis (TG-DTA), zeta potential and elemental analysis. Adsorption tests showed that the MWCNT presented higher adsorption of MB than AR183 in single and binary dye systems, revealing that p-p stacking is the main driving force responsible for the dye-MWCNT interaction. In single dye systems, the MWCNT presented the maximum adsorption capacities of MB and AR183 at 59.7 and 45.2 mg/g, respectively. In a binary dye system, a synergistic effect due to electronic attraction between MB and AR183 was found at low AR183 concentration (10 mg/L), which promotes the adsorption of both dyes on the MWCNT. However, MB adsorption could be reduced at higher AR183 concentration (>20 mg/L) due to a strong electrostatic attraction between MWCNT-AR183.

Simultaneous removal of cationic and anionic dyes by the mixed sorbent of magnetic and non-magnetic modified sugarcane bagasse

“…Congo red served as a bridge to connect basic magenta and AMS. Similar result was reported by Wang et al[26].…”

Novel magnetic NiFe2O4/multi-walled carbon nanotubes hybrids: Facile synthesis, characterization, and application to the treatment of dyeing wastewater

“…Due to high aspect ratio, large accessible external surface area, well developed mesopores and layered structures, CNTs have been proven to possess a great potential as photocatalyst to chemically oxidize organic pollutants or as superior adsorbents for removing many kinds of organic and inorganic contaminants from aqueous solutions [14][15][16][17][18]. Therefore, an upcoming application domain of CNTs is water purification [13].…”

Eco-friendly synthesis of graphene–chitosan composite hydrogel as efficient adsorbent for Congo red

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