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Amine-Modified Mesoporous Magnesium Carbonate as an Effective Adsorbent for Azo Dyes
journal contribution
posted on 2019-02-11, 09:13 authored by Maria Vall, Maria Strømme, Ocean CheungMesoporous magnesium carbonate (MMC)
was evaluated as a potential
candidate material for removal of dyes from textile industry wastewater.
The adsorption property of MMC was analyzed for three different azo
dyes: reactive black 5 (RB5), amaranth (AM), and acid red 183 (AR183).
Further, the effect of porosity, amine modification, ionic strength,
and pH was evaluated. MMC modified with 3-(aminopropyl)triethoxysilane
(aMMC) showed consistently high uptake levels for all of the azo dyes
tested; the uptake of RB5, AM, and AR183 was ∼360, ∼143
and ∼170 mg/g, respectively. The results demonstrated the importance
of porosity and surface chemistry in the effective adsorption of the
azo dye in aqueous systems. The uptake of RB5 and AM on aMMC was not
significantly affected by pH (when varied between 4 and 10), although
reduced uptake of RB5 and AM was observed at pH values <2 and >12.
The addition of NaCl salt at concentrations up to 1000 mM had minimal
effect on the high uptake of RB5 on aMMC. The uptake of AM by aMMC
was reduced by approximately 20% in the presence of NaCl even at low
concentrations. The uptake of AR183 by aMMC varied noticeably by changes
in pH and no specific trend was observed. The presence of NaCl also
adversely affected the uptake of AR183 on aMMC. The adsorption of
the azo dye on aMMC was most likely driven by electrostatic interactions.
We show here that aMMC is a potential candidate adsorbent for the
effective removal of azo dyes from textile wastewaters.