| Summary: | The performance of Carbon Nanotubes hybrid hydrogels for environmental remediation was investigated using Methylene Blue (MB), Rhodamine B (RD), and Bengal Rose (BR) as model contaminating dyes. An acrylate hydrogel network with incorporated CNT was synthesized by photo-polymerization without any preliminary derivatization of CNT surface. Thermodynamics, isothermal and kinetic studies showed favorable sorption processes with the application of an external 12 V electric field found to be able to influence the amount of adsorbed dyes: stronger interactions with cationic MB molecules (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>q</mi><mrow><mi>e</mi><mi>x</mi><mi>p</mi></mrow></msub></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mi>q</mi><mrow><mi>e</mi><mi>x</mi><mi>p</mi></mrow><mrow><mn>12</mn></mrow></msubsup></mrow></semantics></math></inline-formula> of 19.72 and 33.45 mg g<sup>−1</sup>, respectively) and reduced affinity for anionic RD (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>q</mi><mrow><mi>e</mi><mi>x</mi><mi>p</mi></mrow></msub></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mi>q</mi><mrow><mi>e</mi><mi>x</mi><mi>p</mi></mrow><mrow><mn>12</mn></mrow></msubsup></mrow></semantics></math></inline-formula> of 28.93 and 13.06 mg g<sup>−1</sup>, respectively) and neutral BR (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>q</mi><mrow><mi>e</mi><mi>x</mi><mi>p</mi></mrow></msub></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mi>q</mi><mrow><mi>e</mi><mi>x</mi><mi>p</mi></mrow><mrow><mn>12</mn></mrow></msubsup></mrow></semantics></math></inline-formula> of 36.75 and 15.85 mg g<sup>−1</sup>, respectively) molecules were recorded. The influence of pH variation on dyes adsorption was finally highlighted by reusability studies, with the negligible variation of adsorption capacity after five repeated sorption cycles claiming for the suitability of the proposed systems as effective sorbent for wastewater treatment.
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