Synthesis and application of cellulose acetate-acrylic acid-acrylamide composite for removal of toxic methylene blue dye from aqueous solution

Abstract

The aim of this research is to treat a dye (methylene blue) contained in wastewater with a modified novel cellulose acetate-based composite material. The cellulose acetate-based composite viz—cellulose acetate-acrylic acid-acrylamide (CA-AA-AM) is prepared using potassium persulfate as an initiator under the microwave irradiation method. The effect of various operating conditions on the stability of the composite was examined. The dye uptake capacity of the composite was investigated and fitted to Langmuir and Freundlich Isotherms. Pseudo-first and second-order kinetic studies were applied, and the outcome reveals that Langmuir isotherm and pseudo-second-order present an excellent fit. The CA-AA-AM composite was examined with Fourier Transform Infrared Spectroscopy, X-ray diffraction, Scanning Electron Micrography, and Thermal analysis for virgin cellulose acetate and CA-AA-AM composite. The results showed a maximum adsorption capacity of 68.9 mg/g or 89 % of percentage removal using CA-AA-AM composite at optimal conditions. The interaction between cellulose acetate and monomers occurs on the OH functional group of cellulose acetate that leads to the addition of two more functional groups CONH2 (from acrylamide) and COOH (from acetic acid) which were responsible for the active adsorption sites. The MB adsorption process was spontaneous and endothermic from a thermodynamic perspective. The investigations on reusability indicated that the synthesized composite is easily reusable. For up to five cycles, the adsorbent continued to absorb MB. It indicates that the CA-AA-AM composite is a satisfactory adsorbent to remove methylene blue (MB). This study findings showed that the CA-AA-AM composite work well to remove MB from aqueous solutions and are a viable, recyclable adsorbent.