Synthesis, Characterization and Optimization of Bionanocomposites for the Application of Methylene Blue Dye Degradation under Light Irradiation

Abstract

Water hyacinth (Eichornia crassipes) is a free floating aquatic weed that potentially damages the aquatic ecosystem by colonizing rapidly and it causes drying of water bodies. In addition, releasing of colored textile wastewater into nearby water bodies potentially damage the aquatic creatures and surrounding lives. But behind the negative assumptions of Water hyacinth (WH) weed, it is rich in natural fiber content, namely cellulose and its leaves used as a reducing and capping agent during nanoparticles (NPs) synthesis. Therefore; this research mainly focus on utilization of the weed’s stem and leaves to develop cellulose nano crystals (CNCs) and as capping and reducing agent during silver doped zinc oxide nanoparticles (Ag@ZnO NPs) synthesis, respectively. Furthermore; the developed CNCs to behave as a photocatalyst, it was combined with a green synthesized Ag@ZnO NPs to develop a bionanocomposite (BNC). The characterization techniques i.e. UV-Vis spectrophotometer, FTIR, XRD, TGA, BET, DLS and SEM-EDX were confirm the obtained CNCs and Ag@ZnO NPs were effectively synthesized. Also each characterization results exhibit the formation of pure BNCs (i.e. CNC/Ag@ZnO (1:1), CNC/Ag@ZnO (1:0.5) and CNC/Ag@ZnO (0.5:1)). The synthetic Methylene Blue (MB) dye solution and real textile wastewater were used in photodegradation study. Moreover, the effect of operating parameters i.e. pH, BNCs dosage, initial MB concentration, and irradiation time was investigated under sunlight irradiation. According to the results, CNC/Ag@ZnO (1:0.5) BNC has higher photodegradation efficiency (98.8%) than CNC/Ag@ZnO (1:1) and CNC/Ag@ZnO (0.5:1) BNCs at the optimum condition. In addition, the RSM-BBD analysis results showed that pH = 10, CNCs/Ag@ZnO (1:0.5) BNC dosage =18.075 mg/L, MB dye concentration = 17.468 mg/L and Irradiation time = 111.855 min were the optimal level of the studied process parameters using CNC/Ag@ZnO (1:0.5) BNC. Also, the desirability of the process was 1.00; it confirms the acceptance and applicability of the model. Moreover, the recyclability test confirms CNC/Ag@ZnO (1:0.5) BNC has high recyclability efficiency even after 7th round than the left synthesized BNCs. Therefore; the facile synthesis and high degradation efficiency of CNC/Ag@ZnO (1:0.5) BNC photocatalyst make it a promising candidate for real-world dye containing textile wastewater treatment under light irradiation with low operating cost.