Computation of adsorption parameters for the removal of dye from wastewater by microwave assisted sawdust: Theoretical and experimental analysis

- Microwave assistance has been employed for the preparation of an effective adsorbent from saw dust.
- The adsorbent was successfully employed for the sequestration of dye from aqueous solution.
- The quality of the adsorbent was analyzed with characterization techniques.
- Langmuir maximum monolayer sorption capacity was calculated as 58.14 mg/g.
- Adsorption system was best explained by Freundlich and pseudo-second order models.

In this research, the microwave assistance has been employed for the preparation of novel material from agro/natural bio-waste i.e. sawdust, for the effective removal of methylene blue (MB) dye from aqueous solution. The characterization of the newly prepared microwave assisted sawdust (MASD) material was performed by using FTIR, SEM and XRD analyses. In order to obtain the maximum removal of MB dye from wastewater, the adsorption experimental parameters such as initial dye concentration, contact time, solution pH and adsorbent dosage were optimized by trial and error approach. The obtained experimental results were applied to the different theoretical models to predict the system behaviour. The optimum conditions for the maximum removal MB dye from aqueous solution for an initial MB dye concentration of 25 mg/L was calculated as: adsorbent dose of 3 g/L, contact time of 90 min, solution pH of 7.0 and at the temperature of 30 °C. Freundlich and pseudo-second order models was best obeyed with the studied experimental data. Langmuir maximum monolayer adsorption capacity of MASD for MB dye removal was calculated as 58.14 mg of MB dye/g of MASD. Adsorption diffusion model stated that the present adsorption system was controlled by intraparticle diffusion model. The obtained results proposed that, novel MASD was considered to be an effective and low-cost adsorbent material for the removal of dye from wastewater.