Aquananotechnology: oriented-sawdust waste valorization into magnetic nanocellulosic particles for Synozol Red K-HL sorption prospect

Abstract

AbstractHigh loaded textile dying effluents should undergo for treatment prior to final disposal into the environment. The current study aimed to apply naturally abundant and cheap by-product material namely sawdust (SWD) to develop magnetized cellulosic nano-adsorbent based on magnetite nanoparticles for reactive dye removal namely Synozol Red K-HL (R K-HL). The powder of SWD, which is available through various industries, was modified via pre-treatment with acid hydrolysis and bleaching before blending them with magnetite particles which is synthesized via co-precipitation route. Sawdust (SWD) conjugated with Fe3O4at different weight percentages (wt%), i.e. SF-(1:1), SF-(2:1), SF-(3:1), SF-(5:1) and SF-(1:2), then subjected to microwave technique, and then characterized by X-ray diffraction spectroscopy (XRD); transmission electron microscope (TEM); Fourier transform infrared (FTIR). Thereafter, the effects of system parameters on adsorption capability, i.e. pH, temperature and dye loading were studied using the modified adsorbents. The SF-(2:1) adsorbent showed the highest affectivity which achieved the highest (21.71 mg g−1) adsorption uptake with a catalyst dosage of 1 g L−1. Moreover, a complete dye removal (100%) was attained at low initial dye loading in the aqueous medium. Langmuir, Freundlich, Temkin and Dubinin–Radushkevich (D-R) isotherm models and their corresponding constants were calculated and discussed. The experimental results showed that the Langmuir isotherm model is well expressed in the experimental data. The kinetics of R K-HL dye removal was found to depend on operational temperature. A study of three kinetic models has been made, and the Bangham’s kinetic model was found to describe the adsorption of dye R K-HL on all the adsorbents applied. The adsorption of reactive R K-HL onto magnetized sawdust adsorbents was spontaneous and exothermic in nature as concluded from thermodynamic assays. Experimental results verified that dye R K-HL could be successfully eliminated feasibly from the aqueous stream in economic way.