Silica Functionalized Almond Gum Derivatives for Integrated Flocculation Cycles for Natural and Synthetic Water Systems

Natural gum-based flocculants are prevalent for water treatment, still their efficiency can be improved by the incorporation of eco-friendly inorganic fillers. Such inorganic–organic-based hybrid materials need to be explored more in natural and synthetic water systems for their proof of concept and related applications. Hybrid almond gum (Amg) grafted polyacrylamide/silica-based composite (Amg-g-PAM/SiO₂) was synthesized and assessed as a flocculant for natural and synthetic water systems. The synthesis was characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Energy dispersive X-ray spectroscopy (EDS), Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC) and X-ray photoelectron spectroscopy (XPS) to study the chemical, structural, thermal, and surface properties. The synthesized grades of Amg-g-PAM and Amg-g-PAM/SiO₂ were tested for their flocculation performance in kaolin, iron ore and MWCNT suspensions. pH and temperature variations, zeta potential measurements were studied on neutral kaolin suspension. The best flocculation efficiency was observed to be 98%, 96%, 95% and 92% in MWCNT, kaolin, iron ore suspensions and river water respectively at pH 4 and 25 °C. Overall, Amg-g-PAM/SiO₂ flocculant possesses unique characteristics of conventional branched graft copolymers which increases easy approachability towards suspended particles while its inorganic counterpart enhances adsorption. Thus, this hybrid flocculant is better than any of its individual inorganic or organic counterparts in terms of flocculation efficacy.