Novel Hybrid System for Textile Dye Wastewater Treatment

This study presents a novel hybrid technique that combines hydrodynamic cavitation (HC) with hydrogel-packed bed adsorption for the efficient degradation and removal of dye pollutants from wastewater. The process integrates advanced oxidation via cavitation-generated radicals with adsorptive capture of residual dye molecules using synthesized polymeric hydrogels. Poly(acrylic acid) (PAA) nanocomposite hydrogels were prepared through an ultrasound-assisted emulsion polymerization technique, employing bentonite clay, halloysite clay, and graphene oxide (GO) as inorganic cross-linkers. Ultrasound ensured uniform dispersion of nanofillers within the polymer matrix, improving the structural integrity and adsorption capacity of the hydrogels. The synthesized hydrogels were characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM) to confirm morphological and structural features. Operational parameters investigated included inlet pressure, pH, nanoclay concentration, hydrogel quantity, and flow rate, which influenced the overall removal of crystal violet (CV) dye in the hybrid HC–hydrogel system. The combined process demonstrated a significantly higher dye degradation and total organic carbon (TOC) removal efficiency compared to either HC or hydrogel adsorption alone, underscoring its synergistic performance and potential as a sustainable hybrid wastewater treatment approach.