Low-pressure UV-initiated synthesis of cationic starch-based flocculant with high flocculation performance

A kind of starch-based flocculant (starch-graft-poly[(2-methacryloyloxyethyl) trimethyl ammonium chloride], denoted St-g-PDMC-LPUV) has been synthesized by low-pressure ultraviolet initiation and was employed to remove humic acid (HA) for water purification. The physicochemical characteristics of starch and St-g-PDMC-LPUV were characterized by FT-IR, H-1 NMR, XRD, TGA, SEM and BET to confirmed the successful grafting DMC onto starch. Effects of flocculant dosage, pH, the adding amount of Fe3O4, initial HA concentration and stirring speed were investigated systematically. The prepared St-g-PDMC-LPUV flocculant with non-toxic, biodegradability and environmental friendliness exhibited effective performance for removing HA from water in a wide pH range (5-10). The flocculation mechanism was attributed to the effective collision between function groups of the St-g-PDMC-LPUV flocculant and HA by charge neutralization, adsorption, bridging and patching.

Automated summary

A starch-based flocculant was synthesized using low-pressure ultraviolet initiation, which effectively removed humic acid from water across a wide pH range. The mechanism of flocculation was found to involve charge neutralization, adsorption, bridging, and patching between functional groups of the St-g-PDMC-LPUV flocculant and HA.