Degradation of hydroxypropyl guar gum by dual oxidant system catalyzed by hydrotalcite supported zero-valent transition metal

In order to address the issues of slow degradation rate, narrow pH applicability, and poor regeneration of zero-valent transition metal catalysts during the degradation of hydroxypropyl guar gum (HPG), templated hydrotalcite with hierarchical pores was established and hydrogen peroxide-persulfate dual oxidant was used in this work. The results demonstrate that zero-valent copper, supported on multilevel porous hydrotalcites synthesized using worm-like micellar soft templates within a wide pH range from 3 to 11, achieved a viscosity reduction rate of up to 80.92% for HPG within 25 min and a COD removal efficiency of 96.37% after 120 min. And high degradation efficiency, 81.08%, can be obtained even after five recycles at pH 7. Furthermore, free radical quenching experiments, as well as XRD, BET, and SEM characterization, confirm that the degradation of HPG is attributed to the collaborative activation of SO₄⁻·, ·O₂⁻, ¹O₂, and ·OH radicals in the H₂O₂–Na₂S₂O₈ dual oxidant, which provide new insights for the degradation of oilfield pollutants.