Bimetallic Bi/Cu0-catalyzed persulfate-based advanced oxidation processes towards clofibric acid degradation in wastewater

Clofibric acid (CFA), an important blood-lipid regulatory drug is an emerging organic pollutant and widely reported in water resources. A novel bimetallic, bismuth/zero valent cupper (Bi/Cu0) catalyst was prepared which showed better physiological, structural, and catalytic properties than Cu0. The Bi/Cu0 effectively catalyzed persulfate (S2O82-) and caused 85% degradation of CFA. The Bi coupling improved reusability and stability of Cu0. The use of alcoholic and anionic radical scavengers and analyzing change in [S2O82-]0 proved that Bi/Cu0/S2O82-yield hydroxyl radicals (OH) and sulfate radicals (SO4-). The OH and SO4- showed faster reaction with CFA, i.e., 4.65 x 109 and 3.82 x 109 M-1 s-1 and degraded CFA into four degradation products. Under optimal conditions of [Bi/Cu0]0 = 1.0 g/L and [S2O82-]0 = 40 mg/L, 99.5% degradation of the 10 mg/L of CFA was achieved at 65 min. Temperature showed promising effects on the removal of CFA by Bi/ Cu0/S2O82-and caused 98% removal at 323 K than 75% at 298 K at 32 min. The temperature effects were used to calculate activation energy, enthalpy, and rate constant of CFA degradation. The Bi/Cu0/S2O82-showed effective removal of CFA in real water samples also. The ecotoxicity study confirmed non-toxic product formation which suggests high capability of the proposed technology in the treatment of CFA.

Automated summary

A novel bimetallic catalyst, bismuth/zero valent cupper (Bi/Cu0), has been prepared for the efficient degradation of blood-lipid regulatory drug clofibric acid (CFA). The addition of bismuth improves the reusability and stability of the catalyst. The mechanism of CFA degradation by the catalyst is revealed by analyzing the reaction products and rate constants. The experimental results demonstrate the effective removal of CFA by the catalyst in real water samples.