Copper-plating iron filings A new Fenton oxidation catalyst

Advanced oxidation processes (AOPs) are appropriate to eliminate recalcitrant organic pollutants from effluents. Fenton treatment is an important AOP. Hard-decomposed organic compounds could be more quickly and thoroughly oxidized by hydroxyl radical intermediate derived from Fenton's reagent ((FeSO_4)-H_2O_2). Using the reagent as oxidant in waste water treatment is attractive due to the fact that iron is abundant and a non-toxic element and H_2O_2 is easy to handle and environmentally benign. (However), the drawback of the Fenton's oxidation process is that the treatment requires high amount of both reagents. Preliminary laboratory tests have been performed by the present work to evaluate the catalytic efficiency of copper-plating iron filings on Fenton's treatment. The water handled was an effluent (COD_(Cr)=1 900 mg/L) derived from a complex drilling wastewater (COD_(Cr)= 35 200 mg/L) by double (coagulation)-flocculation treatment. Its biodegradability was poor. By using Fe-Cu-H_2O_2 system, the (oxidizing) treatment was capable of lowering the effluent COD_(Cr) concentration to 426 mg/L corresponding to a H_2O_2 utilization factor of 74 mg COD_(Cr)·cm~(-3)H_2O_2, whereas the final COD_(Cr) value reached by classic Fenton reagent was 723 mg/L with an utilization factor of 59 mg COD_(Cr)·cm~(-3)H_2O_2. Results demonstrate that Fe-Cu-H_2O_2 system can obtain higher oxidizing efficiency than the common Fe~(2+)-H_2O_2 system. (Because) copper-plating iron filings are easy prepared and have higher efficiency in reducing COD_(Cr) level of refractory wastewater, this new catalyst is a promising alternative in Fenton oxidation.