Heterogeneous photo-Fenton-like degradation of emerging pharmaceutical contaminants in wastewater using Cu-doped MgO nanoparticles

Authors: SILVA, MANOJ - Lehigh University; BALTRUS, JOHN - US Department Of Energy; Williams, Clinton; Knopf, Allan; ZHANG, LIHUA - Brookhaven National Laboratory; BALTRUSAITIS, JONAS - Lehigh University

Submitted to: Applied Catalysis A: General
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/18/2021
Publication Date: 12/21/2021
Citation: Silva, M., Baltrus, J., Williams, C.F., Knopf, A.L., Zhang, L., Baltrusaitis, J. 2021. Heterogeneous photo-Fenton-like degradation of emerging pharmaceutical contaminants in wastewater using Cu-doped MgO nanoparticles. Applied Catalysis A: General. 630. Article 118468. https://doi.org/10.1016/j.apcata.2021.118468.
DOI: https://doi.org/10.1016/j.apcata.2021.118468

Interpretive Summary: Trace organic compounds, like pharmaceuticals, are ubiquitous in treated municipal wastewater. Current sewage treatment processes are not designed to remove low level concentrations of pharmaceuticals. A new porous nanomaterial made from magnesium oxide with up to 10% copper was manufactured. The novel nanomaterial was shown to be a good catalyst for removing salicylic acid and tetracycline in the presence of UV light and hydrogen peroxide. The catalyst was found to be able to remove all salicylic acid and tetracycline from solution within 15 and 30 minutes respectively. The catalyst was found to maintain reactivity for more than five reaction cycles. Additionally, degradation resulted in no untoward byproducts and the catalyst was conserved. The new catalyst has the potential for use in current wastewater treatment plants to remove trace organics prior to environmental discharge.

Technical Abstract: A facile thermal decomposition method was utilized to synthesize Cu-doped MgO nanoparticles possessing mesoporosity. These mesoporous Cu doped MgO nanoparticles were shown to be efficient photo-Fenton-like catalysts for the degradation of emerging pharmaceutical contaminants in wastewater and were able to completely oxidize salicylic acid within 1 hour under optimized conditions. Tetracycline was shown to be converted to other intermediates with a large portion of it undergoing full mineralization. Batch experiments were conducted to demonstrate the effects of Cu loading on MgO, overall catalyst loading, and H2O2 concentration on the salicylic acid and tetracycline conversion and rate constants. Quenching experiments revealed that both •OH radicals or HO2•/•O2- radicals were involved in the reaction, with the latter showing a higher contribution. The surface dissolution of MgO was shown to facilitate a high pH environment which completely prevented Cu from leaching out of the catalyst while retaining high activity. The catalyst reusability was shown to be satisfactory with high activity and conversion being preserved over five cycles.