Pressurized electro-Fenton for the reduction of the environmental impact of antibiotics

Abstract This work evaluates the performance of a pressurized heterogeneous electro-Fenton (EF) process to transform the antibiotic into compounds that do not promote the appearance of bacteria resistant to antibiotic in the environment. Experimental system consisted of a pressurized non divided microfluidic electrochemical cell equipped with a jet aerator, flow-through electrodes and a fluidized bed of goethite as heterogeneous iron catalyst. Results show that meropenem (model antibiotic) can be degraded by EF and that the degradation rate depends on the gauge pressure applied: the higher is the pressurization, the faster is the abatement of meropenem. The antibiotic effect of the urine is related to meropenem remained in the treated urine, and the contribution of reaction intermediates does not seem to be relevant. The mineralization of the organic load is almost nil. The higher dissolved oxygen concentration of pressurized-EF and thus, the higher hydrogen peroxide generation seems to be the key point to explain the effect of pressure on EF process. Results confirm that moderated pressurized EF process (up to 3 bar) can be satisfactorily used to decrease the chemical risk of synthetic hospital urines, which opens the possibility of an optimized pre-treatment which may help to save cost in the treatment of these hazardous wastes.