Electro-Fenton process is an emerging treatment technology for water and wastewater treatment. Electro-Fenton utilizes hydroxyl radicals to oxidize hazardous contaminants and is especially useful to treat recalcitrant compounds that are not easily degraded in conventional water and wastewater treatment plants. This paper reviews the mechanism of electro-Fenton process and its kinetic modeling. The effects of electrode materials, hydrogen peroxide concentration, ferrous ion concentration, pH, electrolyte, oxygen sparging rate, temperature, initial concentration of pollutant, feeding mode, current density, and distance between electrodes are also reviewed. The performance of electro-Fenton is compared with other treatment technologies. Finally, existing challenges and future perspectives are discussed.

Wastewater discharged from clinical isolation and general wards at two hospitals in Singapore was examined to determine the emerging trends of antibiotic resistance (AR). We quantified the concentrations of 12 antibiotic compounds by analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS), antibiotic-resistant bacteria (ARB), the class 1 integrase gene ( intI1 ), and 16 antibiotic resistance genes (ARGs) that confer resistance to 10 different clinically relevant antibiotics. A subset of 119 antibiotic-resistant isolates were phylogenetically classified and tested for the presence of ARGs encoding resistance to β-lactam antibiotics ( bla _NDM , bla _KPC , bla _SHV , bla _CTX-M ), amikacin [ aac(6′)-Ib ], co-trimoxazole ( sul1 , sul2 , dfrA ), ciprofloxacin ( qnrA , qnrB ), and the intI1 gene. Among these resistant isolates, 80.7% were detected with intI1 and 66.4% were found to carry at least 1 of the tested ARGs. Among 3 sampled locations, the clinical isolation ward had the highest concentrations of ARB and the highest levels of ARGs linked to resistance to β-lactam ( bla _KPC ), co-trimoxazole ( sul1 , sul2 , dfrA ), amikacin [ aac(6′)-Ib ], ciprofloxacin ( qnrA ), and intI1 . We found strong positive correlations ( P < 0.05) between concentrations of bacteria resistant to meropenem, ceftazidime, amikacin, co-trimoxazole, and ciprofloxacin and abundances of bla _KPC , aac(6′)-Ib , sul1 , sul2 , dfrA , qnrA , and intI1 genes.