Sustainable bioremediation of antibacterials, metals and pathogenic DNA in water

Abstract

The global antibacterial resistance requires urgent attention from different fields of engineering. Here, several unit operations were assessed in a novel water treatment train capable of remediating antibacterials, metals and pathogenic DNA to generate clean water. The analyses used 14C-respirometry, spectrometry, and a set of molecular analyses. Multiresistant bacteria hold antibacterial resistance genes (ARGs), which were harnessed for bioremediation of pollutant mixtures. Treatment efficiencies were 25–71% for 8-days with aerobic Cr(VI) reduction and removal of Cd and Pb; and 34.8% erythromycin (ERY) was biodegraded aerobically in 20 days. The anaerobic digestion (AD) bioremediated 65–73% mixed antibacterials ERY and sulfamethoxazol (SMX) in 60 days. However, high concentrations of mixed antibacterials induced inhibition of bacteria and methanogens and higher diversity of ARGs. ARGs were eliminated at 60 °C and 5.8 kPa for 10 min. The suggested coupling sequence of operations was metal, then antibacterial aerobic bioremediation, AD (yielding biomethane as energy source), recirculation of ARGs in situ, and thermo-pressure pathogenic DNA degradation.