Low voltage iron electrocoagulation as a tertiary treatment of municipal wastewater: removal of enteric pathogen indicators and antibiotic-resistant bacteria

Hospital sewage constitutes an important point source for antibiotics and antibiotic-resistant bacteria due to the high antibiotic use. Antibiotic resistance can develop and cause problems in sewage systems within hospitals and municipal wastewater treatment plants, thus, interventions to treat hospital sewage on-site are important. Ozonation has proven effective in treating relatively clean wastewater, but the effect on untreated wastewater is unclear. Therefore, we piloted implementation of ozonation to treat wastewater in a tertiary hospital in Uppsala, Sweden. We measured active pharmaceutical ingredients (APIs) using liquid chromatography-mass spectrometry and antibiotic-resistant Enterobacteriaceae using selective culturing pre- and post-ozonation. Comparing low (1 m3/h) and high (2 m3/h) flow, we obtained a ‘dose-dependent’ effect of API reduction (significant reduction of 12/29 APIs using low and 2/29 APIs using high flow, and a mean reduction of antibiotics of 41% using low vs. 6% using high flow, 25% vs. 6% for all APIs). There was no significant difference in the amount of antibiotic-resistant Enterobacteiaceae pre- and post-ozonation. Our results demonstrate that ozonation of untreated wastewater can reduce API content. However, due to the moderate API decrease and numerous practical challenges in the on-site setting, this specific ozonation system is not suitable to implement at full scale in our hospital.

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Removal of antibiotic residues, antibiotic resistant bacteria and antibiotic resistance genes in municipal wastewater by membrane bioreactor systems

Water Research ◽

10.1016/j.watres.2018.08.060 ◽

2018 ◽

Vol 145 ◽

pp. 498-508 ◽

Cited By ~ 78

Author(s):

Thai-Hoang Le ◽

Charmaine Ng ◽

Ngoc Han Tran ◽

Hongjie Chen ◽

Karina Yew-Hoong Gin

Keyword(s):

Antibiotic Resistance ◽

Resistance Genes ◽

Membrane Bioreactor ◽

Municipal Wastewater ◽

Antibiotic Resistance Genes ◽

Resistant Bacteria ◽

Antibiotic Residues ◽

Antibiotic Resistant Bacteria ◽

Antibiotic Resistant

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The occurrence of antibiotic-resistant bacteria, including Escherichia coli, in municipal wastewater and river water

E3S Web of Conferences ◽

10.1051/e3sconf/201910000061 ◽

2019 ◽

Vol 100 ◽

pp. 00061 ◽

Cited By ~ 1

Author(s):

Adriana Osińska ◽

Ewa Korzeniewska ◽

Monika Harnisz ◽

Sebastian Niestępski ◽

Piotr Jachimowicz

Keyword(s):

Escherichia Coli ◽

Wastewater Treatment ◽

River Water ◽

Municipal Wastewater ◽

High Efficiency ◽

Treated Wastewater ◽

Resistant Bacteria ◽

Antibiotic Resistant Bacteria ◽

Antibiotic Resistant ◽

E Coli

Wastewater treatment plants (WWTPs) are major reservoirs of antibiotic-resistant bacteria (ARB) which are transported to the natural environment with discharged effluents. Samples of untreated wastewater (UWW) and treated wastewater (TWW) from four municipal WWTPs and samples of river water collected upstream (URW) and downstream (DRW) from the effluent discharge point were analyzed in the study. The total counts of bacteria resistant to β-lactams and tetracyclines and the counts of antibiotic-resistant Escherichia coli were determined. Antibiotic-resistant bacteria, including antibiotic-resistant E. coli, were removed with up to 99.9% efficiency in the evaluated WWTPs. Despite the above, ARB counts in TWW samples were high at up to 1.25x105 CFU/mL in winter and 1.25x103 CFU/mL in summer. Antibiotic-resistant bacteria were also abundant (up to 103 CFU/ml) in URW and DRW samples collected in winter and summer. In both UWW and TWW samples, the counts of ARB and antibiotic-resistant E. coli were at least one order of magnitude lower in summer than in winter. The study revealed that despite the high efficiency of bacterial removal in the wastewater treatment processes, considerable amounts of ARB are released into the environment with TWW and that the percentage of ARB in total bacterial counts increases after wastewater treatment.

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