Evaluation of the Effectiveness of the Activated Sludge Process in the Elimination Both ATB-Resistant and ATB-Susceptible E. coli Strains

Abstract

Water reuse is now becoming a global necessity. However, one of the drawbacks in releasing wastewater into the environment is some persistent pollutants that are not completely removed in wastewater treatment plant. Residual bacteria and antibiotics in the inflowing wastewater can contribute to the antibiotic resistance spread in the aquatic environment. This study determined the effectiveness of activated sludge process for fecal coliform bacteria elimination, and also the Escherichia coli resistance to antimicrobial agents as erythromycin, azithromycin, clarithromycin, ofloxacin, ciprofloxacin, trimethoprim, and metronidazole in treated wastewater. The research was carried out using the membrane filtration technique, and the susceptibility of isolates to antimicrobial agents was tested by the disc diffusion method. The concentrations of fecal coliform bacteria and Escherichia coli differed significantly depending on the seasonal period in which it was carried out. Despite up to 99% reduction in the number of sanitary indicators in biologically treated wastewater, 89% of E. coli isolates resistant to the tested antibiotics was found, while 100% of the isolates were susceptible to metronidazole. Most of the isolates showed resistance to trimethoprim, and the fewest isolates were resistant to ofloxacin, indicating that some strains may react differently to antibiotics.

Seasonal prevalence of bacteria in the outflow of two full-scale municipal wastewater treatment plants

“…The authors suggest that it would be desirable to identify also living, metabolically active microorganisms, however, the occurrence of particular groups in the outflow with the wastewater treatment process were not taken into account. Currently, research on the outflow, in particular, focus on the phenomenon of the spread of pathogens, microplastics and antibiotic-resistant bacteria 33 , 34 . The novelty of this article concerns the similarities and differences in the sludge taken from activated sludge and the outflow in terms of the identification of microorganisms from two full-scale WWTPs using the FISH method for 4 key groups of microorganisms (betaproteobacterial ammonia-oxidizing bacteria, Nitrospirae, Chloroflexi, and Candidatus Accumulibacter phosphatis) involved in the wastewater treatment process in the context of their potential technological usefulness.…”

Comparative Evaluation of Membrane Filtration on the Tertiary Treatment of Synthetic Secondary Effluent

“…It can justify the additional cost of replacing the existing sand filtration units with the membrane filtration units. Among the different technologies investigated for reuse, there are coagulation [25], anaerobic baffled reactor [26], chitosan modified membrane [27], adsorption [28][29][30][31][32], and activated sludge [33]. Other than treatment technologies, the integration of energy and water systems are also explored for suitable reuse options [34].…”

Influence of COD in Toxic Industrial Wastewater from a Chemical Concern on Nitrification Efficiency

“…Municipal and industrial wastewater is a carrier of many dangerous organisms and substances, which include parasites and pathogenic organisms [ 1 , 2 , 3 ], toxic substances and compounds disturbing the natural biological balance in treated sewage receivers by increasing the saprobicity and eutrophication of these waters [ 4 , 5 , 6 ]. Such wastewater can be neutralized by mechanical–biological or mechanical–biological–chemical methods of treatment with the use of activated sludge.…”