

@article {3244,
	title = {{Elimination of enteric bacteria in biological-chemical wastewater treatment and tertiary filtration units}},
	journal = {Water Research},
	volume = {37},
	number = {3},
	year = {2003},
	pages = {690{\textendash}698},
	abstract = {The occurrence and removal of salmonellae and faecal indicators in four conventional municipal wastewater treatment plants (MWTP) were investigated. In addition, we tested the efficiency of a semi-technical scale biological nutrient removal process and three pilot-scale tertiary filtration units in microbial removal. All influent samples collected from MWTPs contained salmonellae from 93 to 11000MPN/100ml and indicator bacteria from about 107 to 108CFU/100ml. The reductions in salmonella numbers achieved in full-scale biological-chemical wastewater treatment and semi-technical scale biological nutrient removal processes were usually between 94{\%} and virtually 100{\%} (99.9{\%}) and indicator bacteria reductions between 2 and 3 log units. Microbial numbers in MWTP effluents could be modelled as a function of effluent residual organic matter, suspended solids and total phosphorus concentrations. Pilot-scale tertiary treatment by rapid sand contact filter, chemical contact filter and biological-chemical contact filter reduced salmonella numbers below the detection limit and faecal coliform numbers on average by 99{\%}, 39{\%} and 71{\%}, respectively. A total of 32 Salmonella serovars were identified among 197 Salmonella isolates from municipal wastewaters. Of the isolates, 32{\%} were resistant to nalidixic acid, indicating reduced sensitivity to ciprofloxacin, the drug of choice in the treatment of salmonellosis. In addition, 18{\%} of the isolates were multiresistant. Our results, especially antibiotic resistant Salmonella strains, indicate that conventional municipal wastewater treatment without efficient tertiary treatment, like filtration or disinfection, may constitute a risk for public health. ?? 2002 Elsevier Science Ltd. All rights reserved.},
	keywords = {Coagulant, Filtration, Indicator bacteria, Microorganism removal, Salmonella, Wastewater treatment},
	isbn = {0043-1354 (Print)$\backslash$r0043-1354 (Linking)},
	issn = {00431354},
	doi = {10.1016/S0043-1354(02)00305-6},
	author = {Koivunen, Jari and Siitonen, Anja and Heinonen-Tanski, Helvi}
}
