CPL - Chalmers Publication Library
| Utbildning | Forskning | Styrkeområden | Om Chalmers | In English In English Ej inloggad.

Wastewater discharges and microbial variability in a surface water source

Johan Åström (Institutionen för bygg- och miljöteknik, Vatten Miljö Teknik ; DRICKS Ramprogrammet för dricksvattenforskning vid Chalmers)
Göteborg : Chalmers University of Technology, 2008. - 72 s.
[Licentiatavhandling]

Planning for drinking-water safety in surface waters includes a systematic assessment of hazards in the catchment, and microbial contamination is considered a major health risk. The aim of this thesis was to identify and characterize microbial hazardous events reported for River Göta älv, Sweden. Moreover, the magnitude and variability of the microbial load from municipal sewer systems was determined for varying weather conditions. The raw water intake to Göteborg at River Göta älv, regularly closed to avoid contaminants in the raw water, act as a barrier against various hazardous substances. Occasionally, bacterial peak concentrations penetrate the raw water intake, as not registered in time. Present results show that data on upstream precipitation, turbidity and real-time reporting of wastewater discharges may give valuable guidance to predict high microbial concentrations at the raw water intake. Wastewater treatment plants and sewer networks with about 110,000 persons connected give a substantial pathogen load to the river. Monte Carlo simulations showed that wastewater treatment plants dominated the pathogen load to River Göta älv during dry weather conditions. During wet weather conditions, including sewer overflows and emergency discharges, total microbial loads from the municipal sewer systems were for E. coli about 13 log10 CFU/day and for Cryptosporidium about 8 log10 oocysts/day. Microbial river water concentrations due to municipal wastewater discharges were approximated by simulations. Wastewater contaminations may explain the magnitude and variability of river water sample concentrations of indicator bacteria (E. coli, clostridia and somatic coliphages) and Giardia. Risk reduction options are discussed based on sensitivity analyses for dry and wet weather conditions.

Nyckelord: Hazardous events, catchment, surface water, drinking-water, wastewater, rainfall, variability, pathogens, faecal indicators, microbial risk assessment



Denna post skapades 2008-01-10. Senast ändrad 2014-02-06.
CPL Pubid: 65522

 

Institutioner (Chalmers)

Institutionen för bygg- och miljöteknik, Vatten Miljö Teknik (2005-2017)
DRICKS Ramprogrammet för dricksvattenforskning vid Chalmers

Ämnesområden

Matematisk statistik
Vatten i natur och samhälle
Biologiska vetenskaper
Vattenteknik
Mikrobiologi

Chalmers infrastruktur

Relaterade publikationer

Inkluderade delarbeten:


Identification and management of microbial contaminations in a surface drinking water source


Variability analysis of pathogen and indicator loads from urban wastewater systems along a river for drinking water risk estimations


Examination

Datum: 2008-02-01
Tid: 13:15
Lokal: Sal VK, Sven Hultins gata 6, Chalmers University of Technology
Opponent: Prof. Malte Hermansson, Dept of Cell and Molecular Biology, Göteborg University

Ingår i serie

Lic - Department of Civil and Environmental Engineering, Chalmers University of Technology 2008:1