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- Dienus, Olaf, et al.
(author)
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Norovirus Dynamics in Wastewater Discharges and in the Recipient Drinking Water Source: Long-Term Monitoring and Hydrodynamic Modeling
- 2016
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In: Environmental Science & Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 50:20, s. 10851-10858
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Journal article (peer-reviewed)abstract
- Norovirus (NoV) that enters drinking water sources with wastewater discharges is a common cause of waterborne outbreaks. The impact of wastewater treatment plants (WWTPs) on the river Gota alv (Sweden) was studied using monitoring and hydrodynamic modeling. The concentrations of NoV genogroups (GG) I and II in samples collected at WWTPs and drinking water intakes (source water) during one year were quantified using duplex real-time reverse-transcription polymerase chain reaction. The mean (standard deviation) NoV GGI and GGII genome concentrations were 6.2 (1.4) and 6.8 (1.8) in incoming wastewater and 5.3 (1.4) and 5.9 (1.4) log(10) genome equivalents (g.e.) L-1 in treated wastewater, respectively. The reduction at the WWTPs varied between 0.4 and 1.1 log(10) units. In source water, the concentration ranged from below the detection limit to 3.8 log(10) g.e. L-1. NoV GGII was detected in both wastewater and source water more frequently during the cold than the warm period of the year. The spread of NoV in the river was simulated using a three-dimensional hydrodynamic model. The modeling results indicated that the NoV GGI and GGII genome concentrations in source water may occasionally be up to 2.8 and 1.9 log(10) units higher, respectively, than the concentrations measured during the monitoring project.
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| 2. |
- Blom, Lena B, 1966
(author)
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A Passive Sampling System for Monitoring Metals in the Aquatic Environment
- 2002
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Doctoral thesis (other academic/artistic)abstract
- Water monitoring is undertaken routinely as a requirement of water quality legislation. It is usual that water monitoring is undertaken through spot sampling. A passive sampling system has been developed for the aquatic environment that provides time-averaged (integrated) concentrations for metals. Transport of metal into the passive sampler system is based on Fickian diffusion. The sampler design includes a Nafion-coated diffusion limiting membrane and a receiving membrane where metals are retained. The passive sampler is suitable for a wide range of aquatic environments and can be adapted for both inorganic and organic pollutants. Environmental factors that affect the diffusion rate across the diffusion limiting membrane include turbulence, biological growth and temperature. The effect of turbulence was studied through experiments with; a rotating sampler to change the boundary layer thickness, magnetic stirring to simulate totally mixed flow conditions and double diffusion limiting membranes to eliminate exterior flow conditions. Under turbulent conditions the effect on the diffusion rate is negligible, but under quiescent conditions the diffusion rate is slower. The Nafion coating was found to reduce biofouling under low growth conditions. A Nafion-coated passive sampler was found to provide a speciation procedure due to permselectivity. It is possible to exclude large colloids (natural humic substances) from the Nafion-coated membrane, while small synthetic ligands pass through. Membrane material can be chosen to target metal species or to permit the collection of all metals. The passive sampler was found to give the same concentration as the electroavailable concentration for time-dependent composite samplers in stormwater.
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