Alexander Szabo and Oscar Engle - Svenskt Vatten

Figure 8.8: Above: The water velocity in the inlet chamber for the northern treatment line of the
WSP system during 5-6 November. Below: Precipitation data at site (UTM weather station data)
Measurements
18­19
November
2009
“Holiday
period”
The second measurement period was from the 18 th to the 19 th of November. During this period it
is estimated that approximately two third of the population had left the UTM campus for
vacation. The monsoon had arrived and there was rainfall almost every day from the beginning of
November to the beginning of January. The measurements started at 12:30 on the 18 th of
November and continued every second hour until 10:00 the next day. A rainstorm started at
around 15:00 on the 18 th of November and continued more than one hour. During this period
there is a huge increase in the influent flow. When the rain stops the influent flow is decreasing
rapidly. The flow continues decreasing until late night and starts increasing in the morning. The
behavior of the influent flow and precipitation data can be seen in Figure 8.8. During this
measurement, only one line of the WSP was in operation, hence the velocity is the double
compared to the flow measurements from 5-6 November.
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