The classical disinfection of drinking water using chlorine has some
major disadvantages. If organic acids are present, cancerogenous
Trihalomethanes can be formed. Also, residual traces of chlorine in the
final water can leave an unpleasant taste. One of the alternatives is to use
chlorine dioxide because it doesn’t show the negative effects as mentioned.
In addition, it gives much better disinfection efficiency. Chlorine Dioxide
is generated directly on site immediately before use. The exact measurement
and control of the reactor is crucial. The typical concentration range for
optimal dosing is at around 0.2g/l. Chlorine dioxide measurement can be done
reliably and selectively using an inline absorbance measuring technique at
436 nm.
The absorptiometer ColorPlus from SIGRIST is providing a problem specific
solution for chlorine dioxide measurement. In a special, corrosion resistant
flow cell made from PVDF, the Chlorine Dioxide concentration is measured at
a wavelength of 436 nm. At the same time, the absorption is measured at
546 nm to compensate for any existing turbidity. The applied dual-beam
method results in a high stability and reliability of the measurement. One
of the first customers has been Evides in Rotterdam, who purchased 40 units
for the modernisation of their water treatment facilities.
Products: ColorPlus in-line