Chlorine Monitoring at Essity Paper Mill
In most paper and pulp applications, chlorine is used as a bleaching agent. Bleached paper is favoured over non-bleached as it has a superior quality of brightness, softness and cleanliness. However, chlorine is known to be toxic and therefore the wastewater produced must be monitored to ensure that the effluent only contains safe levels of the bleaching agent.
Pi recently attended Essity Stubbins Paper Mill for a service visit and on behalf of Buckman Chemicals, commissioned the two CRIUS®4.0 controllers connected to two sensors, a residual chlorine monitoring sensor (HaloSense) and a REDOX potential sensor (ORPSense).
Pi’s residual chlorine analyser (HaloSense) is an extremely stable membrane sensor which is insensitive to changes in pH, requires no reagents or buffers, and has reduced maintenance and whole life costs. The HaloSense has many applications such as drinking water and food preparation, but in this instance, is used to monitor the effluent from a paper mill. Zero drift is eliminated with the HaloSense because the membrane amperometric sensors are enhanced with a third reference electrode.
This paper mill utilises the HaloSense from Pi to monitor the residual chlorine levels within the effluent. The ORPSense is used alongside the HaloSense as a secondary measure of chlorine using the redox potential of the sample, providing validation of the membraned electrochemical sensor. This maintains the standards of the wastewater produced, ensuring that is safe for both humans and the environment.
To learn more about Pi’s products please visit: www.processinstruments.co.uk