Experiences with Autocalibrating Dissolved Oxygen Systems in Paper and Pulp Wastewater Treatment Facilities, 1999 Environmental Conference Proceedings

John Watts, PhD

The Capital Controls Group

John Lewyta & Lance K. Mason

Severn Trent Environmental Services

In the harsh environment of rapid biomass growth and extremely low air temperatures coupled with the high oxygen demand of the waste in the pulp and paper industry, a successful history of dissolved oxygen data was produced from three mills in Northern Canada using autocalibrating / self-cleaning instrumentation. The data from this instrumentation was compiled electronically by the use of analog signals and phone modems, which was then analyzed by individuals thousands of miles from the facilities. The software produced graphic representations of the data allowing analysts to spot any problems in calibrations and/or trends in oxygen rates. The temperature effect in the low temperature environment did cause some early problems in the calibration; these were recognized and resolved by the development team remotely back in the U.K. This system has shown through data acquired over a three year period along with minimal problems that low maintenance, autocalibrating / self-cleaning instrumentation is achievable even in the severe climatic conditions of Northern Alberta.