Sweet success for TOC/TN analyser
The Shimadzu TOCN-4100 on-line total organic carbon (TOC) and total nitrogen (TN) analyser has successfully completed a trial at one of Europe's largest sugar processing plants.TOC and TN are important control parameters for treating effluent from sugar beet processing. The resulting wash water from the cleaning of the beets prior to the extraction and crystallisation of the sugar can have chemical oxygen demand (COD) values up to 20,000mg/l and contain high levels of particulates. In addition, the condensate streams from the crystallisation process will be heavily polluted by ammonia and other nitrogen compounds.
The measurement principle is based upon the well established method of oxidation at 680ºC using a platinum catalyst. Carbon compounds are converted to carbon dioxide and measured using a non-dispersive infra-red detector while nitrogen compounds are converted to nitric oxide and measured by means of a chemiluminescence detector.
It is possible to measure TOC and TN from a single sample injection and the analysis time is approximately 5 minutes. The results may be transmitted via current, voltage or serial link for displaying trends and alarm generation, automatic calibration and remote operation are available in the standard unit.