DETERMINATION OF ORGANICS IN WASTEWATER FIVE DECADES OF DEVELOPMENT

The determination of organic carbon in aqueous streams is important in industrial petrochemical plants for detection of chemical process upsets, for impurity analysis in recycle streams, process control in bio-treatment facilities, and in meeting compliance requirements of regulatory permits. A challenge in determining organic carbon is that carbon may exist in many different forms in aqueous samples. The total carbon (TC) amount includes dissolved inorganic carbon (TIC), and dissolved volatile organics (VOC), dissolved non-volatile organics and non-dissolved organics in the form of particulate (NPOC). Total Organic Carbon (TOC) as defined by the EPA method 415 is the Non-Purgable Organic Carbon (NPOC) of the sample and at times the terms are used interchangeably. In most streams the determination of the TOC requires some type of pretreatment of the sample to remove the other carbon sources (TIC and VOC).