Organic Carbon, Total For Water And WastewaterSource: Hach Company
Total Organic Carbon (TOC) testing is important in drinking water treatment as an indicator of potential disinfection by-product formation. In wastewater, TOC is valuable as a surrogate for COD testing and has applications in domestic wastewater pre-treatment standards, effluent discharge limitations, and industrial process waters.
The colorimetric TOC test measures the total amount of non-volatile organic carbon in a sample. The method is based on controlled digestion/diffusion in a sealed glass assembly*. Sample carbon is oxidized to carbon dioxide by persulfate oxidation. The carbon dioxide diffuses into a colored pH indicator solution where it is converted into carbonic acid. The resulting color change is proportional to the concentration of carbon present in the sample.