What is carbon
Before discussing what total organic carbons are, it is important to understand what carbon is. Although its name comes from the Latin carbo, which means "coal", carbon and coal are two completely different materials.
Carbon is a naturally occurring element that comes in three different forms: diamond, graphite & fullerene. Although the first two forms have a crystalline structure, their differences in the arrangement of atoms make them completely distinct. One serves as a decoration on a wedding ring, while the other can be used as a lead in your pencil.
Carbon in its diamond state is composed of a three-dimensional crystal lattice that gives it its particular shape. As for graphite, it is composed of two-dimensional sheets stacked in a hexagonal shape.
Finally, fullerenes are an allotrope of carbon that is distinguished by its formation. In other words, they are a series of hollow molecules that form either a closed cage or a cylinder.
Total organic carbons
TOCs, or total organic carbons, represent the amount of carbon bound to organic compounds in water. In other words, TOCs are used to identify the amount of organic matter present in a water sample. Although the TOC test does not identify which organic compounds are in the water sample, the result of a TOC test is an indicator of water quality.
As with most water tests, there are several methods for identifying the total organic carbons present in a water sample. However, TOC tests all have two things in common:
- The oxidation of organic carbons to carbon dioxide;
- The measurement of the CO2 generated.
The importance of TOC analysis
Comme précisé plus haut, les COT permettent d’identifier la concentration en matière organique dans l’eau. D’ailleurs, l’analyse des COT est parfois utilisée comme alternative à la demande biochimique en oxygène (DBO) ou à la demande chimique en oxygène. Bref, connaitre la concentration en matière organique présente dans un échantillon d’eau qui permet d’identifier le type de traitement nécessaire afin d’en diminuer la concentration et ainsi, minimiser les risques de propagation de toxine pouvant être dangereuse pour la santé ou l’environnement.