DISSOLVED ORGANIC CARBON (DOC)

Dissolved Organic Carbon or DOC is a measurement of the amount of organic matter in water that can be passed through a filter, commonly 0.45 µm.

IMPORTANCE OF DOC FOR DRINKING WATER

For drinking water, Dissolved Organic Carbon is an important water quality parameter measured for several purposes. Elevated levels of DOC may interfere with the effectiveness of disinfection processes such as UV, ozone and chlorination thus should be monitored for removal prior to disinfection. In plants that disinfect with chlorine, DOC concentrations are a primary concern due to the harmful by-products that form when chlorine reacts with organic matter. DOC in finished water can lead to aesthetic problems and increase the potential for bacterial regrowth in the distribution system. Regulations for DOC are specific to each country, with aesthetic objective in drinking water being approximately 5 mg/L. Additionally, DOC is used in the calculation of SUVA which determines the aromatic portion of DOC, a major precursor for THM formation.

DELAYED LAB RESULTS LIMIT ACTION

Relying on grab samples leads to significant delays. When results come back from the lab, the information is usually of little value for process control and improving plant performance. The DOC procedure requires that the sample be passed through a 0.45 um filter prior to analysis. The test involves converting all organic carbon in a water sample to carbon dioxide (CO₂) by utilizing heat and oxygen, chemical oxidants or UV radiation. The resultant CO₂ concentration is measured with an infrared analyzer and reported as organic carbon (mg/L). The test takes 5-10 minutes to yield results in the lab, with continuous reagent-based on-line analyzers also available.

Plants need a practical reagent less solution that delivers continuous information to operations personnel. Real Tech has the solutions to help our clients get the information they need, when they need it. Discover our real-time DOC analyzers here.