Raw water is often contaminated with dissolved substances. These are only visible to the eye if the water is colored in the visible range of light. However, the impurities are often organic compounds that are not visible to the eye. The ColorPlus 3 from Sigrist is used to detect and quantify these.
Dissolved organic substances or dissolved organic carbon (DOC) must be eliminated in the water treatment process. For this reason, the concentration is measured at the entry of the waterworks and after the cleaning stage. The measurement runs continously. The Solution The ColorPlus 3 SAK 254 measures the absorption coefficient at 254 nm. A large number of organic substances absorb at this wavelength. This value is therefore not substance-specific, but merely reflects the general contamination of a water sample with organic substances. The photometer is either connected to a SiCon control unit or to another Sigrist photometer. This makes it easy to set limit values and alarms. These alarms can be transmitted to a control system via a variety of analog and digital outputs.
The measurement of DOC is used to monitor activated carbon filters. Their regeneration is expensive and should only take place when the filter is saturated. For this purpose, the activated carbon is cleaned in a multi-stage process, for which temperatures of up to 800°C are required. The filter service life can be optimized by measuring DOC after filtration. It is estimated that annual costs of CHF 2000 can be saved.
In combination with turbidimeter, the ColorPlus 3 SAK 254 can also be used for efficient flocculant dosing.
In raw water, the measurement of the OilGuard 2 W and the ColorPlus 3 can be partially correlated and gives an idea of the microbiological load of the water.