Application
Wastewater monitor for concentration determination of phosphorus, nitrogen, and COD. The 3 measurement parameters are monitored simultaneously. The NPW-400 analyzer is excellently suited for use in wastewater treatment and control as well as in the food industry. It is designed as an inline monitor that comes close to manual measurement performance. This significantly shortens and simplifies wastewater control. The detection is carried out using absorption photometry and a multi-wavelength detector. For the determination of total phosphorus (TP), the sample is first treated with potassium peroxodisulfate digestion, followed by the molybdenum blue method. The detection of total nitrogen (TN) is done by chemical oxidation after digestion with potassium peroxodisulfate and subsequent absorption photometric measurement.
The determination of COD (Chemical Oxygen Demand) is also carried out via absorption photometric measurement in the range of UV light and visible light. Both the required amount of chemicals and resulting waste liquids could be reduced by half. As a result, only 7.5 liters of wastewater are produced per month. 
