- September 05, 2017
- Endress+Hauser, Inc.
September 5, 2017—Endress+Hauser introduced the Liquiline CA80TP phosphorus analyzer for monitoring industrial wastewater, and inlet and outlet streams of municipal wastewater treatment plants. The CA80TP uses a thermal digestion technique along with colorimetric analysis, requiring only a small quantity of reagents.
In most industrial and water and wastewater plants, phosphorus measurements require that a technician pull a sample manually and take it to a lab for analysis. The CA80TP measures phosphorus in ranges of 0.05 to 10 mg/l or 0.5 to 50 mg/l. It has two 4-20mA outputs with the option for additional outputs including Modbus RS485, Modbus TCP and EtherNet/IP. The 4-20mA outputs transmit the phosphorus measurement value. The other outputs can be used to transmit the process variable, plus status and diagnostic information.
Phosphorus occurs as phosphate in natural water systems and in wastewater. Phosphates enter the water from fertilizers, biological and industrial waste and wastewater—and from substances added in water treatment for corrosion protection. Phosphate is a nutrient, so over-enrichment of phosphate (eutrophication) leads to excessive growth of aquatic plants. When these plants die in the fall, the decay of the additional biomass increases the rate of oxygen consumption. In extreme cases, this may lead to fish kills and decrease the quality of the water system.
To determine total phosphorus, a sample must be digested. Samples are drawn from the process using a suction strainer or can be taken from a bypass piping system using an Endress+Hauser Y Strainer.
A sample volume is digested at high temperature with a digestion reagent. An optical dosing unit, used to dose sample and reagents, uses a redundant light barrier for reliability The temperature in the reaction vessel is kept constant to ensure complete digestion takes place within a short period of time. The CA80TP has a software-controlled safety cover to prevent access to the digestion reactor when it is under operation.
Following digestion, the sample is mixed with colorimetric analysis reagents, causing a characteristic change in the sample color. A photometer measures the level of absorption by the sample at defined wavelengths.