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Colorimetric analysis for Water and Wastewater monitoring 

Among industries that deal with drinking water, wastewater and process water, it is necessary to monitor and control the levels of key substances. National and international water authorities stipulate strict limits for contaminants in drinking water treatment and wastewater discharge. This is particularly important in those that are harmful to human and environmental health, such as chromium and nitrate. In process water applications, such as steam generation, minerals present in water can build up on systems and cause costly damage. Monitoring silica, hardness and sodium are used as indicators of water quality. Colorimetric analyzers identify and quantify these sorts of impurities to help assure high quality water. 

To analyze a sample using colorimetric analysis, a reagent is added to the sample that reacts with the substance of interest, coloring the solution. Next, a beam of light at a known absorbable wavelength is guided through the sample and measured by a photosensor. Some of this light is absorbed, based on the color intensity, as it passes through the solution, in direct proportion to the substance concentration. By measuring the intensity of light that reaches the sensor, concentration can be determined precisely. 

Practical online analysis with CA80 analyzers 

Endress+Hauser’s CA80 line of analyzers use the colorimetric principle to provide precise and regulation-compliant online measurements of many substances in water. These include chromate, iron, silica, aluminum, ammonium, nitrite, hardness and orthophosphate.   

Installation and upkeep are simple and inexpensive, with automatic calibration and cleaning functions that minimize operational costs. These colorimetric analyzers are optimized to conserve reagents during operation. Onboard cooling modules in some analyzers also extend regent life in the analyzer. All required reagents are shipped ready for preparation, with material safety data sheets included. 

CA80 analyzers are built on Endress+Hauser’s Liquiline platform, facilitating uniform operation and communication across a variety of transmitters, analyzers and samplers. Built with advanced diagnostics and remote access capabilities, these instruments help ensure process safety and aid in providing documentation to authorities. Up to four Memosens® sensors can be connected to and automatically recognized by each CA80 analyzer, creating multiuse measuring stations with minimal setup effort.

Low-maintenance phosphate monitoring in a wastewater treatment plant  

Wastewater treatment plants (WWTP) often require systems for controlling phosphate precipitation. These systems are necessary to comply with strict output limit values during both peak and low-load periods. As part of a broader system, a WWTP installed a Liquiline System CA80PH analyzer to monitor phosphate concentrations. Using molybdenum blue as a reagent, this analyzer reliably measures these concentrations, even at the lowest levels. 

The CA80PH analyzer helped the plant optimize its maintenance activities with automated self-calibration and self-cleaning capabilities. This freed up both the operator and technician’s time to tend to other issues as they arose. The analyzer’s reliability and versatility enabled the plant to continue operating even in the midst of difficult inflow conditions by ensuring adherence to discharge regulations. 

Liquiline CA80PH colorimetric analyzer closed
Liquiline System CA80PH
CA80PH open with cooling for extended reagent lifetime

To assist in finding the right analyzer for your application, Endress+Hauser’s knowledgeable engineers will guide you through planning, selection and commissioning. They will partner with you to keep your plant online at full capacity. 

Users can leverage the self-service online Applicator, a convenient tool that makes recommendations based on your specific application parameters. With the help of in-depth product information and comparison tools, choosing the right instrument is simple.  

Not sure where to start? Talk to one of our local sales and service representatives who can help answer your questions.  


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