Online analysis of TOC, TNb, TP, and COD in water

LAR Process Analysers AG provide with its QuickTOCNPO an online analyzer for the measurement of the four parameters in one single unit

TOC TN TP COD analyzer QuickTOCNPO

TOC TN TP COD analyzer QuickTOCNPO

The control of waste water treatment plants is of special importance - from an ecological as well as economic point of view. The most common water parameters for controlling and optimization are the total organic carbon (TOC), chemical oxygen demand (COD), total nitrogen bound (TNb), and total phosphorus (TP). The fast and accurate analysis of these important waste water parameters provides an efficient plant operation as well as optimal calculation of discharge fees.

LAR Process Analysers AG provide with its QuickTOCNPO an online analyzer for the measurement of the four parameters in one single unit. All parameters are determined according to internationally standardized procedures. The heart of the analyzer is the oven, where the thermal oxidation takes place. It works with the ultra high temperature combustion at 1,200°C, guaranteeing the complete oxidation of all organic compounds to carbon dioxide (CO2) and nitrogen monoxide (NO). Oxidation promoting catalysts, such as used with the thermal catalytic combustion method, are not necessary. Downstream of the oven, the produced CO2 and NO will be measured by a NDIR (non dispersive infrared) detector and an electrochemical detector (ECD) resulting in the exact determination of TOC and TNb. The close connection between TOC content to the COD enables an easy correlation of the parameters. The determination of the TP takes place with the photometric molybdenum blue method.

The modular system offers the highest flexibility, while using the parameters in any combination. The combination of parameters in one unit reduces the investment costs, support and maintenance and enables an efficient monitoring of the plants effluent.

Press contact

Benjamin Mattejiet
Manager Marketing Communication

+49 30 27 89 58-59


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The total organic carbon (TOC) is one of the most important sum parameters in the assessment of the organic pollution of water. Since it includes all carbon compounds as one mass, it is exactly defined and an absolute quantity. Therefore, it may be determined directly.

Read more about TOC measurement methods.

Total organic carbon analyzers of LAR Process Analysers AG

The chemical oxygen demand (COD) indicates the amount of oxygen which is needed for the oxidation of all organic substances in water and is thus an important indicator for water analysis. It is considered in the planning and controlling of treatment, as well as assessing its efficiency, thus forming the basis for the calculation of waste water charges.

The COD can be determined in laboratory or online, whereby these methods significantly differ in duration and consumables used.

Read more about COD measurement methods.

COD analyzers of LAR Process Analysers AG

The biochemical oxygen demand (BOD) indicates the amount of oxygen which is needed for the biological degradation of organic substances in water.

Since the generally used BOD5 excludes the nitrification part of the process, this parameter is poorly suited for the control of waste water treatment plants. Alternatively, the total BOD is well-suited, due to the determination of the nitrogen as well as the carbonaceous part of biological degradation.

Read more about the online measurement of BOD.

Toxicity is described as the direct harmful effect of a substance on organisms. These effects can already occur at low concentraions of toxic substances and are dependent on the incubation period and the dosage.

Some test methods that are available on the market can detect toxicity by using fish, daphnia, molluscs, algae or luminous bacteria and testing whether a water sample has a toxic effect on the organisms. They do not, however, identify exactly which toxins are present.

Read more about online toxicity measurements.

BOD / toxicity analyzers of LAR Process Analysers AG

The total nitrogen bound (TNb) shows the pollution of water caused by nitrogen compounds. Nitrogen may be present as ammonia, ammonium salts, nitrites, nitrates and organic nitrogen compounds.

In contrast to single measurements of the above-mentioned components, the TNb determination contains all these substances in a single analysis process.

Read more about online TNb measurements.

The total phosphorus (TP) is a sum parameter that shows the organic and inorganic phosphorus compounds in water. Phosphorus is an essential nutrient for humans as well as flora and fauna. However, the substance – depending on its concentration– may cause serious damage.

Read more about online TP measurements.

TN TP analyzer of LAR Process Analysers AG