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Water analysis : high temperature instead of toxic chemicals

Collaborative project LATECOD develops laboratory equipment that determines the chemical oxygen demand using thermal methods.

product picture COD analyzer for laboratories, QuickCODlab

The decomposition of organic substances always consumes oxygen. At the same time, the oxygen demand during degradation is an indication of the degree of pollution of water with organic substances. Therefore, the so-called Chemical Oxygen Demand (COD) is an important parameter in water analysis: in the case of the standardized wet-chemical method (according to DIN 38409-41) and in rapid tests (according to DIN 38409-1), the COD gives the The amount of oxygen that would be required if only oxygen would serve as the oxidizing agent in the chemical oxidation of all oxidizable compounds contained in the water.

So far, however, this determination is problematic: Firstly, the substances dichromate and mercury used represent a danger to the environment. On the other hand, the use of 150 ° C hot chromic-sulfuric acid is a hazard for laboratory employees. An improved, chemical-free and thus environmentally friendly and user-friendly process is the result of the joint project LATECOD, which is funded by the Federal Ministry of Education and Research (BMBF). Its partners are the Berliner Wasserbetriebe - the largest integrated water and wastewater disposal company in Germany - and the measuring instrument manufacturer LAR Process Analyzers AG.

LATECOD continues to develop a chemical-free high-temperature process based on thermal oxidation of the sample at 1,200 ° C with subsequent detection of oxygen consumption. The process has been extensively studied in various applications and comparative analyzes and control measurements performed. The adaptation to the system, as well as sample preparation was carried out in cooperation with Berliner Wasserbetriebe. The calculations showed that that It would also be worthwhile for the user to compare the procedures with those of the DIN rapid test: With around two samples a day, the comparatively high investment costs pay for themselves after around two years.

The Federal Ministry of Education and Research (BMBF) is supporting the joint project LATECOD ("Testing and Evaluation of a Laboratory Device for Determining the Chemical Oxygen Demand without Potassium Dichromate by means of the High Temperature Method) within the Measure" SME Innovative: Resource Efficiency and Climate Protection " BMBF Program "Research for Sustainable Development" (FONA3).

Press contact

Benjamin Mattejiet
Manager Marketing Communication

+49 30 27 89 58-59
bmattejiet@lar.com

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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.

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Read more about the online measurement of BOD.

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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

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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.

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Read more about online TP measurements.

TN TP analyzer of LAR Process Analysers AG