With wastewater being one of the leading and most impactful causes of water pollution, it is essential that it is properly treated before being pumped back into our water sources.

Whilst there are many tests used to assess the quality of the wastewater before it is discharged into our water systems, there is one test that is synonymous with wastewater testing – Chemical Oxygen Demand (COD).

What is COD testing?

Chemical Oxygen Demand (COD) testing is a measurement of the oxygen required to oxidise organic matter in water. It’s generally used to indirectly measure the total amount of organic compounds in wastewater, providing you with an indication of how your treated wastewater will affect the environment once discharged into receiving waters.

Why is Chemical Oxygen Demand important?

Oxygen in water is needed not only for the survival of aquatic life but is also essential for the breakdown of organic matter. The increase of oxidisable organic matter caused by water pollution increases the amount of oxygen consumed by the breakdown of these substances and thereby reduces dissolved oxygen levels in water. This can lead to the development of anaerobic conditions which can result in the widespread death of fish and other aquatic organisms.

Effective wastewater treatment can help to prevent this by reducing the amount of oxidisable organic matter, but how can you be sure that your process is performing adequately?

These 3 tools from Lasec® will help you perfect your COD analysis of wastewater:

Lasec® is the proud supplier of Lovibond instruments. With over 130 years of experience, Lovibond is a trusted name in the water testing industry. From colorimeters to reagents, we have a solution for you.

1. Colorimeter

Time consuming errors are a thing of the past with the new XD range of water testing spectrophotometers. This range features the latest advancements in water testing equipment, making measurements quick and easy.


The XD range includes more than 150 pre-programmed Lovibond methods for water testing. Each method can be easily identified and selected via the internal or external barcode readers, guaranteeing that the correct testing method is used every time. The automatic vial detection feature of the XD range ensures that the correct vials and pathlengths are used for the selected method. It identifies the type of vial inserted into the sample chamber and will either notify you if an incorrect vial is used or will automatically adjust the measuring range if the method allows for it. This feature, coupled with barcoded methods, reduces the need for costly retesting of samples and minimises reagent wastage.

2. Heating Block

Chemical digestion of the sample is required prior to photometric measurement with the colorimeter.


The Lovibond RD 125 Thermoreactor is capable of simultaneously heating 24 sample vials with a 16mm diameter. The pre-set temperature ranges and heating times not only simplify the operation of the instrument, but also minimise any risk of error during chemical digestion. This ensures that water samples are prepared accurately every time.

3.  COD Vials

The easy to use range of COD vials from Lovibond enables you to perform highly sensitive and precise water testing without compromising on test safety. The optical glass vials contain carefully measured amounts of reagent, ensuring that there is minimal handling of chemicals. These 16mm ø COD vials are the perfect fit for the Lovibond heating block and colorimeters.


There are now four different ranges of COD vials to choose from:

  • LR COD:  3 – 150 mg/L O2
  • MLR COD:  15 – 300 mg/L O2
  • MR COD:  20 – 1500 mg/L O2
  • HR COD:  200 – 15000 mg/L O2
Don’t have a Lovibond colorimeter? No problem! Whilst most water testing reagents are not interchangeable, Lovibond has developed a unique range of reagents that can be used with other brands. 

Lasec® has you covered with easy to use instruments, consumables and reagents that will make COD testing simple and efficient.

Still have questions? We have the answers – get in touch with our Lovibond expert at analytica Lab Africa. 

- Layla Padayachee, Product Manager - Instruments