Saved silver!

Hach Lange has presented the British National Laboratory Service (NLS) with a silver bar made from recycled chemical reagents, in recognition of the organisation’s achievements in waste minimisation. Accepting the ingot on behalf of the NLS laboratory in Nottingham, inorganics team leader Richard Yates said “Tiny quantities of silver are employed in the tests that we conduct for COD - chemical oxygen demand – which is one of the most important tests of wastewater strength, so it is gratifying to be provided with physical proof that our recycling strategy is effective.”

Stuart Dalrymple, Hach Lange
with Richard Yates, NLS

The ingot was forged from silver that has been reclaimed from the spent chemical reagents of approximately 10,000 COD tests that were collected by the company's dedicated recycling centre. In addition to waste reagents; bottles, cuvettes and packaging are also recycled and the facility now recycles over 75% of returned materials.

The NLS, through a national network of laboratories, has undertaken vitally important analytical work on behalf of the Environment Agency since 1996, providing test and measurement services for air, water and soil, applying the very latest techniques and ensuring the best possible levels of accuracy and data reliability.

In the past, the majority of tests at the NLS lab in Nottingham were conducted on behalf of the Agency, but Richard says “In recent years we have taken on a much greater proportion of external commercial work, providing the water industry, waste management businesses and commercial companies with regulatory monitoring services for a wide range of parameters. In addition to COD, inorganic determinands also include BOD, nutrients such as phosphates and nitrates, phenols, suspended solids and many others.”

Presenting the silver ingot, hach Lange’s Stuart Dalrymple said “The accuracy and reliability of environmental analysis is greatly enhanced when reagent quantities are controlled as tightly as possible, so the pre-filled tubes or cuvettes that we supply are ideal because they are manufactured to extremely tight specifications, bar-coded and delivered ready-for-use. This substantially removes the opportunity for human error, because each tube contains precise amounts of reagent chemicals and the bar-code on each tube is recognised by the spectrophotometer. Importantly, whilst the cuvette tests closely follow the reference methods, such as ISO 15705, the COD cuvette test uses 90% less chemical reagents.”

To conduct a COD test, samples of water, wastewater or leachate are added to the pre-filled tubes which are then heated to form a coloured solution which is analysed by a HACH LANGE photometer. The NLS lab in Nottingham employs a HACH LANGE DR3800 spectrophotometer to perform daily COD tests ranging from 30 to 120 tests per day. However, a new DR 3900 instrument with RFID technology has recently been on trial to study the potential advantages in traceability.

Summarising, Mark Gale, NLS Nottingham Laboratory Manager said “The cuvette test for COD provides the level of accuracy and reliability that customers expect from the NLS, and our longstanding commitment to the reagent recycling service exemplifies our determination to provide a leading example of the ways in which laboratories can minimise the effects of their activities on the environment.”