SI Logo

Strathkelvin Instruments

info@strathkelvin.com
+44(0)1698 730400

Testing Services

Overview

Send your wastewater samples for expert analysis at our fully equipped laboratory. Our team of scientists will provide a full, expert analysis on your samples and compile a scientific report for your records.

All our tests are performed on our laboratory instrument, the StrathtoxTM, using activated sludge from a local municipal wastewater treatment plant.

Strathkelvin Instruments offers this service for customers who do not wish to carry out the tests themselves, either because they do not have the facilities or they need the results independently verified.

Please contact us for prices. All of our work is carried out to our stringent quality control standards, with all results explained.

Tests Offered

Strathkelvin offers a toxicity testing service, carried out in our laboratories. This may be useful for customers who need a rapid evaluation of the toxicity of a suspect wastewater or leachate.

Samples are sent to us by courier, and we can normally carry out the tests and email results back within 24-48 hours. The tests are carried out using activated sludge from a local treatment works receiving predominantly domestic sewage.

The tests available are:

  • Respiration inhibition tests (% RI tests)
  • Nitrification inhibition tests (% NI tests)

Toxicity can be measured immediately after mixing the sludge and test solution or following a three-hour exposure of the sludge to the test solution. The three-hour exposure test is more useful if heavy metals toxicity is suspected, since bacteria take longer to display toxicity to these.

Acclimitisation Assays

We can carry out longer assays to determine whether your activated sludge needs a period of time exposed to new waste streams before they are acclimatised.

The respiration inhibition test and the nitrification inhibition test involve the calculation of the EC50, EC20 and EC10, derived from an inhibition against concentration curve, which uses five concentrations of the wastewater. This is critical in determining the magnitude of the toxicity effect and the rate at which the toxic water should be fed into the tanks to minimise damage to the sludge bacteria.

Contract Testing

You can send samples on a regular basis to allow you to get an accurate report on how your treatment is operating. Contact us for competitive rates.

Dispatch Details

Samples of 500 mL to 1 L should be dispatched to us in a sealed and well packaged containers. Please give us 24 hours notice of dispatch, by email, and ensure that the notification contains your purchase order number and specifies the type of test(s) to be carried out.

Effects of Toxicity

Toxicity in wastewater treatment plants can have a huge effect on the daily operations. Toxicity can lead to bulking, deflocculation and failure to meet consents, resulting in negative publicity and financial penalties.