Keeping it clean

Determining the chemical content in wastewater prior to discharge is vital to comply with with consent levels

The Macallan Distillery has recently concluded trials to determine the viability of monitoring the important elements in effluent and provide an early warning of a potential breach of consent. The parameters monitored included ammonia, phosphates, nitrates, pH, oxygen demand and suspended solids.

Using a DiaMon, from Bran + Luebbe Analyzing Technologies, the concentration of chemical components was measured by diode array spectroscopy with data analysed with Sesame software, which makes use of chemometric analysis in several UV wavelengths. During the analysis cycle, the sample is scanned using high intensity flashes of light, with the energy level reaching the diode array and then being integrated. After a set number of flashes, the sample is compared against the calibration and the results determined.

At the Macallan Distillery, the system was complemented by a Partec suspended solids monitor and Mjk in-line pH module. Ammonia and phosphate are analysed using standard WRc colorimetric methods while nitrate, SAC and BOD5 are measured using the spectral characteristics of the sample compared directly to the reference method results and a calibration derived using chemometrics.

According to Andrew Wallace, Process Systems Manager at Analyzing Technologies, the trial revealed that the DiaMon linked to the sampling system at the primary treatment plant could be used as a warning system to reduce the chance of a breech of consent in the final discharge.

The purpose of the trial was to prove the effectiveness of UV spectroscopy in predicting COD, BOD5 and SAC, and the results showed that this technology was more than capable of offering an alternative to traditional laboratory methods.