Faecal attraction
October 1st 2007

MCERTS has become an established scheme for any organisation involved in the operation of a wastewater or industrial effluent treatment plant and for manufacturers of instrumentation used in this industry.The use of MCERTS certificated measurement equipment will help boost OPRA and OMA scores which in turn can reduce EA monitoring charges comments Angus Fosten from Partech Instruments

One area of importance to wastewater treatment companies and industries that use water in their processes is the monitoring of Turbidity and/or the Suspended Solids content in final effluent discharges. It is in these areas that MCERTS will have a major impact for those operators with installations falling under the Integrated Pollution Prevention and Control (IPPC) regulations and who want to self-monitor effluent flows.

Under the IPPC the activities in processing plants are assessed according to the Operator Pollution Risk Assessment (OPRA) guidelines combined with the Operator Monitoring Audit (OMA). Scores in these assessments will dictate the monitoring requirements for the site.Continuous monitoring determinands covered by MCERTS are:Turbidity, pH, Ammonia, COD, TOC, Dissolved Oxygen,Total Phosphorous, Nitrate and Total Oxidised Nitrogen.

Partech Instruments has embraced MCERTS for its instruments and claims its 7200 Monitor and Turbi-Tech 2000LS Sensor combination was the first Turbidity Monitor to be awarded MCERTS certification.The system is suitable for monitoring Turbidity in effluent discharges and can also be configured to monitor Suspended Solids in the final effluent flow.The Turbi-Tech sensor's fully integrated self-cleaning system provides users with low cost ownership.

The breadth of industry sectors that can employ the Turbi-Tech 2000 in its LA and LS versions in conjunction with the 7200 Monitor are considerable, ranging from landfill run-offs, paper and pulp processing to dairy product manufacture.

The treatment of surface water run off and in particular removing Suspended Solids prior to discharge is a problem that almost all landfill sites face.At one landfill site in North Devon, before the water is discharged into a local stream,it is subjected to a treatment process that incorporates a flocculent doing system which is reliant on the performance of two Partech Turbi- Tech monitors.The site's treatment system uses a Turbi-Tech sensor located in a manhole at the inlet to the flocculent dosing station,which provides a 4-20ma signal to the control panel in the dosing station which adjusts the dosing rate in proportion to Turbidity and Flow.The dosing rate is different for flocculent and coagulant and is set in accordance with amounts decided by Devon Waste Management chemists.The PLC program enables the start/finish points and the slope of any curve of the dosing stages for each chemical.The second Turbi- Tech monitor is located in the outlet point and reads the Turbidity level to ensure that it is below the consent level and provides feedback to the main system.

The Partech Turbi-Tech 2000 sensor uses Infrared light that is either scattered or absorbed by the particles in suspension, with the amount of received light being proportional to the level of Suspended Solids or Turbidity.The geometry of the sensor, either light scatter or light attenuation, is chosen to suit the suspended solids or turbidity range.The amount of received light is converted into Suspended Solids by the 7200 Monitor using algorithms that have been developed specifically for these applications.

Throughout the EU and many other parts of the world there is a growing demand for continuous water monitors that conform to a single international certification scheme and it is inevitable that this will come about in the not too distant future.MCERTS certified analysers will give operators the confidence that they are using the equipment that is of a high standard and will ensure that by doing so they are safe in the knowledge that they are meeting the criteria for safe discharge consents.And should plant operators have any doubts about conformity and whether they fall under the IPPC scheme, they can always go to the MCERTS website (www.mcerts.net).

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