BioTector tightens effluent control at Greencore

Published: 9-Feb-2012

Reduces operational costs, avoids downtime and provides greater control

A food manufacturing facility in Selby, North Yorkshire, UK, has improved its wastewater treatment process with the installation of a BioTector continuous TOC (Total Organic Carbon) monitor supplied by Manchester-based Hach Lange.

Greencore Foods’ grocery division is a leading UK manufacturer of bottled recipe products and the Selby site produces branded products across key market sectors.

The site has a dedicated wastewater treatment plant to monitor and control effluent quality and minimise discharge fees. This effluent contains inorganic salts and organic components, which enter the waste stream in part from the intense wash down of processing tanks and lines during clean in place procedures for product changeover.

Overload of organics on the effluent treatment plant adversely affects the efficiency of the treatment process. If the waste is not treated to the required standard, then the site will be unable to achieve the river discharge parameters set by the Environment Agency.

A specialist team from Veolia Water Industrial Outsourcing manages the effluent treatment plant. Raw feed water entering the facility is analysed for TOC to control the strength of the feed transferred to the treatment plant.

Greencore’s environment manager David Murtagh explains: “In the past, samples were manually collected from the site drains pit and transported to the laboratory at a second location. Given the geographical distance between sites this led to significant waste, both in terms of time and resources. We had a small team in the laboratory who performed a number of analyses on the delivered samples, which was quite labour-intensive and delayed results.”

A further key driver for the installation was the impending tightening of the consent to discharge to river by the Environment Agency.

“We needed more frequent, more detailed, prompt, accurate and reliable influent TOC data to help manage the effluent treatment plant more efficiently and provide feedback on the process,” said Murtagh.

“We were wary of online TOC instruments due to poor experiences in the past; while they worked well on cleaner, particulate-free effluent samples, the high solids, fats, oils and greases, and variable TOC loads coming from raw influent was a major issue for delicate fine capillary tubing and valves, which typically caused instrument seizure.”

To achieve continuous function in harsh process environments the BioTector uses a patented advanced oxidation process to offer aggressive breakdown of organics without thermal dependence. This is achieved by exposing high pH reagents to ozone. A self-cleaning facility with micro-bubbles prevents particles becoming trapped and an inbuilt salt trap allows salt loads as high as 30% and calcium loads of up to 12% without dilution.

Unaffected by fats, greases, salts and particulates up to 2mm diameter, a representative sample is achieved without pre-filtering allowing in excess of 80,000 continuous measurements each year. According to Hach Lange, maintenance requirements are minimal and the overall result is a 99+% uptime for the end user.

“The signals from the BioTector unit have been integrated into both Veolia Water's effluent plant control system and Greencore’s own data acquisition system. Veolia uses the analysis to control the strength of feed transferred to the site effluent treatment plant. Any loads that exceed a pre-determined level are diverted to the site calamity tank. This control has enabled the performance of the effluent treatment plant to be greatly improved.

As Veolia’s continuous improvement manager Marcus Hardiker explains: “All previous concerns regarding the use of an online TOC meter were addressed with practical solutions. The instrument takes samples from the raw effluent that is fed to the site's treatment plant. However, we needed the sample to be as representative as possible and therefore no in-line filters were installed in the sample line. The sampling arrangement deals with the site's unique type of effluent containing high sand and silt content.

“The signals from the TOC meter are also transmitted to Greencore’s production areas, and the on-line data is visible for process personnel who can now see the effect that their activities are having on the effluent loads being discharged to the site treatment plant.”

With tailored solutions to match client needs, BioTector is simple to use and can reduce operational costs, avoid downtime and provide greater insight into processes for true real-time control.

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