Food Manufacturer – Rotherham
Case Study: Food Manufacturer, Rotherham
Estimated capitol cost – Unknown. Volumetric consent to discharge – 100mᵌ per day.
Achieved – Highly toxic effluent, 10m3 per day / 90% removal of COD – Consultant to upgrade works, the new plant will efficiently manage highly toxic production effluent (including cooking oil) with minimal cost implications.
The treatment plant at KP was failing to meet its COD discharge consent limitation, with sufficient chemical dosing and clarification installations to utilise JEMS was asked to determine why the plant could not effectively treat the effluent.
Consent To Discharge Limitations
- BOD: 300mg/l
- TSS: 100mg/l
- NH4-N: 10mg/l
JEMS began a flow and load survey to determine precisely what effluent was being discharged throughout an entire production cycle. Clarification tests were carried out to identify the treatability of the effluent and a survey of the existing works was done to ensure proper operation.
Initially primary balancing was a concern as there was only two hours of space at peak flows leading to highly untreatable effluent, a tanker was brought in to provide a temporary 40m3 volume of space which was utilised as a primary settlement tank.
The existing basket strainers were quick to fill requiring attention up to 8 times per day.
On day four of the flow and load survey a massive quantity of cooking oil entered the treatment works, it was thoroughly analysed and found to be a very expensive form of ‘honey tack glue’ used in food production, its COD content was determined to be 1,600,000 mg/l!
The primary factor for the breach in COD consent was the presence of ‘honey tack’, now that operators are recycling this substance a large amount of money has been saved and the influence upon the ETP has been dramatically reduced allowing normal operations to resume.
In an effort to better prepare the effluent for treatment a different grade mesh was fitted to the basket strainers to allow more fluent operation, the tanker will be replaced with a permanent primary settlement tank and the small balancing tank will be fitted with agitators.
Onsite operators were provided further training in the use of the chemical dosing units and were more than capable of producing quality effluent.