Context:

As part of the process for Diageo to obtain their discharge license, updated by Northern Ireland Water, it became crucial to monitor and control effluent limits.

Throughout studies it became apparent that all parameters were within their respective limits, except for pH, which was fluctuating out of its limit.

To address this challenge, Colloide was contracted to provide Diageo with a comprehensive pH control system. The objective was to regulate the pH of the effluent leaving the plant, ensuring it consistently complied with the license limits of 5 - 10.

Challenge:

Throughout testing it was found that the pH levels were crossing both upper and lower limits, making it necessary to adjust the pH value in both directions.

Solution

Colloide proposed an acid and sodium hydroxide dosing system to allow the pH to be regulated in both directions.

Project deliverables:

  • New pumping station to pump effluent to an above ground contact tank for chemical mixing.

  • Current flow direction altered through the valve chamber to allow flow to pass into new pumping station.

  • A contact tank mounted at ground level. Acid and sodium hydroxide are dosed at the inlet end of the tank.

  • A pH measurement system of 3 separate probes, operating within triple validation mode, mounted on the outlet of the tank.

  • Acid storage and dosing system with a 1000L capacity tank and bund, duty/standby dosing pumps, pipeworks etc.

  • Antifoam dosing system.

  • Control system to monitor and control all of the plant from main process pumps to dosing systems.

The result

Following completion, equipment training and handover consultation Diageo have reached the desired limits set by Northern Ireland Water standards.

Diageo are now confident that if any issues are to arise their newly installed validation system will allow them to control and fluctuations in pH going forward.