Kellogg’s Wrexham Factory – Replacement Biofilter System

At Kellogg’s Wrexham factory, the waste flow passes over a single Biofilter for BOD reduction before solids separation through a DAF unit and discharge to sewer. The system needed to be replaced to maintain discharge consent.

ACWA’s robust solution involved the complete replacement of the biofilter system utilising the existing concrete structures. After the demolition and removal of the failing system, the concrete structures were accessed, rebuilt/cast and coated with a heavy duty acid resistant coating to protect all wetted areas of the system.

A new glass lined steel tank was installed complete with a new galvanised steel access staircase providing access at high level to the distributor unit. New structured media complete with supporting floor and GRP access walkway was also installed. The new distributor was constructed from stainless steel ensuring resistance to low pH effluent, along with improved flow distribution. Finally a new corrosion resistant feed pump and stainless steel feed pipework was installed to complete the system. From start up, the system was seeded and meeting consent within 6 weeks.


ACWA’s installed solution provides:

  • Robust flexible solution
  • Existing WWTP footprint reused
  • Designed to operate under abnormal pH conditions
  • Design maximised treatment surface area with structured media
  • Simple to operate and maintain