Luton WWTP: No New Struvite Scale in Centrate Lines

Home 9 Case Studies and Results 9 Luton WWTP: No New Struvite Scale in Centrate Lines
Key results
0 new scale formation
6 month trial duration
Reduced maintenance demand

Case Study from HYDROPATH

Centrate line struvite scale at a sewage works

Centrate line struvite scale at East Hyde Sewage Works, Luton, was severe and reappeared within weeks of every clean. Maintenance was frequent, pipes were being bypassed to keep the plant running, and limited access made internal inspection difficult. One HydroFLOW® unit was fitted to the sludge feed pipe for a six-month trial, mounted in the ceiling of an adjacent building chosen for access and power supply. No new struvite scale formed for the duration. Maintenance intervention fell, pipe bypassing was no longer needed and the centrifuge ran more efficiently. Luton was the first site to show struvite stopping in a centrate line.

The Challenges

  • Centrate line struvite scale was severe and recurring
  • Scaling reappeared within weeks of each clean
  • Frequent maintenance and pipe bypassing were needed to keep running
  • Limited access made internal inspection difficult
  • The centrifuge was losing efficiency to the fouled lines

Centrate pipe before and after treatment at East Hyde

The Solution

  • Unit installed: One HydroFLOW® unit
  • Installation point: sludge feed pipe, mounted in the ceiling of an adjacent building
  • Trial: six months

The unit was fitted to the sludge feed pipe from the ceiling of an adjacent building, a position chosen for access and power supply. The signal disrupts the conditions that let struvite bond to surfaces, preventing further build-up in the centrate line. Over the six-month trial no new centrate line struvite scale formed, maintenance intervention fell and centrifuge efficiency improved.

Key Outcomes

R

No additional scale during the 6-month trial

R

Centrifuge operated more efficiently

R

Lower maintenance from stable scale conditions

R

Longer service intervals achieved

Independent Verification

All results in this study were measured and verified by third-party facilities managers and technical staff.

Summary

No new struvite scale formed across the six-month trial, maintenance intervention fell and pipe bypassing was no longer needed. Two of the US struvite case studies on this site cite Luton as their reference, and it remains the UK anchor for the struvite set. For UK water companies, it is the nearest reference to their own centrate systems and the one to read first.

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