Screw press struvite at a Utah treatment plant
Screw press struvite was costing a Utah wastewater plant $8,000 a month in chemicals and up to 30 hours of cleaning per press per month. The deposits in both presses were described as concrete-like. One HydroFLOW® Custom 8 inch unit was fitted to the sludge line feeding one of the two presses, and chemical dosing was stopped at the start so the treatment could be judged on its own over two months. After 30 days the treated press did not need its usual monthly clean. At 60 days the pressure wash took under four hours instead of up to 30, and payback was calculated at three months.
The Challenge
- Screw press struvite accumulated continuously inside both of the plant’s presses
- The plant spent $8,000 per month on a struvite reduction chemical
- Each of the two presses required cleaning every month
- Hard, concrete-like deposits made cleaning take as long as 30 hours
- Chemical cost and cleaning time were both running high at the same time
The Solution
- Unit installed: one HydroFLOW® Custom 8 inch
- Installation point: sludge line feeding one of the two screw presses
- Dosing stopped: struvite reduction chemical, from the start of the test
- Trial: two months, with checks at 30 and 60 days
Screw press struvite was left with no chemical control from day one, so any change on the treated press could be put down to the unit alone. The unit treated the sludge feeding one press only. That press was checked at 30 days, when its monthly clean would normally fall due, and again at the 60 day pressure wash.
Testimonial
“Outstanding results! Night and day difference before and after HydroFLOW®.” — Maintenance Manager
