Mini Sulfite Analyzer Continuously Monitors Dechlorination Residual
UOSA Instrument Specialist Amanda Fromer uses a mini Sulfite analyzer for maintenance-free monitoring of sulfite residuals after dechlorination at a 54 MGD advanced wastewater treatment plant.
The UOSA Water Reclamation Plant uses sodium hypochlorite for disinfection but is required to dechlorinate prior to discharging or reusing the wastewater. Sodium bisulfite is used for dechlorination. The plant operates three 52 gph chlorine pumps for disinfection and three 52 gph bisulfite pumps for dechlorination.
Sodium bisulfite is an oxygen-demanding chemical, making it preferable as a means to minimize any excess amount in the plant effluent by performing an on-line analysis to continuously monitor the residual concentration.
A prior sulfite analyzer in use at the plant had issues with drift and excessive maintenance. Readings from the analyzer were suspect because the values did not correspond to stoichiometric calculations based on the amounts of chemicals being applied.
What’s more, sulfite in a process sample is unstable and can degrade within minutes of collecting a sample, making it difficult to calibrate and verify an analyzer.
The plant had already been successfully operating a ChemScan mini oP Analyzer. When they learned that ChemScan also manufactured a mini sulfite analyzer, they invited...