Process issues at water resource reclamation facilities are common but can have large impacts on the performance of facilities. At Bucklin Point Wastewater Treatment Facility (WWTF), an advanced biological nutrient removal facility in Providence, R.I., the temporary loss of a single recirculation pump demonstrates the importance of all process components working together to accomplish treatment goals.
Bucklin Point WWTF monitors their nitrogen removal process with the YSI IQ SensorNet (IQSN) online instrumentation system. In normal operation, the YSI VARiON (ammonium and nitrate) and SensoLyt (ORP) sensors provide trending that helps make informed decisions about process adjustments. For instance, the facility adjusts swing zones and recirculation based upon where the ammonia is lowest and nitrate is highest to increase nitrogen removal. Also, these sensors provide assurance that the process is operating correctly and alert the operators of any process issues. As an example, when the facility lost a recirculation pump in one of their trains, SCADA showed significant changes in ammonia, nitrate and ORP. The YSI sensors were not only able to alert the operators of the process issue, but it documented the drastic process changes with one pump malfunction.
Sharp changes occurred in both their anoxic and aerobic zones. Anoxic ammonia doubled from 7 to 14 mg/L, while the aerobic ammonia reduced from 2.5 mg/L to 0.5 mg/L and aerobic nitrate decreased from 7 mg/L to 4.5 mg/L. The ORP trends in each zone suggest significant changes to biological activity with the anoxic zone decreasing by 50 mV and the aerobic ORP decreasing by 30 mV. However, the operators at Bucklin Point were quick to react to the malfunctioning recirculation pump and returned to normal operation in only three hours. WW
YSI is part of Xylem Analytics and a leading provider of water measurement solutions. Learn more at www.ysi.com.
