Fault detection and diagnosis of the wastewater nitrate and nitrite sensors using PCA and FDA combined with assessment of the economic and environmental impact of the faults.

One of the leading challenges in Water Resource Recovery Facility monitoring and control is the poor data quality and sensor consistency due to the tough and complex circumstances of the process operation. This paper presents a new principal component analysis fault detection approach for the nitrate and nitrite concentration sensor based on Water Resource Recovery Facility measurements, together with the Fisher Discriminant Analysis identification of fault types. Five malfunction cases were considered: constant additive error, ramp changing error in time, incorrect amplification error, random additive error, and unchanging sensor value error.

Reducing energy costs of the wastewater treatment plant by improved scheduling of the periodic influent load.

The wastewater treatment plant (WWTP) is a major actor of the water-energy nexus. This study proposes to partially store in available WWTP tank infrastructure the wastewater received during the day-time and schedule the purification of the stored wastewater at night-time. The intended operational approach aims to shift part of the WWTP electrical energy consumption from day-time into the night-time period when the energy has lower prices, also contributing to the balance of the electrical power generation system.