Semiadaptive Fault Diagnosis via Variational Bayesian Mixture Factor Analysis with Application to Wastewater Treatment

Table 1

Selected sensors for process monitoring.

Variables	Comments	Symbol
1	Total nitrogen concentration in effluent (mg N/L)	TN
2	Total chemical oxygen demand in the effluent (mg COD/L)	TCOD
3	NH4^+ + NH3 nitrogen in effluent (mg N/L)
4	Suspended solids concentration in effluent (mg SS/L)	SS
5	Biological oxygen demand concentration in effluent [g COD m^−3]	BOD
6	Suspended solids concentration in influent (mg SS/L)	SS
7	NH4^+ + NH3 nitrogen in influent (mg N/L)
8	Oxygen in the third reactor g (−COD)⋅m^−3;
9	Nitrate and nitrite nitrogen in the third reactor (mg N/L)
10	NH4^+ + NH3 nitrogen in the third reactor (mg N/L)
11	Oxygen in the fifth reactor g (COD)/m^3;
12	Nitrate and nitrite nitrogen in the fifth reactor (mg N/L)
13	NH4^+ + NH3 nitrogen in the fifth reactor (mg N/L)
14	Flowrate in the third reactor m^3/d	Flowrate
15	Oxygen transfer coefficient in the third reactor	KLa
16	Flowrate in the fifth reactor m^3/d	Flowrate