FIG 1.
Schematic of wastewater treatment plant in this study with operational parameters used in statistical analysis. Note that secondary treatment consists of a four-stage process, where the first stage is unaerated and thus operates anaerobically; the remaining three stages are aerated with pure oxygen as an input. TSS, total suspended solids (in milligrams per liter); MLVSS, mixed liquor volatile suspended solids (in milligrams VSS per liter); SRT, solids retention time (in days); Qeffluent = Qinfluent − Qwaste.