Analytical Fuzzy Predictive Control Applied to Wastewater Treatment Biological Processes

Table 1

Main variables of the WWTP with activated sludge.

Influent	Biological reactor	Secondary settler and recirculation flows	Effluent
: input flow rate	: reactor input-output flow rate	: total sludge recirculation flow rate; : purge flow rate; : sludge recirculation flow rate (to the reactor)	: output flow rate
: input substrate concentration; : input biomass concentration	: substrate concentration in the input of the reactor; : biomass concentration in the input of the reactor; s: output substrate concentration; : output biomass concentration; c: output oxygen concentration; : aeration factor	: biomass concentration in the top layer of the settler; : biomass concentration in the middle layer of the settler; : biomass concentration in the lower layer of the settler	: output substrate concentration