Program Control Commands
MEN -- Causes a list of available commands to be typed. In the graphics version, requires a carriage return to be typed before entering any more commands.
SIM -- Allows the user to run the simulation for periods of hours and minutes.
DAY -- Allows the user to run the simulation for periods of days and hours.
TRE -- Used to produce a display of trended variables.
INI -- Used to initialize the four variables that will be trended.
END -- Ends trending and wipes out all stored data.
SAV -- Saves the current situation for future restoring.
RES -- Restores simulation to the most recently saved condition.
DES -- Design a new system, wiping out the current one.
INF -- Enable or disable use of input file.
OUT -- Enable or disable generation of output file.
STO -- Stop ESIM and return to DOS.
Process Control Variables
RET -- Change the return rate.
WAS -- Change the waste rate.
FEE -- Change the fraction of the feed entering each pass (in step-feed only).
FLO -- Change the average flow, but the flow continues to vary with the hour of the day.
FLS -- Set the flow to a constant, independent of time of day.
FLD -- Set hourly influent flow rates, in MGD.
BOD -- Change the influent biochemical oxygen demand.
KLA -- Change the aeration rate. The KLA is proportional to the amount of air, so doubling the KLA is equivalent to doubling the volume of air (7.0 per hour)
SVI -- Change the sludge volume index. An SVI less than 160 slows down the simulation.
EFF -- Proportionality factor for effluent suspended solids (15).
Model coefficients
Y1-- Changes yield coefficient for the conversion of stored to active mass (0.66).
Y2-- Yield coefficient for conversion of active mass to inert mass (0.25).
OXS -- The saturation value for dissolved oxygen (69 lbs./million gallons).
KDO -- Monod constant for oxygen utilization (8.0 lbs/MG).
RT -- Rate constant for conversion of S to XS (3 per hour).
RXA -- Rate constant for conversion of XS to XA (0.2 per hour).
RXI -- Rate constant for conversion of XA to XI (0.00125 per hr).
CF -- Correction factor for oxygen uptake rate (24).
KS -- Monod coefficient for substrate uptake (1250 lbs/MG).
KXS -- Monod coefficient for conversion of XS to XA (150 lbs/MG).
FH -- Maximum ratio of XS to XT (0.45).
DISPLAY COMMANDS
SCH -- Produces schematic display.
BAR -- Produces bar-graph display.
NUM -- Produces numerical display.
MRK -- Places a mark on time scale of trend display.
PRN -- Print the display.
TBL -- Print a table of trended results.
BOD -- Influent biochemical oxygen demand (mg/l).
FLO -- Influent flow (MGD).
RET -- Return flow (MGD).
WAS -- Waste flow (MGD).
MLSS - Mixed liquor suspended solids (mg/l).
RAS -- Return activated sludge suspended solids (mg/l).
ESS -- Effluent suspended solids (mg/l).
EBOD - Effluent biochemical oxygen demand (mg/l).
KLA -- Aeration rate constant (per hour).
SLR -- Solids loading rate on the clarifier (lbs/day/sq ft).
MASS - Total pounds of biomass in the system (lbs).
SVI -- Sludge volume index (ml/g).
AVDO - Avg dissolved oxygen concentration in the aerator (mg/l).
WLD -- Waste load, pounds per hour wasted (lbs/hr).