Tutorial on how to specify influent

Constant influent

Let’s assume you influent has constant values over time. Then, we can specify the influent as a python dictionary. Below, we specify an influent with the flow rate 10 m3/d, a concentration of organic compounds of 100 g/m3 COD, and an ammonium concentration of 50 g/m3 N. All other parameters, such as S_NO2, S_NO3, X_OHO, X_AOB, X_NOB, X_AMX, X_CMX, X_I, are assumed to be zero in this case (but we can of course include a value for them as well).

influent = {'Q':10, 'S_s':100, 'S_NH4':50}

When we create a reactor object, we can add the influent specified above:

import biops
r = biops.ifas.Reactor(influent=influent)

Influent that varies with time

Now let’s assume we have a file with influent values that change over time. The influent data should be written in .csv file (comma-separated values). You can use Excel to create such a file. When you do Save as in Excel, choose CSV in the ‘Save as type’ field. We need to have a column with the heading Time, which is the time in days, and a column with the heading Q, which is the flow rate in m3/d. Then, we can have optional columns with S_s, S_NH4, S_NO2, S_NO3, X_OHO, X_AOB, X_NOB, X_AMX, X_CMX, and X_I as headings. If a parameter is not present in the file, it is assumed to be zero.

Time	Q	S_s	S_NH4	S_NO3
0	1200	220	28	12
0.2	1220	180	29	11
0.4	1100	190	32	8
0.6	1004	188	36	9

Next, we want to load this file into python. We use pandas.

import pandas as pd
influent = pd.read_csv('path_to_csv_file')

When we create a reactor object, we can add the influent specified above:

import biops
r = biops.ifas.Reactor(influent=influent)