Excretion¶

QSDsan: Quantitative Sustainable Design for sanitation and resource recovery systems

This module is developed by:

This module is under the University of Illinois/NCSA Open Source License. Please refer to https://github.com/QSD-Group/QSDsan/blob/main/LICENSE.txt for license details.

Note: unit_operations/dynamic/_excretion.py is a separate module holding ExcretionmASM2d, a dynamic-capable subclass of Excretion defined here.

class qsdsan.unit_operations.static._excretion.Excretion(ID='', ins: Sequence[AbstractStream] | None = None, outs: Sequence[AbstractStream] | None = (), thermo=None, init_with='WasteStream', waste_ratio=0, **kwargs)¶

Estimation of N, P, K, and COD in urine and feces based on dietary intake for one person based on Trimmer et al.

Parameters:

waste_ratio (float) – A ratio in [0, 1] to indicate the amount of intake calories and nutrients (N, P, K) that is wasted.

Examples

>>> from qsdsan.utils import create_example_sanitation_components
>>> cmps = create_example_sanitation_components()
>>> from qsdsan.unit_operations import Excretion
>>> U1 = Excretion('U1')
>>> U1.simulate()
>>> urine, feces = U1.outs
>>> round(urine.TN, 1)  # total nitrogen in urine, mg/L
4278.1
>>> round(feces.COD, 1)  # COD in feces, mg/L
123314.0

See bwaise systems for use in a complete sanitation system.

References

[1] Trimmer et al., Navigating Multidimensional Social–Ecological System Trade-Offs across Sanitation Alternatives in an Urban Informal Settlement. Environ. Sci. Technol. 2020, 54 (19), 12641–12653. https://doi.org/10.1021/acs.est.0c03296

property Ca_fec¶

[float] Calcium excreted in feces, [g Ca/cap/d].

property Ca_ur¶

[float] Calcium excreted in urine, [g Ca/cap/d].

property K_cal¶

[float] Potassium intake relative to caloric intake, [g K/1000 kcal].

property K_exc¶

[float] Potassium excretion factor, [% of intake].

property K_ur¶

[float] Potassium recovered in urine, [wt%].

property Mg_fec¶

[float] Magnesium excreted in feces, [g Mg/cap/d].

property Mg_ur¶

[float] Magnesium excreted in urine, [g Mg/cap/d].

property N_exc¶

[float] Nitrogen excretion factor, [% of intake].

property N_fec_NH3¶

[float] Reduced inorganic nitrogen in feces, modeled as NH3, [% of total feces N].

property N_prot¶

[float] Nitrogen content in protein, [wt%].

property N_ur¶

[float] Nitrogen recovered in urine, [wt%].

property N_ur_NH3¶

[float] Reduced inorganic nitrogen in urine, modeled as NH3, [% of total urine N].

property P_exc¶

[float] Phosphorus excretion factor, [% of intake].

property P_prot_a¶

[float] Phosphorus content in animal protein, [wt%].

property P_prot_v¶

[float] Phosphorus content in vegetal protein, [wt%].

property P_ur¶

[float] Phosphorus recovered in urine, [wt%].

property e_cal¶

[float] Caloric intake, [kcal/cap/d].

property e_exc¶

[float] Energy excretion factor, [% of intake].

property e_fec¶

[float] Percent of excreted energy in feces, [%].

property fec_exc¶

[float] Feces generated per day, [g/cap/d].

property fec_moi¶

[float] Moisture (water) content of feces, [wt%].

line: str = 'Excretion'¶

class-attribute Name denoting the type of Unit class. Defaults to the class name of the first child class

property p_anim¶

[float] Animal protein intake, [g/cap/d].

property p_veg¶

[float] Vegetal protein intake, [g/cap/d].

run()¶

Run mass and energy balance. This method also runs specifications user defined specifications unless it is being run within a specification (to avoid infinite loops).

See also

_run, specifications, add_specification, add_bounded_numerical_specification

property ur_exc¶

[float] Urine generated per day, [g/cap/d].

property ur_moi¶

[float] Moisture (water) content of urine, [wt%].

property waste_ratio¶

[float] The amount of intake calories and nutrients (N, P, K) that is wasted.

Note

Not considered for Mg and Ca.