Pollutants

Note

Engine: OpenSWMM 6 — refactored.

Pollutants and their fate parameters. Shape mirrors Nodes — solver.pollutants is the collection, Pollutant is the wrapper.

Reference: openswmm_pollutants.h.

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Quickstart

from openswmm.engine import Solver, ConcentrationUnits

with Solver("model.inp") as s:
    tss = s.pollutants["TSS"]
    print(tss.units, tss.kdecay, tss.init_conc)

    # Decay / fate
    tss.kdecay = 0.05

    # Runtime injection at a node or link.
    s.pollutants.set_node_quality("J1", "TSS", 12.0)
    s.pollutants.set_link_quality("C1", "TSS", 8.0)

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Collection

Operation	What it does
len(s.pollutants) / for p in s.pollutants: / s.pollutants[key]	Standard container protocol over Pollutant wrappers.
s.pollutants.get_index(id) / get_id(idx)	Id ↔ index lookup.
s.pollutants.add(id, units=ConcentrationUnits.MG_PER_L)	Append a pollutant. Returns the new Pollutant.
s.pollutants.set_node_quality(node, pollutant, conc)	Runtime quality injection at a node.
s.pollutants.set_link_quality(link, pollutant, conc)	Runtime quality injection in a link.

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Wrapper: Pollutant

Property	Type	Mode	Meaning
id / index	str / int	read-only
units	ConcentrationUnits	read-only
kdecay	float	read/write	First-order decay coefficient.
mwt	float	read/write	Molecular weight.
rain_conc / gw_conc / init_conc / rdii_conc	float	read/write	Inflow concentrations.
snow_only	bool	read/write
co_pollutant	(Pollutant, float) | None	read-only

Use Pollutant.set_co_pollutant(other, fraction)() to set the co-pollutant link.

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See also

• Nodes — Node.quality() and set_quality_mass_flux.

• Links — Link.quality().

• Subcatchments — Subcatchment.quality().

• Error handling, edge cases & debugging.