Polishing Filter

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.

class qsdsan.unit_operations.static._polishing_filter.PolishingFilter(ID='', ins: Sequence[AbstractStream] | None = None, outs: Sequence[AbstractStream] | None = (), thermo=None, init_with='WasteStream', filter_type='aerobic', biomass_ID=None, OLR=0.09375, HLR=0.275, X_decomp=0.74, X_growth=0.22, biodegradability=1.0, split={}, solids=(), solids_conc=10.5, T=303.15, include_degassing_membrane=False, F_BM={'Membrane': 1.15, 'Pump building': 1.1800826, 'Pumps': 1.1800826}, lifetime={'Pump pipe stainless steel': 15, 'Pump stainless steel': 15, 'Pumps': 15}, **kwargs)

A superclass for anaerobic and aerobic polishing as in Shoener et al. [1] Some assumptions adopted from Humbird et al. [2]

Parameters:

  • ins (Inlets(obj)) – Influent, recycle, air (optional & when aerobic).

  • outs (Outlets(obj)) – Biogas (when anaerobic), effluent, waste sludge, air (optional & when aerobic).

  • filter_type (str) – Can either be “anaerobic” or “aerobic”.

  • biomass_ID (str) – ID of the component that represents the biomass (e.g., 'X_OHO'). Must be specified explicitly — there is no default because component IDs vary by model.

  • OLR (float) – Organic loading rate of influent, [kg COD/m3/hr].

  • HLR (float) – Hydraulic loading rate of influent, [m3/m2/hr].

  • X_decomp (float) – Fraction of the influent COD converted to biogas (filter_type == “anaerobic”) or CO2 (filter_type == “aerobic”).

  • X_growth (float) – Fraction of the influent COD converted to biomass growth.

  • solids (Iterable(str)) – IDs of the solid components. If not provided, will be set to the default solids attribute of the components.

  • split (dict) – Component-wise split to the treated water. E.g., {'NaCl': 1, 'X_OHO': 0} indicates all of the NaCl goes to the treated water and all of the X_OHO goes to the wasted sludge. Default splits (based on the membrane bioreactor in [2]) will be used if not provided. Note that the split for Water will be ignored as it will be adjusted to satisfy the solids_conc setting.

  • biodegradability (float or dict) – Biodegradability of components, when shown as a float, all biodegradable components are assumed to have the same degradability.

  • solids_conc (float) – Concentration of the biomass in the waste sludge, [g/L].

  • T (float) – Temperature of the filter tank. Will not control temperature if provided as None.

  • include_degassing_membrane (bool) – If to include a degassing membrane to enhance methane (generated through the digestion reaction) recovery. No degassing membrane will be added if filter_type is “aerobic”.

  • kwargs (dict) – Other keyword arguments (e.g., t_wall, t_slab for aerobic concrete dimensions; _t_wall_an, _t_slab_an for anaerobic).

References

property D

[float] Depth of the filter tank, [ft].

property D_B

[float] Depth of the reactor building, [ft].

property HLR

[float] Hydraulic loading rate, [m3/m2/hr].

property L_B

[float] Length of the reactor building, [ft].

property N_degasser

[int] Number of degassing membrane needed for dissolved biogas removal (optional).

property N_filter

[int] Number of filter tanks.

property OLR

[float] Organic loading rate, [kg COD/m3/hr].

property Q_cmd

[float] Influent volumetric flow rate in cubic meter per day, [cmd].

property Q_mgd

[float] Influent volumetric flow rate in million gallon per day, [mgd].

property W_B

[float] Width of the reactor building, [ft].

property X_decomp

[float] Fraction of the influent COD converted to biogas (filter_type == “anaerobic”) or CO2 (filter_type == “aerobic”).

property X_growth

[float] Fraction of the influent COD converted to biomass growth.

auxiliary_unit_names: tuple[str, ...] = ('heat_exchanger',)

Auxiliary unit operation names.

property biodegradability

[float of dict] Biodegradability of components, when shown as a float, all biodegradable component are assumed to have the same degradability.

property biomass_ID

[str] ID of the Component that represents the biomass.

property constr_access

[float] Extra room for construction access, [ft].

property d

[float] Diameter of the filter tank, [ft].

property d_max

[float] Maximum filter diameter, [m].

property decomp_rxns

[tmo.ParallelReaction] Organics to biogas (filter_type == “anaerobic”) or CO2 (filter_type == “aerobic”) reactions.

property excav_slope

[float] Slope for excavation (horizontal/vertical).

property filter_type

[str] Can either be “anaerobic” or “aerobic”.

property freeboard

[float] Freeboard added to the depth of the reactor tank, [ft].

property growth_rxns

[tmo.ParallelReaction] Biomass growth reactions.

property i_rm

[np.array] Removal of each component in this filter tank.

line: str = 'Polishing filter'

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

property organic_rm

[float] Overall organic (COD) removal rate.

property recir_ratio

[float] Internal recirculation ratio — recirculated flow / raw influent flow. For anaerobic filters this is a design output: _design sets it to the minimum value that keeps filter depth ≤ 6 m. A value of R means the total hydraulic throughput is Q * (1 + R), which widens the cross-sectional area and reduces depth for a given packing volume; it also sizes the recirculation pump. Falls back to the ratio of actual inlet flows if not yet set by design.

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 solids_conc

Concentration of solids in the waste sludge, [g/L].

property split

Component-wise split to the treated water.

property t_slab

[float] Concrete slab thickness, [ft].

property t_wall

[float] Concrete wall thickness, [ft].