# -*- coding: utf-8 -*-
# Bioindustrial-Park: BioSTEAM's Premier Biorefinery Models and Results
# Copyright (C) 2021-2024, Yalin Li <mailto.yalin.li@gmail.com>
#
# This module is under the UIUC open-source license. See
# github.com/BioSTEAMDevelopmentGroup/biosteam/blob/master/LICENSE.txt
# for license details.
import math
import biosteam as bst
from . import (
default_insolubles,
InternalCirculationRx, WWTpump,
compute_stream_COD, format_str, get_BD_dct, get_split_dct, cost_pump,
)
DesignError = bst.exceptions.DesignError
__all__ = ('AnMBR',)
_ft_to_m = 0.3048 # auom('ft').conversion_factor('m')
_ft2_to_m2 = 0.09290 # auom('ft2').conversion_factor('m2')
_ft3_to_m3 = 0.02832 # auom('ft3').conversion_factor('m3')
_ft3_to_gal = 7.4805 # auom('ft3').conversion_factor('gallon')
_m3_to_gal = 264.1721 # auom('m3').conversion_factor('gal')
_cmh_to_mgd = _m3_to_gal * 24 / 1e6 # cubic meter per hour to million gallon per day
_lb_to_kg = 0.4536 # auom('lb').conversion_factor('kg')
# %%
[docs]
class AnMBR(bst.Unit):
"""
Anaerobic membrane bioreactor (AnMBR) for wastewater treatment as in
Shoener et al. [6]_ Some assumptions adopted from Humbird et al. [2]_
In addition to the anaerobic treatment, an optional second stage can be added,
which can be aerobic filter or granular activated carbon (GAC).
Parameters
----------
ins :
* [0] influent
* [1] recycle (optional)
* [2] NaOCl
* [3] citric acid
* [4] bisulfite
* [5] air (optional)
outs :
* [0] biogas
* [1] effluent
* [2] waste sludge
* [3] air (optional)
reactor_type : str
Can either be "CSTR" for continuous stirred tank reactor
or "AF" for anaerobic filter.
membrane_configuration : str
Can either be "cross-flow" or "submerged".
membrane_type : str
Can be "hollow fiber" ("submerged" configuration only),
"flat sheet" (either "cross-flow" or "submerged" configuration),
or "multi-tube" ("cross-flow" configuration only).
membrane_material : str
Can be any of the plastics ("PES", "PVDF", "PET", "PTFE")
for any of the membrane types ("hollow fiber", "flat sheet", "multi-tube"),
or "sintered steel" for "flat sheet",
or "ceramic" for "multi-tube".
membrane_unit_cost : float
Cost of membrane, [$/ft2]
include_aerobic_filter : bool
Whether to include an aerobic filtration process in this AnMBR,
can only be True in "AF" (not "CSTR") reactor.
add_GAC : bool
If to add granular activated carbon to enhance biomass retention,
can only be True for the "submerged" configuration.
include_degassing_membrane : bool
If to include a degassing membrane to enhance methane
(generated through the digestion reaction) recovery.
Y_biogas : float
Biogas yield, [kg biogas/kg consumed COD].
Y_biomass : float
Biomass yield, [kg biomass/kg consumed COD].
biodegradability : float or dict
Biodegradability of chemicals,
when shown as a float, all biodegradable chemicals are assume to have
the same degradability.
split : dict
Component-wise split to the treated water.
E.g., {'Water':1, 'WWTsludge':0} indicates all of the water goes to
the treated water and all of the WWTsludge goes to the wasted sludge.
Default splits (based on the membrane bioreactor in [2]_) will be used
if not provided.
sludge_conc : float
Concentration of biomass in the waste sludge stream, in g/L.
Note that the solids content of the effluent should be smaller than the
solids content of the waste sludge stream.
T : float
Temperature of the reactor.
Will not control temperature if provided as None.
include_pump_building_cost : bool
Whether to include the construction cost of pump building.
include_excavation_cost : bool
Whether to include the construction cost of excavation.
kwargs : dict
Other keyword arguments (e.g., J_max, SGD).
"""
_N_ins = 6 # influent, recycle (optional), naocl, citric acid, bisulfite, air (optional)
_N_outs = 4 # biogas, effluent, waste sludge, air (optional)
# Equipment-related parameters
F_BM_pumps = 1.18 * (1+0.007/100) # 0.007 is for miscellaneous costs
_F_BM_default = {
'Membrane': 1 + 0.15, # assume 15% for replacement labor
'Pumps': F_BM_pumps,
'Pump building': F_BM_pumps,
'Pump excavation': F_BM_pumps,
'Blowers': 2 * 1.11,
'Blower building': 1.11,
# Set bare module factor to 1 if not otherwise provided
'Reactor excavation': 1,
'Wall concrete': 1,
'Slab concrete': 1,
'GAC': 1,
'Air pipes': 1,
'Degassing membrane': 1,
}
_default_equipment_lifetime = {
'Membrane': 10,
'Pumps': 15,
'Blowers': 15,
}
_N_train_min = 2
_cas_per_tank_spare = 2
_mod_surface_area = {
'hollow fiber': 370,
'flat sheet': 1.45/_ft2_to_m2,
'multi-tube': 32/_ft2_to_m2
}
_mod_per_cas = None
_mod_per_cas_range = {
'hollow fiber': (30, 48), # min, max
'flat sheet': (150, 200),
'multi-tube': (44, 48)
}
_cas_per_tank = None
_cas_per_tank_range = (16, 22)
_N_blower = 0
_W_tank = 21
_D_tank = 12
_W_dist = 4.5
_W_eff = 4.5
_L_well = 8
_W_well = 8
_D_well = 12
_excav_slope = 1.5
_constr_access = 3
# Operation-related parameters
_HRT = 10
_J_max = 12
_TMP_dct = {
'cross-flow': 2.5,
'submerged': 2.5,
}
_TMP_aerobic = None
_recir_ratio = 2.25 # from the 0.5-4 uniform range in ref [1]
_v_cross_flow = 1.2 # from the 0.4-2 uniform range in ref [1]
_v_GAC = 8
_SGD = 0.625 # from the 0.05-1.2 uniform range in ref [1]
_AFF = 3.33
_sludge_conc = 10.5
_refresh_rxns = InternalCirculationRx._refresh_rxns
# Other equipment
auxiliary_unit_names = ('heat_exchanger',)
_pumps = ('perm', 'retent', 'recir', 'sludge', 'naocl', 'citric', 'bisulfite',
'AF', 'AeF')
def _init(self,
reactor_type='CSTR',
membrane_configuration='cross-flow',
membrane_type='multi-tube',
membrane_material='ceramic',
membrane_unit_cost=8,
include_aerobic_filter=False,
add_GAC=False,
include_degassing_membrane=True,
Y_biogas=0.86,
Y_biomass=0.05, # from the 0.02-0.08 uniform range in ref [1]
biodegradability={},
split={},
sludge_conc=10.5,
T=35+273.15,
include_pump_building_cost=False,
include_excavation_cost=False,
**kwargs
):
self.reactor_type = reactor_type
self.include_aerobic_filter = include_aerobic_filter
self.membrane_configuration = membrane_configuration
self.membrane_type = membrane_type
self.membrane_material = membrane_material
self.membrane_unit_cost = membrane_unit_cost
self.add_GAC = add_GAC
self.include_degassing_membrane = include_degassing_membrane
self.Y_biogas = Y_biogas
self.Y_biomass = Y_biomass
self.biodegradability = \
biodegradability if biodegradability else get_BD_dct(self.chemicals)
self.split = split if split else get_split_dct(self.chemicals)
self.sludge_conc = sludge_conc
self.T = T
self.include_pump_building_cost = include_pump_building_cost
self.include_excavation_cost = include_excavation_cost
# Initialize the attributes
ID = self.ID
self._inf = bst.Stream(f'{ID}_inf')
self._mixed = bst.Stream(f'{ID}_mixed')
self._retent = bst.Stream(f'{ID}_retent')
self._recir = bst.Stream(f'{ID}_recir')
hx_in = bst.Stream(f'{ID}_hx_in')
hx_out = bst.Stream(f'{ID}_hx_out')
# Add '.' in ID for auxiliary units
self.heat_exchanger = bst.HXutility(ID=f'.{ID}_hx', ins=hx_in, outs=hx_out)
self._refresh_rxns()
for k, v in kwargs.items(): setattr(self, k, v)
self._check_design()
def _check_design(self):
reactor_type = self.reactor_type
m_config = self.membrane_configuration
m_type = self.membrane_type
m_material = self.membrane_material
if reactor_type == 'CSTR':
if self.include_aerobic_filter:
raise DesignError('Aerobic filtration cannot be used in CSTR.')
if m_config == 'submerged':
if not m_type in ('hollow fiber', 'flat sheet'):
raise DesignError('Only "hollow fiber" or "flat sheet" is allowed '
'for "submerged" membrane, not {m_type}.')
else: # cross-flow
if not m_type in ('flat sheet', 'multi-tube'):
raise DesignError('Only "flat sheet" or "multi-tube" is allowed '
'for "cross-flow" membrane, not {m_type}.')
if self.add_GAC:
raise DesignError('No GAC should be added '
'(i.e., `add_GAC` can only be False'
'for "cross-flow" membrane.')
plastics = ('PES', 'PVDF', 'PET', 'PTFE')
if m_type == 'hollow fiber':
if not m_material in plastics:
raise DesignError(f'Only plastic materials {plastics} '
'allowed for "hollow fiber" membrane',
f'not "{m_material}".')
elif m_type == 'flat sheet':
if not m_material in (*plastics, 'sintered steel'):
raise DesignError(f'Only plastic materials {plastics} and "sintered steel"'
'allowed for "flat sheet" membrane',
f'not "{m_material}".')
else: # multi-tube
if not m_material in (*plastics, 'ceramic'):
raise DesignError(f'Only plastic materials {plastics} and "ceramic"'
'allowed for "multi-tube" membrane',
f'not "{m_material}".')
@staticmethod
def _degassing(original_stream, receiving_stream):
InternalCirculationRx._degassing(original_stream, receiving_stream)
@staticmethod
def compute_COD(stream):
r"""
Compute the chemical oxygen demand (COD) of a given stream in kg-O2/m3
by summing the COD of each chemical in the stream using:
.. math::
COD [\frac{kg}{m^3}] = mol_{chemical} [\frac{kmol}{m^3}] * \frac{g O_2}{mol chemical}
"""
return compute_stream_COD(stream)
# =========================================================================
# _run
# =========================================================================
def _run(self):
raw, recycled, naocl, citric, bisulfite, air_in = self.ins
biogas, perm, sludge, air_out = self.outs
degassing = self._degassing
# Initialize the streams
biogas.phase = 'g'
biogas.empty()
mixed = self._mixed
mixed.mix_from((raw, recycled))
self._inf.copy_like(mixed) # this stream will be preserved (i.e., no reaction)
# Chemicals for cleaning, assume all chemicals will be used up
# 2.2 L/yr/cmd of 12.5 wt% solution (15% vol)
naocl.empty()
naocl.imass['NaOCl', 'Water'] = [0.125, 1-0.125]
naocl.F_vol = (2.2/1e3/365/24) * (mixed.F_vol*24) # m3/hr solution
# 0.6 L/yr/cmd of 100 wt% solution, 13.8 lb/kg
citric.empty()
citric.ivol['CitricAcid'] = (0.6/1e3/365/24) * (mixed.F_vol*24) # m3/hr pure
# 0.35 L/yr/cmd of 38% solution, 3.5 lb/gal
bisulfite.empty()
bisulfite.imass['Bisulfite', 'Water'] = [0.38, 1-0.38]
bisulfite.F_vol = (0.35/1e3/365/24) * (mixed.F_vol*24) # m3/hr solution
# For pump design
self._compute_mod_case_tank_N()
Q_R_mgd, Q_IR_mgd = self._compute_liq_flows()
retent, recir = self._retent, self._recir
retent.copy_like(mixed)
recir.copy_like(mixed)
retent.F_mass *= Q_R_mgd / self.Q_mgd
recir.F_mass *= Q_IR_mgd / self.Q_mgd
# Effluents
self.growth_rxns(mixed.mol)
self.biogas_rxns(mixed.mol)
mixed.split_to(perm, sludge, self._isplit.data)
degassing(perm, biogas)
degassing(sludge, biogas)
sludge_conc = self._sludge_conc
insolubles = tuple(i.ID for i in self.chemicals if i.ID in default_insolubles)
m_insolubles = sludge.imass[insolubles].sum()
if m_insolubles/sludge.F_vol <= sludge_conc:
diff = sludge.ivol['Water'] - m_insolubles/sludge_conc
sludge.ivol['Water'] = m_insolubles/sludge_conc
perm.ivol['Water'] += diff
if perm.imass['Water'] < 0:
raise ValueError('Not enough moisture in the influent for waste sludge '
f'with {sludge_conc} g/L sludge concentration.')
# Gas for sparging, no sparging needed if submerged or using GAC
air_out.link_with(air_in)
air_in.T = 17 + 273.15
self._design_blower()
if self.T is not None: perm.T = sludge.T = biogas.T = air_out.T = self.T
# Called by _run
def _compute_mod_case_tank_N(self):
N_mod_min, N_mod_max = self.mod_per_cas_range[self.membrane_type]
N_cas_min, N_cas_max = self.cas_per_tank_range
mod_per_cas, cas_per_tank = N_mod_min, N_cas_min
J_max = self.J_max
while self.J > J_max:
mod_per_cas += 1
if mod_per_cas == N_mod_max + 1:
if cas_per_tank == N_cas_max + 1:
self.N_train+=1
mod_per_cas, cas_per_tank = N_mod_min, N_cas_min
else:
cas_per_tank += 1
mod_per_cas = N_mod_min
self._mod_per_cas, self._cas_per_tank = \
mod_per_cas, cas_per_tank
# Called by _run
def _compute_liq_flows(self):
m_type = self.membrane_type
if m_type == 'multi-tube':
# Cross-flow flow rate per module,
# based on manufacture specifications for compact 33, [m3/hr]
Q_cross_flow = 53.5 * self.v_cross_flow
Q_R_cmh = self.N_mod_tot * Q_cross_flow # total retentate flow rate, [m3/hr]
Q_R_mgd = Q_R_cmh * _cmh_to_mgd # [mgd]
Q_mgd, recir_ratio = self.Q_mgd, self.recir_ratio
if Q_mgd*recir_ratio >= Q_R_mgd:
Q_IR_mgd = Q_mgd*recir_ratio - Q_R_mgd
else:
Q_IR_mgd = 0
# # Gives really large recir_ration,
# # probably shouldn't back-calculate this way
# self._recir_ratio = Q_R_mgd / Q_mgd
if self.add_GAC:
Q_upflow_req = (self.v_GAC/_ft_to_m) * \
self.L_membrane_tank*self.W_tank*self.N_train * 24 * _ft3_to_gal / 1e6
Q_IR_add_mgd = max(0, (Q_mgd+Q_IR_mgd)-Q_upflow_req)
Q_IR_mgd += Q_IR_add_mgd
self._recir_ratio = Q_IR_mgd / Q_mgd
return Q_R_mgd, Q_IR_mgd
# Called by _run
def _design_blower(self):
air = self.ins[-1]
if (not self.add_GAC) and (self.membrane_configuration=='submerged'):
gas = self.SGD * self.mod_surface_area*_ft2_to_m2 # [m3/h]
gas /= (_ft3_to_m3 * 60) # [ft3/min]
gas_train = gas * self.N_train*self.cas_per_tank*self.mod_per_cas
TCFM = math.ceil(gas_train) # total cubic ft per min
N = 1
if TCFM <= 30000:
CFMB = TCFM / N # cubic ft per min per blower
while CFMB > 7500:
N += 1
CFMB = TCFM / N
elif 30000 < TCFM <= 72000:
CFMB = TCFM / N
while CFMB > 18000:
N += 1
CFMB = TCFM / N
else:
CFMB = TCFM / N
while CFMB > 100000:
N += 1
CFMB = TCFM / N
gas_m3_hr = TCFM * _ft3_to_m3 * 60 # ft3/min to m3/hr
air.ivol['N2'] = 0.79
air.ivol['O2'] = 0.21
air.F_vol = gas_m3_hr
else: # no sparging/blower needed
TCFM = CFMB = 0.
N = -1 # to account for the spare
air.empty()
D = self.design_results
D['Total air flow [CFM]'] = TCFM
D['Blower capacity [CFM]'] = CFMB
D['Blowers'] = self._N_blower = N + 1 # add a spare
# =========================================================================
# _design
# =========================================================================
def _design(self):
D = self.design_results
D['Treatment train'] = self.N_train
D['Cassette per train'] = self.cas_per_tank
D['Module per cassette'] = self.mod_per_cas
D['Total membrane modules'] = self.N_mod_tot
# Step A: Reactor and membrane tanks
# Call the corresponding design function
# (_design_CSTR or _design_AF)
func = getattr(self, f'_design_{self.reactor_type}')
wall, slab, excavation = func()
D['Wall concrete [ft3]'] = wall
D['Slab concrete [ft3]'] = slab
D['Excavation [ft3]'] = excavation
# Optional addition of packing media (used in filters)
ldpe, hdpe = 0., 0.
for i in (self.AF, self.AeF):
if i is None:
continue
ldpe += i.design_results['Packing LDPE [m3]']
hdpe += i.design_results['Packing HDPE [m3]']
# Optional addition of GAC
D['GAC [kg]'] = self._design_GAC()
# Step B: Membrane
# Call the corresponding design function
# (_design_hollow_fiber, _design_flat_sheet, or _design_multi_tube)
m_type = format_str(self.membrane_type)
func = getattr(self, f'_design_{m_type}')
D['Membrane [m3]'] = func()
# Step C: Pumps
pipe, pumps, hdpe = self._design_pump()
D['Pipe stainless steel [kg]'] = pipe
D['Pump stainless steel [kg]'] = pumps
D['Pump chemical storage HDPE [m3]'] = hdpe
# Step D: Degassing membrane
D['Degassing membrane'] = self.N_degasser
# Total volume
D['Total volume [ft3]'] = self.V_tot
### Step A functions ###
# Called by _design
def _design_CSTR(self):
N_train = self.N_train
W_dist, L_CSTR , W_eff, L_membrane_tank = \
self.W_dist, self.L_CSTR, self.W_eff, self.L_membrane_tank
W_PB, W_BB, D_tank = self.W_PB, self.W_BB, self.D_tank
t_wall, t_slab = self.t_wall, self.t_slab
SL, CA = self.excav_slope, self.constr_access
### Concrete calculation ###
W_N_trains = (self.W_tank+2*t_wall)*N_train - t_wall*(N_train-1)
D = D_tank + 2 # add 2 ft of freeboard
t = t_wall + t_slab
get_VWC = lambda L1, N: N * t_wall * L1 * D
get_VSC = lambda L2: t * L2 * W_N_trains
# Concrete for distribution channel, [ft3]
VWC_dist = get_VWC(L1=(W_N_trains+W_dist), N=2)
VSC_dist = get_VSC(L2=(W_dist+2*t_wall))
# Concrete for CSTR tanks, [ft3]
VWC_CSTR = get_VWC(L1=L_CSTR, N=(N_train+1))
VSC_CSTR = get_VSC(L2=L_CSTR)
# Concrete for effluent channel, [ft3]
VWC_eff = get_VWC(L1=(W_N_trains+W_eff), N=2)
VSC_eff = get_VSC(L2=(W_eff+2*t_wall))
# Concrete for the pump/blower building, [ft3]
VWC_PBB = get_VWC(L1=(W_N_trains+W_PB+W_BB), N=2)
VSC_PBB = get_VSC(L2=(W_PB+t_wall+W_BB))
if self.membrane_configuration == 'submerged':
VWC_membrane_tank, VSC_membrane_tank, VWC_well, VSC_well = \
self._design_membrane_tank(self, D, N_train, W_N_trains,
self.L_membrane_tank)
else:
VWC_membrane_tank, VSC_membrane_tank, VWC_well, VSC_well = 0., 0., 0., 0.
# Total volume of wall concrete, [ft3]
VWC = VWC_dist + VWC_CSTR + VWC_eff + VWC_PBB + VWC_membrane_tank + VWC_well
# Total volume of slab concrete [ft3]
VSC = VSC_dist + VSC_CSTR + VSC_eff + VSC_PBB + VSC_membrane_tank + VSC_well
### Excavation calculation ###
get_VEX = lambda L_bttom, W_bottom, diff: \
0.5 * D_tank * (L_bottom*W_bottom+(L_bottom+diff)*(W_bottom+diff)) # bottom+top
L_bottom = W_dist + L_CSTR + W_eff + L_membrane_tank + 2*CA
W_bottom = W_N_trains + 2*CA
diff = D_tank * SL
# Excavation volume for membrane tanks, [ft3]
VEX_membrane_tank = get_VEX(L_bottom, W_bottom, diff)
# Excavation volume for pump/blower building, [ft3]
VEX_PBB = get_VEX((W_PB+W_BB+2*CA), W_bottom, diff)
VEX = VEX_membrane_tank + VEX_PBB
return VWC, VSC, VEX
# Called by _design
def _design_AF(self):
raise RuntimeError('Design not implemented.')
# Called by _design_CSTR/_design_AF
def _design_membrane_tank(self, D, N_train, W_N_trains, L_membrane_tank,
t_wall, t_slab):
L_well, W_well, D_well = self.L_well, self.W_well, self.D_well
# Concrete for membrane tanks, [ft3]
t = t_wall + t_slab
VWC_membrane_tank = (N_train+1) * t_wall * L_membrane_tank * D
VSC_membrane_tank = t * L_membrane_tank * W_N_trains
# Concrete for wet well (mixed liquor storage), [ft3]
L = L_well + 2*t_wall
W = W_well + 2*t_wall
VWC_well = 2 * t_wall * (L_well+W) * D_well
VSC_well = (t_slab+t_wall) * L * W
return VWC_membrane_tank, VSC_membrane_tank, VWC_well, VSC_well
# Called by _design
def _design_GAC(self):
if not self.add_GAC: return 0
raise RuntimeError('Design not implemented.')
### Step B functions ###
# Called by _design
def _design_hollow_fiber(self):
raise RuntimeError('Design not implemented.')
# Called by _design
def _design_flat_sheet(self):
raise RuntimeError('Design not implemented.')
# Called by _design
def _design_multi_tube(self):
# # 0.01478 is volume of material for each membrane tube, [m3]
# # L_tube OD ID
# V_tube = 3 * math.pi/4 * ((6e-3)**2-(5.2e-3)**2)
# V_SU = 700 * V_tube # V for each small unit [m3]
# M_SU = 1.78*1e3 * V_SU # mass = density*volume, [kg/m3], not used
return self.N_mod_tot*0.01478
### Step C function ###
# Called by _design
def _design_pump(self):
rx_type, m_config, pumps = \
self.reactor_type, self.membrane_configuration, self._pumps
ins_dct = {
'perm': self.outs[1].proxy(),
'retent': self._retent,
'recir': self._recir,
'sludge': self.outs[2].proxy(),
'naocl': self.ins[2].proxy(),
'citric': self.ins[3].proxy(),
'bisulfite': self.ins[4].proxy(),
}
type_dct = {
'perm': f'permeate_{m_config}',
'retent': f'retentate_{rx_type}',
'recir': f'recirculation_{rx_type}',
'sludge': 'sludge',
'naocl': 'chemical',
'citric': 'chemical',
'bisulfite': 'chemical',
}
inputs_dct = {
'perm': (self.cas_per_tank, self.D_tank, self.TMP_anaerobic,
self.include_aerobic_filter),
'retent': (self.cas_per_tank,),
'recir': (self.L_CSTR,),
'sludge': (),
'naocl': (),
'citric': (),
'bisulfite': (),
}
WWTpump._batch_adding_pump(self, pumps[:-2], ins_dct, type_dct, inputs_dct)
self.AF_pump = self.AF.lift_pump if self.AF else None
self.AeF_pump = self.AeF.lift_pump if self.AeF else None
pipe_ss, pump_ss, hdpe = 0., 0., 0.
for i in pumps:
p = getattr(self, f'{i}_pump')
if p == None: continue
p.simulate()
pipe_ss += p.design_results['Pipe stainless steel [kg]']
pump_ss += p.design_results['Pump stainless steel [kg]']
hdpe += p.design_results['Chemical storage HDPE [m3]']
return pipe_ss, pump_ss, hdpe
# =========================================================================
# _cost
# =========================================================================
def _cost(self):
D, C = self.design_results, self.baseline_purchase_costs
# Concrete and excavation
VEX, VWC, VSC = \
D['Excavation [ft3]'], D['Wall concrete [ft3]'], D['Slab concrete [ft3]']
# 27 is to convert the VEX from ft3 to yard3
C['Reactor excavation'] = VEX/27*8 if self.include_excavation_cost else 0.
C['Wall concrete'] = VWC / 27 * 650
C['Slab concrete'] = VSC / 27 * 350
# Membrane
C['Membrane'] = self.membrane_unit_cost * D['Membrane [m3]'] / _ft2_to_m2
# GAC
# $13.78/kg
C['GAC'] = 13.78 * D['GAC [kg]']
# Packing material
ldpe, hdpe = 0., 0.
for i in (self.AF, self.AeF):
if i is None:
continue
ldpe += i.baseline_purchase_costs['Packing LDPE [m3]']
hdpe += i.baseline_purchase_costs['Packing HDPE [m3]']
# Heat loss, assume air is 17°C, ground is 10°C
T = self.T
if T is None: loss = 0.
else:
N_train, L_CSTR, W_tank, D_tank = \
self.N_train, self.L_CSTR, self.W_tank, self.D_tank
A_W = 2 * (L_CSTR+W_tank) * D_tank
A_F = L_CSTR * W_tank
A_W *= N_train * _ft2_to_m2
A_F *= N_train * _ft2_to_m2
loss = 0.7 * (T-(17+273.15)) * A_W # 0.7 W/m2/°C for wall
loss += 1.7 * (T-(10+273.15)) * A_F # 1.7 W/m2/°C for floor
loss += 0.95 * (T-(17+273.15)) * A_F # 0.95 W/m2/°C for floating cover
loss *= 3.6 # W (J/s) to kJ/hr
# Stream heating
hx = self.heat_exchanger
inf = self._inf
hx_ins0, hx_outs0 = hx.ins[0], hx.outs[0]
hx_ins0.copy_flow(inf)
hx_outs0.copy_flow(inf)
hx_ins0.T = inf.T
hx_outs0.T = T
hx.H = hx_outs0.H + loss # stream heating and heat loss
hx.simulate_as_auxiliary_exchanger(ins=hx.ins, outs=hx.outs)
# Pump
# Note that maintenance and operating costs are included as a lumped
# number in the biorefinery thus not included here
pumps, building = cost_pump(self)
C['Pumps'] = pumps
C['Pump building'] = building if self.include_pump_building_cost else 0.
C['Pump excavation'] = VEX/27*0.3 if self.include_excavation_cost else 0.
# Blower and air pipe
TCFM, CFMB = D['Total air flow [CFM]'], D['Blower capacity [CFM]']
C['Air pipes'], C['Blowers'], C['Blower building'] = self._cost_blower(TCFM, CFMB)
# Degassing membrane
C['Degassing membrane'] = 10000 * D['Degassing membrane']
# Pumping
pumping = 0.
for ID in self._pumps:
p = getattr(self, f'{ID}_pump')
if p is None: continue
pumping += p.power_utility.rate
# Gas
sparging = 0. # submerge design not implemented
degassing = 3 * self.N_degasser # assume each uses 3 kW
self.power_utility.rate = sparging + degassing + pumping
# Called by _cost
def _cost_blower(self, TCFM, CFMB):
AFF = self.AFF
# Air pipes
# Note that the original codes use CFMD instead of TCFM for air pipes,
# but based on the coding they are equivalent
if TCFM <= 1000:
air_pipes = 617.2 * AFF * (TCFM**0.2553)
elif 1000 < TCFM <= 10000:
air_pipes = 1.43 * AFF * (TCFM**1.1337)
else:
air_pipes = 28.59 * AFF * (TCFM**0.8085)
# Blowers
if TCFM <= 30000:
ratio = 0.7 * (CFMB**0.6169)
blowers = 58000*ratio / 100
elif 30000 < TCFM <= 72000:
ratio = 0.377 * (CFMB**0.5928)
blowers = 218000*ratio / 100
else:
ratio = 0.964 * (CFMB**0.4286)
blowers = 480000*ratio / 100
# Blower building
area = 128 * (TCFM**0.256) # building area, [ft2]
building = area * 90 # 90 is the unit price, [USD/ft2]
return air_pipes, blowers, building
### Reactor configuration ###
@property
def reactor_type(self):
"""
[str] Can either be "CSTR" for continuous stirred tank reactor
or "AF" for anaerobic filter.
"""
return self._reactor_type
@reactor_type.setter
def reactor_type(self, i):
if not i.upper() in ('CSTR', 'AF'):
raise ValueError('`reactor_type` can only be "CSTR", or "AF", '
f'not "{i}".')
self._reactor_type = i.upper()
@property
def membrane_configuration(self):
"""[str] Can either be "cross-flow" or "submerged"."""
return self._membrane_configuration
@membrane_configuration.setter
def membrane_configuration(self, i):
i = 'cross-flow' if i.lower() in ('cross flow', 'crossflow') else i
if not i.lower() in ('cross-flow', 'submerged'):
raise ValueError('`membrane_configuration` can only be "cross-flow", '
f'or "submerged", not "{i}".')
self._membrane_configuration = i.lower()
@property
def membrane_type(self):
"""
[str] Can be "hollow fiber" ("submerged" configuration only),
"flat sheet" (either "cross-flow" or "submerged" configuration),
or "multi-tube" ("cross-flow" configuration only).
"""
return self._membrane_type
@membrane_type.setter
def membrane_type(self, i):
i = 'multi-tube' if i.lower() in ('multi tube', 'multitube') else i
if not i.lower() in ('hollow fiber', 'flat sheet', 'multi-tube'):
raise ValueError('`membrane_type` can only be "hollow fiber", '
f'"flat sheet", or "multi-tube", not "{i}".')
self._membrane_type = i.lower()
@property
def membrane_material(self):
"""
[str] Can be any of the plastics ("PES", "PVDF", "PET", "PTFE")
for any of the membrane types ("hollow fiber", "flat sheet", "multi-tube"),
or "sintered steel" for "flat sheet",
or "ceramic" for "multi-tube".
"""
return self._membrane_material
@membrane_material.setter
def membrane_material(self, i):
plastics = ('PES', 'PVDF', 'PET', 'PTFE')
if i.upper() in plastics:
self._membrane_material = i.upper()
elif i.lower() in ('sintered steel', 'ceramic'):
self._membrane_material = i.lower()
else:
raise ValueError(f'`membrane_material` can only be plastics materials '
f'{plastics}, "sintered steel", or "ceramic", not {i}.')
### Reactor/membrane tank ###
@property
def AF(self):
"""[:class:`~.FilterTank`] Anaerobic filter tank."""
if self.reactor_type == 'CSTR':
return None
return self._AF
@property
def AeF(self):
"""[:class:`~.FilterTank`] Aerobic filter tank."""
if not self.include_aerobic_filter:
return None
return self._AeF
@property
def N_train(self):
"""[int] Number of treatment train."""
if not hasattr(self, '_N_train'):
return self._N_train_min
return self._N_train
@N_train.setter
def N_train(self, i):
self._N_train = math.ceil(i)
@property
def cas_per_tank_spare(self):
"""[int] Number of spare cassettes per train."""
return self._cas_per_tank_spare
@cas_per_tank_spare.setter
def cas_per_tank_spare(self, i):
self._cas_per_tank_spare = math.ceil(i)
@property
def mod_per_cas_range(self):
"""
[tuple] Range (min, max) of the number of membrane modules per cassette
for the current membrane type.
"""
return self._mod_per_cas_range
@mod_per_cas_range.setter
def mod_per_cas_range(self, i):
self._mod_per_cas_range[self.membrane_type] = \
tuple(math.floor(i[0]), math.floor(i[1]))
@property
def mod_per_cas(self):
"""
[float] Number of membrane modules per cassette for the current membrane type.
"""
return self._mod_per_cas or self._mod_per_cas_range[self.membrane_type][0]
@property
def cas_per_tank_range(self):
"""
[tuple] Range (min, max) of the number of membrane cassette per tank
(same for all membrane types).
"""
return self._cas_per_tank_range
@cas_per_tank_range.setter
def cas_per_tank_range(self, i):
self._cas_per_tank_range = tuple(math.floor(i[0]), math.floor(i[1]))
@property
def cas_per_tank(self):
"""
[float] Number of membrane cassettes per tank for the current membrane type.
"""
return self._cas_per_tank or self._cas_per_tank_range[0]
@property
def N_mod_tot(self):
"""[int] Total number of memberane modules."""
return self.N_train * self.cas_per_tank * self.mod_per_cas
@property
def mod_surface_area(self):
"""
[float] Surface area of the membrane for the current membrane type, [m2/module].
Note that one module is one sheet for plat sheet and one tube for multi-tube.
"""
return self._mod_surface_area[self.membrane_type]
@mod_surface_area.setter
def mod_surface_area(self, i):
self._mod_surface_area[self.membrane_type] = float(i)
@property
def L_CSTR(self):
"""[float] Length of the CSTR tank, [ft]."""
if self.reactor_type == 'AF':
return 0
return self._inf.F_vol/_ft3_to_m3*self.HRT/(self.N_train*self.W_tank*self.D_tank)
@property
def L_membrane_tank(self):
"""[float] Length of the membrane tank, [ft]."""
return math.ceil((self.cas_per_tank+self.cas_per_tank_spare)*3.4)
@property
def W_tank(self):
"""[float] Width of the reactor/membrane tank (same value), [ft]."""
return self._W_tank
@W_tank.setter
def W_tank(self, i):
self._W_tank = float(i)
@property
def D_tank(self):
"""[float] Depth of the reactor/membrane tank (same value), [ft]."""
return self._D_tank
@D_tank.setter
def D_tank(self, i):
self._D_tank = float(i)
@property
def W_dist(self):
"""[float] Width of the distribution channel, [ft]."""
return self._W_dist
@W_dist.setter
def W_dist(self, i):
self._W_dist = float(i)
@property
def W_eff(self):
"""[float] Width of the effluent channel, [ft]."""
return self._W_eff
@W_eff.setter
def W_eff(self, i):
self._W_eff = float(i)
@property
def t_wall(self):
"""
[float] Concrete wall thickness, [ft].
Minimum of 1 ft with 1 in added for every ft of depth over 12 ft.
"""
return 1 + max(self.D_tank-12, 0)/12
@property
def t_slab(self):
"""
[float] Concrete slab thickness, [ft].
2 in thicker than the wall thickness.
"""
return self.t_wall+2/12
@property
def V_tot(self):
"""[float] Total volume of the unit, [ft3]."""
return self.D_tank*self.W_tank*self.L_CSTR*self.N_train
@property
def OLR(self):
"""[float] Organic loading rate, [kg COD/m3/hr]."""
return self.compute_COD(self.ins[0])*self.ins[0].F_vol/(self.V_tot*_ft3_to_m3)
### Pump/blower ###
@property
def N_blower(self):
"""
[int] Number of blowers needed for gas sparging
(not needed for some designs).
Note that this is not used in costing
(the cost is estimated based on the total sparging gas need).
"""
if not self.add_GAC and self.membrane_configuration=='submerged':
return self._N_blower
return 0
@property
def N_degasser(self):
"""
[int] Number of degassing membrane needed for dissolved biogas removal
(optional).
"""
if self.include_degassing_membrane:
return math.ceil(self.Q_cmd/24/30) # assume each can hand 30 m3/d of influent
return 0
@property
def W_PB(self):
"""[float] Width of the pump building, [ft]."""
if self.membrane_configuration == 'submerged':
N = self.cas_per_tank
else: # cross-flow
N = math.ceil(self.L_CSTR/((1+8/12)+(3+4/12)))
if 0 <= N <= 10:
W_PB = 27 + 4/12
elif 11 <= N <= 16:
W_PB = 29 + 6/12
elif 17 <= N <= 22:
W_PB = 31 + 8/12
elif 23 <= N <= 28:
W_PB = 35
elif N >= 29:
W_PB = 38 + 4/12
else:
W_PB = 0
return W_PB
@property
def L_BB(self):
"""[float] Length of the blower building, [ft]."""
if self.membrane_configuration == 'submerged':
return (69+6/12) if self.cas_per_tank<=18 else (76 + 8/12)
return 0
@property
def W_BB(self):
"""[float] Width of the blower building, [ft]."""
if self.membrane_configuration == 'submerged':
return (18+8/12) if self.cas_per_tank<=18 else 22
return 0
### Wet well (submerged only) ###
@property
def L_well(self):
"""
[float] Length of the wet well, [ft].
Only needed for submerged configuration.
"""
return self._L_well if self.membrane_configuration == 'submerged' else 0
@L_well.setter
def L_well(self, i):
self._L_well = float(i)
@property
def W_well(self):
"""
[float] Width of the wet well, [ft].
Only needed for submerged configuration.
"""
return self._W_well if self.membrane_configuration == 'submerged' else 0
@W_well.setter
def W_well(self, i):
self._W_well = float(i)
@property
def D_well(self):
"""
[float] Depth of the wet well, [ft].
Only needed for submerged configuration.
"""
return self._D_well if self.membrane_configuration == 'submerged' else 0
@D_well.setter
def D_well(self, i):
self._D_well = float(i)
### Excavation ###
@property
def excav_slope(self):
"""[float] Slope for excavation (horizontal/vertical)."""
return self._excav_slope
@excav_slope.setter
def excav_slope(self, i):
self._excav_slope = float(i)
@property
def constr_access(self):
"""[float] Extra room for construction access, [ft]."""
return self._constr_access
@constr_access.setter
def constr_access(self, i):
self._constr_access = float(i)
### Operation-related parameters ###
@property
def Q_mgd(self):
"""
[float] Influent volumetric flow rate in million gallon per day, [mgd].
"""
return self.ins[0].F_vol*_m3_to_gal*24/1e6
@property
def Q_gpm(self):
"""[float] Influent volumetric flow rate in gallon per minute, [gpm]."""
return self.Q_mgd*1e6/24/60
@property
def Q_cmd(self):
"""
[float] Influent volumetric flow rate in cubic meter per day, [cmd].
"""
return self.Q_mgd *1e6/_m3_to_gal # [m3/day]
@property
def Q_cfs(self):
"""[float] Influent volumetric flow rate in cubic feet per second, [cfs]."""
return self.Q_mgd*1e6/24/60/60/_ft3_to_gal
@property
def HRT(self):
"""
[float] Hydraulic retention time, [hr].
"""
return self._HRT
@HRT.setter
def HRT(self, i):
self._HRT = float(i)
@property
def recir_ratio(self):
"""
[float] Internal recirculation ratio, will be updated in simulation
if the originally set ratio is not adequate for the desired flow
required by GAC (if applicable).
"""
return self._recir_ratio
@recir_ratio.setter
def recir_ratio(self, i):
self._recir_ratio = float(i)
@property
def J_max(self):
"""[float] Maximum membrane flux, [L/m2/hr]."""
return self._J_max
@J_max.setter
def J_max(self, i):
self._J_max = float(i)
@property
def J(self):
"""[float] Membrane flux, [L/m2/hr]."""
# Based on the flux of one train being offline
SA = (self.N_train-1) * self.cas_per_tank * self.mod_per_cas * self.mod_surface_area
return self._inf.F_vol*1e3/SA # 1e3 is conversion from m3 to L
@property
def TMP_anaerobic(self):
"""[float] Transmembrane pressure in the anaerobic reactor, [psi]."""
return self._TMP_dct[self.membrane_configuration]
@TMP_anaerobic.setter
def TMP_anaerobic(self, i):
self._TMP_dct[self.membrane_configuration] = float(i)
@property
def TMP_aerobic(self):
"""
[float] Transmembrane pressure in the aerobic filter, [psi].
Defaulted to half of the reactor TMP.
"""
if not self._include_aerobic_filter:
return 0.
else:
return self._TMP_aerobic or self._TMP_dct[self.membrane_configuration]/2
@TMP_aerobic.setter
def TMP_aerobic(self, i):
self._TMP_aerobic = float(i)
@property
def SGD(self):
"""[float] Specific gas demand, [m3 gas/m2 membrane area/h]."""
return self._SGD
@SGD.setter
def SGD(self, i):
self._SGD = float(i)
@property
def AFF(self):
"""
[float] Air flow fraction, used in air pipe costing.
The default value is calculated as STE/6
(STE stands for standard oxygen transfer efficiency, and default STE is 20).
If using different STE value, AFF should be 1 if STE/6<1
and 3.33 if STE/6>1.
"""
return self._AFF
@AFF.setter
def AFF(self, i):
self._AFF = float(i)
@property
def v_cross_flow(self):
"""
[float] Cross-flow velocity, [m/s].
"""
return self._v_cross_flow if self.membrane_configuration=='cross-flow' else 0
@v_cross_flow.setter
def v_cross_flow(self, i):
self._v_cross_flow = float(i)
@property
def v_GAC(self):
"""
[float] Upflow velocity for GAC bed expansion, [m/hr].
"""
return self._v_GAC if self.add_GAC==True else 0
@v_GAC.setter
def v_GAC(self, i):
self._v_GAC = float(i)
@property
def biodegradability(self):
"""
[float of dict] Biodegradability of chemicals,
when shown as a float, all biodegradable chemicals are assumed to have
the same degradability.
"""
return self._biodegradability
@biodegradability.setter
def biodegradability(self, i):
if not isinstance(i, dict):
if not 0<=i<=1:
raise ValueError('`biodegradability` should be within [0, 1], '
f'the input value {i} is outside the range.')
self._biodegradability = dict.fromkeys(self.chemicals.IDs, i)
else:
for k, v in i.items():
if not 0<=v<=1:
raise ValueError('`biodegradability` should be within [0, 1], '
f'the input value for chemical "{k}" is '
'outside the range.')
self._biodegradability = dict.fromkeys(self.chemicals.IDs, i).update(i)
self._refresh_rxns()
@property
def sludge_conc(self):
"""Concentration of biomass ("WWTsludge") in the waste sludge, [g/L]."""
return self._sludge_conc
@sludge_conc.setter
def sludge_conc(self, i):
self._sludge_conc = i
@property
def i_rm(self):
"""[:class:`np.array`] Removal of each chemical in this reactor."""
return self._i_rm
@property
def split(self):
"""Component-wise split to the treated water."""
return self._split
@split.setter
def split(self, i):
self._split = i
self._isplit = self.chemicals.isplit(i, order=None)
@property
def biogas_rxns(self):
"""
[:class:`tmo.ParallelReaction`] Biogas production reactions.
"""
return self._biogas_rxns
@property
def growth_rxns(self):
"""
[:class:`tmo.ParallelReaction`] Biomass (WWTsludge) growth reactions.
"""
return self._growth_rxns
@property
def organic_rm(self):
"""[float] Overall organic (COD) removal rate."""
Qi, Qe = self._inf.F_vol, self.outs[1].F_vol
Si, Se = self.compute_COD(self._inf), self.compute_COD(self.outs[1])
return 1 - Qe*Se/(Qi*Si)