# -*- 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.
from math import pi, ceil
from warnings import warn
import biosteam as bst
from thermosteam.reaction import ParallelReaction as PRxn
from . import (
default_insolubles,
InternalCirculationRx, WWTpump,
compute_stream_COD, get_digestion_rxns, get_split_dct, cost_pump,
)
__all__ = ('PolishingFilter',)
_ft_to_m = 0.3047 # 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('gallon')
_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')
_d_to_A = lambda d: pi/4*(d**2)
_A_to_d = lambda A: ((4*A)/pi)**0.5
# %%
[docs]
class PolishingFilter(bst.Unit):
"""
A superclass for anaerobic and aerobic polishing as in
Shoener et al. [6]_ Some assumptions adopted from Humbird et al. [2]_
Parameters
----------
ins :
* [0] influent
* [1] recycle
* [2] air (optional & when aerobic).
outs :
* [0] biogas (when anaerobic)
* [1] effluent
* [2] waste sludge
* [3] air (optional & when aerobic).
filter_type : str
Can either be "anaerobic" or "aerobic".
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.
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.
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".
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.
"""
_N_ins = 3 # influent, recycle, air (optional)
_N_outs = 4 # biogas (optional), effluent, waste sludge, air (optional)
_N_filter_min = 2
_d_max = 12
_t_wall = 8/12
_t_slab = 1
_excav_slope = 1.5
_constr_access = 3
_sludge_conc = 10.5
# Other equipment
auxiliary_unit_names = ('heat_exchanger',)
_pumps = ('lift', 'recir', 'eff', 'sludge')
def _init(self,
filter_type='aerobic',
OLR=(0.5+4)/2/24, # from the 0.5-4 kg/m3/d uniform range in ref [1]
HLR=(0.11+0.44)/2, # from the 0.11-0.44 uniform range in ref [1]
X_decomp=0.74, X_growth=0.22, # X_decomp & X_growth from ref[2]
split={}, T=30+273.15,
include_degassing_membrane=False,
include_pump_building_cost=False,
include_excavation_cost=False,
hxn_ok=False
):
self.filter_type = filter_type
self.OLR = OLR
self.HLR = HLR
self.X_decomp = X_decomp
self.X_growth = X_growth
self.split = split if split else get_split_dct(self.chemicals)
self.T = T
self.include_degassing_membrane = include_degassing_membrane
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')
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.hxn_ok = hxn_ok
self._refresh_rxns()
def _refresh_rxns(self, X_decomp=None, X_growth=None):
X_decomp = X_decomp if X_decomp else self.X_decomp
X_growth = X_growth if X_growth else self.X_growth
self._growth_rxns = growth_rxns = \
get_digestion_rxns(self.ins[0], 1., 0., X_growth, 'WWTsludge')
if self.filter_type == 'anaerobic':
self._decomp_rxns = get_digestion_rxns(self.ins[0], 1.,
X_decomp, 0., 'WWTsludge')
else: # aerobic
decomp_rxns = []
get = getattr
chems = self.chemicals
for chem_ID in growth_rxns.reactants:
decomp_rxns.append(get(chems, chem_ID).get_combustion_reaction())
self._decomp_rxns = PRxn(decomp_rxns)
self._decomp_rxns.X *= X_decomp
self._i_rm = self._decomp_rxns.X + self._growth_rxns.X
@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)
def _run(self):
raw, recycled, air_in = self.ins
biogas, eff, waste, 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)
self.growth_rxns(mixed.mol)
self.decomp_rxns.force_reaction(mixed.mol)
mixed.split_to(eff, waste, self._isplit.data)
sludge_conc = self._sludge_conc
insolubles = tuple(i.ID for i in self.chemicals if i.ID in default_insolubles)
m_insolubles = waste.imass[insolubles].sum()
if m_insolubles/waste.F_vol <= sludge_conc:
diff = waste.ivol['Water'] - m_insolubles/sludge_conc
waste.ivol['Water'] = m_insolubles/sludge_conc
eff.ivol['Water'] += diff
biogas.phase = air_in.phase = air_out.phase = 'g'
if mixed.imol['O2'] < 0:
air_in.imol['O2'] = - mixed.imol['O2']
air_in.imol['N2'] = - 0.79/0.21 * mixed.imol['O2']
mixed.imol['O2'] = 0
else:
air_in.empty()
if self.filter_type == 'anaerobic':
degassing(eff, biogas)
degassing(waste, biogas)
air_in.empty()
air_out.empty()
else:
biogas.empty()
air_out.empty()
degassing(eff, air_out)
degassing(waste, air_out)
air_out.imol['N2'] += air_in.imol['N2']
air_out.imol['O2'] += air_in.imol['O2']
self._recir_ratio = None
if self.T is not None: biogas.T = eff.T = waste.T = air_out.T = self.T
def _design(self):
### Concrete and excavation ###
D = self.design_results
func = self._design_anaerobic if self.filter_type=='anaerobic' \
else self._design_aerobic
V, VWC, VSC, VEX = func()
D['Volume [ft3]'] = V
D['Wall concrete [ft3]'] = VWC
D['Slab concrete [ft3]'] = VSC
D['Excavation [ft3]'] = VEX
### Pumps ###
('lift', 'recir', 'eff', 'sludge')
ins_dct = {
'lift': self.ins[0].proxy(),
'recir': self.ins[1].proxy(),
'eff': self.outs[1].proxy(),
'sludge': self.outs[2].proxy(),
}
type_dct = {
'lift': 'lift',
'recir': 'recirculation_AF',
'eff': 'retentate_AF',
'sludge': 'sludge',
}
inputs_dct = {
'lift': (self.N_filter, self.D),
'recir': (self.N_filter, self.d, self.D),
'eff': (self.N_filter, self.D),
'sludge': (),
}
WWTpump._batch_adding_pump(self, self._pumps, ins_dct, type_dct, inputs_dct)
pipe_ss, pump_ss = 0., 0.
for i in self._pumps:
p = getattr(self, f'{i}_pump')
p.simulate()
pipe_ss += p.design_results['Pipe stainless steel [kg]']
pump_ss += p.design_results['Pump stainless steel [kg]']
### Packing ###
# Assume 50%/50% vol/vol LDPE/HDPE
# 0.9 is void fraction, usually 85% - 95% for plastic packing media
# 925 is density of LDPE (910-940), [kg/m3] (not used)
# 950 is density of LDPE (930-970), [kg/m3] (not used)
# M_LDPE_kg = 0.5 * (1-0.9) * 925 * V_m
# M_HDPE_kg = 0.5 * (1-0.9) * 950 * V_m
D['Packing LDPE [m3]'] = D['Packing HDPE [m3]'] = 0.05 * V
### Degassing ###
D['Degassing membrane'] = self.N_degasser
def _design_aerobic(self):
inf, N, SL, CA \
= self._inf, self._N_filter_min, self.excav_slope, self.constr_access
Q = inf.F_vol
### Concrete ###
get_V = lambda N: ((Q/N)*self.compute_COD(inf)) / self.OLR # m3
get_A = lambda N: Q/N/self.HLR
V, A = get_V(N), get_A(N)
d = _A_to_d(A)
D = V / d # D is depth
# Check if more than one filter is needed
while d > self.d_max:
N += 1
V, A = get_V(N), get_A(N)
d = _A_to_d(A)
D = V / d
self._OLR = ((Q/N)*self.compute_COD(inf)) / V
V_ft3 = V / _ft3_to_m3 * N
d_ft = d / _ft_to_m
D_ft = D / _ft_to_m
self._N_filter, self._d, self._D = N, d, D_ft
# Volume of wall/slab concrete, [ft3]
# 8/12 is wall thickness, 3 is freeboard
VWC = self.t_wall * pi * d_ft * (D_ft+3)
VWC *= N
# 1 is slab thickness
VSC = 2 * 1 * _d_to_A(d_ft)
VSC *= N
### Excavation ###
# 50/30/10 are building length/width/depth, [ft]
L_B, W_B, diff = (50+2*CA), (30+2*CA), (10*SL)
Area_B = L_B * W_B
Area_T = (L_B+diff) * (W_B+diff)
VEX = 0.5 * (Area_B+Area_T) * 10 # [ft3]
return V_ft3, VWC, VSC, VEX
# def _design_anaerobic_filter(
# self, Q_mgd,
# Ss, # readily biodegradable (soluble) substrate concentration, [kg COD/m3]
# Sp, # slowly biodegradable (particulate) substrate concentration, [kg COD/m3]
# OLR_AF, # organic loading rate, [kg-COD/m3/day]
# HL_AF, # hydraulic loading rate, [m3/m2/hr]
# R_AF # recirculation ratio
# ):
# ### Filter material ###
# N_AF = 2
# Q_cmd = self.Q_cmd
# # Volume of the filter packing media in each filter, [m3]
# V_m_AF = (Q_cmd/N_AF) * (Ss+Sp) / OLR_AF
# # Diameter (d) / depth (D) of each filter, [m]
# d_AF, D_AF = _get_d_AF(Q_cmd, R_AF, N_AF, HL_AF, V_m_AF)
# while D_AF > 6: # assumed maximum depth assumption, [m]
# R_AF = R_AF + 0.1;
# d_AF, D_AF = _get_d_AF(Q_cmd, R_AF, N_AF, HL_AF, V_m_AF)
# while d_AF > 12: # assumed maximum diameter, [m]
# N_AF = N_AF + 1;
# d_AF, D_AF = _get_d_AF(Q_cmd, R_AF, N_AF, HL_AF)
# # Unit conversion
# d_AF /= _ft_to_m # [ft]
# D_AF /= _ft_to_m # [ft]
# V_m_AF /= _ft3_to_m3 # [ft3]
# ### Concrete material ###
# # External wall concrete, [ft3]
# # 6/12 is wall thickness and 3 is freeboard
# VWC_AF = N_AF * 6/12 * pi * d_AF * (D_AF+3)
# VWC_AF *= N_AF
# # Floor slab concrete, [ft3]
# # 8/12 is slab thickness
# VSC_AF = _d_to_A(d_AF)+ 8/12 * _d_to_A(d_AF)
# VSC_AF *= N_AF
# ### Excavation ###
# SL = 1.5 # slope = horizontal/vertical
# CA = 3 # construction Access, [ft]
# # Excavation of pump building
# PBL, PBW, PBD = 50, 30, 10 # pump building length, width, depth, [ft]
# Area_B_P = (PBL+2*CA) * (PBW+2*CA) # bottom area of frustum, [ft2]
# Area_T_P = (PBL+2*CA+PBW*SL) * (PBW+2*CA+PBD*SL) # top area of frustum, [ft2]
# VEX_PB = 0.5 * (Area_B_P+Area_T_P) * PBD # total volume of excavation, [ft3]
# return N_AF, d_AF, D_AF, V_m_AF, VWC_AF, VWC_AF, VEX_PB
def _cost(self):
# Concrete and excavation
D, C, F_BM, lifetime = self.design_results, self.baseline_purchase_costs, \
self.F_BM, self._default_equipment_lifetime
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['Filter tank excavation'] = VEX/27*8 if self.include_excavation_cost else 0.
C['Wall concrete'] = VWC / 27 * 650
C['Slab concrete'] = VSC / 27 * 350
# Packing material
# 195 is the cost of both LDPE and HDPE in $/m3
C['Packing LDPE'] = 195 * D['Packing LDPE [m3]']
C['Packing HDPE'] = 195 * D['Packing HDPE [m3]']
# 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.
F_BM['Pumps'] = F_BM['Pump building'] = F_BM['Pump excavation'] = \
1.18 * (1+0.007) # 0.007 is for miscellaneous costs
lifetime['Pumps'] = 15
# Degassing membrane
C['Degassing membrane'] = 10000 * D['Degassing membrane']
# Set bare module factor to 1 if not otherwise provided
for k in C.keys():
F_BM[k] = 1 if not F_BM.get(k) else F_BM.get(k)
# Heat loss, assume air is 17°C, ground is 10°C
T = self.T
if T is None: loss = 0.
else:
N_filter, d, D = self.N_filter, self.d, self.D
A_W = pi * d * D
A_F = _d_to_A(d)
A_W *= N_filter * _ft2_to_m2
A_F *= N_filter * _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 *= 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, hxn_ok=self.hxn_ok)
# Pumping
pumping = 0.
for ID in self._pumps:
p = getattr(self, f'{ID}_pump')
pumping += p.power_utility.rate
# Degassing
degassing = 3 * self.N_degasser # assume each uses 3 kW
self.power_utility.rate = pumping + degassing
@property
def filter_type(self):
"""[str] Can either be "anaerobic" or "aerobic"."""
return self._filter_type
@filter_type.setter
def filter_type(self, i):
if i.lower() in ('anaerobic', 'aerobic'):
self._filter_type = i.lower()
else:
raise ValueError('`filter_type` can only be "anaerobic" or "aerobic", '
f'not "{i}".')
@property
def OLR(self):
"""[float] Organic loading rate, [kg COD/m3/hr]."""
return self._OLR
@OLR.setter
def OLR(self, i):
if i < 0:
raise ValueError('`OLR` should be >=0, '
f'the input value {i} is outside the range.')
self._OLR = i
@property
def HLR(self):
"""[float] Hydraulic loading rate, [m3/m2/hr]."""
return self._HLR
@HLR.setter
def HLR(self, i):
self._HLR = i
@property
def d_max(self):
"""[float] Maximum filter diameter, [m]."""
return self._d_max
@d_max.setter
def d_max(self, i):
self._d_max = i
@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)
@property
def N_filter(self):
"""[int] Number of filter tanks."""
return self._N_filter
@property
def d(self):
"""[float] Diameter of the filter tank, [ft]."""
return self._d
@property
def D(self):
"""[float] Depth of the filter tank, [ft]."""
return self._D
@property
def t_wall(self):
"""[float] Concrete wall thickness, [ft]."""
return self._t_wall
@t_wall.setter
def t_wall(self, i):
self._t_wall = float(i)
@property
def t_slab(self):
"""[float] Concrete slab thickness, [ft]."""
return self._t_slab
@t_slab.setter
def t_slab(self, i):
self._t_slab = float(i)
@property
def N_degasser(self):
"""
[int] Number of degassing membrane needed for dissolved biogas removal
(optional).
"""
if self.include_degassing_membrane:
if self.filter_type=='aerobic':
warn('No degassing membrane needed for when `filter_type` is "aerobic".')
return 0
return ceil(self.Q_cmd/24/30) # assume each can hand 30 m3/d of influent
return 0
@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 recir_ratio(self):
"""[float] Internal recirculation ratio."""
return self._recir_ratio or self.ins[1].F_vol/self.ins[0].F_vol
@recir_ratio.setter
def recir_ratio(self, i):
self._recir_ratio = float(i)
@property
def i_rm(self):
"""[:class:`np.array`] Removal of each chemical in this filter tank."""
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 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 X_decomp(self):
"""
[float] Fraction of the influent COD converted to biogas
(`filter_type`=="anaerobic") or CO2 (`filter_type`=="aerobic").
"""
return self._X_decomp
@X_decomp.setter
def X_decomp(self, i):
if not 0 <= i <= 1:
raise ValueError('`X_decomp` should be within [0, 1], '
f'the input value {i} is outside the range.')
self._X_decomp = i
@property
def X_growth(self):
"""
[float] Fraction of the influent COD converted to biomass growth.
"""
return self._X_growth
@X_growth.setter
def X_growth(self, i):
if not 0 <= i <= 1:
raise ValueError('`X_growth` should be within [0, 1], '
f'the input value {i} is outside the range.')
self._X_growth = i
@property
def decomp_rxns(self):
"""
[:class:`tmo.ParallelReaction`] Organics to biogas (`filter_type`=="anaerobic")
or CO2 (`filter_type`=="aerobic") reactions.
"""
return self._decomp_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)
