Sludge Treatment¶
QSDsan: Quantitative Sustainable Design for sanitation and resource recovery systems
This module is developed by:
Saumitra Rai <raisaumitra9@gmail.com>
Joy Zhang <joycheung1994@gmail.com>
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.sanunits._sludge_treatment.Centrifuge(ID='', ins: Sequence[AbstractStream] | None = None, outs: Sequence[AbstractStream] | None = (), thermo=None, isdynamic=False, init_with='WasteStream', F_BM_default={'Bowl stainless steel': 1, 'Conveyor': 1, 'Pump': 1.1800826, 'Pump building': 1.1800826, 'Pumps': 1, 'Scraper': 1, 'Slab concrete': 1.0, 'Wall concrete': 1.0, 'Wall stainless steel': 1.0, 'v notch weir': 1}, thickener_perc=28, TSS_removal_perc=98, solids_feed_rate=70, g_factor=2500, rotational_speed=2500, LtoD=4, F_BM={'Bowl stainless steel': 1, 'Conveyor': 1, 'Pump': 1.1800826, 'Pump building': 1.1800826, 'Pumps': 1, 'Scraper': 1, 'Slab concrete': 1.0, 'Wall concrete': 1.0, 'Wall stainless steel': 1.0, 'v notch weir': 1}, polymer_dosage=20, h_cylindrical=2, h_conical=1, **kwargs)¶
Centrifuge based on BSM2 Layout.
- Parameters:
ID (str) – ID for the Dewatering Unit. The default is ‘’.
ins (class:WasteStream) – Influent to the Dewatering Unit. Expected number of influent is 1.
outs (class:WasteStream) – Treated effluent and sludge.
thickener_perc (float) – The percentage of Suspended Sludge in the underflow of the dewatering unit.[1]
TSS_removal_perc (float) – The percentage of suspended solids removed in the dewatering unit.[1]
solids_feed_rate (float) – Rate of solids processed by one centrifuge in dry tonne per day (dtpd). Default value is 150 dtpd. [6]
g_factor (float) – Factor by which g (9.81 m/s2) is multiplied to obtain centrifugal acceleration. g_factor typically lies between 1500 and 3000. centrifugal acceleration = g * g_factor = k * (RPM)^2 * diameter [3]
rotational_speed (float) – rotational speed of the centrifuge in rpm. Typical rpm is between 2000-3000 rpm [MOP-8, PAGE 1733]
LtoD (The ratio of length to diameter of the centrifuge.) – The value typically lies between 3-4. [4]
polymer_dosage (float) – mass of polymer utilised (lb) per tonne of dry solid waste (lbs/tonne).[5] Depends on the type of influents, please refer to [5] for appropriate values. Default value of 20 lbs/tonne is taken from [5], based on Primary + WAS aerated undigested value.
h_cylindrical (float) – length of cylindrical portion of dewatering unit.
h_conical (float) – length of conical portion of dewatering unit.
References
[1] Gernaey, Krist V., Ulf Jeppsson, Peter A. Vanrolleghem, and John B. Copp. Benchmarking of control strategies for wastewater treatment plants. IWA publishing, 2014.
[2] Metcalf, Leonard, Harrison P. Eddy, and Georg Tchobanoglous. Wastewater engineering: treatment, disposal, and reuse. Vol. 4. New York: McGraw-Hill, 1991.
[3] Design of Municipal Wastewater Treatment Plants: WEF Manual of Practice No. 8 ASCE Manuals and Reports on Engineering Practice No. 76, Fifth Edition.
[5] United States Environmental Protection Agency (EPA) ‘Biosolids Technology Fact Sheet Centrifuge Thickening and Dewatering’
[6] San Diego (.gov) Chapter - 3 ‘Solids Treatment Facility’ (https://www.sandiego.gov/sites/default/files/legacy/mwwd/pdf/mbc/chapterthree.pdf)
- line: str = 'Centrifuge'¶
class-attribute Name denoting the type of Unit class. Defaults to the class name of the first child class
- class qsdsan.sanunits._sludge_treatment.Incinerator(ID='', ins: Sequence[AbstractStream] | None = None, outs: Sequence[AbstractStream] | None = (), thermo=None, isdynamic=False, init_with='WasteStream', F_BM_default=None, process_efficiency=0.9, calorific_value_sludge=12000, calorific_value_fuel=50000, ash_component_ID='X_Ig_ISS', nitrogen_ID='S_N2', water_ID='H2O', carbon_dioxide_ID='S_CO2', **kwargs)¶
Fluidized bed incinerator.
- Parameters:
ID (str) – ID for the Incinerator Unit. The default is ‘’.
ins (class:WasteStream) – Influent to the Incinerator Unit. Expected number of influent streams are 3. Please remember the order of influents as {wastestream, air, fuel}
outs (class:WasteStream) – Flue gas and ash.
process_efficiency (float) – The process efficiency of the incinerator unit. Expected value between 0 and 1.
calorific_value_sludge (float) – The calorific value of influent sludge in KJ/kg. The default value used is 12000 KJ/kg.
calorific_value_fuel (float) – The calorific value of fuel employed for combustion in KJ/kg. The default fuel is natural gas with calorific value of 50000 KJ/kg.
Examples
>>> import qsdsan as qs >>> cmps = qs.Components.load_default() >>> CO2 = qs.Component.from_chemical('S_CO2', search_ID='CO2', ... particle_size='Soluble', ... degradability='Undegradable', ... organic=False) >>> cmps_test = qs.Components([cmps.S_F, cmps.S_NH4, cmps.X_OHO, cmps.H2O, ... cmps.S_CH4, cmps.S_O2, cmps.S_N2, cmps.S_H2, ... cmps.X_Ig_ISS, CO2]) >>> cmps_test.default_compile() >>> qs.set_thermo(cmps_test) >>> ws = qs.WasteStream('ws', S_F=10, S_NH4=20, X_OHO=15, H2O=1000) >>> natural_gas = qs.WasteStream('nat_gas', phase='g', S_CH4=1000) >>> air = qs.WasteStream('air', phase='g', S_O2=210, S_N2=780, S_H2=10) >>> from qsdsan.sanunits import Incinerator >>> Inc = Incinerator(ID='Inc', ins= (ws, air, natural_gas), ... outs=('flu_gas', 'ash'), ... isdynamic=False) >>> Inc.simulate() >>> Inc.show() Incinerator: Inc ins... [0] ws phase: 'l', T: 298.15 K, P: 101325 Pa flow (g/hr): S_F 1e+04 S_NH4 2e+04 X_OHO 1.5e+04 H2O 1e+06 WasteStream-specific properties: pH : 7.0 Alkalinity : 2.5 mg/L COD : 23873.0 mg/L BOD : 14963.2 mg/L TC : 8298.3 mg/L TOC : 8298.3 mg/L TN : 20363.2 mg/L TP : 367.6 mg/L TK : 68.3 mg/L TSS : 11124.4 mg/L [1] air phase: 'g', T: 298.15 K, P: 101325 Pa flow (g/hr): S_O2 2.1e+05 S_N2 7.8e+05 S_H2 1e+04 WasteStream-specific properties: None for non-liquid waste streams [2] nat_gas phase: 'g', T: 298.15 K, P: 101325 Pa flow (g/hr): S_CH4 1e+06 WasteStream-specific properties: None for non-liquid waste streams outs... [0] flu_gas phase: 'g', T: 298.15 K, P: 101325 Pa flow (g/hr): H2O 1e+06 S_N2 7.8e+05 S_CO2 2.67e+05 WasteStream-specific properties: None for non-liquid waste streams [1] ash phase: 's', T: 298.15 K, P: 101325 Pa flow (g/hr): X_Ig_ISS 2.37e+05 WasteStream-specific properties: None for non-liquid waste streams
References
[1] Khuriati, A., P. Purwanto, H. S. Huboyo, Suryono Sumariyah, S. Suryono, and A. B. Putranto. “Numerical calculation based on mass and energy balance of waste incineration in the fixed bed reactor.” In Journal of Physics: Conference Series, vol. 1524, no. 1, p. 012002. IOP Publishing, 2020.
[2] Omari, Arthur, Karoli N. Njau, Geoffrey R. John, Joseph H. Kihedu, and Peter L. Mtui. “Mass And Energy Balance For Fixed Bed Incinerators A case of a locally designed incinerator in Tanzania.”
- property calorific_value_fuel¶
Calorific value of fuel in KJ/kg.
- property calorific_value_sludge¶
Calorific value of sludge in KJ/kg.
- line: str = 'Incinerator'¶
class-attribute Name denoting the type of Unit class. Defaults to the class name of the first child class
- property process_efficiency¶
Process efficiency of incinerator.
- class qsdsan.sanunits._sludge_treatment.Thickener(ID='', ins: Sequence[AbstractStream] | None = None, outs: Sequence[AbstractStream] | None = (), thermo=None, isdynamic=False, init_with='WasteStream', F_BM_default={'Bowl stainless steel': 1, 'Conveyor': 1, 'Pump': 1.1800826, 'Pump building': 1.1800826, 'Pumps': 1, 'Scraper': 1, 'Slab concrete': 1.0, 'Wall concrete': 1.0, 'Wall stainless steel': 1.0, 'v notch weir': 1}, thickener_perc=7, TSS_removal_perc=98, solids_loading_rate=4, h_thickener=4, downward_flow_velocity=36, F_BM={'Bowl stainless steel': 1, 'Conveyor': 1, 'Pump': 1.1800826, 'Pump building': 1.1800826, 'Pumps': 1, 'Scraper': 1, 'Slab concrete': 1.0, 'Wall concrete': 1.0, 'Wall stainless steel': 1.0, 'v notch weir': 1}, **kwargs)¶
Thickener based on BSM2 Layout.
- Parameters:
ID (str) – ID for the Thickener. The default is ‘’.
ins (class:WasteStream) – Influent to the clarifier. Expected number of influent is 1.
outs (class:WasteStream) – Thickened sludge and effluent.
thickener_perc (float) – The percentage of solids in the underflow of the thickener.[1]
TSS_removal_perc (float) – The percentage of suspended solids removed in the thickener.[1]
solids_loading_rate (float) – Solid loading rate in the thickener in [(kg/hr)/m2]. Default is 4 kg/(m2*hr) [2] If the thickener is treating: Only Primary clarifier sludge, then expected range: 4-6 kg/(m2*hr) Only WAS (treated with air or oxygen): 0.5-1.5 kg/(m2*hr) Primary clarifier sludge + WAS: 1.5-3.5 kg/(m2/hr)
float (h_thickener =) – Side water depth of the thickener. Typically lies between 3-4 m. [2] Height of tank forming the thickener.
downward_flow_velocity (float, optional) – Speed on the basis of which center feed diameter is designed [m/hr]. [3] The default is 36 m/hr. (10 mm/sec)
F_BM (dict) – Equipment bare modules.
Examples
>>> from qsdsan import set_thermo, Components, WasteStream >>> cmps = Components.load_default() >>> cmps_test = cmps.subgroup(['S_F', 'S_NH4', 'X_OHO', 'H2O']) >>> set_thermo(cmps_test) >>> ws = WasteStream('ws', S_F = 10, S_NH4 = 20, X_OHO = 15, H2O=1000) >>> from qsdsan.sanunits import Thickener >>> TC = Thickener(ID='TC', ins= (ws), outs=('sludge', 'effluent')) >>> TC.simulate() >>> sludge, effluent = TC.outs >>> sludge.imass['X_OHO']/ws.imass['X_OHO'] 0.98 >>> TC.show() Thickener: TC ins... [0] ws phase: 'l', T: 298.15 K, P: 101325 Pa flow (g/hr): S_F 1e+04 S_NH4 2e+04 X_OHO 1.5e+04 H2O 1e+06 WasteStream-specific properties: pH : 7.0 Alkalinity : 2.5 mg/L COD : 23873.0 mg/L BOD : 14963.2 mg/L TC : 8298.3 mg/L TOC : 8298.3 mg/L TN : 20363.2 mg/L TP : 367.6 mg/L TK : 68.3 mg/L TSS : 11124.4 mg/L outs... [0] sludge phase: 'l', T: 298.15 K, P: 101325 Pa flow (g/hr): S_F 1.56e+03 S_NH4 3.11e+03 X_OHO 1.47e+04 H2O 1.56e+05 WasteStream-specific properties: pH : 7.0 COD : 95050.4 mg/L BOD : 55228.4 mg/L TC : 34369.6 mg/L TOC : 34369.6 mg/L TN : 24354.4 mg/L TP : 1724.0 mg/L TK : 409.8 mg/L TSS : 66748.0 mg/L [1] effluent phase: 'l', T: 298.15 K, P: 101325 Pa flow (g/hr): S_F 8.44e+03 S_NH4 1.69e+04 X_OHO 300 H2O 8.44e+05 WasteStream-specific properties: pH : 7.0 COD : 9978.2 mg/L BOD : 7102.9 mg/L TC : 3208.8 mg/L TOC : 3208.8 mg/L TN : 19584.1 mg/L TP : 102.9 mg/L TK : 1.6 mg/L TSS : 265.9 mg/L
References
[1] Gernaey, Krist V., Ulf Jeppsson, Peter A. Vanrolleghem, and John B. Copp. Benchmarking of control strategies for wastewater treatment plants. IWA publishing, 2014.
[2] Chapter-21: Solids Thicknening (Table 21.3). WEF Manual of Practice No. 8. 6th Edition. Virginia: McGraw-Hill, 2018.
[3] Introduction to Wastewater Clarifier Design by Nikolay Voutchkov, PE, BCEE.
[4] Metcalf, Leonard, Harrison P. Eddy, and Georg Tchobanoglous. Wastewater engineering: treatment, disposal, and reuse. Vol. 4. New York: McGraw-Hill, 1991.
- property TSS_removal_perc¶
The percentage of suspended solids removed in the thickener
- line: str = 'Thickener'¶
class-attribute Name denoting the type of Unit class. Defaults to the class name of the first child class
- property solids_loading_rate¶
solids_loading_rate is the loading in the thickener
- property thickener_perc¶
The percentage of suspended solids in the thickened sludge, in %.