Thickener & Dewatering Unit Model Documentation (#1017)

* Add thickener and dewatering unit model documentation * Add spaces inside Non-particulate component list * typo fixes * Fix typos * Update docs/technical_reference/unit_models/dewatering.rst Co-authored-by: Adam Atia <aatia@keylogic.com> * Points to the ASM1 documentation for definition of components --------- Co-authored-by: Adam Atia <aatia@keylogic.com>
watertap-org · May 18, 2023 · e5df7c5 · e5df7c5
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diff --git a/docs/technical_reference/unit_models/dewatering.rst b/docs/technical_reference/unit_models/dewatering.rst
@@ -0,0 +1,77 @@
+Dewatering Unit
+===============
+
+.. index::
+   pair: watertap.unit_models.dewatering;dewatering
+
+The main assumptions of the implemented model are as follows:
+
+1) Single liquid phase only
+2) Steady state only
+3) Has no volume
+
+Introduction
+------------
+Dewatering is a process commonly used in wastewater treatment plants to separate water from solids using centrifugal motion
+and/or vacuums. In doing so, the dewatering unit reduces the sludge volume, which improves system operation and mitigates costs
+related to storage, processing, disposal, etc. This implementation of the dewatering unit is based on the `IDAES separator unit <https://idaes-pse.readthedocs.io/en/stable/reference_guides/model_libraries/generic/unit_models/separator.html>`_.
+
+Degrees of Freedom
+------------------
+The degrees of freedom in a dewatering unit model are the inlet feed state variables:
+
+    * temperature
+    * pressure
+    * component mass compositions
+
+Model Structure
+---------------
+The dewatering unit model does not use ControlVolumes, and instead writes a set of material, energy and momentum
+balances to split the inlet stream into two outlet streams. Dewatering models have a single inlet Port
+(named inlet) and two outlet Ports (named overflow and underflow).
+
+Sets
+----
+.. csv-table::
+   :header: "Description", "Symbol", "Indices"
+
+   "Time", ":math:`t`", "[0]"
+   "Phases", ":math:`p`", "['Liq']"
+   "Particulate Components", ":math:`j`", "['X_I', 'X_S', 'X_P', 'X_BH', 'X_BA', 'X_ND']"
+   "Non-particulate Components", ":math:`j`", "['H2O', 'S_I', 'S_S', 'S_O', 'S_NO', 'S_NH', 'S_ND', 'S_ALK']"
+
+NOTE: These components are defined in the `ASM1 Property Package <https://watertap.readthedocs.io/en/latest/technical_reference/property_models/ASM1.html>`_ documentation.
+
+Parameters
+----------
+.. csv-table::
+   :header: "Description", "Symbol", "Variable Name", "Index", "Value", "Units"
+
+   "Percentage of suspended solids in the underflow", ":math:`p_{dewat}`", "p_dewat", "None", "0.28", ":math:`\text{dimensionless}`"
+   "Percentage of suspended solids removed", ":math:`TSS_{rem}`", "TSS_rem", "None", "0.98", ":math:`\text{dimensionless}`"
+
+
+Equations and Relationships
+---------------------------
+
+.. csv-table::
+   :header: "Description", "Equation"
+
+   "Suspended solid concentration", ":math:`C_{TSS} = 0.75 (C_{X_{I}} + C_{X_{IP}} + C_{X_{BH}} + C_{X_{BA}} + C_{X_{S}})`"
+   "Dewatering factor", ":math:`f_{dewat} = p_{dewat} (\frac{10}{C_{TSS}})`"
+   "Remove factor", ":math:`f_{q_{du}} = \frac{TSS_{rem}}{100 * f_{dewat}}`"
+   "Overflow particulate fraction", ":math:`split_{particulate} = 1 - TSS_{rem}`"
+   "Overflow soluble fraction", ":math:`split_{soluble} = 1 - f_{q_{du}}`"
+
+Class Documentation
+-------------------
+.. currentmodule:: watertap.unit_models.dewatering
+
+.. autoclass:: DewateringUnit
+    :members:
+    :noindex:
+
+References
+----------
+J. Alex, L. Benedetti, J.B. Copp, K.V. Gernaey, U. Jeppsson, I. Nopens, M.N. Pons, C. Rosen, J.P. Steyer & P. A. Vanrolleghem
+Benchmark Simulation Model no. 2 (BSM2)
diff --git a/docs/technical_reference/unit_models/index.rst b/docs/technical_reference/unit_models/index.rst
@@ -21,5 +21,7 @@ Unit Models
    anaerobic_digestor
    ion_exchange_0D
    mvc
+   thickener
+   dewatering
    translators/index
    zero_order_unit_models/index
diff --git a/docs/technical_reference/unit_models/thickener.rst b/docs/technical_reference/unit_models/thickener.rst
@@ -0,0 +1,77 @@
+Thickener
+=========
+
+.. index::
+   pair: watertap.unit_models.thickener;thickener
+
+The main assumptions of the implemented model are as follows:
+
+1) Single liquid phase only
+2) Steady state only
+3) Has no volume
+
+Introduction
+------------
+Sludge thickening is a process commonly used in wastewater treatment plants to increase the sludge concentration of a stream
+as well as reduce its volume by removing free water. In doing so, the thickener reduces the load of downstream processes,
+such as digestion and dewatering. This implementation of the thickener unit is based on the `IDAES separator unit <https://idaes-pse.readthedocs.io/en/stable/reference_guides/model_libraries/generic/unit_models/separator.html>`_.
+
+Degrees of Freedom
+------------------
+The degrees of freedom in a thickener unit model are the inlet feed state variables:
+
+    * temperature
+    * pressure
+    * component mass compositions
+
+Model Structure
+---------------
+The thickener unit model does not use ControlVolumes, and instead writes a set of material, energy and momentum
+balances to split the inlet stream into two outlet streams. Thickener models have a single inlet Port
+(named inlet) and two outlet Ports (named overflow and underflow).
+
+Sets
+----
+.. csv-table::
+   :header: "Description", "Symbol", "Indices"
+
+   "Time", ":math:`t`", "[0]"
+   "Phases", ":math:`p`", "['Liq']"
+   "Particulate Components", ":math:`j`", "['X_I', 'X_S', 'X_P', 'X_BH', 'X_BA', 'X_ND']"
+   "Non-particulate Components", ":math:`j`", "['H2O', 'S_I', 'S_S', 'S_O', 'S_NO', 'S_NH', 'S_ND', 'S_ALK']"
+
+NOTE: These components are defined in the `ASM1 Property Package <https://watertap.readthedocs.io/en/latest/technical_reference/property_models/ASM1.html>`_ documentation.
+
+Parameters
+----------
+.. csv-table::
+   :header: "Description", "Symbol", "Variable Name", "Index", "Value", "Units"
+
+   "Percentage of suspended solids in the underflow", ":math:`p_{thick}`", "p_thick", "None", "0.07", ":math:`\text{dimensionless}`"
+   "Percentage of suspended solids removed", ":math:`TSS_{rem}`", "TSS_rem", "None", "0.98", ":math:`\text{dimensionless}`"
+
+
+Equations and Relationships
+---------------------------
+
+.. csv-table::
+   :header: "Description", "Equation"
+
+   "Suspended solid concentration", ":math:`C_{TSS} = 0.75 (C_{X_{I}} + C_{X_{IP}} + C_{X_{BH}} + C_{X_{BA}} + C_{X_{S}})`"
+   "Thickening factor", ":math:`f_{thick} = p_{thick} (\frac{10}{C_{TSS}})`"
+   "Remove factor", ":math:`f_{q_{du}} = \frac{TSS_{rem}}{100 * f_{thick}}`"
+   "Overflow particulate fraction", ":math:`split_{particulate} = 1 - TSS_{rem}`"
+   "Overflow soluble fraction", ":math:`split_{soluble} = 1 - f_{q_{du}}`"
+
+Class Documentation
+-------------------
+.. currentmodule:: watertap.unit_models.thickener
+
+.. autoclass:: Thickener
+    :members:
+    :noindex:
+
+References
+----------
+J. Alex, L. Benedetti, J.B. Copp, K.V. Gernaey, U. Jeppsson, I. Nopens, M.N. Pons, C. Rosen, J.P. Steyer & P. A. Vanrolleghem
+Benchmark Simulation Model no. 2 (BSM2)