WasteWater.ASM2d.SecClar.Takacs.Interfaces

Information

This package contains connectors and interfaces (partial models) for the ASM2d 
secondary clarifier model based on Takacs [1] (double-exponential settling velocity).

Main Author:
 
          Gerald Reichl
          Technische Universitaet Ilmenau
          Faculty of Informatics and Automation
          Department Dynamics and Simulation of ecological Systems
          P.O. Box 10 05 65
          98684 Ilmenau
          Germany
          email: gerald.reichl@tu-ilmenau.de

References:

[1]  I. Takacs and G.G. Patry and D. Nolasco: A dynamic model of the clarification-thickening
      process. Water Research. 25 (1991) 10, pp 1263-1271.

Copyright (C) 2001 - 2002, Gerald Reichl

The Modelica package is free software; it can be redistributed and/or modified under the terms of the Modelica license, see the license conditions and the accompanying disclaimer in the documentation of package Modelica in file "Modelica/package.mo".

WasteWater.ASM2d.SecClar.Takacs.Interfaces.ratios

Information

partial model for ASM2d ratios of solid components

Modelica definition

partial model ratios "partial model for ratios of solid components" 
  
  // ratios of solid components
  Real rXi;
  Real rXs;
  Real rXh;
  Real rXpao;
  Real rXpp;
  Real rXpha;
  Real rXa;
  Real rXmeoh;
  Real rXmep;
  
end ratios;

WasteWater.ASM2d.SecClar.Takacs.Interfaces.SCParam

Information

partial model providing clarifier parameters

Parameters

Name	Default	Description
zm		height of m-th secondary clarifier layer [m]
Asc		area of secondary clarifier [m2]

Modelica definition

partial model SCParam "partial model providing clarifier parameters" 
  
  package SI = Modelica.SIunits;
  parameter SI.Length zm;
  parameter SI.Area Asc;
  
  
end SCParam;

WasteWater.ASM2d.SecClar.Takacs.Interfaces.SCVar

Information

partial models providing ASM2d variables

Modelica definition

partial model SCVar "partial models providing variables" 
  
  package WWU = WasteWater.WasteWaterUnits;
  WWU.MassConcentration X "total sludge concentration in m-th layer";
  WWU.MassConcentration Xf "total sludge concentration in clarifier feed";
  WWU.SedimentationVelocity vS "sink velocity in m-th layer";
  WWU.SedimentationFlux Jsm "sedimentation flux m-th layer";
  
  WWU.MassConcentration So "Dissolved oxygen";
  WWU.MassConcentration Sf "Readily biodegradable substrate";
  WWU.MassConcentration Sa "Fermentation products";
  WWU.MassConcentration Snh "Ammonium";
  WWU.MassConcentration Sno "Nitrate (plus nitrite)";
  WWU.MassConcentration Spo "Phosphate";
  WWU.MassConcentration Si "Inert, non biodegradable organics";
  WWU.Alkalinity Salk "Bicarbonate alkalinity";
  WWU.MassConcentration Sn2 "Dinitrogen";
  
end SCVar;

WasteWater.ASM2d.SecClar.Takacs.Interfaces.LowerLayerPin

Information

Connector for ASM2d information and mass exchange between 
layers below the influent layer (feed_layer).

Modelica definition

connector LowerLayerPin "Connector below influent layer" 
  
  package WWU = WasteWater.WasteWaterUnits;
  
  // return and waste sludge flow Qr, Qw
  flow WWU.VolumeFlowRate Qr;
  flow WWU.VolumeFlowRate Qw;
  
  // sedimentation flux
  flow WWU.SedimentationFlux SedFlux;
  // total sludge concentration in m-th layer
  WWU.MassConcentration X;
  
  // total sludge concentration and sink velocity in
  // (m-1)-th layer (dn=down)
  WWU.MassConcentration X_dn;
  WWU.SedimentationVelocity vS_dn;
  
  // soluble components
  WWU.MassConcentration So;
  WWU.MassConcentration Sf;
  WWU.MassConcentration Sa;
  WWU.MassConcentration Snh;
  WWU.MassConcentration Sno;
  WWU.MassConcentration Spo;
  WWU.MassConcentration Si;
  WWU.Alkalinity Salk;
  WWU.MassConcentration Sn2;
  
end LowerLayerPin;

WasteWater.ASM2d.SecClar.Takacs.Interfaces.UpperLayerPin

Information

Connector for ASM2d information and mass exchange 
between layers above the influent layer (feed_layer).

Modelica definition

connector UpperLayerPin "Connector above influent layer" 
  
  package WWU = WasteWater.WasteWaterUnits;
  
  // effluent flow
  flow WWU.VolumeFlowRate Qe;
  
  // sedimentation flux
  flow WWU.SedimentationFlux SedFlux;
  
  // total sludge concentration and sink velocity in
  // (m-1)-th layer (dn=down)
  WWU.MassConcentration X_dn;
  WWU.SedimentationVelocity vS_dn;
  
  // soluble components
  WWU.MassConcentration So;
  WWU.MassConcentration Sf;
  WWU.MassConcentration Sa;
  WWU.MassConcentration Snh;
  WWU.MassConcentration Sno;
  WWU.MassConcentration Spo;
  WWU.MassConcentration Si;
  WWU.Alkalinity Salk;
  WWU.MassConcentration Sn2;
  
end UpperLayerPin;

WasteWater.ASM2d.SecClar.Takacs.Interfaces.vSfun

Information

Takacs double-exponential sedimentation velocity function.

Parameters

Name	Default	Description
v0slash	250.0	max. settling velocity in m/d
v0	474.0	max. Vesilind settl. veloc. in m/d
rh	0.000576	hindered zone settl. param. in m3/(g SS)
rp	0.00286	flocculant zone settl. param. in m3/(g SS)
fns	0.00228	non-settleable fraction in -

Modelica definition

function vSfun "Sedimentation velocity function" 
  
  // total sludge concentration in m-th layer in g/m3 or mg/l
  input Real X;
  
  // total sludge concentration in clarifier feed in g/m3 or mg/l
  input Real Xf;
  
  // sink velocity in m/d
  output Real vS;
  
  parameter Real v0slash=250.0 "max. settling velocity in m/d";
  parameter Real v0=474.0 "max. Vesilind settl. veloc. in m/d";
  parameter Real rh=0.000576 "hindered zone settl. param. in m3/(g SS)";
  parameter Real rp=0.00286 "flocculant zone settl. param. in m3/(g SS)";
  parameter Real fns=0.00228 "non-settleable fraction in -";
algorithm 
  
  // computation of sink velocity
  vS := max(0.0, min(v0slash, v0*(exp(-rh*(X - fns*Xf)) - exp(-rp*(X - fns*Xf)))));
  
end vSfun;