BIOSCREEN AND BIOCHLOR Natural Attenuation Modeling Tools

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BIOSCREEN AND BIOCHLOR Natural Attenuation
Modeling Tools
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BIOSCREEN

• easy-to-use screening model that simulates
  remediation by natural attenuation (RNA) of
  dissolved hydrocarbons at petroleum fuel release
  sites
• programmed in the Microsoft? Excel spreadsheet
• based on the Domenico analytical solute transport
  model, has the ability to simulate advection,
  dispersion, adsorption, and biological decay
  (aerobic and anaerobic)

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BIOSCREEN

• Includes three different model types
• 1) Solute transport without decay,
• 2) Solute transport with biodegradation modeled
  as a first-order decay process (simple,
  lumped-parameter approach),
• 3) Solute transport with biodegradation modeled
  as an "instantaneous" biodegradation reaction
  (approach used by BIOPLUME models)

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Intended uses for BIOSCREEN

• BIOSCREEN attempts to answer the questions
• How far will a dissolved BTEX plume extend if no
  engineered controls or source area reduction
  measures are implemented?
• How long will the plume persist until natural
  attenuation processes cause it to dissipate?
• BIOSCREEN is intended to be used in two ways
• 1. As a screening-level model to determine if
  RNA is
  feasible at a fuel hydrocarbon site.
• 2. As the primary RNA groundwater model at
  smaller sites.

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Limitations of BIOSCREEN

• As an analytical model, BIOSCREEN assumes simple
  ground-water flow conditions.
• As a screening tool, BIOSCREEN only approximates
  more complicated processes that occur in the
  field.

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BIOSCREEN input screen
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BIOCHLOR

• easy-to-use screening model that simulates
  remediation by natural attenuation (RNA) of
  dissolved solvents at chlorinated solvent release
  sites
• programmed in the Microsoft? Excel spreadsheet
• based on the Domenico analytical solute transport
  model, has the ability to simulate 1-D advection,
  3-D dispersion, linear adsorption, and
  biotransformation via reductive dechlorination

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BIOCHLOR

• reductive dechlorination assumed anaerobic
• biodegradation follows a sequential first-order
  decay process
• includes three different model types
• solute transport without decay,
• solute transport with biotransformation
  (sequential first-order decay process),
• solute transport with biotransformation
  (sequential first-order decay process with two
  different reaction zones)

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Intended uses for BIOCHLOR

• BIOCHLOR attempts to answer the question How far
  will a dissolved chlorinated solvent plume extend
  if no engineered controls or source area
  reduction measures are implemented?
• BIOCHLOR is intended to be used in two ways
• 1. As a screening-level model to determine if
  RNA is
  feasible at a chlorinated solvent site.
• 2. As an RNA ground-water model to address
  selected chlorinated solvent problems

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Limitations of BIOCHLOR

• As an analytical model, BIOCHLOR assumes simple
  ground-water flow conditions.
• As a screening tool, BIOCHLOR assumes uniform
  hydrogeologic and environmental conditions over
  the entire model area.
• BIOCHLOR is primarily designed for simulating the
  sequential reductive dechlorination of
  chlorinated ethanes and ethenes.

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BIOCHLOR input screen