Introduction to BIOPLUME III

BIOPLUME III Model engine written by Hanadi Rifai GUI developed by ZEi/MicroEngineering, Inc. Version 1.0 released September, 1997 New version due September, 2000 Available from the U.S. EPA at http://www.epa.gov/ada/csmos.html

Differences from BIOPLUME II Graphical User Interface Models 6 components (Hydrocarbon, 5 electron acceptors) Allows 3 kinds of reaction kinetics First order Monod Instantaneous

Biodegradation Solution Research indicates aerobic and anaerobic biodegradation paths Electron acceptors available in the following preferential order: Oxygen Nitrate Iron(III) Sulfate Carbon Dioxide

Sequential Reactions Nitrate only used when all oxygen depleted Iron(III) only used when all nitrate depleted Each subsequent electron acceptor is only available when the previous one is depleted

Kinetic Methods Each reaction can be simulated via one of three possible methods: First-order decay - Note: error in decay code Instantaneous reaction Monod kinetics Each reaction is limited to the available electron acceptor supply Monod kinetics does not simulate microbial growth

Error in Decay Code Do Not Use this option. First-Order Decay designed to be used in two modes Radioactive decay: HC decays, not limited by available electron acceptors. This option works. Electron acceptor-limited decay: HC reduction and rate coefficients tied to each electron acceptor in the decay sequence. The Electron acceptor-limited decay option has serious bugs. Do Not Use this option.

Applicability and Limitations Developed to simulate natural attenuation of hydrocarbons using O2, NO3-, Fe3+, SO42-, and CO2 Can be used to answer following questions: How long will plume extend if no controls? How long will plume persist until NA? How long will plume extend/persist if controls/remediation are applied?

Other Uses of BIOPLUME III Bioremediation with added electron acceptors Low flow rate Air Sparging Advection/Dispersion/Sorption with no biodegradation

Notes on Usability BIOPLUME III (Version 1.0) has several bugs Contaminant concentrations at constant head cells Crashes – Save fairly often Occasional cosmetic naming problem Electron acceptors names get messed up Problem with first-order decay