BIO1D is a one-dimensional finite difference model for simulation of biodegradation and sorption of a degradable hydrocarbon. Advective and dispersive transport of a substrate and an electron acceptor are considered, assuming an uniform flow field in either the saturated or unsaturated zone. The reactions may include first-order, aerobic (Monod function), or anaerobic (Michaelis-Menten kinetics) degradation, and adsorption described by a linear, Freundlich or Langmuir equilibrium isotherm. Dirichlet, Neumann, or Cauchy boundary conditions are allowed. The resulting nonlinear problem is solved using a Newton-Raphson iterative technique. The program includes an user-friendly preprocessor and post simulation display graphics. The program assumes flow velocities are known.

For graphics, BIO1D uses PLOT 88 software from PLOTWORKS, Inc. which supports various printers and plotters. The proprietary BIO1D runs in the DOS environment and provides an excellent tool for educational and conceptual purposes.

SYSTEM REQUIREMENTS

Intel 80i86 based computer with a minimum of 560 Kb free RAM, math coprocessor, and VGA graphics.

Developers: P. Srinivasan and J.W. Mercer (GeoTrans, Inc.).