Analytical approximation to characterize the performance of in situ aquifer bioremediation

The performance of in situ bioremediation to remove organic contaminants fr om contaminated aquifers depends on the physical and biochemical parameters . We characterize the performance by the contaminant removal rate and the r egion where biodegradation occurs, the biologically active zone (BAZ). The numerical fronts obtained by one-dimensional in situ bioremediation modelin g reveal a traveling wave behavior: fronts of microbial mass, organic conta minant and electron acceptor move with a constant velocity and constant fro nt shape through the domain. Hence, only one front shape and a linear relat ion between the front position and time is found for each of the three comp ounds. We derive analytical approximations for the traveling wave front sha pe and front position that agree perfectly with the traveling wave behavior resulting from the bioremediation model. Using these analytical approximat ions, we determine the contaminant removal rate and the BAZ. Furthermore, w e assess the influence of the physical and biochemical parameters on the pe rformance of the in situ bioremediation technique. (C) 1999 Elsevier Scienc e Ltd. All rights reserved.