Analytical Modelling Tool Development for Subsurface Contaminant Transport and Biodegradation Modelling

Abstract

Conventional methods of contaminated site remediation are often costly and upkeep intensive. Bioremediation is an alternative of particular interest, as it degrades contaminants on-site. Modelling the fate of contaminants is key for understanding the processes involved and what effects can be expected from bioremediation in the field. In this study we developed a Python package (anatrans) for modelling solute transport including biodegradation, as part of the EU-funded MIBIREM project. The base functionality of anatrans is based on the functionality of BIOSCREEN (an Excel based screening model), using the Domenico analytical multidimensional transport model. Our analytical transport model (anatrans) is modular, fully tested, well documented and well-structured to allow for adaptation and use in various field situations. Biodegradation can be modelled both as simple first-order decay and as an instantaneous field-wide reaction based on electron acceptor concentrations. The tool is validated by comparing example field data with results from BIOSCREEN. anatrans is shown to have improved spatial and temporal resolution and has corrected flaws from the latest version of BIOSCREEN. Finally, field data from the Constructed Wetland pilot study is analysed to comment upon the effectiveness of the pilot study and to evaluate how anatrans may be adapted to different site conditions. The pilot study shows promising preliminary results, with decreasing BTEX concentrations and electron acceptor concentrations over its flow path.