Molecular Modeling of Chem-Bio (CB) Contaminant Sorption/Desorption and Reactions in Chlorinated Water Systems

Army installations contain a high density of mission-critical buildings that require constant protection from accidental or deliberate contamination of water distribution systems. Current simulations of contaminant fate and transport in pipe systems do not accurately portray reality. The simulations assume pure hydraulic transport of contaminants and do not account for sorption of the contaminant on pipe walls. Additionally, subsequent reactions such as hydrolysis are not considered. These omissions reduce predictability of a contaminant s progression and effect in the distribution system. In addition, inadequate understanding of contaminant fate and transport may result in an unacceptable risk to mission readiness. However, performing laboratory tests for every known and emerging chemical or biological contaminant to obtain uptake and reaction parameters is not feasible with regard to time or cost investments. This report documents advances in molecular modeling predictions for the transport of contaminants using: the Nanoscale Molecular Dynamics program, the influence of bacterial biofilms on spore viability within a chlorinated water distribution system, the computational chemistry predictions of the rate of hydrolysis of a specific contaminant, and the inclusion of results into the pre-dictive software, EPANet. This work opens the way for better vulnerability assessments, protection, real-time response, remediation, and planning. The original document contains color images.