A statistical approach to assess the efficiency of bioremediation methods

Cynthia Lynn Glickman, University of Nevada, Las Vegas


There are a number of Superfund sites in which biotreatability studies are used to assess whether an addition of some surfactants have a positive effect on the rates of biodegradation of PAH concentrations when compared to a control. U.S. EPA, in many situations, will require a minimum of 40% reduction over the control before approving the bioremediation method. Typically, samples of PAH concentrations are collected from an experiment involving the bio-treatment and the control conditions. The percent reduction is calculated by the formula: {dollar}\rm{\=x\sb1-\=x\sb2\over x\sb1}\times100\%.{dollar}; If the above percent reduction exceeds 40%, then the biotreatment is considered to be effective. This approach clearly ignores the inherent sampling variability. In this study, I will consider two approaches to the above problem: (1) Confidence Interval Estimation of the percent Reduction; (2) A Hypothesis Testing Formulation of the above problem. Simulation will be used to provide examples.