Fig. 3 Microbial transformation of pentachlorophenol (PCP) in Louisiana salt marsh sediments (LSM) under four electron acceptor reducing conditions: (A) O₂; (B) NO^-₃; (C) SO^2-₄; and (D) CO₂. Initial and final NO^-₃ and SO^2-₄ refer to concentrations at the beginning and end of the experiment. Each value represents the mean of three replications ± one standard deviation