Energy derived waters (EDWs) (e.g. petroleum refinery effluents, produced waters) can contain a variety of constituents [e.g. selenium (Se), arsenic (As), low molecular weight organics (LMWOs)]. The overall objective of this research was to provide an approach for remediation of specific constituents of concern in these waters and to measure a relationship between Se removal and abundance of Se reducing microbes. The specific objectives of this research were to: (1) evaluate removal of Se from simulated refinery effluent (SRE) using a pilot-scale constructed wetland treatment system (CWTS); (2) evaluate removal of Se, As, and LMWOs from a generic simulated fresh produced water (SFPW) using a pilot-scale CWTS; and (3) compare removal of Se from a SFPW to abundance of Se reducing microbes in a pilot-scale CWTS. Characterizations of each EDW (e.g. refinery effluent and produced water) were conducted in order to determine constituent concentrations and formulate simulated experimental EDWs for this research. An evaluation of the performance of a pilot-scale CWTS for removal of Se was conducted with pretreatment levels of 42-44 μg Se/L. Previous research indicated improved Se removal with addition of an organic carbon source; an outflow Se concentration goal of 5 μg/L was reached with this amendment. The concept of simultaneous constituent treatment of metalloids (e.g. Se, As) and LMWOs was evaluated. Pretreatment levels were approximately 50 μg Se/L, 20 μg As/L, and 25 mg LMWO/L with treatment goals of 5 μg Se/L, 5 μg As/L, and 1 mg LMWO/L, respectively. These goals were achieved for Se and LMWOs, but treatment of As was not sufficient to reach the goal of 5 μg As/L. Se removal rate coefficients and removal extents were calculated and measured, respectively, and compared to abundance of Se reducing microbes in pilot-scale CWTS sediment pore water. Relationships were calculated statistically by regression analysis and a parametric relationship was established
