Craig Divine, PhD, PG, is a National Technical Expert and Vice President at Arcadis US, Inc. He has 20 years of experience in hydrogeology, geochemistry, subsurface characterization, and groundwater remediation. Specific project experience includes work for public and private clients at military bases, DOT yards, aerospace facilities, chemical plants, landfills, steel mills, oil refineries, mines and smelters, natural gas production facilities, power generation and transmission facilities, gasoline service stations, and various manufacturing plants. During his time at Arcadis, Dr. Divine has held technical, project management, and operations leadership roles. As a member of the senior leadership for North America, Dr. Divine helps Arcadis’ teams provide the highest value for our clients and drive organic growth for the Environment business line.
Laboratory and Field Validation of Min-Traps for Collection and Analysis of Reactive Iron Sulfide Minerals for Abiotic CVOC Degradation
The degradation of chlorinated compounds by reactive minerals (e.g., iron sulfides) is a subject of much active research, however, cost-effective tools to evaluate these treatment processes in field applications are limited, and collection of samples to evaluate in situ mineral formation is costly due to drilling requirements. The Min-Trap is a simple and cost-effective approach for the collection of samples to directly confirm the formation of reactive minerals in situ without the need for drilling. Recently field testing was conducted as at three sites part of the full-scale treatment of chloromethanes and chloroethenes in groundwater using organic carbon and zero valent iron substrates. SEM/EDS and AMIBA results confirmed that Min-Traps successfully captured reduced iron and sulfide minerals being precipitated and reduced iron and sulfide minerals were also identified in co-located core samples. These data provide insight into geochemical changes that impact reactive iron sulfide precipitation over time; specifically, 1) the variability in iron sulfide mineral precipitation processes over time, 2) the correlation between the abundance of precipitates in core samples and Min-Traps, 3) the variability in mineral precipitation processes at different locations, 4) the correlation of mineral precipitation processes with groundwater geochemical data, and 5) the utility of Min-Trap data to support the evaluation of remedy performance and impact remedial decision making.