Field methods and example applications for the Min‐Trap® mineral sampler

Abstract

Important reactive minerals are commonly created during in situ groundwater remediation activities; for example, iron sulfides formed during enhanced reduction approaches can abiotically degrade many chlorinated solvents. However, cost‐effective tools to evaluate these treatment processes in field applications are limited and the collection of samples to evaluate in situ mineral formation is costly due to drilling requirements. The new passive Min‐Trap sampler is a simple and cost‐effective tool that can directly measure the formation of reactive minerals in situ without the need for additional drilling or soil core collection. The methods presented here describe how Min‐Traps deployed in conventional monitoring wells can measure reactive minerals and how these minerals can be identified through commercially available analytical methods. Several examples are presented that show how Min‐Traps can be used to characterize the rate and spatial variability of reactive mineral precipitation and these data may support operation and optimization decisions.

Min‐Trap® Samplers to Passively Monitor In‐Situ Iron Sulfide Mineral Formation for Chlorinated Solvent Treatment

“…These methods are generally consistent with similar sampling protocols described by Wilkin (2006) but do not require the use of a field glove box. Further detailed descriptions of field deployment, sampling, and preservation procedures are presented in Divine et al (2023).…”

“…The Min-Trap® sampler was specifically developed to address this challenge by providing a reliable and low-cost method to collect direct physical evidence of reactive mineral formation from monitoring wells without collecting soil/rock core samples. Results from laboratory prototype testing and an initial limited field pilot test were previously presented in Horst et al (2019) and Ulrich et al (2021aUlrich et al ( , 2021b, and specific details on Min-Trap sampling and preservation methods are presented in Divine et al (2023). This paper presents new data from a comprehensive field study designed to evaluate the performance and applicability of Min-Traps for collecting mineralogical data in the context of in-situ remediation of chlorinated solvents.…”