Abiotic reduction kinetics database (ARK) - Version 1

The ARK (Abiotic Reduction Kinetics) database is a compilation of rate constants and associated meta-data from published studies of contaminant removal (i.e., disappearance) from aqueous-environmental media under conditions where the removal is known or assumed to be primarily due to reaction (i.e., transformation) by chemical reduction. The current scope includes all chemical contaminants (organic and inorganic) for which suitable kinetic data are available (halocarbons, nitroaromatics, metal oxyanions, etc.) and all reducing systems (homogeneous and heterogenous) that are relevant to natural biogeochemical processes and engineered treatment systems (usually characterized by Fe(0), Fe(II), and/or S(−II)). Currently, almost all of the rate constants are pseudo first order (i.e., kobs) obtained from laboratory batch experiments, but the database is designed to accommodate other types of kinetic data (e.g., pseudo zero-order) and other experimental methods (e.g., column and field) as suitable results become available. The scope is not intended to include kinetics of contaminant disappearance mainly due to non-reactive losses such as adsorption, non-reductive losses due to hydrolysis or oxidation (e.g., due to ROS from Fe(II)+O2), or (co)metabolism by microorganisms. However, in some cases, these processes could be (hopefully minor) contributors to the observed contaminant disappearance. Also, ARK currently includes no data that are believed to be photochemically activated. The database is provided here as a spreadsheet in .xlsx and .ods format. The file includes one Main Sheet with 4000+ rows (individual experimental results from 200+ references) and about 100 columns containing various types of kinetic data and associated meta-data. Note that some data are calculated by formulas, which should be indicated by italic text. More details on the criteria and conventions used in developing the database will be described in a future publication. This version of the ARK database (ARK-v1) was checked extensively, but it is not completely accurate or complete. In fact, we are well aware that many new papers are missing, especially in very-active areas of research such as modified forms of zerovalent iron. So, we plan to make additions and corrections, and publish the result as ARK-v2 within about 1 year. For this, we welcome additions and corrections submitted by users. Minor changes can be submitted simply as itemized corrections to [e-mail]. For more extensive changes—especially to submit data from publications that currently are entirely missing from the database—a template version of ARK is provided here. Please send it as an attachment to [e-mail]. In addition to ad hoc contributions (requested above), we are open to adding co-authors who make major contributions to future versions of ARK. For that, please send a brief proposal (< 1 page ± a bibliography) describing how you might expand or improve ARK. Send this as an attachment to [e-mail]. Caveats: For critical applications, we recommend tracking down the primary sources (listed in the spreadsheet) and using them for data, conditions, and other qualifications. Obviously, we do not accept any responsibility for what anyone does with information obtained from this database.