title: Biogeochemical redox processes and their impact on contaminant dynamics.
abstract: Life and element cycling on Earth is directly related to electron transfer (or redox) reactions. An understanding of biogeochemical redox processes is crucial for predicting and protecting environmental health and can provide new opportunities for engineered remediation strategies. Energy can be released and stored by means of redox reactions via the oxidation of labile organic carbon or inorganic compounds (electron donors) by microorganisms coupled to the reduction of electron acceptors including humic substances, iron-bearing minerals, transition metals, metalloids, and actinides. Environmental redox processes play key roles in the formation and dissolution of mineral phases. Redox cycling of naturally occurring trace elements and their host minerals often controls the release or sequestration of inorganic contaminants. Redox processes control the chemical speciation, bioavailability, toxicity, and mobility of many major and trace elements including Fe, Mn, C, P, N, S, Cr, Cu, Co, As, Sb, Se, Hg, Tc, and U. Redox-active humic substances and mineral surfaces can catalyze the redox transformation and degradation of organic contaminants. In this review article, we highlight recent advances in our understanding of biogeochemical redox processes and their impact on contaminant fate and transport, including future research needs.
authors.affiliation: Department of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado, USA. borch@colostate.edu
authors.forename: Thomas
authors.initials: T
authors.lastname: Borch
authors.forename: Ruben
authors.initials: R
authors.lastname: Kretzschmar
authors.forename: Andreas
authors.initials: A
authors.lastname: Kappler
authors.forename: Philippe Van
authors.initials: PV
authors.lastname: Cappellen
authors.forename: Matthew
authors.initials: M
authors.lastname: Ginder-Vogel
authors.forename: Andreas
authors.initials: A
authors.lastname: Voegelin
authors.forename: Kate
authors.initials: K
authors.lastname: Campbell
mesh_terms: D001671:Biochemistry; D004785:Environmental Pollutants / Q000737:chemistry*; D005844:Geology; D010084:Oxidation-Reduction; D012988:Soil Microbiology; D014131:Trace Elements / Q000737:chemistry; D014871:Water Microbiology
chemical_list: D004785:Environmental Pollutants; D014131:Trace Elements