Mechanisms of iron photoreduction in a metal-rich, acidic stream (St. Kevin Gulch, Colorado, U.S.A.)

Kimball, Briant A.; McKnight, Diane M.; Wetherbee, Gregory A.; Harnish, R.A.

doi:10.1016/0009-2541(92)90130-w

Cited by 55 publications

(38 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous workers (McKnight and Bencala 19971988;McKnight et al , 2001Kimball et al 1992;Voelker et al ;Sullivan et al 1998;Emmenegger et al 2001;McKnight and Duren 2004;Gammons et al 2005bGammons et al , 2008Sherman 2005;Parker et al 2008;Nimick et al 2011) have documented diel (24-h) cycles in the concentration and redox speciation of dissolved iron in streams that are acidic due to pyrite oxidation. These cycles are caused by day-time photoreduction of dissolved or colloidal Fe III to dissolved Fe 2+ (reactions 7.1, 7.2) and re-oxidation of Fe 2+ to dissolved or colloidal Fe III compounds at night (reactions 7.3, 7.4), as follows:…”

Section: Modelling Schwertmannite Stabilitymentioning

confidence: 95%

“…7.1) or (Eq. 7.2) creates a short-lived OH · radical which is destroyed by reaction with other redox-sensitive species (Collienne 1983;Kimball et al 1992;Voelker et al 1997), such as dissolved organic carbon (DOC). David and David (1976) showed that photo-reduction of Fe(III) occurs in the ultraviolet (UV) to near-UV region of 200 to 450 nm, with a local maximum near 300 nm, and is sensitive to changes in pH, temperature, light intensity, major solute chemistry, and Fe(II) concentration.…”

Section: Modelling Schwertmannite Stabilitymentioning

confidence: 99%

See 1 more Smart Citation

Acid Rivers and Lakes at Caviahue-Copahue Volcano as Potential Terrestrial Analogues for Aqueous Paleo-Environments on Mars

Aguilar

Varekamp

Bergen

et al. 2015

Active Volcanoes of the World

View full text Add to dashboard Cite

Mars carries primary rock with patchy occurrences of sulfates and sheet silicates. Both Mg-and Fe-sulfates have been documented, the former being rather uncommon on Earth. To what extent can a natural acidic river system on Earth be a terrestrial analog for early Mars environments? Copahue volcano (Argentina) has an active acid hydrothermal system that has precipitated a suite of minerals in its hydrothermal reservoir (silica, anhydrite, alunite, jarosite). Leakage from this subterranean system through hot springs and into the crater lake have formed a strongly acidified watershed (Río Agrio), which precipitates a host of minerals during cooling and dilution downstream. A suite of more than 100 minerals has been found and conditions for precipitation of the main phases are simulated with speciation/saturation routines. The lower part of the watershed (Lake Caviahue and the Lower Río Agrio) have abundant deposits of ferricrete since 2003: hydrous ferric oxides and schwertmannite occur, their precipitation being mediated by Fe-oxidizing bacteria and photochemical processes. Further downstream, at greater degrees of dilution, hydrous aluminum oxides and sulfates form and create 'alcretes' lining the river bed. The watershed carries among others jarosite, hematite, anhydrite, gypsum and silica minerals and the origin of all these minerals

show abstract

Section: Modelling Schwertmannite Stabilitymentioning

confidence: 95%

Section: Modelling Schwertmannite Stabilitymentioning

confidence: 99%

Acid Rivers and Lakes at Caviahue-Copahue Volcano as Potential Terrestrial Analogues for Aqueous Paleo-Environments on Mars

Aguilar

Varekamp

Bergen

et al. 2015

Active Volcanoes of the World

View full text Add to dashboard Cite

show abstract

“…in the presence of light was extensively applied in chemical actinometry (e.g., Parker 1953;Hatchard and Parker 1956), where ferric oxalate was used to measure the light intensity. Since then, many papers have addressed the importance of light-induced redox transformations of organic carbon, iron, and other transition metals in diverse natural systems, such as sea water (e.g., Kuma et al 1996;Uher and Andreae 1997;Rijkenberg et al 2005Rijkenberg et al , 2006, river water (e.g., Madsen et al 1986;Amon and Benner 1996), acid mine drainage (AMD)-impacted rivers (e.g., McKnight et al , 2001Bencala 1988, 1989;Kimball et al 1992;Hrncir and McKnight 1998;Sullivan et al 1998;McKnight and Duren 2004;Gammons et al 2005aGammons et al , b, 2008Butler and Seitz 2006), natural neutral lakes (e.g., McMahon 1967McMahon , 1969Sivan et al 1998;Emmenegger et al 2001), natural acidic lakes (e.g., Collienne 1983;Sulzberger et al 1990), acidic mining lakes (AML) (e.g., Herzsprung et al 1998;Friese et al 2002), or atmospheric water droplets (e.g., Weschler et al 1986;Faust and Hoigne 1990;Zuo and Hoigne 1992;Hoigne et al 1994). From all this substantial amount of research, it is well known that the interaction of solar (mainly UV-A) radiation with dissolved and particulate Fe(III) in natural and acidic waters provokes the reduction of dissolved Fe(III) and ferric mineral phases (e.g., goethite, lepidocrocite, and ferrihydrite) to Fe 2?…”

Section: Antecedents and Previous Workmentioning

confidence: 99%

“…. The photoreduction process can take place via homogeneous (aqueous) and/or heterogeneous (solid surface) mechanisms, which are commonly represented by the following simplified equations (David and David 1976;Waite and Morel 1984;Kimball et al 1992):…”

Section: Antecedents and Previous Workmentioning

confidence: 99%

Photoreduction of Fe(III) in the Acidic Mine Pit Lake of San Telmo (Iberian Pyrite Belt): Field and Experimental Work

2008

View full text Add to dashboard Cite

show abstract

“…The iron content measured in OD-4 could be Fe(II) transfered (and not yet oxidized) by the acidic effluent of San Platón (1,670 mg/L Fe(II)), but the Esperanza mine effluent (which has no Fe(II)) can not account for the Fe content in OD-6. Kimball et al (1992) and McKnight et al (1998) have demonstrated that the photoreduction of Fe(III) in streams affected by AMD can be a relevant reaction in the control of the Fe(II)/Fe(III) redox chemistry. Thus, it seems probable that the Fe(III) colloids (either suspended in the water column and/or sedimented in the river banks) could have been partly reduced by photochemical processes and thus contribute with dissolved Fe(II) to the aqueous chemistry of the Odiel river.…”

Section: Evolution Of Watermentioning

confidence: 98%

The Impact of Acid Mine Drainage on the Water Quality of the Odiel River (Huelva, Spain): Evolution of Precipitate Mineralogy and Aqueous Geochemistry Along the Concepción-Tintillo Segment

España

Pamo

Pastor

et al. 2006

Water Air Soil Pollut

View full text Add to dashboard Cite

The Odiel river emerges in Sierra de Aracena (N Huelva, Spain) as a clean, circumneutral river which shows abundant fish and fluvial microfauna. At 20 km from the riverhead and along a 7 km-long reach, this river receives four small discharges of acid mine water emanating from several abandoned mines of the Iberian Pyrite Belt (namely, Concepción, San Platón, Esperanza and La Poderosa-El Soldado). During two field studies performed in October 2003 and May 2004, it has been observed that these acidic waters (with flow rate of 0.2-8.5 L/s and pH 2.3-2.8) transfer to the Odiel river significant amounts of acidity and dissolved metals (specially Fe, Al, Mn, Cu, Zn, Cd, Co and Ni) and sulphate. Despite this mine-related pollution, the pH of the river remains near-neutral (pH = 7-8, flow rate = 220-1,000 L/s), as the alkalinity of the river (108-155 mg/L CaCO 3 eq.) neutralizes the acidity and causes the precipitation of dissolved Fe and Al in the form of ochreous to whitish minerals (ferrihydrite, Al-oxyhydroxides). These poorly crystallized minerals retain, by sorption (including adsorption and coprecipitation), large amounts of trace metals (specially Cu and Zn). Subsequently, the Odiel river converges with the acidic Tintillo river (pH = 2.5-2.8, flow rate = 48-240 L/s), which drains a vast mining area occupied by large waste-rock piles and tailings impoundments around Corta Atalaya (Riotinto mines). At this confluence, all the alkalinity is totally consumed and the pH drastically decreases to around 3. The mineral paragenesis of the ochreous precipitates is then dominated by schwertmannite, which shows a very limited sorption capacity under such acidic conditions. Consequently, metal concentrations are sharply increased from near-zero to tens of mg/L (e.g., 18 mg/L Fe, 76 mg/L Al, 14 mg/L Mn, 10 mg/L Cu, and 20 mg/L Zn in May 2004). The buffering capacity of the Fe(III) hydrolysis stabilizes the pH of the Odiel river around 3 ± 0.5 along the rest of its course to the Huelva estuary, and the water quality of the river is thus irreversibly damaged.

show abstract

Mechanisms of iron photoreduction in a metal-rich, acidic stream (St. Kevin Gulch, Colorado, U.S.A.)

Cited by 55 publications

References 16 publications

Acid Rivers and Lakes at Caviahue-Copahue Volcano as Potential Terrestrial Analogues for Aqueous Paleo-Environments on Mars

Acid Rivers and Lakes at Caviahue-Copahue Volcano as Potential Terrestrial Analogues for Aqueous Paleo-Environments on Mars

Photoreduction of Fe(III) in the Acidic Mine Pit Lake of San Telmo (Iberian Pyrite Belt): Field and Experimental Work

The Impact of Acid Mine Drainage on the Water Quality of the Odiel River (Huelva, Spain): Evolution of Precipitate Mineralogy and Aqueous Geochemistry Along the Concepción-Tintillo Segment

Contact Info

Product

Resources

About