Relationship of mercury with aluminum, iron and manganese oxy-hydroxides in sediments from the Alto Pantanal, Brazil

• Published in: The Science of the total environment Vol. 260; no. 1; pp. 97 - 107
• Main Authors: Hylander, Lars D., Meili, Markus, Oliveira, Lázaro J., de Castro e Silva, Edinaldo, Guimarães, Jean R.D., Araujo, Danielle M., Neves, Raquel P., Stachiw, Rosalvo, Barros, Antonio J.P., Silva, Gercino D.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier B.V 09-10-2000; Elsevier Science
• Subjects: Aluminum; Aluminum - analysis; Aluminum - chemistry; Applied sciences; Brazil; Brazil, Alto Pantanal; Continental surface waters; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental Monitoring; Exact sciences and technology; Floodplain lakes; Fresh Water - analysis; Geologic Sediments - analysis; Gold; Hydroxides - chemistry; Iron; Iron - analysis; Iron - chemistry; Manganese; Manganese - analysis; Manganese - chemistry; Mercury; Mercury - analysis; Mining; Natural water pollution; Oxides - chemistry; Pollution; Pollution sources. Measurement results; Pollution, environment geology; River sediments; Soil and sediments pollution; Soil Pollutants - analysis; Suspended particulate matter; Water Pollutants, Chemical - analysis; Water treatment and pollution; South America; Brazil; America; Aluminum; Suspended particulate matter; Iron; River sediments; Mercury; Floodplain lakes; Manganese; Gold ore; Oxidation reduction; Chemical analysis; Pollutant behavior; Tropical zone; Mobility; Aluminium Hydroxides oxides; Soil pollution; Sediments; Iron Hydroxides oxides; Heavy metal; Suspended particle; Ore mining; Flood plain; Content; Lakes; Manganese Hydroxides oxides; Stream; Water pollution; Geochemical cycle; GOLD; AMAZON; SOILS; river sediments; mercury; suspended particulate matter; CONTAMINATION; aluminum; ADSORPTION; manganese; WETLAND; iron; floodplain lakes
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/S0048-9697(00)00544-1

Sediments from nine floodplain lakes in Pantanal were analyzed for a large-scale (300 km) survey of mercury (Hg) load in sediments and soils of the Alto Pantanal and to study the relationship between Hg and reactive aluminum, iron, and manganese oxy-hydroxides. The results were compared with the Hg content in river and stream sediments from the Poconé gold mining area, where Hg has been extensively used and still is in use. The results indicate that the Hg concentrations were elevated in river sediment close to the mining area in Bento Gomes river basin (average in the <74-μm fraction 88.9 ng Hg g
−1 dry wt.; interquartile range 50.3–119.5), but there was no clear indication that the local Hg emissions have contaminated the remote floodplain lakes, where concentrations were surprisingly low (average in the <74-μm fraction 33.2 ng Hg g
−1 dry wt. sediment; interquartile range 18.4–46.8), in particular when considering geochemical characteristics of the sediment. The sediment from the floodplain lakes contained less Hg-tot and more reactive iron oxy-hydroxides than soils from the Tapajós area in the Amazon basin. This resulted in a mass ratio between Hg and amorphous oxy-hydroxides of only 5×10
−6 for Hg-tot/Fe-oxa (interquartile range 3–7×10
−6).