Innovative Precipitation-Flocculation Process for Treating Turbid Waters from Gualaxo do Norte River, Brazil

  • H. A. Oliveira
  • A. Azevedo
  • J. RubioEmail author
Technical Note


Physical and chemical characterization and solid/liquid separation of turbid waters from a river affected by an iron tailing rupture disaster (Gualaxo do Norte River, Brazil) were studied at bench scale. Parameters such as turbidity, pH, surface tension, electrical conductivity, total suspended solids (TSS), particle size distribution (micro- and nanoparticles), and zeta potential were analyzed from samples collected at three different river depths. The results in all samples showed the presence of micro- and nanoparticles, ranging in diameters from 100 nm to 200 μm. Best results for flocculation and settling were obtained at pH 7.5, through an innovative combination of eco-friendly reagents: (i) ferric hydroxide precipitates (10 mg L−1 Fe3+) to sweep (enmesh) the dispersed solids and (ii) gelatinized starch (5 mg L−1) to form large flocs. The results showed removals between 90 and 100% of total suspended solids (micro- and nanoparticles), resulting in clear water with residual turbidity < 7 NTU. It is believed that this innovative alternative has a high potential for flocculating and treating the turbid water at Gualaxo do Norte River, assisting the water treatment stations.


Polluted rivers Turbid water Flocculation Corn starch 



The authors thank the Brazilian Institutes, namely, CNPq, CAPES, and Renova Foundation, for supporting our research. Special thanks to our University—UFRGS—and to all students for their collaboration.

Compliance with Ethical Standards

Conflict of Interest

The authors declare that there is no conflict of interest.


  1. 1.
    National Department of Mineral Production – DNPM (in Portuguese), 2016. Sumário Mineral. Vol. 35. Available at: Accessed on April 2019
  2. 2.
    Kossoff D, Dubbin WE, Alfredsson M, Edwards SJ, Macklin MG, Hudson-Edwards KA (2014) Mine tailings dams: characteristics, failure, environmental impacts, and remediation. Appl Geochem 51:229–245. CrossRefGoogle Scholar
  3. 3.
    Carmo FF et al (2017) Fundão tailings dam failure: the environment tragedy of the largest technological disaster of Brazilian mining in global context. Perspect Ecol Conserv 15(3):145–151. CrossRefGoogle Scholar
  4. 4.
    Fuerstenau MC, Yoon RH, Jameson GJ, 2007; Froth flotation: a century of innovation. Society for Mining, Metallurgy, and Exploration-SME, ISBN: 978-0873352529, 891Google Scholar
  5. 5.
    Mudd GM (2007) Global trends in gold mining: towards quantifying environmental and resource sustainability. Res Policy 32(1–2):42–56. CrossRefGoogle Scholar
  6. 6.
    Adiansyah JS, Rosano M, Vink S, Keir G (2015) A framework for a sustainable approach to mine tailings management: disposal strategies. J Clean Prod 108(A):1050–1062. CrossRefGoogle Scholar
  7. 7.
    Water National Agency - ANA (in Portuguese), 2017. Encarte especial sobre a qualidade das águas do Rio Doce após 2 anos do rompimento da barragem de Fundão 2015–2017. Available at Accessed on August 2018
  8. 8.
    Golder Associates, Brasil Consultoria e Projetos Ltda. Programa de Caracterização Geoquímica de Rejeitos, Solos e Sedimentos, 2007. Available at In Portuguese. Accessed on August, 2018
  9. 9.
    Water National Agency – ANA (in Portuguese), 2016. Conjuntura dos Recursos Hídricos no Brasil Informe 2015. Available at: Accessed on August, 2018
  10. 10.
    European Chemicals Bureau, 2002. European Union Risk Assessment Report: acrylamide. Vol. 24. CAS No: 79-06-1. EINECS No: 201-173-7. Available at: Accessed on August 2018
  11. 11.
    Weisseborn PK, Warren LJ, Dunna JG (1995) Selective flocculation of ultrafine iron ore. 1. Mechanism of adsorption of starch onto hematite. Colloids Surf A Physicochem Eng Asp 10:11–27. CrossRefGoogle Scholar
  12. 12.
    Shrimali K, Atluri V, Wang Y, Bacchuwar S, Wang X, Miller JD (2018) The nature of hematite depression with corn starch in the reverse flotation of iron ore. J Colloid Interface Sci 524:337–349. CrossRefGoogle Scholar
  13. 13.
    Etchepare R, Azevedo A, Calgaroto S, Rubio J (2017) Removal of ferric hydroxide by flotation with micro and nanobubbles. Sep Purif Technol 184:347–353. CrossRefGoogle Scholar
  14. 14.
    Pavlovic S, Brandao PRG (2003) Adsorption of starch, amylose, amylopectin and glucose monomer and their effect on the flotation of hematite and quartz. Miner Eng 16:1117–1122. CrossRefGoogle Scholar
  15. 15.
    Rao KH, Forssberg KSE. (2007) Chemistry of iron oxide flotation. In: Fuerstenau MC, Jameson GJ, Yoon R-H, editors. Froth flotation: a century of innovation. Littleton, Colorado: Society for Mining, Metallurgy, and Exploration - SME. p. 498–513Google Scholar
  16. 16.
    Peres AEC, Correa MI (1996) Depression of iron oxides with corn starches. Miner Eng 9(12):1227–1234. CrossRefGoogle Scholar
  17. 17.
    Sengil A, Ozdemir A (2012) Simultaneous decolorization of binary mixture of blue disperse and yellow basic dyes by electrocoagulation. Desalin Water Treat 46(1–3):1–12. CrossRefGoogle Scholar
  18. 18.
    Xiao F, Zhang X, Ma J (2009) Indecisiveness of electrophoretic mobility determination in evaluating Fe(III) coagulation performance. Sep Purif Technol 68(2):273–278. CrossRefGoogle Scholar
  19. 19.
    Hendricks DW 2006. Water treatment unit processes: physical and chemical. 1st Ed., CRC Press, ISBN 9780824706951, Chapter 3, page 310Google Scholar
  20. 20.
    Filippov LO, Severov VV, Filippov IV (2013) Mechanism of starch adsorption on Fe–Mg–Al-bearing amphiboles. Int J Miner Process 123:120–128. CrossRefGoogle Scholar

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© Society for Mining, Metallurgy & Exploration Inc. 2019

Authors and Affiliations

  1. 1.Laboratório de Tecnologia Mineral e Ambiental (LTM), Departamento de Engenharia de Minas (DEMIN), PPGE3MUniversidade Federal do Rio Grande do SulPorto AlegreBrazil

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