Remediation experiment of Ecuadorian acid mine drainage: geochemical models of dissolved species and secondary minerals saturation

Autor: C. Barba-Brioso, Joaquín Delgado, Tomasz Boski, Diana Ayala, Sandra Torres, Flavio López, Edmundo Calderón
Rok vydání: 2019
Předmět:
Metal removal
Caustic magnesia
Health
Toxicology and Mutagenesis
Passive treatment
Sw
Environmental pollution
AMD
010501 environmental sciences
Ferric Compounds
01 natural sciences
chemistry.chemical_compound
Zaruma-Portovelo mining district
Environmental Restoration and Remediation
Minerals
Rare-earth-elements
Iberian Pyrite Belt
Sulfates
Chemistry
Hydro-geochemistry
General Medicine
Pollution
Stream waters
Metals
Environmental chemistry
Carbonate
Ecuador
Environmental Monitoring
Environmental remediation
Iron
Mine waste revalorization
engineering.material
Mining
Water remediation
Ferrihydrite
Rivers
Jarosite
Mining cctivities
Environmental Chemistry
Ecosystem
0105 earth and related environmental sciences
Schwertmannite
Puyango river-basin
Acid mine drainage
Phosphate
Models
Chemical
Secondary mineral cycles
engineering
Metals
Rare Earth
Acids
Iron Compounds
Water Pollutants
Chemical
Zdroj: Repositório Científico de Acesso Aberto de Portugal
Repositório Científico de Acesso Aberto de Portugal (RCAAP)
instacron:RCAAP
ISSN: 1614-7499
0944-1344
DOI: 10.1007/s11356-019-06539-3
Popis: Acid mine drainage is one of the main environmental hazards to ecosystems worldwide and it is directly related to mining activities. In Ecuador, such acidic-metallic waters are drained to rivers without treatment. In this research, we tested a laboratory combined (Ca-Mg) Dispersed Alkaline Substrate (DAS) system as an alternative to remediate acid drainage from the Zaruma-Portovelo gold mining site, at El Oro, Ecuador. The system worked at low and high flow hydraulic rates during a period of 8 months, without signs of saturation.. Analysis of physico-chemical parameters and water composition (ICP-OES, ICP-MS) demonstrated that treatment effectively increased water pH and promoted the retention of about 80% of Fe, Al, Mn and Cu. Under acid conditions As, Cr and Pb concentrations decreased with Fe and possible precipitation of jarosite and schwertmannite. However, the homogeneous depletion of Cr at pH above 6 could be related to ferrihydrite or directly with Cr (OH)(3) precipitation. After DAS-Ca, sulphate, phosphate and rare earth elements (REE) concentrations decreased to 1912, 0.85 and 0.07 mg/L respectively, while DAS-Mg contributed to form a complex model of minor carbonate and phosphate phases as main sink of REE. DAS-Mg also promoted the retention of most divalent metals at pH values over seven. Thus, this low cost treatment could avoid environmental pollution and international conflicts. Anyway, further investigations are needed to obtain higher Zn retention values. PROMETEO Ecuadorian program (Secretary of Superior Education, Science, Technology and Innovation) info:eu-repo/semantics/publishedVersion
Databáze: OpenAIRE
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