Abstract
The role of soil could be decisive for the neutralization of the acid solution and immobilization of the metallic contaminants produced by mining industry. We studied micromorphological indicators of the interaction between the acid solution and soil material in the profile of Fluvisol at the Bacanuchi river (Sonora River Basin, Mexico) terrace affected by the catastrophic mine spill and in analyzing sample from a soil column treated with an acid liquid imitating the spill. Original unaffected soil is sandy with poorly developed pedogenetic features, however, frequent primary and secondary micritic and sparitic carbonates define high pH values. In the soil influenced by acid solutions under natural and laboratory conditions, carbonates were absent whereas neoformed gypsum crystals with radial intergrowth were observed together with accumulation of fine material enriched in ferruginous pigment. Micromorphometric quantification of the iron-rich fine material has shown its increase after interaction with the acid solution. We conclude that the interaction consisted of the neutralization reaction between the more reactive phases of the soil and the acid solution during which carbonates were consumed and gypsum was neoformed. Fine iron oxides precipitated after neutralization of acidity, the pH increased and the color changed. It is highly probable that other metallic contaminants co-precipitated with the ferruginous components.
Highlights
Copper is a metal that has been used by man for 5 thousand years, at the present time it is widely used in modern industry
The basin of the Sonora River сovers an area of 30,913 km2, the study area is limited to the Bacanuchi River, which is part of the Sonora river basin
Near to the concentrations of ferruginous fine material we identified neoformed gypsum with radial intergrowth (Figure 6D), whereas carbonates are absent
Summary
Copper is a metal that has been used by man for 5 thousand years, at the present time it is widely used in modern industry. The predominant kind of extraction is the surface mining that drastically transforms the local environment. The mining operations can have physical, chemical and biological effects on soil and rock (solid phase), groundwater and surface water (liquid phase) and air and pore gases (gaseous phase) (Morin and Hutt 2001). An example of this is the Cananea mining district in Sonora-Mexico, ranked among the 11 major mineral-producing countries in the world. Ore extraction during 150 years has removed entire hills in the area (Suppen et al 2006). The continuous infiltration of acid leachate from the mines to the rivers changes the water quality, endangering human health and aquatic fauna (Gómez et al 1986, 1990)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
