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Sulfuric material refers to soil material that has a pH of less than 4 owing to the oxidation of sulfidic material. [ 27 ] Sulfidic material refers to “soil materials containing detectable inorganic sulfides (≥0.01% sulfidic sulfur) that can exist as horizons or layers at least 30 mm thick or as surficial features”, [ 27 ] and is further ...
The chemistry of oxidation of pyrites, the production of ferrous ions and subsequently ferric ions, is very complex, and this complexity has considerably inhibited the design of effective treatment options. [6] Although a host of chemical processes contribute to acid mine drainage, pyrite oxidation is by far the greatest contributor.
On Earth, jarosite is mainly associated with the ultimate stage of pyrite oxidation in clay environment, and can also be found in mine tailings waste where acidic conditions prevail. Against all expectations, jarosite has also been fortuitously discovered in minute quantities in the form of small dust particles in ice cores recovered from a ...
In ore deposit geology, supergene processes or enrichment are those that occur relatively near the surface as opposed to deep hypogene processes. Supergene processes include the predominance of meteoric water circulation (i.e. water derived from precipitation) with concomitant oxidation and chemical weathering.
Pyrite oxidation is sufficiently exothermic that underground coal mines in high-sulfur coal seams have occasionally had serious problems with spontaneous combustion. [47] The solution is the use of buffer blasting and the use of various sealing or cladding agents to hermetically seal the mined-out areas to exclude oxygen.
In situ chemical reduction (ISCR) is a type of environmental remediation technique used for soil and/or groundwater remediation to reduce the concentrations of targeted environmental contaminants to acceptable levels. It is the mirror process of In Situ Chemical Oxidation (ISCO).
Two scientists prepare samples of soil mixed with oil to test a microbe's ability to clean up contaminated soil. Microbial remediation is used in soils to remove contaminants and pollutants. Microbes play a key role in many biogeochemistry cycles and can effect a variety of soil properties, such as biotransformation of mineral and metal ...
The microbial oxidation process occurs at the cell membrane of the bacteria. The electrons pass into the cells and are used in biochemical processes to produce energy for the bacteria while reducing oxygen to water. The critical reaction is the oxidation of sulfide by ferric iron. The main role of the bacterial step is the regeneration of this ...