Effect of CO2 on the activity and formation of secondary iron minerals by Acidithiobacillus ferrooxidans
The effects of 0.03％(CO2 content in air),3％,6％,9％and 12％CO2 concentrations on the activity of Acidithiobacillus ferrooxidans and the formation of secondary iron minerals were studied using shaking flask experiments to simulate the iron-rich and sulfate-rich environment.The pH,Fe2+oxidation rate and oxidation rate,total Fe precipitation rate and secondary iron mineral phase-related indicators were analysed.The results showed that when the concentration of CO2 was 3％,the ability of bacteria to oxidise Fe2+was the strongest and the oxidation efficiency of Fe2+reached 100％at 72h.At the end of the experiment,the total Fe precipitation rate was the highest,at 42.8％.With the increase in CO2 concentration,the activity of A.ferrooxidans in each system was inhibited.The final minerals obtained in different CO2 concentration systems were all jarosite minerals mixed with a small amount of schwertmannite.An appropriate increase in CO2 concentration is therefore helpful to improve the activity of A.ferrooxidans and promote hydrolysis mineralisation,thus increasing mineral yield.This study provides a theoretical basis for the treatment of acid mine waste water.
CO2A.ferrooxidansbiooxidationsecondary iron minerals
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