Study On Activities Of Acidithiobacillus Ferrooxidans And Their Effects On Desulfurization From Coal Gangue

Acidithiobacillus ferrooxidans(A.f) can effectively remove sulfur from the coal gangue and make them profitable and related to the activity of A.ferrooxidans the desulfurization effect is directly.For detecting the activity of acidithiobacillus ferrooxidans,and their activity effects on desulfurization from coal gangue,three pure strains named YQ-01,YQ-02 and YQ–03 were isolated by using 9k liquid medium and modified 9k solid medium from acidic mine drainage(AMD)in Yangquan,Shanxi province.their shape and structure were observed by optical microscope and scanning electron microscope(SEM)their quality were identified using gram staining method and their activity was detected by both chemiluminescence and potassium dichromate titration methods;Then,they were used to desulfurize from coal gangue.The concentrations of sulfate ion in leachate were detected,and the desulfurization rate was calculated by measuring the change of S content,the relationship between desulfurization rate and activity of A.ferrooxidans was studiedThe results showed that:(1)The three bacterial species YQ-01,YQ-02,and YQ-03,which were about 1-2mm in length and about 0.5-0.8mm in width,can use elemental sulfur,thiosulfate and ferrous ions as energy substances,and they were Gram-negative bacteria and the autotrophic,indicating these three bacterial all belong to the Acidithiobacillus ferrooxidans;(2)The time of luminous intensity from trough to the peak was linearly related with the concentration of ferrous ions,the time of luminous intensity from trough to the peak increases with the concentration of ferrous ions increasing.Through the standard curve about the time and the concentration of ferrous ions,the latter can be calculated by the former.The results from chemiluminescence method and the potassium dichromate titration method were similar,Paired t test results showed there were no significant difference between the two methods,the recovery test of chemiluminescence and potassium dichromate titration showed that the recovery rate was 95%~105%,and the relative standard deviation(RSD)<3.3%.The ferrous oxide activity of these three bacterial from low to high is YQ-02,YQ-01 and YQ-03.(3)The total sulfur removal rates of the experimental groups of YQ-01,YQ-02,and YQ-03 were 52.89%,59.45%,and 47.21%,respectively,and the total sulfur removal rate of the control group without bacteria inoculation was 15.61%.The above results indicated that both chemiluminescence and potassium dichromate titration can be used to determine the activity of Acidithiobacillus ferrooxidans.Acidithiobacillus ferrooxidans will significantly increase the desulfurization efficiency during the coal gangue leaching process,and the desulfurization effect is positively correlated with the ferrous activity of the bacteria.This study can provide a new method for detecting the activity of Acidithiobacillus ferrooxidans and provide theoretical guidance for the screening of Acidithiobacillus ferrooxidans in desulfurization of coal gangue.