Investigation On Occurrence Process Of Vanadium Contamination In Geological Environment In Panzhihua And Bioremediation Evaluation

Vanadium is a typical redox sensitive element.Due to geological weathering and human activities such as mining and smelting,the contamination of vanadium in soil and groundwater has become more and more serious,which has aroused widespread concern.Vanadium is a typical redox-sensitive metal.Due to geological weathering and human activities such as mining and smelting,the contamination of vanadium with soil and groundwater has become more and more serious,which has aroused widespread concern,however the research on the occurrence process of vanadium pollution in geological environment is few,and research on related repair technologies is still weak.This study carried out the following studies for the Panzhihua region:The leaching of six industrial ash samples produced during the smelting of vanadium-titanium magnetite was studied.It was found that there are different degrees of vanadium release,and the maximum amount of V?V?drenching of removal?VR?and thick broken removal dust?TB?are 124.5±2.4 mg/L and 31.4±2.3 mg/L,respectively.However,the V?V?concentration in the leachate is significantly decreased after mixing with the soil.At the same time,light,carbon sources,oxygen,and nitrate affect the leach of V?V?.Microbial sequencing shows that in all systems,the microbial communities changed significantly after leaching,and the four genes of Sphingomonas,Symbiobacterium,Anaerobacillus and Gemmatimonas were highly enriched,which may be closely related to the leach and reduction of V?V?.The soil column leaching experiment is used to simulate the migration and transformation process of V?V?in soil.It is found that in addition to the retention of the soil itself,soil microorganisms had a certain V?V?fixed ability during the leaching process,and the presence of nitrates weakened the ability of the soil to adsorb V?V?.The long-term leaching rate process can significantly change the physical and chemical indicators of the soil,such as the increase of oxidation-reduction potential,the increase of pH value,the decrease of organic matter and the increase of soil enzyme activity.The 16S rDNA analysis showed that the abundance of Nitrospira,Polycyclovorans and Arthrobacter increased significantly after leaching,and they may be the main functional microorganisms for reducing and fixing V?V?.The feasibility of microbial reduction fixation V?V?and the interaction with common coexisting electron acceptors in groundwater are explored.The results showed that the presence of NO₃^-slowed down the removal of V?V?but eventually led to a similar reduction efficiency to that in the reactor without NO₃^-.The addition of Fe³⁺,SO₄²-,or CO₂ decreased the efficiency of V?V?reduction.Furthermore,the microbial reduction of these coexisting electron acceptors was also adversely affected by the presence of V?V?.High-throughput 16S rRNA gene pyrosequencing analysis indicated the accumulation of Geobacter,Longilinea,Syntrophobacter,Spirochaeta and Anaerolinea,which might be responsible for the reduction of multiple electron acceptors.The results obtained in this study can deepen the understanding of the process of vanadium pollution,its migration in soil and the restoration of groundwater vanadium pollution,and provide theoretical and technical support for the prevention and repair of vanadium pollution in soil and groundwater.