The Study Of Nickel Biomineralization Induced By Sporosarcina Pasteurii And Its Applications

Biomineralization is a ubiquitous phenomenon in nature,which is the process of generating inorganic minerals based on biochemical reactions.Microorganisms can carry out life activities under different environmental conditions,and can also play their own roles in some extreme environments.Bacteria have relatively large surface area and volume ratios,and can accumulate various metal ions on the surface or in the body,regulate the material circulation process in the ecosystem,and maintain the relative stability of the earth’s environmental conditions.Microbial induced mineralization is a kind of biomineralization,this technology has often used in engineering in recent years.Among them,bacteria that can produce urease to catalyze the decomposition of urea into carbonate radicals were widely used in many fields such as remediation,environmental protection,and medicine due to their extremely high reaction efficiency and conversion rate.Nickel is a transition element distributed in water,soil,plants and microorganisms.Nickel metals and compounds are widely used in stainless steel,alloys,and electroplating.Nickel waste is generated in industry,and untreated discharge cause to pollute water and soil.Nickel-plating wastewater is a kind of industrial nickel wastewater with high toxicity and difficult to degrade.The existing physical and chemical treatment methods have their own advantages and disadvantages.Compared with these disadvantages,biological methods have the benefits of mild conditions and low energy consumption.At the same time,the use of biomineralization to synthesize metal compounds with application value has become popular in recent years,which can improve material properties and reduce pollution.In this paper,the urealytic bacteria,Sporosarcina pasteurii from soil was used as the bacteria to study the biomineralization phenomenon and products of nickel,and analyze the removal of nickel ions after mineralization.In this study,the culture method of Sporosarcina pasteurii was optimized,and bacteria with high urease activity were obtained.At the same time,the mineralization of nickel ions was studied with it,and the product was determined to be spherical nickel minerals Ni₂CO₃（about 100 nm in diameter）.Then the mechanism and influencing factors were analyzed.The mechanism and influencing factors were analyzed.In addition,the removal rate of nickel ions after solution mineralization was also analyzed,and the highest was 99.52%.In view of the high nickel removal rate of Sporosarcina pasteurii cultured by this method,this paper attempts to treat the electroless nickel plating wastewater.The mass concentration analysis determined that the concentration of nickel can be reduced to within 0.5 mg/L of the emission standard.In conclusion,this thesis studied the biomineralization phenomenon and products of nickel induced by Sporosarcina pasteurii from the perspective of material characterization.The optimum amount of components was obtained,and the highest removal rate was obtained.The chemical nickel plating wastewater was treated by the mineralization method,and the discharge standard of nickel content was reached.At the same time,the products of bacterial mineralization of various metal ions were explored,and the results will promote the research process based on the biomineralization of Sporosarcina pasteurii.