Study On The Preparation Of Biochar Based Solid Bacterial Agent And Its Application In Hydrogen Production

The problem of energy shortage and environmental pollution is becoming increasingly serious,and the development of renewable and clean energy that can replace fossil fuels is imperative.High calorific value and low pollution hydrogen energy is considered the most ideal alternative.Anaerobic fermentation for hydrogen production has become a hot research topic due to its wide range of available substrate sources,mild reaction conditions,low environmental impact,and high hydrogen production.However,traditional anaerobic dark fermentation for hydrogen production generally uses liquid inoculum inoculation,which has problems such as easy bacterial infection,complex inoculation process,difficult storage,and low hydrogen production efficiency.This project uses biochar materials as carriers to prepare biochar based solid bacterial agents,which improve the anaerobic dark fermentation hydrogen production performance.At the same time,the bacterial agents are applied to the fermentation hydrogen production process using food waste as the substrate,achieving high-value utilization of waste resources.The above research results can provide reference for the industrial preparation and application of biochar based solid bacterial agents.The main research content is as follows:（1）Preparation and hydrogen production capacity exploration of biochar based solid bacterial agents.In order to avoid the drawbacks of liquid inoculum inoculation,this paper uses biochar materials as carriers and anaerobic activated sludge as the source of bacterial strains,successfully preparing solid bacterial inoculums based on corn straw biochar,rice husk biochar,and bamboo charcoal biochar.The fermentation results showed that inoculation with corn straw biochar based,rice husk biochar based,and bamboo charcoal biochar based solid bacterial agents could successfully produce hydrogen.When using 12 g/L xylose,glucose,and soluble starch as substrates for fermentation,the inoculation group with corn straw biochar based solid bacterial agents achieved the highest cumulative hydrogen production and hydrogen production rate,with hydrogen production rates of1.45 mol H₂/mol xylose,2.03 mol H₂/mol glucose,and 1.92 mol H₂/mol glucose,respectively.（2）Optimization for hydrogen production of biochar based solid bacterial agents.In order to improve the hydrogen production efficiency of anaerobic dark fermentation,this paper studied the immobilization time,preparation culture ratio,modification of L-cysteine,and the effect of inoculum amount on hydrogen production during the fermentation process.The research results indicate that the corn straw biochar based solid bacterial agent prepared with a immobilized time of 24 hours and a preparation culture ratio of 1.0:100 has the best performance.Under the fermentation conditions of 12 g/L starch as the substrate,the maximum hydrogen production rate was2.13 mol H₂/mol glucose,which is better than the fermentation results obtained by inoculating liquid free sludge.L-cysteine modified bacterial agents can further improve hydrogen production performance.When the mass ratio of L-cysteine content to biochar addition is 1:1 during the bacterial preparation process,the cumulative hydrogen production obtained by fermentation is the highest,with a hydrogen production rate of 2.31 mol H₂/mol glucose.（3）Expanding research on the application of biochar based solid bacterial agents.In order to improve the convenience and efficiency of industrial application of biochar based solid bacterial agents,the preservation activity of the bacterial agent during cold storage was experimentally investigated.After six months of storage,the bacterial agent still had a preservation activity of93.9%,indicating that the bacterial agent is convenient for industrial storage and transportation;By measuring the surface loaded biomass and dehydrogenase activity of the bacterial agent,the hydrogen production capacity of the bacterial agent can be preliminarily predicted,making it easier to screen out inactive bacterial agents before application.In order to expand the application range of biochar based solid bacterial agents,the bacterial agents were applied to the fermentation process using food waste as the substrate.The experiment showed that the hydrogen production performance of food waste was significantly improved after oil removal and high-temperature pretreatment.The addition of biochar based solid bacterial agents can further improve the hydrogen production performance,and the maximum hydrogen production rate by inoculating solid bacterial agents can reach 133.37 m L H₂/g VS.In summary,this paper starts from the preparation of biochar based solid bacterial agents,optimizes the experimental conditions for hydrogen production in the solid bacterial agent fermentation system,expands its application scenarios,and successfully applies biochar based solid bacterial agents to the anaerobic dark fermentation hydrogen production process.This article provides another idea for the efficient and low-pollution inoculation method of biological hydrogen production.The characteristics of biochar based solid bacterial agents that are convenient for storage and transportation,as well as the diversity of application fields,are of great significance for the industrial development of biological hydrogen production.