Experimental Study On The Effect Of Vermicompost Humidity On Hydrogen Sulfide Gas Purification

With the continuous improvement of China's economic level,people's awareness of environmental protection is gradually enhancing,and their vision for a better living environment has become stronger and stronger.In the past,the work and research focusing on dust as the characteristic pollutant have been far from meeting people's requirements on living environment quality.Hydrogen sulfide,the key component of malodorous pollution,has attracted the attention of researchers all over the world.At present,all kinds of materials and methods for the treatment of hydrogen sulfide foul gas have their own advantages and disadvantages.Some materials have poor treatment effect,because they can't solve the problem of hydrogen sulfide odor pollution fundamentally;Some of them are expensive and difficult to obtain.We have difficulty obtaining materials in time,which will lead to treatment failure.Based on the current situation,this paper chose vermicompost as a kind of porous media biological adsorption material with good deodorization effect,green environmental protection,convenient access,economic benefits to remove the malodorous gas of hydrogen sulfide.This experiment chose vermicompost as adsorption material,and chose hydrogen sulfide as the testing material.Vermicompost with different humidity was used as comparison in this experiment.The removal process of hydrogen sulfide by vermicompost was simulated in 1L serum bottle under normal temperature and normal pressure.The treatment effects and reasons,adsorption and degradation process and deodorization mechanism of vermicompost with different humidity on hydrogen sulfide odor gas were studied to provide data reference for the follow-up study on treating odorous gas with vermicompost as reactor.The main results and conclusions of this paper are shown as follows:?1?In this experiment,five humidity gradient namely 30%,40%,50%,60%and 70%,were selected as the removal matrix of hydrogen sulfide fetid gas in vermicompost.The experimental results show that the removal effect of hydrogen sulfide is remarkable when the humidity of vermicompost is 50%-60%,and the concentration of the effluent gas can basically meet the national first-level emission standard of fetid pollutants.Within this humidity range,vermicompost has moderate water content and good adsorption performance.The sulfur-oxidizing bacteria can adapt to the growing environment and increase the number in vermicompost.?2?The pH of vermicompost with each humidity levels did not decrease significantly as described in other papers before and after the reaction.On the contrary,the pH of vermicompost was close to that of the original vermicompost and remained neutral,indicating that vermicompost has a good buffer capacity for pH changes.?3?After the end of this experiment,the EC of vermicompost with various humidity levels increased compared with that of the original vermicompost,especially in vermicompost with the humidity level of 50%.The contents of nutrients such as N,P,K in the matrix of vermicompost with 50%humidity are abundant,and the metabolism activity of microorganisms is strong.Microbial action accelerates the decomposition of organic matter in vermicompost,releasing soluble mineral salts and inorganic ions,etc.Therefore,EC increases.?4?After the end of this experiment,the species and quantity of sulfur oxidizing bacteria in vermicompost with a humidity of 50%were significantly higher than that in vermicompost with a humidity of 30%.Water condition,porosity,pH condition and nutrient condition were all suitable for the survival of sulfur-oxidizing bacteria.However,the moisture condition of vermicompost with a humidity of 30%was not good,and the sulfur oxidizing bacteria died before the end of domestication,only leaving physical adsorption.After adsorption and saturation,the treatment capacity of vermicompost will be reduced to 0.The final product of the reaction is SO₄^2-.?5?During the whole removal process,N,P,K and the other nutrients were reduced,but they could be absorbed and utilized by sulfur oxidizing bacteria and maintain a high removal capacity.Therefore,in the process of this experiment,the nutrients were not an obstacle condition in the process of systematic deodorization.