Research Of Biochemical Treatment Of Sludge To Removal Heavy Metals

With the popularity of sewage treatment facilities in our country,the sludge is growing.The traditional sludge disposal ways of sludge land use to solve the problem of sludge disposal can still play an important role.Based on the biological characteristics of microbial leaching to remove heavy metals in the sludge,the object of this study choose the sludge of urban sewage treatment plant,to remove the heavy metals in the sludge biological leaching method was studied,Mainly includes: strain selection,process parameter optimization,discussing influence factors,biological lixiviate reactor operation and mechanism is discussed,and the use of electric repair technology and the combination of the biological leaching technology and the operation effect is analyzed.The results show that:Solid concentration for pH lower sludge has obvious effect;Thiobacillus ferrous oxide and sulfur oxide thiobacillus for sludge lower p H have different rate and the minimum initial pH,Among them,the oxidation of ferrous sulfur bacillus of biological leaching action more quickly in the start stage,while the reaction time is longer,sulfur oxide sulfur bacillus reach discharge standards of treatment effects take a long time.So using thiobacillus ferrous oxide as test strains.By adding the mixed mode of sulfur bacteria inoculation fluid,increase the leaching of heavy metals removal effect,shorten the cycle;This paper contrast research with sulfur bacteria mixture quantity of 5%,10%,15% and 20% respectively of drain out the effect of heavy metals in sewage sludge.Also compared the concentration of 5 g/L respectively,10 g/L,20 g/L and 30 g/L ferrous sulfate substrates under the effect of biological leaching reaction.In consideration of various factors such as the cost and effect of microbial treatment,inoculation amount of 10% sulfur bacteria mixture concentration and 10g/L sulfur concentration for the best effect of experimental parameters.The article also analyzed through experiment contrast of city sludge initial pH value,the sludge solids concentration on the influence of the biological leaching efficiency of heavy metal sludge.This paper discusses the use of electric,with the method of repairing technology and biological leaching technology,optimize the sludge biological leaching technology.Electric repair technology and biological leaching technology in addressing the problem of heavy metal sludge respectively are flawed,but the two together can make up for the defects.Biological leaching process of heavy metals from sulfide form into ionic form,electric repair will be in the form of ion migration of heavy metals to the cathode area,is helpful to remove the heavy metals in the sludge.But no ion selective ion migration mechanism of electric repair,the ferrous ions in the substrate will be synchronous migration,causing oxidation leaching process of ferrous sulfur bacillus in late lose energy source,which is difficult to convert heavy metals,affect the leaching effect.So can't synchronize biological leaching and electric repair at the same time.This paper argues that the biological leaching after first electric repair is more reasonable than synchronized.