Release And Control Of Hydrogen Sulfide In Sewage Sludge

During the treatment and disposal process of sludge,there is inevitably a number of different kinds of odour gases released.There are eight odours in GB14554-93: hydrogen sulfide,methyl mercaptan,a sulfide,dimethyl disulfide,carbon disulfide, ammonia,trimethylamine and styrene.The odour from sludge contains almost all of the above pollutants,five of them are sulphur compounds.Sludge contains a lot of microorganisms,and because hydrogen sulfide is the end-product of microbial action, so hydrogen sulfide released from different sludges' is mainly studied.Hydrogen sulfide is related to microorganisms(mainly sulfate-reducing bacteria) in sludge.Beginning with the release mechanism of hydrogen sulfide,three areas were studied.First of all,the characteristic of sludge related to sulfate-reducing bacteria is researched in order to estimate whether there is a preliminary environment for sulfate-reducing bacteria.Secondly,on the base of sufficient evidence of sulfate-reducing bacteria's entity,a farther investigate which cultivating sulfate-reducing bacteria of sludge is done and a preliminary exploration of ultrasonic on sulfate-reducing bacteria is conducted.Finally hydrogen sulfide form sludge is absorbed by copper-iron absorption,and the relationship between sulfate-reducing bacteria and hydrogen sulfide is explored.Four sludges,Hefei municipal sludge, Sibao municipal sludge,dyeing sludge and leather sludge are researched.The major results were summarized as follows:1.There is a environment for sulfate-reducing bacteria to grow and reproduce.2.Sludge possess the substance to satisfy the growth of sulfate-reducing bacteria;The entity of sulfate-reducing bacteria in sludge is confirmed,the growth of sulfate-reducing bacteria in sludge is different by various preservation;Ultrasonic with same frequency effect on sludges,sulfate-reducing bacteria in Sibao municipal sludge and leather sludge is deactived,while Hefei and dyeing sludge's is still in active.3.The quantity of hydrogen sulfide released from Hefei municipal sludge and Sibao municipal sludge are 1000 times more than dyeing sludge and leather sludge.The process that hydrogen sulfide released from Sludge can be divided into four stages. The more SRB in sludge the more hydrogen sulfide emission is detected.Copper-iron absorption rate of hydrogen sulfide with high concentrations is all close to 100 percents,while low concentration is relate to the concentration of hydrogen sulfide; Hydrogen sulfide emission from Sibao municipal sludge,dyeing sludge and leather sludge,which via copper-iron absorption can reach first-degree of factory sector standards.Hefei municipal sludge's can meet the second-degree standard.