Studies On Screening Of High-efficiency Bacteria Of Degrading H₂S And Extracellular Polymeric Substances And Biomass

Stench brought about an increasing number of problems to people's lives,it has become a serious social problems and environmental issues.Biological methods removing the gas of the stench have developed from the mid-20th century,which have some advantages,such as high removal efficiency,simple treatment plant,low-cost,the easy operation and maintenance,avoiding secondary pollution and so on.In this paper, it removed H₂S to use the biological filter,and researched the biofilm of this system.First,the sludge from the sugar factory had been domesticated,and isolated six different bacteria which were designated L1,L2,L3,L4,L5,L6.These bacteria had a degradation experiment,which found that the removing effect of bacteria L2 is the best in the shortest possible time.So,the bacteria L2 had been researched in different growing environment,the experiment showed that the growth of the bacteria at 20℃～35℃,pH 6.0～7.0 is the best.And the bacteria L2 had been used the bio-trickling reactor.In this reaction system,the packing were ceramisites which have a big porosity and surface area,and this system had used a gas-liquid counter-current culture.The experimental results showed that in the residence time of 70s,this system could deal with H₂S gas of 1200mg/m³ concentration,and the removal efficiency could reach to 87%.Secondly,After the stability of the system,selected the ultrasonic method to extract the biofilm of the reaction system on the ceramisites by comparing physical methods and chemical methods,and the experimental results showed that the ultrasound time of the best extraction was 25min.In addition,in this experiment,extracellular polysaccharides were used to replace the EPS,therefore,it determine extracellular polysaccharides to use the phenol sulfuric acid method,and the reliability of the method was researched,the results showed that the stability,the precision,the reproducibility, the recovery of the method was relatively good.And then,in different environmental conditions such as temperature,pH,different fill height,different the inlet concentration of H₂S,the polysaccharides were determined,experimental results showed that the growth of the polysaccharides was the best at 20℃～30℃,pH 6.0～7.0,the polysaccharides were more the upper fill than the lower fill,and the relation between the polysaccharides and the removal rate had the good correlation,it illustrated the polysaccharides had an adsorption to H₂S.Finally,it determined the activity of biofilm biomass to use the Colorimetric phospholipid method,and the biomass in different inlet H2S concentration,different packing layer height were measured,the results showed that the biomass of the upper tower were more than the lower,and the relation between the biomass and the removal rate were good correlation as well as the relation between the biomass and the polysaccharides.