Study On The Effect Of Chemical Accelerant On The Purification Of Industrial Waste Gas By Biofilm Filler Tower

Formaldehyde has great harm to the ecological environment and human health,and it has to attract people's attention.In order to minimize the damage of formaldehyde,researchers at home and abroad have been looking for ways to purify formaldehyde pollutants.The biological method of purification of waste gas has received wide attention,on this basis,the suitable chemical accelerator can be combined with formaldehyde in liquid phase to form more easily captured and degraded substances by microorganisms.Therefore,the effect of choosing high performance chemical accelerator on the purification ability of liquid phase accumulated formaldehyde is also a hot topic.In this study,formaldehyde waste gas was used as the object,the activated sludge was used to bio-acclimate the packed tower,The effects of the acid and thiosulfate on the purification performance of formaldehyde were studied,and using high-throughput sequencing to identify the microorganism flora in the packing tower and observe the change of the biological flora after the addition of the chemical accelerator.The conclusions are as follows:(1)The purification efficiency and biochemical removal of the packed column tend to be stable in about 40 days,and the purification effect can be put into use.(2)When the concentration of formic acid was 0.025 mol/L,the purification effect of formaldehyde in circulating liquid was the best.In the range of 5~20 L/h,the maximum biological removal rate of formic acid group was 9.3 mg/(L·h)higher than that of the blank group by 1.8 mg/(L·h).When the gas flow rate was more than 0.15m~3/h,the maximum biochemical removal capacity of blank group was 11 mg/(L·h),and that of formic acid group was 12.3 mg/(L·h),which was higher in formic acid group than that in blank group.(3)The concentration of Sodium Thiosulfate 0.05 mol/L was the best for the purification of formaldehyde,so the concentration of 0.05 mol/L was chosen to carry out the following related experimental study.In the range of 100~400 mg/L of formaldehyde inlet concentration,The efficiency of formaldehyde purification in sodium thiosulfate group is higher than that in blank group,and the biochemical removal capacity of sodium thiosulfate group was the highest13 mg/(L·h)than that of blank group.The removal efficiency of formaldehyde was above 99.5%in the 5~20 L/h range of circulating liquid flow,and the highest removal rate of formaldehyde in blank group and sodium thiosulfate group was 7.8 mg/(L·h).The gas flow rate in the0.05~0.25 m~3/h range was 99.3~99.6%in the blank group,99.6~99.9%in the sodium thiosulfate group,and higher in the sodium thiosulfate group than in the blank group.The highest biochemical removal capacity of sodium thiosulfate group was higher than that of formic acid group under the changes of the inlet concentration of formaldehyde,the flow rate of circulating liquid and the flow rate of gas.(4)In the formic acid group,the sodium thiosulfate group and the blank group received 566935,552847 and 555901 quality sequences respectively.The results of Alpha diversity analysis showed that the bacterial sparse curve of each sample was not close to the plateau phase,but the level of the sample was basically approaching,and the amount of sequencing of the samples was not significant enough to excavate more OTUs.Pseudomonas,Methylophilus,Stenotrophomonas,Sphingopyxis and Methyloversatilis are considered to be the dominant formic acid groups.Formic acid promoted the growth of Pseudomonas,Methyloversatilis and Methylophilus.Methylophilus,Methylobacterium,Methyloversatilis,Pseudomonas,Stenotrophomonas are considered to be the dominant microbiota of sodium thiosulfate group.Sodium thiosulfate promotes the growth of Methylophilusus,Methylobacterium,Pseudomonas.