Pollution Profiles And Biodegradation Of Typical Industry Odor Waste Gas

Odor pollution is a very serious air pollution around the world.This pollution can seriously affect people's physical and mental health.There are many kinds of odor pollution and a wide range of sources.Among them,sulfur-containing odor pollutants are the main pollutants with great influence in the environment.They have low olfactory thresholds and very unpleasant smell.Among the different technologies to purify these pollutants,biodegradation of malodorous organic waste gas has begun to receive more extensive attention and application,because of the bio-degradation of malodorous exhaust gas has greater advantages than other methods.This study examined and analyzed the malodorous gas emissions from the waste transfer station and the garbage compression station;and applied the spray tower-biofilter tower combined device to the odorous waste gas discharged from the textile printing and dyeing wastewater treatment plant,from the pollution of the odorous exhaust gas.And the purification and the microbial community in the biological filtration tower were analyzed.Finally,a highly efficient degrading bacterium was isolated and purified by using sulfur-containing odor pollutant as a substrate,and its degradation performance was studied.The main research contents and main results are as follows:?1?The monitoring and analysis of gaseous pollutants were carried out in the household garbage transfer station and the garbage compression station in Guangzhou,China.We found that the concentrations of the same components of the two stations were almost the same.The main components were NH₃,NO,N2 and HCl,and their concentrations were up to several hundred ppb.Comparatively,the contribution of other components including sulfur compounds,acids and ketones were not so high.The average proportion of NH₃ in the odorous substances studied in the two stations reached 47.9%,the average proportion of NO was 23%,the average ratio of N2 was 18.5%,the average proportion of HCl was 6.9%,and the average proportion of other odorous components was only about 3.75%.The main malodorous substances produced by the garbage in the two stations are nitrogen-containing compounds.?2?The spray tower-biofilter?ST-BF?combined device was used to treat the exhaust gas emitted from the textile printing and dyeing wastewater treatment plant.It was found that the largest proportion of volatile organic compounds?VOC?components were nitrogencontaining and oxygen-containing compounds?NAOCCs?,which reached 85.1%,followed by aliphatic hydrocarbons?AIHs?with 7.05%,aromatic hydrocarbons?AHs?with 6.3% and halogenated hydrocarbons?HHs?with 1.53%.After 90 days of continuous operation,the average removal efficiencies of NAOCCs,AIHs,AHs and HHs were 66.7%,67.9%,11.7% and 52.08%,respectively,indicating that the combined device can effectively remove the tested VOCs.At the same time,it was found that the hazard ratios of samples on the 1st,20 th,and 90 th day was greater than 1,indicating potential cancer risk to the workers.However,after ST-BF treatment,the cancer risks of all studied VOCs were greatly reduced.Obviously,significantly reduce the risk of cancer from VOC emissions can be achieved after the ST-BF treatment.Further research on the obtained microbial community found that Proteobacteria is the main degrading bacteria of VOC,and Acidithiobacillus is the dominant species in the degradation process of VOC.Changes in microbial communities are significantly associated with emitted VOCs.?3?A high-efficiency bacterial strain capable of simultaneously degrading ethanethiol and dimethyl disulfide was isolated and purified from a landfill leachate.The strain was Grampositive bacterium.According to the physiological and biochemical identification and 16 s r RNA analysis,the isolated bacterium is in the same branch as Lysinibacillus fusiformis with the homology of 100%,which is a spindle-shaped lysine and we named it as Lysinibacillus fusiformis GDUTAN6.The most suitable growth temperature for this bacterial strain is 35?,the optimum p H is 7,and at 200 and 250 rpm.About 93.17% of ethanethiol?5 ppm?could be removed after 120 h degradation.Further,this bacterial strain could also remove all the dimethyl disulfide with the initial concentration less thang 75 ppm after 68 h degradation.