Quantitative Relation Study Of Odorous Pollutants Based On Sensory Measurement And GC/MS

Odor pollutants are gas pollutants that stimulate the olfactory organs to cause unpleasantness and damage to the living environment.Among them,urban sewage treatment plants are one of the main ways of generating odor.With the acceleration of urban construction,the construction of urban sewage treatment plants has also increased.Most of them are located in densely populated areas such as residential areas and commercial areas.Therefore,the treatment and discharge requirements of the city's sewage treatment plants for their own odors need to be stricter than ever.However,at present,there are few standard controlled pollutants for malodorous emissions in China,and the treatment of malodors in sewage plants is mainly concentrated on sulfur compounds and nitrogen-containing compounds in existing standards,resulting in the foul smell of the sewage plant even if it meets the standard discharge,it will receive complaints from surrounding residents.And the determination of odor concentration in China's standards is seriously affected by subjective factors,and it is also one of the reasons why the sewage plant cannot correctly evaluate malodorous.Therefore,it is not only of practical significance to explore the characteristics of odorous gas emission from sewage treatment plants,but also to establish an objective quantitative model of odor concentration,which also provides certain scientific support for the evaluation of odorous gases in sewage plants.In this paper,the pollutant concentration and odor concentration of the malodorous in the sewage plant are tested to explore the emission characteristics of the odorous in the municipal sewage treatment plant,and the typical malodorous substances in each unit are determined.A preliminary quantitative model of odor concentration was established by SPSS software and the malodorous marker substances of each unit were selected.Finally,through the laboratory simulation of the marker gas mixture,the laboratory odor concentration quantitative model is established and the sample simulated odor concentration model is compared,and the odor concentration quantitative model is optimized by the interaction between the markers.In order to explore the characteristics of odorous emission from municipal wastewater treatment plants,this study used gas chromatography-mass spectrometry(GC-MS),ultra-high performance liquid chromatography(UPLC)and ultraviolet spectrophotometer to detect the odor of six treatment units in a sewage treatment plant in Shenzhen,a total of 47 odor pollutants were detected.The odor concentration of each unit is determined by manual smear and from big to small is sludge concentration,grid,grit chamber,primary sedimentation,biochemical and secondary sedimentation.Combining the detection concentration of the instrument with the odor concentration,it is found that hydrogen sulfide,organic sulfide,benzene series,and terpenes can respectively represent odor concentrations of 54 %,76 %,85 %,and 63 %.In order to establish a quantitative model of odor concentration in each unit,the odor pollutants were subjected to principal component discriminant analysis and index discrimination,and the verification score(VS)was equal to 95 %,and 24 typical odor pollutants were selected.The odor concentration model of each unit was established by IBM SPSS 2.0 software and the odor markers of each unit were obtained.The model simulation results showed that the relative error of grid and grit chamber simulation is 37 %,the initial settling tank is 12 %,and the biochemical is 0.7 %,the secondary settling tank is 50 %,and the sludge concentration is 14 %.Based on the determination of the markers of each unit,according to the laboratory simulation of single substance and mixed odor concentration curves,it was concluded that during the mixing process,the grid markers were inhibited by 0.8 % of hydrogen sulfide,0.7 % of methyl mercaptan,and enhancement by 4 % of limonene;grit chamber was inhibited by 0.9 %,methyl mercaptan was inhibited by 0.8 %,and toluene was enhanced by 7 %;hydrogen sulfide in the primary sedimentation tank was inhibited by 0.8 %,allyl methyl sulfide was inhibited by 0.3 %,ammonia gas was enhanced by 47 %;biochemical tank ammonia gas was inhibited by 0.5 %,toluene was enhanced by 45 %,and alphapinene was enhanced by 27 %;secondary sedimentation tank,ammonia gas was suppressed by 0.3 %,toluene was enhanced by 19 %,and formaldehyde was enhanced by 53 %;hydrogen sulfide in the sludge concentration unit was inhibited by 0.8 %,allylmethyl disulfide was inhibited by 0.8 %,and pentylmethyl sulfide was enhanced by 15 %.Comparing the slope of the laboratory simulated mixture curve with the actual sample curve,the deviation coefficients of each marker were obtained to optimize the quantitative model of odor concentration.The correlation between the simulated value of the optimized model and the actual odor concentration is high,R2 is greater than 0.5,and the average of relative errors of the simulation are less than 20 %.