Study On The New Technology Of Odour Evaluation System

The odor, as a kind of sense social effect pollution, has become a one of world environment pollution. Great Attention has been paid to the study of odor public nuisance in many countries, besides, a series of regulations in odor determination, evaluation and control system were formulated. As the olfactory thresholds of most odor substance are low, it is hard to determine the odorous substance concentration. Odor concentration is an important index in the process of odor evaluation, which is determined by the sense organ methods mostly comparing with other methods. And here are still some shortages to the national standard Triangle bags method, while the Dynamic Olfactometry with high-automation and high-accuracy is commonly used in the developed countries.This thesis did systemic comparison between the two odor determination methods Triangle bags method and Dynamic Olfactometry. At the following aspects, panel sceening, absorption function of sampling bags, quality of laboratory and method standard,the latter surpassed the former. It showed that it is importamt to do research on the correlation of the two odor determination methods and establish accurate mathematical conversion formulas. Introducing the advanced Dynamic Olfactometry into National standard method,will greatly promote the application of the odor determination technology in China, that has great significance and using value.Hydrogensulfide,ammonia, the mixture of hydrogensulfide and butanol, and the mixture of ammonia and butanol were chosen as the study objects. The odor concentration of each species gas was determined respectively by the two methods Triangle bags method and Dynamic Olfactometry, according to their standard determination procedures. The gases were mixed by dynamic gas mix system, whose stability was good that was checked by calibration experiment. The results showed that the two groups of data of odor concentration from the two determination methods can be associated in some different certain for all the studying gases. The odor gases are different, the relationship formulas and relavent coefficients R2 are different too. The gases of the same kind in different substance concentration range, also have the different relationship formulas. Based on the relationship formulas,the odor concentration determined by Dynamic Olfactometry can be changed into Triangle bags method's value, that can be used in odor pollution evaluation bounded to National standard.The Dynamic Olfactometry also has the superiorty on determination of odor intensity. It can be used conveniently on the determination of the relationship formula between odor concentration and odor intensity. Hydrogensulfide,ammonia and the two kinds of mixture gases were still chosen as the study objects. The experiments found out the relationship formulas between odor concentration and odor intensity for each gas chosen. The DOC means distinct odor concentration. The study shows that the DOC value of hydrogensulfide is 6.3ou·m-3 which is the smallest, that is to say it has the heaviest influence on human's olfactory. And the compound gases take second place,ammonia is the weakest. At last Putforward the establish of odor intensity standard for environment odor.