In this study, the removal efficiency of 24 odorous compounds was measured in diverse control process units of 7 individual chemical companies located in Ban-Wall & Shi-Wha Industrial Complex in Gyeonggi-do, Korea from March to August, 2007. To quantify the removal efficiency rates of major odorous compounds, we collected odor samples from the inside process and both the front and rear side of 7 control process units. As the results of this study, it was shown that toluene, ammonia, trimethylamine (TMA) and acetaldehyde were dominant odorous compounds in the inside process. In addition, VOCs, TMA and acetaldehyde were also detected at higher concentrations in the stacks and 10 (toluene, acetone, ethyl benzene, xylene etc.) out of 24 index compounds were found to have negative removal efficiencies. According to the removal efficiency evaluation of seven odor control facilities, a company equipped with two connected absorption processes was shown to have positive (＋) removal efficiencies for 16 odor substances and NH₃, TMA, acetaldehyde, the priority odor substances, which meant the proper control system was installed and operated. Hence, to obtain best removal efficiency of odorous pollutant emission, the database on source characteristics and the development of management techniques of diverse control process units are continually needed.

Odor managements were divided from air pollution prevention law because of sensory, temporary, partial, and distributive characteristics. Therefore, odor prevention law and odor analysis method were published for malodor management in Feb. 2004, and Feb. 2005, respectively. In this study, we considered problems of odor prevention law and odor analysis method according to their enforcement, and then we suggested an alternative idea. In the odor prevention law, we thought over odor emission point, application of emission standard, and requirement of odor analysis organization. And also, we considered odor analysis methods such as sampling time, judgment procedure of dilution ratio values of the threshold limit for complex odor, field blank for aldehydes analysis, display of valid figure.

This study was conducted to evaluate the dilution accuracy of the dynamic olfactometer made in Republic of Korea and analyze the correlation of odor levels from the olfactometry method and Liquid Chromatography/Mass Spectrometry (LC/MS). The evaluation of dilution accuracy using CH₄ standard gas for the dynamic olfactometer at lower dilution ratios of 3, 10, 30, 100 and 300, and at higher dilution ratios of 100, 300, 1000, 3000 and 10000 showed the relative errors of 1.48~3.40% and 2.06~4.76% respectively showing a good dilution accuracy. Twenty odor samples from the stacks of odor-monitoring factories in the industrial complex located at the western coastal area of ROK were analyzed with the dynamic olfactometer for complex odor and LC/MS for five types of aldehydes, and a very weak correlation of R² = 0.1276 between OU(Odor Unit) from the olfactometer data and SOQ (Summation of Odor Quotient) from LCjMS data was obtained. Because of the complexity of the odor composition, using concentration of single or group of gases to represent odor level has not been proved to fully estimate the presence or level of odors. Therefore, the dynamic olfactometry which has a good dilution accuracy and a standardized odor evaluation system is considered as a very resonable method to assess complex odor.

Formaldehyde is important because of its irritant and toxic properties, mutagenicity and carcinogenicity, In this study, liquid chromatography/mass spectrometry (LC/MS) was used for the analysis of formaldehyde after derivatization with 2,4-dinitrophenylhydrazine (DNPH) cartridge. Analytical parameters such as linearity, repeatability and minimum detection limit were evaluated. The linearity (r²) was 0.9999 when analyte concentration ranges from 50 to 400 ㎍/L. The relative standard deviation (%RSD) was 0.83% for the concentration of 400 ㎍/L, and the minimum detection limit (MDL) was 0.27 ppbv. We investigated the distribution of formaldehyde concentrations based on a total of 96 samples(industrial area : 32, complex boundary line : 32, affected (residential) area : 32) measured at the Shi-Hwa industrial complex from April to October 2006. By the statistical analysis of these measurement data, the average level of formaldehyde from industrial area, complex boundary line, and affected area was 2.7, 2.1, and 2.2 ppb during the daytime (10:00~16:00), and 1.4, 1.1, and 1.6 ppb during the nighttime (19:30~23:00), respectively. And also, we investigated the emission concentrations of formaldehyde from various emission sources of 33 individual companies located in the Shi-Hwa industrial complex from September to November 2006. The results of our study showed that the emission concentrations of formaldehyde greatly varied according to industrial and source types. The emission concentrations of formaldehyde showed in the descending oder of 11.4 ppm for insulation cable process, 2.0 ppm for sand casting process, 1.7 ppm for synthesis rubber process, and 1.3 ppm for hexamine process.

We investigated dilution ratio values of the threshold limit (DRVTL) and 12 odorous compounds from a number of emission points (stack and process) and boundary areas of 10 chemical industries in the Ban-Woll and Shi-Wha Industrial Complex in Gyeonggi Province. The results of our study suggest that differences in odor emission concentrations are caused by such as factors as : suitability and operational conditions of prevention equipment, suitability hood of process and exhaust ventilation system, differences of raw materials of chemical industry. It was found that trimethylamine and hydrogen sulfide recorded the highest contribution from two types of emission points (stack and process), respectively. Show some actual concentration values here, hydrogen sulfide recorded its maximum values from leather industry, while trimethylamine for hexamine production industry. On the other hand, the results of dimethyl sulfide, dimethyl disulfide and methyl mercaptan were not useful, as their concentrations were not significantly high enough to judge from such respect. In the view-point of dilution ratio values of the threshold limit, the average emission ratio of stack and process from 10 chemical industries was 57, 43%, respectively. Therefore, it is important that the odor emission value from process and stack have to minimize and regulate for management of industrial odor.