In this study, the recovery rate of thermal desorbing (TD) method was investigated in relation to sample concentration and loading volume of reduced sulfur compounds (RSC). All the analysis of RSC was made by gas chromatography/pulsed flame photometric detector (GC/PFPD) combined with air server/thermal desorber (AS/TD). The RSC measurement data were obtained by loading gaseous RSC standards prepared at 4 concentrations (10, 20, 50, 100 ppb) at 6 injection volumes (40, 80, 200, 400, 800, and 1200 mL). The recovery rates of each RSC were computed in terms of relationship between expected vs. measured values. According to our analysis, the following conclusions can be drawn. First, the results were less stable at short loading time (1 and 2 min at 40 mL/min) with reduced recovery rate, especially with light RSCs (H₂S and CH₃SH). On the other hand, at sufficiently high loading volume, their quantification was limited by off-scale peaks (at a near 50 ng) due to the breakthrough of cold trap in TD. Thus, the optimization of TD-based analysis may be considered as a prerequisite for analyzing the RSC in a reliable manner.

We studied an analytical method for 4 organic acids will be regulated in 2010 using on-line thermal desorber with gas chromatograph/flame ionization detector. Results for each compounds showed good linearity(r² ＞ 0.99) and good precision(RSD ＜ 3%). Minimum detection limit values are about 2~3ppb when we sampled 1.5 L. These values will be reduced to 0.4~0.5 ppb when sampling 10L. We analyzed the 56 ozone precursor standard gas using the same method to see if there are any peaks to be overlapped in ambient air and the results showed that there is no peak overlapped. The linearity, precision and MDL in this study satisfied the guideline of Korean standard method for 4 organic acids. This analytical method in this study could be utilized effectively as on-line monitoring instrument to detect 4 organic acids.

In this study, the removal characteristics of reduced sulfur compounds (RSC) were investigated against activated carbon (AC) by means of electric cooling and thermal desorption. To this end, three types of AC materials were selected and tested against gaseous RSC standards prepared at 50 ppb concentration. Each of these AC materials designated with its own target odorant compounds was tested for the removal rate of RSC by comparing their quantities between prior to and after passing the adsorption tube. All the analysis of RSC was made by Gas Chromatography (GC)/Pulsed Flame Photometric Detector (PFPD) combined with Air Server (AS)/Thermal Desorber (TD). The rate of RSC removal was quantified as a function of RSC loading time (Exp. 1) and of RSC flow rate into TD (Exp. 2). The results of Exp. 1 showed that the adsorption of RSC increased with RSC loading time (from as little as 1 to 20 min). In Exp. 2, the adsorption of RSC also increased in relation to RSC flow rate (10 to 100 mL/min). The removal rate of RSC was also distinguished by chemical properties such as the compounds of low molecular weights (H₂S and CH₃SH) vs. high ones (DMS and DMDS).

In order to accurately analyze trace-level, reduced sulfur compounds (RSC) in ambient air, one needs to rely on the thermal desorption technique (TD) to atone for the limited sensitivity of direct gas chromatography (GC) analysis. In this study, the relative performance of GC/PFPD system combined with TD unit was evaluated to help accurately determine RSC based on the comparative analysis of two types of calibration approaches. Hence, calibration results of RSCs were compared by controlling sample transfer system (air server (AS) and TD unit) between the two contrasting calibration approaches such as: incremental-loading of a given standard with the fixed standard concentration (FSC) vs. supply of standards made at multiple concentration points at the fixed standard volume (FSV). The results of our study indicate that RSC calibration is affected fairly sensitively by sample loading conditions of the AS/TD system. It is hence necessary to delicately control the TD operation conditions for the accurate quantification of RSCs, when GC/PFPD system with TD is employed for RSC analysis.

In this study, we attempt to analyze for 4 compounds (MEK, MIBK, n-Butyl acetate, i-Butyl alcohol) in ambient air using on-line thermal desorber (on-line TD) with gas chromatograph/flame ionization detector (GC/FID). These compounds will be regulated by KMOE (Korean ministry of environment) within 2010. We tested two different experimentation. First, we try to find the influence of Nafion dryer for the 4 compounds. Second, we want to know basic analytical characteristic of target compounds through the linearity, reproducibility, and minimum detection limit. According to this study, target compounds are removed in Nafion dryer more than 80 percent, respectively. So, we progressed next experimentation progressed without Nafion dryer using hydrophobic cold trap. Results for each compounds showed good linearity (r²＝0.99 upper) and good precision (RSD＝1 % below). In additional, we analyzed the ozone precusors standard gas (56 compounds) using the same method to see if there are any peaks to be overlapped in ambient air. These results showed that there is no peak overlapped. This means that analytical system of this study could be used on-line analytical system. Minimum detection limit (MDL) value for this system are less than minimum malodor threshold concentration.

This paper examined reasonable operating factor for treatment of carcass burial leachate in High Temperature Thermal Desorption (HTTD) and calculated the amount of fuel used in each device using heat and mass balance under condition of 4 scenarios. As a result, we concluded that rotary kiln for dryness and thermal desorption shoud be separated dual type and mixing ratio of sawdust and soil should be restricted no more than 1 : 14. Also, operating temperature should be kept 260, 550, 850 or higher in dryer kiln, thermal desorption kiln and secondary chamber respectively and residence time should be kept 30min in each kiln. The total amount of fuel used in each device was compared under 4 scenarios on the mixing ratio. According to a study, it showed the highest value under the scenario of 1 : 1, which showed 2.5 times higher than the scenario of 1 : 14 in terms of treatment of leachate per unit of LNG.

This study analyzed concentration and characteristics of hazardous substances in treatment of leachate from carcass burial areas by using high temperature thermal desorption (HTTD). Concentrations of pollutants emitted from HTTD treatment of leachate contaminated soil of carcass burial sites satisfied the emission standards for 11 pollutants from domestic waste incineration facilities. Dioxin concentration was 0.0060 ng I-TEQ/Sm3 and 0.0061 (0.0055-0.0070) ng ITEQ/ Sm3 in the normal operation condition and the experimental condition, respectively, which are much lower than the MSWI Standard of 0.1ng I-TEQ/Sm3. As a result, it was considered that leachate from carcass burial areas could be treated by high temperature thermal desorption (HTTD).