In order to improve the management of food waste treatment facility, this study investigated the emission characteristics of odorous compounds around treatment process and deodorization equipment of three food waste treatment facilities(the transformation, feed production and composting facility). Furthermore, the removal experiment of odorous compounds using various absorbent was conducted.
The odor concentrations of food waste storage hopper and separation process were higher than other processes and the major odorous compounds were methyl mercaptan, acetaldehyde, hydrogen sulfide and ammonia. The odor removal efficiencies of deodorization equipment such as activated carbon tower, wet scrubber and biofilter were mostly insufficient. Especially, the removal efficiency of wet scrubber is lower than the others, therefore the improvement of optimal operating condition is required. As a result of removal experiment of various absorbent, the removal efficiency was over 98% in case of 1% H₂SO₄+K₂HPO₄ for ammonia, KMnO₄ for acetaldehyde and KMnO₄ and 5% NaOH+KH₂PO₄ for hydrogen sulfide and methyl mercaptan. To achieve the effective odor control of food waste treatment facility, it is necessary increasing the removal efficiency of scrubber by using optimal absorbent for target odorous compounds.
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 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.
This article addresses the question of how the operational architecture for a railway safety information system should be developed. A successful railway safety information system can be developed by fully reflecting the business process and needs at the enterprise level. To date, there has been minimal research effort towards the development of the operational architecture for a railway safety information system. To this end, a variety of enterprise architectures have been studied so far. In this paper, as an important guideline, DoDAF (Architecture Framework) is selected to be used in developing a railway safety information system. In particular, we propose a method to implement the operational architecture based on DoDAF.
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.
In this study, QA/QC (quality control/quality assurance) data of reduced sulfur compounds from several institutes were obtained and compared based on the Korean standard method for off-odor. From the results, attempts were made to optimize the analytical conditions and improve the measurement reliability of reduced sulfur compounds analyses from detailed CF/TD and GC/PFPD information. Analysis results (minimum detection limit, precision, recovery rate) of reduced sulfur compounds based on the each analytical condition corresponded with the Korean standard methods for off-odor. Therefore, we expect that we could execute the exact analysis if we use the analytical condition of CF/TD and GC/PFPD in this study
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.
버섯재배사에서 표고생산은 3월부터 11월에 이루어지며, 자연환경 조건의 변화를 이용하여 화고의 생산도 함께 추진하 였다. 5℃이하인 동절기에는 연료비에 대한 비용부담이 커서 이재배사는 버섯생산을 하지 않는 상황이었다. 그러나 상대 습도는 계속 75%를 유지하여 배지가 너무 건조하지 않도록 관리하였다. 보온과 난방으로 표고에 의한 소득을 올리는 재배 사관리가 고려될 가치가 있다고 생각한다. 1월은 버섯가격이 높으나 버섯생산이 적은 기간이다. 이것은 온도가 낮기 때문 이며, 톱밥재배사에서는 보온재와 햇볕을 이용하여 1월 중에는 -2℃~ 5℃로 유지하였다. 10월중에는 온도를 20도 이하 로 유지하였으며 상대습도를 60 ~85%로 유지하였다. 버섯품질은 상대습도에 크게 좌우되므로, 배지를 수직으로 180cm 에 이르는 7-8단으로 배열한 중국식 톱밥재배는 지면에서 높아질수록 수분관리가 불리할 수가 있다. 그러므로 수시로 재 배사의 통풍을 조절하여 상하 습도를 균질화시켰다. 이렇게 함으로써 육면체 배지의 모든 방향에서 표고를 발생시켰다. 노출된 배지로부터 수분관리 효과적으로 하기 위하여 온도를 조절하여 상대습도를 조절하고 있다. 이에 비하여 대만식 톱 밥재배에서는 25cm 높이에서 버섯이 발생하므로 이 위치에서 온도 습도를 집중 관리함으로써 고품질의 버섯생산을 추구 하고 있었다. 톱밥재배사에서 하루 중의 변화는 상당히 극심한 편이다. 1월 중에는 0~ 12℃까지 변하며, 이에 따라 상대습 도는 70%에서 거의 100%에 달하였다. 이 조건은 버섯생장은 느리지만 수분유지에는 좋은 조건으로 화고의 생산이 고려 된다. 10월 중에도 밤낮의 온도변화가 10~24℃로써 폭이 14℃나 되면서 상대습도는 60~100%를 유지하여 버섯생산이 매우 유리한 상황이다. 특히 이 기간에는 버섯가격이 낮으므로, 고품질의 표고생산이 매우 중요하다.