This study was performed to investigate the distribution of indoor air pollutants in medical facility in Gyeonggi-do area from February to November, 2012, and to conduct the health risk assessment from obtained data. PM10, CO₂, formaldehyde, CO, and total bacteria count(TBC) did not exceed the maintained standards, but mean concentration of TVOC was 402.3 ㎍/㎥ and thirteen of them exceeded the recommended standard. In the concentration distribution of pollutants for the monthly samples, CO₂, formaldehyde, TVOC, TBC were the highest level in August. From the factor analysis of indoor air pollution provided three factors; the first factor was seasonal factor (indoor temperature and humidity, TBC and formaldehyde), the second factor was ventilation factor (CO₂, PM10 and CO), and the third factor was building(or interior) factor (TVOCs). In the health risk assessment results, the excess carcinogenesis of formaldehyde for resonable maximum exposure worker was 1.21×10-⁴ which means exceeding the cancer criteria(1.0×10-⁴). We confirmed the probability of health effect caused by TVOC. The lifetime excess cancer risk of carcinogens(benzene, formaldehyde) and hazard quotient of non-carcinogens(toluene, ethylbenzene, xylene, styrene), and risk of regulation substances(PM10, CO₂) were safety level for inpatients and out patients.
Odorous compounds were monitored and dispersion modeling was conducted using AERMOD model. for Songtan Industrial Complex (SIC) located in Mogok-dong, Pyeongtaek city. The complex odor at the target area showed an average dilution ratio of 4.5 and low ammonia concentrations were observed (78.3 ppb). Sulfide, methyl iso-buthyl ketone, methyl ethyl ketone and styrene were not detected. The toluene concentration showed as 1233.3 ppb, which was the highest in the target compounds. The diffusion effect of odorous pollutants by wind was confirmed by descending order of concentration, inner-SIC (282 ppb) > downwind site (182 ppb) > upwind site (11.6 ppb). The results of the modeling demonstrated that the complex odors on the west and, south, north and east of the boundaries were dilution ratios of 10 24 and 20, respectively indicating the north and the east of SIC were more vulnerable to odor pollution than other regions.
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.
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.