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D염색공단의 폴리에스테르 알카리 감량폐수가 혼합된 실제 혼합염색폐수를 처리하기 위하여 Pseudomonas sp. 및 Bacillus cereus/thuringiensis를 고정한 폐타이어담체를 충전한 유동상 바이오필터를 운전하였다. 또한 유동상 바이오필터와 450 W의 UV/광촉매반응기를 결합한 하이브리드 재순환시스템을 구축하여 stage I에서는 UV/광촉매반응기를 바이패스하고 유동상 바이오필터만을, stage II-i, ii, iii에서는 하이브리드 재순환시스템을 각각 운전하였다. 유동상 바이오필터만을 사용하였을 경우에 $COD_{Cr}$ 및 색도 제거효율은 각각 75~80% 및 67%를 나타내었다. 한편 하이브리드 재순환시스템 운전에서 stage I에서 stage II-i로 전환되었을 때에 UV/광촉매산화공정의 $COD_{Cr}$ 제거율이 20~30%에 달하여 총 $COD_{Cr}$ 제거율은 75%로부터 80~85%까지 제고되었다. 한편 stage I에서 stage II-i로 전환되었을 때에 UV/광촉매산화공정의 색도제거율은 0~5%에 불과하였으나 총 색도제거율은 45~65%로부터 65~70%까지 제고되었다. 색도 제거에서는 $COD_{Cr}$ 제거와 다르게 UV/광촉매산화공정에 의하여 유동상 바이오필터의 효율이 제고되어서 하이브리드 재순환시스템의 시너지효과가 나타났다. 또한 색도제거에서는 $COD_{Cr}$ 제거와 다르게 반송비 증가에 따른 광촉매 비활성화가 관찰되지 않았고, $COD_{Cr}$ 제거에서 반송비 증가에 따른 광촉매 비활성화는 비가역적으로 관찰되었다. 【A fluidized biofilter was filled with Pseudomonas sp. and Bacillus cereus/thuringiensis-fixed waste-tire crumb media and was run to treat authentic textile-dyeing wastewater mixed with alkaline polyester-weight-reducing wastewater. As a result, its removal efficiency of $COD_{Cr}$ and color were 75~80% and 67%, respectively. In addition, upon constructing hybrid-recirculating system composed of the fluidized biofilter and a 450 W-UV/photocatalytic reactor, only fluidized biofilter was run bypassing UV/photocatalytic reactor at stage I. Subsequently, the hybrid system was continuously run at stage II-i, ii and iii. At stage II-i, the total removal efficiency of $COD_{Cr}$ was enhanced to be 80~85%, compared to 75% at stage I, owing to 20~30% removal efficiency of the UV/photocatalytic reactor. However, at stage II-i, the total removal efficiency of color was enhanced to be 65~70%, compared to 45~65% at stage I, even though the removal efficiency of the UV/photocatalytic reactor was tantamount to merely 0~5%. As far as the removal efficiency of fluidized biofilter of the hybrid-recirculating system is concerned, its removal efficiency of color was enhanced by the synergy effect of the hybrid-recirculating system unlike $COD_{Cr}$ . Besides, despite of the increase of hybrid-recirculating system-recycle ratio, the deactivation of photo-catalytic activity was scarcely observed to eliminate the color while its irreversible deactivation was observed to eliminate $COD_{Cr}$ .】

The preparation conditions for both a high yield without aggregation and a small mean-size of chitosanfucoidan nanoparticles were sought by a screening method, i.e., discarding the ones satisfying neither of both to prepare them by polyelectrolyte complexation with chitosan and fucoidan. The effect of the pH level of chitosan solution and the chitosan-fucoidan mass ratio was investigated on the following aspects: the turbidity and aggregation pattern of suspension, the yield of dried mass, electrostatic interaction, fucoidan loading efficiency, the particle size distribution and the morphology of the polyelectrolyte complex prepared by polyelectrolyte complexation between chitosan and fucoidan. The mean size of prepared nanoparticle ranges between 365-900 nm. The nanoparticles tended to grow as the pH of chitosan was increased up to 3.69, after which they became smaller. This pattern of growth is prominent as the mass ratio of chitosan and fucoidan decrease. The conditions of pH 5 and 1: 1 chitosan-fucoidan mass ratio were suggested as ad hoc optimum conditions by the screening method to prepare chitosan-fucoidan nanoparticles for high yield, small size and good suspension stability. They were almost consistent with the optimum conditions for the maximum value of chitosan-fucoidan nanoparticles prepared per unit input mass, which were analyzed by response surface methodology (RSM).

퇴비공장 또는 공공시설에서 발생되는 악취폐가스의 대표적인 제거대상 오염원인 암모니아를 포함한 악취폐가스를 처리하기 위하여 여러 운전 조건 하에서의 광촉매반응기와 바이오필터로 구성된 하이브리드시스템을 운전하였다. 암모니아 총 제거효율은 하이브리드시스템의 운전부하가 운전 단계별로 커졌음에도 불구하고 약 80%로 유지되었다. 광촉매반응기에서의 암모니아 제거효율은 광촉매반응기로의 암모니아 유입부하량이 증가함에 따라서 광촉매반응기의 암모니아 제거효율은 65%에서 약 22%로 감소하였다. 같은 암모니아 유입부하량일지라도 암모니아농도가 클 때보다 적은 경우에 광촉매반응기의 암모니아 제거효율이 상대적으로 높았다. 반면에 바이오필터의 경우는 운전 전반부에는 암모니아 처리효율이 현저하게 억제되었으나 광촉매반응기의 경우와 반대로 시간이 경과하면서 암모니아 유입부하량이 증가함에도 불구하고 바이오필터의 암모니아 제거효율은 지속적으로 약 78%까지 증가하여서 Lee 등의 연구결과에서의 암모니아 제거효율과 비슷하게 도달하였다. 광촉매반응기에 의한 최대 암모니아 제거용량( $EC_{PR}$ )은 약 16 g-N/ $m^3$ /h 이었고, 바이오필터에 의한 암모니아 제거용량( $EC_{BF}$ )은 운전 초기에 암모니아 총 부하가 작은 경우에는 암모니아 총 부하증가에 따른 $EC_{BF}$ 의 증가추세가 미약하였으나 운전 후반부에 암모니아 총 부하가 큰 경우에는 암모니아 총 부하증가에 따른 $EC_{BF}$ 의 증가추세가 급격하게 커졌다. 하이브리드시스템 운전 6단계에서 암모니아 총 부하가 약 80 g-N/ $m^3$ /h일 때에 광촉매반응기에서의 $EC_{PR}$ 은 약 16 g-N/ $m^3$ /h이었고, 2차 공정이고 주공정인 바이오필터에 걸리는 암모니아 부하는 나머지인 약 64 g-N/ $m^3$ /h이고 주공정인 바이오필터의 $EC_{BF}$ 은 약 48 g-N/ $m^3$ /h로 산출되었다. 이러한 바이오필터의 암모니아 제거용량은 Kim 등의 연구결과로서 최대 암모니아 제거용량인 1,200 g-N/ $m^3$ /day와 거의 비슷하였다. 【The hybrid system composed of a photocatalytic reactor and a biofilter was operated under various operating conditions in order to treat malodorous waste air containing ammonia which is a major air pollutant emitted from composting factories and many publicly owned treatment works. Total ammonia removal efficiency of the hybrid system was maintained to be ca. 80% even though its inlet loads were increased at a higher operating stage according to an operating schedule of the hybrid system. The ammonia removal efficiency of photocatalytic reactor was decreased from 65% to 22% as ammonia inlet loads to photocatalytic reactor were increased. In spite of same inlet loads of ammonia to the photocatalytic reactor, the ammonia removal efficiency of photocatalytic reactor with lower ammonia concentration of fed-waste air was higher than that with higher ammonia concentration of fed-waste air. To the contrary, during the first half of the hybrid system operation the ammonia removal efficiency of a biofilter was quite suppressed while, despite of increased ammonia inlet loads, the ammonia removal efficiency of the biofilter was continuously increased to 78% and reached the ammonia removal efficiency similar to what Lee et al. attained. The maximum ammonia elimination capacity of the photocatalytic reactor was observed to be ca. 16 g-N/ $m^3$ /h. In an incipient stage of hybrid system run, the ammonia elimination capacity of the biofilter showed little sensitivity against ammonia inlet loads to the hybrid system. However, in the 2nd half of its run, the ammonia elimination capacity of the biofilter was increased abruptly in case of high ammonia inlet loads to the hybrid system. In 6th stage of hybrid system run, total ammonia inlet load attained at ca. 80 g-N/ $m^3$ /h corresponding to 16 g-N/ $m^3$ /h of ammonia elimination capacity of the photocatalytic reactor. Then, the remaining ammonia inlet load to the 2nd and main process of the biofilter and its elimination capacity was expected and shown to be ca 64 g-N/ $m^3$ /h and ca 48 g-N/ $m^3$ /h, respectively. The ammonia elimination capacity of the biofilter was close to 1,200 g-N/ $m^3$ /day of the maximum elimination capacity of the investigation performed by Kim et al.】

The effect of photocatalyst-carrying media porosity on the photocatalytic removal efficiency of malodor and VOC of waste air was evaluated when the photocatalytic removal efficiency of porous silica-based media was compared with that of glass bead as control. The amount of photocatalyst coated on the surface of porous silica-based media was observed to be , which was 250% as much as that of nonporous glass bead (control) of . The removal efficiencies of hydrogen sulfide and toluene in case of porous silica-based media were observed to be 22% and 82%, respectively, while the removal efficiencies of hydrogen sulfide and toluene in case of nonporous glass bead media were observed to be 19% and 53%, respectively. Therefore, the removal efficiencies of hydrogen sulfide and toluene increased by 16% and 55%, respectively, when the removal efficiencies of porous silica-based media were compared with those of nonporous glass bead media. Thus the increment ratio of the removal efficiency of toluene was observed to be 3.4 times higher than that of hydrogen sulfide.

A dynamic adsorption model was proposed using the lumping process for an adsorption system. This novel approach uses a four-component structure model: gas phase, enclosed aqueous phase, sorption volume and porous media surface adsorption. A clouding effect represented by ka (dynamic adsorption constant) was adopted to explain the adsorption process. The clouding effect assumes that the adsorption rate is decreased as the adsorption sites on the media surface are occupied. In the equilibrium stage the Freundlich adsorption isotherm was adopted. The proposed dynamic adsorption model was then predicted in comparison with the experimental data of an adsorption-column to estimate adsorption model parameter values in a biofilter fed with ethanol at 4,100 mg ethanol/m3 (or 2,000 ppmv). Model validation was performed for the adsorption column fed with ethanol at 2,050 mg ethanol/m3 (or 1,000 ppmv). Results showed that the mechanistic model was able to simulate the dynamic behavior of an adsorption process successfully according to the corresponding adsorption experimental data.

A dynamic biofilter model was suggested to integrate the effect of biofilter-medium adsorption capacity on the removal efficiency of volatile organic compound (VOC) contained in waste air. In particular, the suggested biofilter model is composed of four components such as biofilm, gas phase, sorption volume and adsorption phase and is capable of predicting the unsteady behavior of biofilter-operation. The process-lumping model previously suggested was limited in the application for the treatment of waste air since it was derived under the assumption that the adsorbed amount of VOC equilibrated with biofilter-media would be proportional to the concentration of dissolved VOC in the sorption volume of biofilter-media. Therefore a Freundlich adsorption isotherm was integrated into a robust biofilter process-lumping model applicable to a wide range of VOC concentration. The values of model parameters related to biofilter-medium adsorption were obtained from the dynamic adsorption column experiments in the preceding article and literature survey. Furthermore a separate biofilter experiment was conducted to treat waste air containing ethanol and the experimental result was compared with the model predictions with various values of Thiele modulus (). The obtained value of Thiele modulus () was close to 0.03.

The objective of this study is to develop the process conditions of a w/o emulsification method for the preparation of the smallest agar nanoparticles possible in a low nanometer range with the highest yield, prior to adding an aqueous solution containing an unstable drug such as a protein drug for its encapsulation. The volume ratio between the organic phase and aqueous phase was set as 10 : 1, the lowest ratio among those of previous investigations. Agar solutions of 0.5, 1 and 2%w/v concentration were emulsified in soybean oil. Then, various homogenizer speeds were investigated for the yield of agar nanoparticles and their particle size distribution under those agar concentrations. The visual appearance of the re-dispersed emulsion-converted-to suspension was turbid without any visible aggregates, even though the suggested methodology is more economically efficient in terms of the ratio between the organic phase and aqueous phase, than those of previous investigations. In terms of agar concentration, the yields of agar nanoparticles were optimized at 1%w/v of agar concentration for all the homogenizer speeds of 13000, 15000 and 17000 rpm. Accordingly, the yield of 76.5% was the highest at the preparation conditions of 1%w/v agar concentration and 15000 rpm homogenizer speed.

The surface compositions of crude by-product polyolefin wax (wax K) from a naphtha cracking unit, fractionated commercial paraffin wax (wax J) and their blend (wax M) were compared, under various conditions, by using FT-IR. Then a practical criterion was theoretically derived by back-of-the-envelope-calculation to estimate the diffusivity for the surface enrichment of hydrophilic functional groups. The hydrophobicity in terms of chemical structure and functional groups was altered by changing the environment as well as by blending wax K with wax J. The surface properties of wax J and wax M turned out more hydrophobic than that of wax K within the experimental period of water-submerged condition, even though the structure and functional groups on the surfaces of all waxes under ambient atmospheric condition are extremely similar. Thus the blend of wax M behaved unlike wax K but similarly to wax J in terms of alteration of hydrophobicity. Such values of diffusivity as 1.35×10−11 cm2/s and 1.96×10−11 cm2/s are established for wax J and wax M, respectively, under 1 day water-submerged condition. Furthermore, under 1 week water-submerged condition, the values of their diffusivity for wax J, wax K and wax M are estimated as 3.06×10−12 cm2/s, 7.23×10−11 cm2/s and 1.50×10−11 cm2/s, respectively. The obtained values of diffusivity are consistent, in terms of the order of magnitude, with the value of diffusion coefficient of 5.75×10−11 cm2/s obtained, using a very complicated empirical-formula, by Chen et al. for the investigation of surface-modifier enrichment. Thus, the suggested criterion may be very useful and practically applied to clarify the process of surface enrichment from general polymer-blends.

An experiment for five stages of a biofilter-run was performed to investigate the effect of hydrophilic ethanol and hydrophobic toluene on the biodegradation of hydrophobic toluene and hydrophilic ethanol, respectively, when waste-air containing toluene and ethanol was treated by a biofilter. Removal efficiencies of toluene and ethanol began to decrease when inlet load surpassed 90 g/m3/h and 100 g/m3/h consistent with maximum elimination capacities of toluene and ethanol, respectively. At the end of the biofilter-run, removal efficiencies for toluene and ethanol were decreased and maintained at 65% and 40%, respectively. The concentration of toluene at 1st sampling port was raised by factor of two in the 3rd stage of the biofilter run when the inlet load of ethanol co-feed was increased by 1.5 times, while the process conditions of toluene were maintained the same as those of the 2nd stage of biofilter-run. According to the result of Mohseni and Allen, it may be interpreted that removal efficiency of hydrophobic toluene was affected by the presence of hydrophilic ethanol when high load of hydrophobic toluene was applied like that of the 1st sampling port of the biofilter. However it was not the case when a low load of hydrophobic toluene was applied like those of the 2nd, 3rd and 4th sampling ports since hydrophobicity of toluene is much less that of α-pinene. Thus, it may be suggested that biodegradation of hydrophobic VOC was interfered by hydrophilic VOC dissolved in the biolayer and the degree of interference was proportional to the inlet load of hydrophobic VOC as well as that of hydrophilic VOC and was inversely proportional to the solubility of hydrophobic VOC. However, it was inferred that the existence of hydrophobic toluene from waste-air can hardly inversely hinder the removal of hydrophilic ethanol in the biofilter when timeevolutions of hydrophilic ethanol concentrations of this experiment were compared with those of the previous experiment of biofilter to treat waste-air containing ethanol only.

The transient behavior of a hybrid system composed of biofilter and photo-catalytic reactor was observed at the height of each sampling port to treat waste-air containing ethanol. The biofilter packed with mixed media (of granular activated carbon and compost) was inoculated with a pure culture ofBurkholderia cepacia G4 andPseudomonas putida, while a photo-catalytic reactor was composed of 15W UV-A lamps and annular pyrex tubes packed with glass beads coated with sol type of TiO2 before calcination. The maximum elimination capacities of toluene and ethanol turned out to be 130 g/m3/h and 230 g/m3/h, respectively, which were greater by 40 g/m3/h and 130 g/m3/h, respectively, than those from the experiments performed with a biofilter only. Thus, the maximum elimination capacities for toluene and ethanol increased by 44% and 130%, respectively, by use of a hybrid system. The photo-catalytic process contributed to the maximum elimination capacities of hybrid system on toluene and ethanol by 30.8% and 56.5%, respectively, which contributions for the elimination capacities on toluene and ethanol were allocated indirectly by 25.4% and 44.3% as well as directly by 5.4% and 12.2%, respectively. Direct contributions of photo-catalytic process were 17.5% and 21.5% to the increments of the elimination capacities on toluene and ethanol, respectively, while its indirect contributions were 82.5% and 78.5% to those on toluene and ethanol, respectively.

Transient behavior of a biofilter packed with mixed media (of granular activated carbon and compost) inoculated with a pure culture ofPseudomonas putida was observed at the height of each sampling port to treat wasteair containing ethanol. In addition, flooding effects of an excess supply of buffer solution was observed at each sampling port of the biofilter until it recovered the status prior to the flooding. Unlike previous investigations, various process conditions were applied to successive biofilter runs in order to monitor the corresponding unsteady behavior of the biofilter in this work. In early stage of biofilter run the removal efficiency of ethanol maintained almost 100%. However, it began to decrease when inlet load surpassed 100 g/m3/h consistent with maximum elimination capacity. At the end of biofilter-run removal efficiency was decreased and maintained at 40%. The results of this work were compared to those of such biofiltration studies as the work of Christen et al. from the point of view that pure cultures of microorganism were used in both works. Except for the period of flooding effect of the 2nd stage, the inlet load and removal efficiency continued at 105.5 g/m3/h and 95%, respectively, while they were 93.7 g/m3/h and 95%, respectively, according to the result of Christine et al. Removal efficiency remained at 90% for the beginning period of 3 days of the 3rd stage, and it gradually decreased to 60% for remaining 5 days of the stage with an inlet load of 158.26 g/m3/h, which may be interpreted as better than the result of Christine et al. Their result was that the removal efficiency on the inlet load of 154 g/m3/h of ethanol was continued to be 60% for 6 days of a separate biofilter run and decreased to 40% later. Thus, with similar inlet loads of ethanol, removal efficiency of this work was equivalent to or higher than that of Christine et al.

The types of biofilter modeling may be primarily classified in accordance with whether a biofilm is differ- entiated from other phases in each model. It may be a secondary classification with regard to biofilter-modeling whether sorption volume and/or adsorption are adopted as reservoirs or not. Thirdly, biofilter models are classified as to whether adsorption is assumed to exist through gas phase and/or a biofilm. Among all the biofilter-models of previous inves- tigators all model-components including gas phase, a biofilm, sorption volume and adsorption surface are considered only in the model of Lim. Since his model does not require a numerical solution but an algebraic solution to describe the concentration of organic pollutants in waste-air-streams along the height of a biofilter even under unsteady-state conditions, it satisfies the condition of simplicity that is one of the important model requirements. In spite of its simplicity, Lim's model predictions are fairly good to fit Hodge and Devinny's experimental data.