The vertical distributions of nitrifying bacteria in aerobic fixed biofilm were investigated to evaluate the relationship between nitrification performance and microbial community at different HRT. Fluorescent in situ hybridization (FISH) and portable ion selective microelectrode system were adopted to analyze microbial communities and ions profiles according to the biofilm depth. Cilia media packed MLE (Modified Ludzack-Ettinger) like reactor composed of anoxic, aerobic Ⅰ/Ⅱ was operated with synthetic wastewater having COD 200 mg/L and NH4 +-N 40 mg/L at HRT of 6 hrs and 4 hrs. Total biofilm thickness of aerobic Ⅰ, Ⅱ reactor at 4 hrs condition was over two times than that of 6 hrs condition due to the sufficient substrate supply at 4 hrs condition (6 hrs; aerobic Ⅰ 380 ㎛ and Ⅱ 400 ㎛, 4 hrs; aerobic Ⅰ 830 ㎛ and Ⅱ 1040 ㎛). As deepen the biofilm detection point, the ratio of ammonia oxidizing bacteria (AOB) was decreased while the ratio of nitrite oxidizing bacteria (NOB) was maintained similar distribution at both HRT condition. The ratio of AOB was higher at 4 hrs than 6 hrs condition and NH4 +-N removal efficiency was also higher at 4 hrs with 89.2% than 65.4% of 6 hrs. However, the ratio of NOB was decreased when HRT was reduced from 6 hrs to 4 hrs and NO2 --N accumulation was observed at 4 hrs condition. Therefore, it is considered that insufficient HRT condition could supply sufficient substrate and enrichment of AOB in all depth of fixed biofilm but cause decrease of NOB and nitrite accumulation.

The ion selective microelectrodes (ISME) have been applied to observe the continuous profiles of NO3-N and NH4-N in bulk solutions or biofilms. In order to evaluate the performance and applicability of ion concentration measuring system, the characteristics, such as slope of calibration curve, detection limit and potentiometric selectivity coefficient were investigated. The slopes of calibration curve showed high degree of correspondence for each target ion concentrations. And the detection limits of nitrate and ammonia ion selective microelectrode were 10-4.7 M and 10-4.4 M, respectively. These ion selective microelectrodes were proved that their own performance could be maintained for 16 days after making. NO3-N and NH4-N selective microelectrodes were also adapted to detect the continuous ion profiles of cilia media packed MLE (Modified Ludzack-Ettinger) process. And the monitored nitrate and ammonia ion profiles with the ion selective microelectrode were stable and well corresponded to the results with conventional ion chromatograph. However, the electric potential was unstable until 8 hr because of the unknown noise. The tip shape and performance of the ion selective microelectrode was stably kept over 2 days continuous monitoring.

본 연구는 난과 식물의 암모니아 피해 증상을 정확하게 알기 위해 팔레놉시스, 심비디움, 덴파레, 온시디움을 이용하여 밀폐된 챔버에서 수행하였다. 암모니아 가스처리 농도는 0, 30, 60, 100, 300, 400mg･L-1으로 하였다. 암모니아 가스 처리 조건은 온도 26±1.9℃, 습도 82.4±11.2%로 15시간 처리하여 피해 증상과 정도를 조사하였다. 하루 중 가스 피해 증상이 심한 시간대를 알기 위해 암모니아에 민감한 온시디움를 이용하여 200mg･L-1 농도로 하여 가스 노출시간을 2, 4시간씩 6등분하여 처리하였다. 팔레놉스시는 암모니아 300mg･L-1 이상이 되어야 피해가 발생하며 심비디움, 온시디움, 덴파레는 100mg･L-1 이상에서 피해가 발생하였다. 특히 온시디움이 가장 민감하였다. 가스 농도가 증가할수록 피해엽율은 증가하였는데 400mg･L-1에서는 83.4%였다. 엽록소 형광측정값(Fv/Fm) 또한 감소하였다. 하루 중 시간대별 피해증상은 주간 06～18시에 주로 나타나며 10～16시가 심하게 나타났다. 잎의 주요 피해 증상은 잎이 회갈색으로 급격히 마르며 가장 자리가 말리고 피해 받은 잎은 점점 옅은 황갈색으로 변하거나 건조되었다.

Phenylalanine ammonia-lyase (PAL), a key enzyme of the phenylpropanoid biosynthesis pathway, is activated by a number of developmental and environmental cues. The coding region of the NtPAL4 gene was 2,154 bp in length, and its deduced protein was composed of 717 amino acids. Sequence analysis of NtPAL4 cDNA from tobacco (Nicotiana tabacum L.) revealed high structural similarity to PAL genes of other plant species. The NtPAL4 gene exists as a single copy in the tobacco plant, and its transcripts were strongly expressed in flowers and leaves. NtPAL4 expression was significantly induced in response to NaCl, mannitol, and cold treatments, but it was not induced by abscisic acid (ABA). NtPAL4 expression decreased gradually after treatment with ABA and H2O2; however, NtPAL4 transcripts accumulated after treatment with methyl viologen (MV). Our results suggest that the NtPAL4 gene may function in response to abiotic stresses.

Allium sativum, belongs to a member of the onion family (Alliaceae) are economically important vegetables because of the culinary value and medicinal purpose. Using PCR strategy with degenerated primers targeted to conserved regions of orthologous phenylalanine ammonia-lyase (PAL) and cinnamate 4-hydroxylase (C4H) sequences available, full-length PAL and C4H from A. sativum. The amino acid sequence of these genes is highly conserved, particularly AsPAL and AsC4H has greater than 70% amino acid identity to other plants. AsPAL and AgC4H were most highly expressed in roots of A. sativum, whereas lowest level of transcript was detected in flower. Phenolic compounds most highly produced in flowers of A. sativum. The presented sequences and expression an alysis of PAL and C4H will provide possible material to enhance the understading of phenolic compounds synthesis in A. sativum.

Aerated submerged bio-film (ASBF) pilot plant has been developed. The presented studies optimized an inexpensive method of enhanced wastewater treatment. The objectives of this research were to describe pilot scale experiments for efficient removal of dissolved organic and nitrogen compounds by using ASBF reactor in plug-flow reactor (PFR) and improve understanding of dissolved organic matter and nitrogen compounds removal rates with dynamic relationships between heterotrophs and autotrophs in the fixed-film reactor. This research explores the possibility of enhancing the performance of shallow wastewater treatment lagoons through the addition of specially designed structures. This direct gas-phase contact should increase the oxygen transfer rate into the bio-film, as well as increase the micro-climate mixing of water, nutrients, and waste products into and out of the bio-film. This research also investigated the efficiency of dissolved organic matter and ammonia nitrogen removals in the ASBF. As it was anticipated, nitrification activity was highest during periods when the flow rate was lower, but it seemed to decline during times when the flow rate was highest. And ammonia nitrogen removal rates were more sensitive than dissolved organic matter removal rates when flow rates exceeded 2.2 L/min.

Ammonia (NH3 ) volatilization from a silty clay loam paddy soil applied with non, straight urea, and coated urea, respectively, under transplanting in Milyang, Korea from 2002 and 2003 was simulated by a Water and Nitrogen Management Model (WNMM). Based on the data from the in-situ measurements, NH3 volatilization during the rice growth was 6.04% and 1.46% of the applied nitrogen (N) from straight urea and coated urea, respectively. The bulk aerodynamic approach in WNMM satisfactorily predicted the difference in NH3 loss during the given rice growing seasons from the two urea fertilizers. R2 for the correlation between the predicted and observed NH3 loss during the calibration year (2002) was 0.53 less than 0.68 of the application year (2003). This difference could be due to the weather condition such as heavy rainfall and temperature during the calibration year.

Simultaneous removal of NH3, H2S and toluene in a contaminated air stream was investigated over 185 days in a biofilter packed with Zeocarbon granule as microbial support. In this study, multi-microorganisms including Nitrosomonas and Nitrobacter for nitrogen removal, Thiobacillus thioparus (ATCC 23645) for H2S removal, and Pseudomonas aeruginosa (ATCC 15692), Pseudomonas putida (ATCC 17484) and Pseudomonas putida (ATCC 23973) for toluene removal were used simultaneously. The empty bed residence time (EBRT) was 40-120 seconds and the feed (inlet) concentrations of NH3, H2S and toluene were 0.02-0.11, 0.05-0.23 and 0.15-0.21 ppmv, respectively. The observed removal efficiency was 85%-99% for NH3, 100% for H2S, and 20-90% for toluene, respectively. The maximum elimination capacities were 9.3, 20.6 and 17 g/m3/hr for NH3, H2S and toluene, respectively. The results of kinetic model analysis showed that there were no particular evidences of interactions or inhibitions among the microorganisms, and that the three biodegradation reactions took place independently within a finite area of biofilm developed on the surface of the Zeocarbon carrier.

This study was carried out to obtain the optimal ammonia removal efficiency using pyroligenous liquid for the economical and environment-friendly odor removal at a petty livestock farmhouse. The ammonia removal efficiencies were evaluated due to changing dilution rates(×10, ×20, ×30, ×50 and ×100 times) and different spray amounts(10㎖ and 20㎖) of pyroligenous liquid. The wet scrubber device was used to remove odor in closed-type livestock farmhouse. According to dilution rate of the pyroligenous liquid, the optimum rate was 20 times and the removal efficiency increased by decreasing dilution rates. In the case of spray amounts with the optimum dilution, the amount was 20 ㎖ and the removal efficiency increased by increasing spray amount. Also, the removal efficiency by using wet deodorizing device was 83.0～97.0% with 20 times diluted liquid.

겨울철에 금강하류에서는 암모니아성 질소(NH3-N) 농도가 주기적으로 높게 검출되어, 부여지점에서 취수하는 정수장의 수처리 공정에 큰 장애가 되고 있다. 질소농도 저하와 소독부산물 생성 억제를 위해 종종 대청댐의 추가 방류가 검토되고 있으나, 방류량과 직소농도 관계의 정량적 분석에 어려움이 있었다. 본 연구에서는 8년간의 일별 수질자료와 댐 방류량 자료를 이용하여 겨울철(12월∼3월) 동안 일별 NH3-N 농도를 예측할 수 있는 다중회귀모형을 개발하고,

This study was conducted to know the removal characteristics of ammonia nitrogen by commercially available cation exchange resins. Eight acidic cation exchange resins were investigated in batch reactors. Among them, the most effective resin for ammonia removal in solution was PK228, which was a strong acidic resin of Na+ type. PK228 was compared with activated carbon and natural zeolite. The effects of cation exchange capacity, ammonia concentration, resin amount, temperature and pH on ammonia removal by PK228 were investigated in batch reactor, and the effect of effluent velocity in continuous column reactor. Strong acidic resins of porous type were more effective than week acidic resins or gel type resins for ammonia removal in solution. PK228 was more effective than activated carbon and natural zeolite for ammonia removal in batch reactor. With increasing initial ammonia concentration, the amount of ammonia removed by PK228 increased, but the proportion of removed ammonia to initial ammonia concentration decreased. The effect or temperature on ammonia removal by PK228 was very slight. The ammonia removal to acidic solution was more effective than that at basic solution. With decreasing effluent velocity of solution through column, breakthrough point extended, and ammonia removal capacity increased.

Immobilized nitrifier bead in airlift bioreactor were used to remove high levels of ammonia nitrogen from synthetic wastewater. Polyvinylalcohol (PVA) bead for immmobilization of nitrifier consortium were prepared by PVA-boric acid method by varying concentration of PVA and nitrifier consortium. By determining viscosity, sphercity and tailing, the characteristics of prepared beads were investigated and the continous immobilization process was developed. Synthetic wastewater containg 25g/㎥ of ammonia nitrogen could be treated within 0.5 hour and the highest removal rate of ammonia nitrogen was 934.2g/㎥ ·day.

Nitrifier consortium entrapped in Ca-alginate bead were packed into aerated packed bed bioreactor and non aerated packed bed bioreactor and the performances of two bioreactors were evaluated for the removal of ammonia nitrogen from synthetic aquaculture water. Total ammonia nitrogen(TAN) removal rate was decrease in aerated packed bed bioreactor below 0.3hr of hydraulic residence time(HRT), but increased in non aerated packed bed bioreactor until 0.5hr of HRT. At HRT of 0.05 hr, TAN removal rate of non aerated packed bed bioreactor was about 335g TAN/㎥/day and the optimum ratio of packing height and inside diameter of reactor (H/D) was 4. The performance of two bioreactors indicated that non aerated packed bed bioreactor was better than aerated packed bed bioreactor in ammonia removal from synthetic aquaculture water.