콘택트렌즈 관리용액의 보존제 성분 중 Benzalkonium Chloride<BAC) 가 L929세포 주에 세포독성과 세포 자연사룰 유도하는지 조사하고자 시행하였다. 생쥐 섬유모세포 인 L929 cell line을 배양하여 양성 대조군으로 0.01% H20~， 음성 대조군으로 Media 를 처리하였으며 세포독성은 BAC룰 배양세포에 시간별 (24， 때hr) ， 농도별(0.0001 ， 0.001, 0.005, 0.01, 0.05, 0.1%) 로 처리하여 대조군과 처리꾼올 비교하여 세포독성 농 도를 산출하였다. Hematoxylin-Eosin Staining후 광학현미 경으로 형태적 변화를 관 찰하고， MTT Assay와 LDH Activity 로 검정하였으며， MTT 정량과 LDH(Lactate Dehydrogenase) 활성도로 세포독성 농도룹 산출하였다. MTT 정량결과， 세포 독성이 0.0001% 에서는 8%, 0.005% 에서는 30%, 0.001%에서논 65%5'_ 농도 의존적으로 독성 이 나따났으며， 0.001% 에서 LDH 유출정도가 대조꾼과 비교하여 차이를 나타내지 않 았으나， 0.01% 의 농도에서 2.9 배， 0.1%의 농도에서 대조군에 비해 3.35배정도 높은 LDH 의 유출율을 보였다. 세포자연사 (Apoptosis) 륜 관찰하기 위 해 Hoechst33342와 DNA Laddering과 Flow cytometry를 실시한 결과， 0.1%에서쓴 세포괴사 (necrosis) 에 의해， 0.001%-0.01%에서는 세포자연사(apoptosis) 에 의한다는 것을 알 수 있었다.

The raw drinking water quality is getting worse because of the winter drought and the conventional treatment system is'nt suitable to obtain the satisfied quality of water. So, the advanced water system, BAC(Biological Activated Carbon) process is said to be effective to remove dissolved organics and ammonia nitrogen. In our study, the BAC pilot plant using Nak-dong river water is tested in low temperature. Following results are found from the study. The ammonia nitrogen removal rate of BAC system using wood-based carbon (PICABIOL) was 99% in $6^{\circ}C$ temperature. Chlorine dosage in wood-based BAC effluent was reduced to 67% of that in sand filtered wate. It resulted from the removal of ammonia nitrogen. Also, THM formed by chlorine addition in wood-based BAC effluent was decreased to 65% of that in sand filtered water. In the case of dual-filter, the removal efficiency of ammonia nitrogen was increased 30% more than in conventional sand filter. According to this result, the ammonia nitrogen load to BAC system could be lessened by the use of dual-filter.

Today a conventional water treatment system has many problems. The ozone/GAC process, sometimes termed Biological Activated Carbon(BAC), appeared to be effective for the removal of soluble organic matters in the drinking water. The water quality of Nak-dong river in Pusan, generally shows BDOC 30-40% and NBDOC 60-70%. The pilot plant installed at the Duk-san water works that was been largest treatability(1,650,000ton/day) in Pusan. A experimental water in the pilot plant made use of the water after sand-filteration. Following results are drawn from this study. Initial adsorption velocity($DOC/DOC_o/T$) in the pure adsorption of GAG had a 0.0225, it's velocity changed to 0.006 after ozone added and the optimum ozone dose ranged of $1.4-2.0mgO_3/L$. A experimental water in the pilot plant composed with humic material(78%). Humic material composed with humic acid(20%) and fulvic acid(56%), and it's rate changed to 18 and 50% respectively after ozone added. DOC constantly decreased in the EBCTs and removal efficieny in the 15min of EBCT was 45-50%. It showed the largest removal rate of BDOC in the EBCT 5 and among the season, characteristics of removal varied. The HPC distributed over $10^6-10^7CFU/cm^3$ in the bed depth and among the season, distribution of HPC were differential.

In Korea, many drinking water treatment plants (DWTPs) have introduced and are going to introduce biological activated carbon (BAC) process to treated dissolved organic matter (DOM) in water which are difficult to control by conventional water treatment processes. Even though more decade have passed since introduced BAC in Korea, most of BAC operating method was followed to the modified sand filter operating manuals. In case of BAC backwashing, many DWTPs set the periods of backwashing about 3∼5 days. In this study, we have collected data to set the proper BAC backwashing periods from both pilot-plant and real DWTPs. We had measured heterotrophic plate count (HPC), turbidity, water temperature, dissolved organic carbon (DOC) and headloss from just after backwashing to the next backwashing time for two years. Considering water quality factors, the BAC run time from backwashing to the next backwashing could extend more 30 days without water quality deterioration if the head loss do not reach the limited level which depends on each BAC facilities’ condition. It means the BAC treated water could be saved in the proportion of extended the backwashing period to the existing backwashing period.

In this study we followed biofilm formation and development in a granular activated carbon (GAC) filter on pilot-scale during the 12 months of operation. GAC particles and water samples were sampled from four different depths (-5, -25, -50 and –90 cm from surface of GAC bed) and attached biomass were measured with adenosine tri-phosphate (ATP) analysis and heterotrophic plate count (HPC) method. The attached biomass accumulated rapidly on the GAC particles of top layer throughout all levels in the filter during the 160 days (BV 23,000) of operation and maintained a steady-state afterward. During steady-state, biomass (ATP and HPC) concentrations of top layer in the BAC filer were 2.1 μg·ATP/g·GAC and 3.3×108 cells/g·GAC, and 85%, 83% and 99% of the influent total biodegradable dissolved organic carbon (BDOCtotal), BDOCslow and BDOCrapid were removed, respectively. During steady-state process, biomass (ATP and HPC) concentrations of middle layer (-50 cm) and bottom layer (-90 cm) in the BAC filter were increased consistently. Biofilm development (growth rate) proceed highest rate in the top layer of filter (μATP = 0.73 day-1; μHPC = 1,74 day-1) and 78%∼87% slower in the bottom layer (μATP = 0.14 day-1; μHPC = 0.34 day-1). This study shows that the combination of different analytical methods allows detailed quantification of the microbiological activity in drinking water biofilter.

Cucumis melo L. is an economically important crop. Genetically, Cucumis melo and Cucurbita maxima belong to Cucurbitaceae family, however, genetic characteristics such as genome size and stress tolerance, are different. To provide genomic resources for the Cucurbitaceae crop improvement, we constructed two bacterial artificial chromosome (BAC) libraries for oriental melon (Gotgam chamoe) and squash (Cucurbita Maxima), named ‘Gotgamchamoe BACH1’ and ‘Maxma BACH1’, respectively. Three hundred eighty four BACs were randomly selected and analyzed by Not I restriction enzyme digestion in order to evaluate the libraries in terms of insert size, empty clone ratio. Gotgamchamoe BACH1 was consisted of 92,160 BAC clones with an average insert size of 116kb ranging from 8 to 252kb. Maxima BACH1 was comprised 158,380 clones with an 116Kb of an average insert size ranging 8 to 305Kb. The both libraries were represented 20 haploid genome equivalents based on the reported genome sizes of 500Mb and 900Mb for Gotgamchamoe and maxima. The empty ratios of both libraries were 1.04 and 1.50% for Gotgamchamoe and maxima, respectively. These high quality BAC resources will provide a useful platform for genomic research and crop improvement for Cucurbitacea crops.