We examined whether several reeds, which are found around Ulsan area, could be used for downflow reed-bed to remove pollutants of sewage. Three kinds of reed, such as Phagnltes auspuis, ha orientdls, and Phduis aundinacea L., were collected from their habitats near the Taehwa River in Ulsan City. In the minimized model system of dowMlow reed-bed, P.auskdls appeared to reduce BOD more than others did but s119h11y Increase total amount of nitrogen(N). When p. auspdis were placed in the sterilized water. total nitrogen was found to be signincantly increased dependent on the number of experimental plant In the sterilized state, but it was rather decreased in the non-sterilized state. With these results, nlicroorganisms attached to p.auspuis roots can be thought to work for removal of pollutants. Therefore, these microorganisms and their habitat, p. auskdis reed bed, together can be used for sewage treatment It was suggested that oxygen Is produced by photosynthesis reaction of P ecustrdis. The increased oxygen may help microorganisms in their habitats to work on the removal of pollutants.

The experiment was performed to elucidate the effect of simulated acrid rain on growth of the seven crops(caucus carota vu sativa DC. , Fagopyrum esculenkm Moench, Brassica cmpespis subsp. napus var. pekinensis Makino , Raphuus satlws vu. hortensis for. acnMormis Makino, Brassica dbogjabra Bailey, Caphslcum mum L., and Perilla frutescens Britton). The pH levels of simulated acid rain ranged pH 3.1, 3.6, 4.1, 4.6, 5.1 and 5.6. The germination 10 each crop was influenced from stimulated acrid rain except buckwheat and kale. A general decrease of growth in crops was observed with Increasing pH concentrations. The pattern of soluble protein was observed a tendency to decrease from acidic pH eradlents. According to acidity, total DNA contents of each crop was showed a definite reduction. In conclusion, plant growth was stimulated decreasln and the chanties of total Protein Patterns and BNA contents extracted from leaves trended with stimulated acrid rain was showed seriously.

To investigate the effects of sulfite on the chloroplast development, etiolated barley seedlings were treated with 100 mM sulfite solution every 3 hour by spraying during 96 hours greening Period. The effects were determined by chlorophyll a, b and carotenoids contents, photosynthetic electron transport activity, chlorophyll fluorescence yield and fluorescence quenching parameters. The contents of chlorophyll a and carotenoids were decreased than that of control by treatment of salfite over 48 hours greening. PS II Is more sensitive to sulfite than PS I Is. And by the addition of DPC to the chloroplasts of the barley seedling treated with sulfite, the photoreduction of DCPIP was not recovered. In greening with suite treated barley leaves, Fo, Fv and Nlh ratio were decreased with little difference from that of control. But qP, qNP and qR were lowed in comparison with those of controls whereas qE was markedly higher than that of control. Especially, It is Interesting that qR was decreased markedly compared to that of control. The results in the change of PS I activity, Nf and qP suggest that the strate of Inhibition by suite Is carbon dioxide reduction cycle.

Effects of alumlnlum(AA), soil pH and calcium(Cal on growth response and heavy metal accumulation and regulation of nitrogen fixation In Melilotus suaveolens seedlings, a biennial legume plant dominating in the disturbed area, were quantitatively analyzed during the growing periods. Accumulation of metals In each organ of M. suaveojens was Increased UC the lowering of pH. Al contents In leaf and root treat- ed with 30ppm Al at pH 4.2 on the 28th day after treatment were 8 and 11 folds higher than those of control, while the contents with 100ppm AA were 21 and 24 folds as compared to control. The significent inhibition in Al contents was induced by 100ppm AA and Ca at pH 6.5. Increased metals inhibited higher at pH 4.2 and the growth inhibition due to Al was reversed by the addition of Ca, suggesting that growth correlates to the pH value. Chlorophyll contents in leaves increased during growth stave were inhibited by Al treatments. The biomass was decreased UD the lowering of pH and the increase of concentrations. 100ppm Ca treatment resulted in 5.1-5.9% increase of the biomass as compared to that of 100ppm Al. Specific nitrogen fuation activities In nodules In the 100ppm Al at pH 4.2 and pH 6.5 were reduced to 35. 2% and 52.2% of control, on the 28th day after treatment, while the combination of Al and Ca induced reduced by 10% as compared to control with the treatment of 100ppm AA at pH 4.2 due to the inhibition bination of 100ppm Al and Ca and lowering of pH.

Enoronmental problems caused by certain geologic conditions Include pollution of soil by heavy metal, acidization of souls , acid mine drainage, Pound-water pollution, and natural radioactivity, as well as zoo-logical hazards such as landslide and subsidence. The acrid mine drainage contains large amount of heavy metals nO, therefore. cause serious pollution onto the nearby drainage systems and soils. In spite of this prospective environmental danger, few studies have been done on the acid mine drainage derived from non-metallic ore deposits such as pyrophyllitefNapseok) deposits. The sudo-bearing pyrophyllite ores, alteration zones, and mine talllngs of pyrophylllte deposits produce acrid mine drainage by the okidation of weathering. Compared to the fresh host rocks, the ores and altered rocks of pyrophyllite deposits produce acidic solution which contain higher amount of heavy metals because of OeP lower buffering capacity to acrid solution. The pus of urine water and nearby stream water of pyrophyllite deposits are 2.1~3.7, which are strong- ly acidic and much lower than that (6.2~7.2) of upstream water and than that (6.8~7.6) of the stream water derived from the non-mineralized area. This study reveals that this acrid mine drainage can affect the downstream area which is 8km far from the pyrophyllite deposits, even though the drain Is diluted with abundant non-contaminated river water This suggmists that not only acid mine drainage but also the sulfide-bearing sediments originated from the pyrophyllite deposits move downstream and form acidic water through continuous oxidation reaction. The heavy metals such as Pb, Zn, Cu, Cd, Nl, Mn and Fe are enriched In the mine water of low pH, and their contents decrease as the pH of mine water Increases because of the Influx of fresh stream wainer. SoUs of the Pyrophyulte deposits are characterized by high contents of heavy metals. The stream sediments containing the yellowish brown precipitates formed by neutralization of acid mine drainage occur in all parts of the stream derived from the pyrophyllite deposits, and the sediments also contain high amounts of heavy metals. In summary, the acid mine drainage of the pyrophyllite deposits is located in the upstream part of Hoidong water reservoir in Pusan contains large amounts of heavy metals and flows into the Holdong water reservoir without any purification process. To protect the water of Holdong reservoir, the acid mine drainage should be treated with a proper purification process.

preliminary study on the chemical compositions of forty seven precipitations from March 1994 to May 1995 In Yeoncheon-gun, which Is adjacent to the southern boundary of demilitarized zone (DMZ) in the northernmost tip of Kyunggi Province has been Performed. The metal cation and anion concentrations were measured by atomic absorption spectrometer and ion chromatography, respectively. pH/lon meter and direct nesslerization method were used for the concentration measurements of $H^+$ ion and $NH_46+$ ions, respectively Based on the data, the quantitative orders of the cation and anion average concentrations were $Ca^{2+}>NH_4^+>Na^+>K^+>Mg^{2+}>H^+ and SO_4^{2+}>Cl^-> NO_3^-$, respectively..The ratio of average total anion concentration to average total cation concentration was 0.97. The average pH value of the precipitations was 5.60. These results, correlation coefficients between the ion concentrations, and monthly variations of pH value and precipitation amount are used for chemical analysis on the environmental Pollution and Pollutant sources In Yeoncheon-gun of Kyunggi province near DMZ.

The purpose of thins study was to investigate the pollutions of water Qualities in 30 water samples from Nakdong River Western Nakdong River, and Suyoung Stream. COB, BOD. T-N and negative ion(F, Cl+, NO3-, SO42-) of water samples were analysed and the correlationships between water qualities were examined. The mean concentrations of COD(20.26ppm), BOD(25.36ppm), and T-N(18.05ppm) were the highest in the water sample of Suyoung Stream among the three streams and those of F-(0.25ppm), Cl+(2770ppm), and SO42-(37.66ppm) In Western Nakdong River, that of NO3-(10.8 ppm) in Nakdong River. The water quality of Suyoung Stream was the worst among the three streams in hsn area. The correlationships between water qualities were as follows , BOD and COD showed very high correlationship(correlation cofficient, r=0.97),50,2- and NO3'did high one(0.75), and NOa'and COD, BOD did relatively high ones(0.56 and 0.48, respectively).

This study was conducted to evaluate water quality utilizing principal component analysis in the Nakdong River Estuary. From the results of analysis, water quality in the Nakdong River Estuary could be explained up to 65.3 Percente by three factors which were Included In river loadlnwastes from the Nakdong River and rainfalls : 39.1%1, sediment resuspension(13.7BS) and metabolism(12.5%). In the eastern part of estuary In flowing the Nakdong River, river loading factor score(factor 1 Pas higher than that In western part. Sediment resuspension factor score(factor 2) was high in shallow water, while metabolism factor score(factor 3) was high in deeper water. For seasonal variations of factors score, factor 1 was h19h- 1y related to rainfall season.

1981년부터 1990년까지 10년간 발생한 274개의 호우사례를 분류하여,한반도에서 호우시에 나타나는 강수량의 공간분포를 여섯 종류로 나누고 각각의 정관적 특성을 분석하였다. 첫때, 강하게 발달한 지표 저기압에 연관되어 발생하는 호우보다 상, 하층 제트를 동반한 채 발달중인 저기압에 연관되어 발생하는 호우가 많다. 둘째, 재부분의 호우역은 하층 제트의 위치와 방향 그리고 지표 온나전선의 위치에 연관되어 있다. 셋째, 500hPa 면의 저기압 중심이나 기압골의 위치가 서쪽으로 멀어질수록 한반도에어 호우는 고위도에서 발생하는 경향이 있다. 넷째, 한반도에 호우를 초래하는 500hPa의 저기압 중심은 하계몬순의 발달을 따라 서쪽으로 자리잡는 경향이 있으나 해마다 차이가 있다.차이가 있다.

$PM_{10}$ concentrations were measured In underground stores located In 4 major cities, Chunchon, Wonju, Donghae and Sockcho, In Kangwon-Do using scattering light Integated type digital dust indicator. Per- sonal exposure to $PM_{10}$ for two women(housekeeper and gaduate students and a man(undergraduate student) were measured also. The dimensional conversion factors for mass concentrations(K) showed some difference among un- derground stores which were 2.0, 2.7, 3.4, 2.6 mg/$m^2$.CPM In chunchon, Wonju, Donghae and Sockcho, respectively. Average PMlo concentrations at underground stores were 178mg/$m^2$ in Chunchon, 141mg$m^2$ in Wonju, 125 mg/$m^2$ Donghe and 59mg/$m^2$) Sockcho. The portion of $PM_{10}$ In total suspended particles was about 50~60% as deight The exposure of graduate student, housekeeper and undergraduate to $PM_{10}$ during 12 hours were 1004. 3 (mg/$m^2$) .hr, 907.0 (mg/$m^2$) hr and 691.2 (mg/$m^2$) hr, respectively. Personal exposure to $PM_{10}$ showed very different according to heP activity pattern and they had more than 90 % of their $PM_{10}$ exposure at Indoor environment.

In this research, two stochastic models are considered to detect and estimate the effect of air temperature change due to Industrialization In Ulsan area. Using the monthly mean minimum air temperature anomalies, the data are divided Into pre-Industrialization part and Industrialization one for analysis. The ARM(autoregressive moving-average) model and intervention model have been applied to the data for the analysis. The results show that the variability of minimum temperature anomalies are very significant In 1989, and also significant In 1971 when the Industrialization have started. Therefore, It Is stochastically possible to estimate the time when the affection of Increase of the temperature concerning Industrialization to climate change In Usm area has happened.

The low level atmospheric obsewation carried out to Investigate magnitude, formation and dissipation of nocturnal surface Inversion layer, also to survey relation to each meterological parameter In Inversion layer at Pusan power plant for Oct. 13, 1996. As coastal area, the surface Inversion layer height was relatively high(186m), and after sunset unstable layer formated firom surface to around 40m, and the Inversion layer was left still in the upper layer. The surface Inversion layer dissipated at 0920LST perfectly. The layer that strong Inversion layer was formated, showed steep variation of potential temperature and wand speed and relative humidity.

A simple on-line measurement system consisting of a conventional peristaltic pump, a HPLC-type heater, and a flow-through spectrophotometer is introduced for the determination of chemical oxygen demand(CODI. The system was configured such that the reaction mixture in the highly concentrated surffuric acrid medium flowing through the PTFE reaction tubing was heated at 150℃ and the absorbance of dichromate was continuously moutored at 445 m. The same addation principle as in the standard procedure was employed akcept the use of CoSO4 as a new effective catalyst. To test the system, potassium hydrogen phthalate was selected as a COD standard material. With suitably optimized reaction condition, the applicable concentration range depends on the concentration of potassium dichromate in the oxidizing reagent. With 2.0×10-3 M and 5.0×10-4M dichromate, the linear dynamic range was observed up to 400 ppm and 100 ppm, respectively. The standards in the Unear ranges were shown to be completely oxidized, which was confirmed with sodium oxalate or Mohr's salt. In all cases, the typical reproduclbility for betweenruns was 2% or less. The proposed measurement system provides the valuable in- formation for the further development of automated analysis system based on the present standard procedure.

Nanofiltration[NF45] and reverse osmosis membrane(HR98PP) separation treatment of dyestuff wastewater was carried out In order to separate relatively pure water from synthetic dyestuff wastewater, which consists of reactive dye, acid dye, basic dye, direct dye, and disperse dye. The experiments were performed by using the plate and frame membrane module. In the nanofiltration and reverse osmosis membrane separation, When the NaCl concentration was 0.1, 5.0, and 20.091, retention was 63.0, 46.0, 0.9%, respectively. When permeate flux was 125.0, 67.5, and 45.0 L/$m^2$ h, the osmotic pressure increased with Increasing the NaCl concentration. Permeate flux of two membranes Increased as temperature Increased due to segmental movement of polymer of the membrane and the rejection rate of dyestuff was decreased gradually. It was found that the rejection rate was about 95% in the nanofiltratlon, while the reverse osmosis membrane showed a high rejection rate of 99% under all temperature and pressures conditions.

Organics matters including algae are the major contaminants of Nak-dong river and it's concentration Is more Increasing now. The use of coagulants has been Incresed for the effective treatment of drinking water, and aluminum coagulants have been the most widely used in raw water treatment. However, when inorganic metal coagulant is excessively used for long period, it would result in secondary problems, such as increasing sludge production, enhancing the cost of water treatment process, and increasing concentration of residual metal, especially aluminum. Therefore, recently. in order to reduce the use of metal coagulant and enhance the coagulation effectiveness, several alternative coagulants, such as polymeric Inorganic coagulants and organic polymers, have been used In water treatment plants. The objectives of thins research were (11 to determine optimum dosage concentration and compare the coajuiation efnciency at various pH ranees with alum alone, alum+cationic polymer, and alum+anlonlc polymer, (21 to evaluate the amount of alum reduced by using organic polymer, (31 to maximize removal officiency of organic matter and minimize the concentration of residual aluminum.

득량만의 조석주기에 따른 성층특성을 연구하기 위하여 우선 30여개 관측점에서 관측된 수온, 염분, 밀도, 해류, 열수지, 바람, 밀도류 자료를 조사하였다. 이 관측자료를 토대로 성층현상을 규명할 수 있는 해석적 모델을 개발하였으며 이 해석적모델을 이용하여 얻어진 연구결과에 따르면, 득량만의 성층을 이루는 요인은 조석, 태양열, 밀도,류인 것으로 나타났으며, 성층을 파과할 수 있는 조석에너지의 혼합에너지의 에너지 기여율 $\varepsilon$ 은 약 0.020 - 0.021정도 되는 것으로 나타났다.

This study Is concerned with properties of a thermal convection in a stably stratified Boussinesq fluid caused by partial heating at the lower boundary. For thins purpose, two-dimensional, nonrotating system was employed. U the heating is very strong, convection takes the form of a turbulent plume. Othenuse, remains laminar. If the partial heating at the bottom boundary Is symmetric. the convection takes the form of a trubuient plume. Otherwise remains but beating form Is not so signiacant as to alter the vergence in the lower layer at the center of the partial heating area. The temperature perturbation is characterized by the temperature 'Cross-Over' over the partial heating area. These features are cleared ac- cording to the Increase of temperature difference between the center and side part of the bottom boundary.