간행물
한국환경과학회지 KCI 등재 Journal of Environmental Science International
- 발행기관 한국환경과학회
- 자료유형 학술지
- 간기 월간
- ISSN 1225-4517 (Print)2287-3503 (Online)
- 수록기간 1992 ~ 2023
- 주제분류 자연과학 > 자연과학일반 자연과학 분류의 다른 간행물
- 십진분류KDC 539DDC 628
권호리스트/논문검색
제4권 제3호 (1995년 8월) 15건
1.
1995.08
서비스 종료(열람 제한)
Recycling is receiving increasing social attention today as our nation begins to grapple with the significant problems caused by huge amount of municipal solid waste. The topic of recycling is not simple but extremely complicated. This study attempts to provide basic data and policy options for expanding and improving separated collection and recycling in public residential areas, through three case study of apartment housing areas in Taegu Metropolitan City. The main results of this study are summarized as follows. For the significant period of time, all three case areas had in common the extreme difficulty in establishing and operating the system of connecting public participation, collection and storage, transportation, and actual recycling of materials because of a variety of problems involved in this process. Both amounts of and prices for collected materials fluctuated considerably over time mainly due to monthly changes in recyclable home materials and the dynamic nature of recycling markets. Public questionnaire survey revealed the very high level of participation in separated collection, not only because almost all respondents well understood the necessity and importance of recycling, but because they also knew how to do separated collection. But overall activities were rated low and most respondents suggested the enlargement of public participation, the improvement of collection and storage facilities, and collection transportation networks. In particular, most respondents had little experience of using recycled products and used mainly reproduced soap and bathroom tissue. Furthermore, they were considerably unsatisfied with low variety and quality of recycled products, their high prices and low availability in the market. Finally potential policy options and activities for improving separated collection and recycling are suggested.
2.
1995.08
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A study on phytoplankton community was carried out from June, 1992 to May, 1993 at selected stations in Hoedong Reservoir. The phytoplankton are identified as 176 taxa including 5 phylum, 67 genera. The important species in this reservoir were Asterionella formosa, C. meneghiniana, Dictyasphaerium pulchellum, Fragilaria crotonensis, Melosira distans, M. granulata, M. granulata var. angustissima, M. granulata var, angustissima f. spiralis, Micractiniurn pussillum, Microcystis aeruginosa, Pandorina morum, Pediastrum boryanum, P. duplex, Peridinium sp., Scenedesmus quadricauda, Synedra acus, S. rumpens and S. ulna. The causative species of water bloom were identified as Microcystis aeruginosa, Trachellomonas hispida, Ceratium hirundinella, Peridinium sp., Melosira italica, Staurastrum dorsidentiferum var. ornatum in the area. During the study periods standing crops of phytoplankton were maximum in August, 1992 and minimum in December, 1992. The species dominance index and diversity index were ranged 24.7-99.9, 0.001-3.06, respectively.
3.
1995.08
서비스 종료(열람 제한)
The seasonal changes and composition of phytoplankton of the Choonsan reservior were studied from November 1990 to October 1991. 195 taxa which belong to 65 genera, 150 species, 40 varieties and 1 forms were identified. Species number during summer monthes was higher than that of other seasons. Standing crops of phytoplankton were varied from 7.8 × 10 exp (5) cells/ℓto 2.2 × 10 exp (6) cells/ℓ The dominant species were Cryptomonas erosa and Trachelomonas uolvocina. Chlorophyll a contents of phytoplankton was varied from 1.36 ㎍/ℓto 127.46 ㎍/ℓ. The biotic indices of phytoplankton were very similar among three sites. Saprobien-system by index of species diversity suggests that the Choonsan reservior belongs to the oligosaprophic.
4.
1995.08
서비스 종료(열람 제한)
Phosphorus and nitrogen loadings from the main tributaries into the Nakdong River were estimated by measuring phosphorus and nitrogen concentration in the main tributaries, Nakdong River(Kangjung), Kumho River, Heichun, Hwang River, Nam River, Milyang River, and Yangsanchun from May 1994 to October. Total phosphorus concentration of Kumho River was vary high, average 1.0 ㎎P/ℓ. The other rivers were the range 0.05∼0.15 ㎎P/ℓ. Total nitrogen concentration of Kumho River was vary high, average 6.27 ㎎N/ℓ. The other rivers were the range 1.5∼3.0 ㎎N/ℓ. The phosphorus loading from Kumho River, Nakdong River(Kangjung), Nam River, Milyang River, Hwang River, Yangsanchun, and Heichun were calculated to be 1,108, 603, 198, 57, 34, 23, and 21 tP/yr, respectively. Therefore, the loading from Kumho River accounted for 45 % of total loading, 2,042 tP/yr. The nitrogen loading from Nakdong River (Kangjung), Kumho River, Nam River, Milyang River, Hwang River, Heichun, and Yangsanchun were calculated to be 12,636, 7,411, 2,611, 1,523, 779, 608, and 391 tN/yr, respectively. Therefore, the loading from Nakdong River(Kangjung) and Kumho River accounted for 50 % and 30% of total loading, 25,959 tN/yr, respectively.
5.
1995.08
서비스 종료(열람 제한)
Surface heat balance of the northern sea of Cheju Island for summer in 1993 and 1994 is analyzed using the observation data obtained by Marine Research Institute, Cheju National University. Each flux elements at the sea surface is derived from the marine meteorological reports with application of an aerodynamical bulk method for the turbulent heat fluxes, and empirical formulae for the long-wave radiation heat fluxes. The flux divergence of oceanic heat transport and the rate of heat storage in the ocean are estimated as residual. The features of the surface heat balance are mainly decided by the solar radiation flux and the latent heat flux for 1994. But the Bowen Ratios were large for 1993. This means that the sensible heat fluxes were nearly equal to the latent heat fluxes for 1993. In this period, mean flux divergence of oceanic heat transport is about 130 W/㎡.
6.
1995.08
서비스 종료(열람 제한)
In order to study on the long-term change of water quality, water analysis was conducted at 16 sites surrounding the Kumho river system for 11 times from September 1990 to August 1993. Analytical items for the study of water quality are as follows; water temperature, pH, COD, BOD, DO, SS, electrical conductivity, NH_3-N, NO_2^- -N, NO_3^- -N, PO_4^3- -P, total-P, hardness, oil and grease, ABS, phenol, zinc, chromium, cadmium, manganese, iron, lead and color. The long-term change of water quality in the Kumho river for the period studied was found that the values of water temperature, electrical conductivity, phenol, NO_2^- -N and NH_3-N were increasing and those of COD, BOD, SS, oil and grease, ABS, NO_3 -N, PO_4^3- -P, copper, zinc, chromium, cadmium, manganese and lead were decreasing, while those of pH, hardness, iron and manganese were steady.
7.
1995.08
서비스 종료(열람 제한)
Stability of reactor and effect on biofilm characteristics were investigated by varying the hydraulic residence time in an inverse fluidized bed biofilm reactor(IFBBR). The SCOD removal efficiency was maintained above 90 % in the HRT range of 12hr to 2hr, but the TCOD removal efficiency was dropped down to 50 % because of biomass detachment from overgrown bioparticles. The reactor was stably operated up to the conditions of HRT of 2hr and F/M ratio of 4.5㎏COD/㎥/day, but above the range there was an abrupt increase of filamentous microorganisms. The optimum biofilm thickness and the biofilm dry density in this experiment were shown as 200 ㎛ and 0.08 g/㎤, respectively. The substrate removal rate of this system was found as 1st order because the biofilm was maintained slightly thin by the increased hydraulic loading rate.
8.
1995.08
서비스 종료(열람 제한)
This study was investigated with denitrification of wastewater containing nitrate using upflow sludge blanket process. Contents of this study were the NO_3^- -N removal efficiency by various hydrogen donor addition, determination of optimum COD/NO_3^- -N ratio and characteristics of granular sludge.
9.
1995.08
서비스 종료(열람 제한)
This study was investigated with denitrification of wastewater containing nitrate using upflow sludge blanket process. Contents of this study were the nitrogen gas production, relationship between HRT and COD/NO_^3- -N ratio in case of various hydrogen donor addition, relationship between nitrate loading rate and various hydrogen donor addition.
10.
1995.08
서비스 종료(열람 제한)
PCBs have been measured using GC-ECD, GC-MS, GC-ELCD, HPLC, TLC, NMR and Immunoassay. The analysis of PCBs using GC- ECD include the peak pattern method as none derivatization and the perchlorination method as derivatization. This study was conducted to establish the perchlorination method with SbCl_5 from PCBs to decachlorinated biphenyl(DCB). The aroclor 1242 of PCBs was chlorinated and then, converted into the DCB which showed a single peak in GC-ECD chromatogram. The detection limit of DCB was 2pg. The quantification detection concentration of PCBs extracted with soxhlet was 0.5ng/g in the soil. PCBs were not detected in the suburban soil, but 174ng/g in the soil of industrial complex. Mean PCBs concentration of Shinchun stream at Kumho river and Jinchun stream at Nakdong river was calculated average 88ng/g in the sediment. PCBs concentration in the sediment of Kumho river near 2-7㎞ from conjunction with Nakdong river was average 154ng/g. PCBs concentration in the sediment of Nakdong river near conjunction with Kumho river was average 159ng/g.
11.
1995.08
서비스 종료(열람 제한)
This study was conducted to evaluate the effects of pressure and dissolved oxygen concentration on the activated sludge and to determine the optimum depth of deep shaft process. Some results from this study were summarized as follows. 1. It is considered that low sludge product in the activated sludge system maintaining high dissolved oxygen concentration is attributed to the increase of endogeneous respiration rate caused by the increase of aerobic zone in the sludge floc. 2. The increase of dissolved oxygen concentration does not affect to the increase of organic removal efficiency greatly and therefore the limiting factor is the substrate transfer into the inner part of floc. 3. The yield coefficient, Y is decreased in proportion to the increase of oxygen concentration. In this study, Y values arre ranged from 0.70 to 0.41 according to the variation of dissolved oxygen concentration from 18.0㎎/ℓ to 258 ㎎/ℓ. 4. The optimum depth of deep shaft process should be determined within the limits of non-toxicity to the microorganism and it is about 100m in this study.
12.
1995.08
서비스 종료(열람 제한)
An experimental research was conducted in order to study the treatability of municipal landfill leachate using a combined physio-chemical and biological treatment. The leachate was obtained from Nanjido landfill site in Seoul. Several sets of bench-scale sequencing batch reactor(SBR) and physio-chemical reactors were used as experimental apparatus. This experiment lasted for about 2 years. The results are as follows: 1. The characteristics of Nanjido landfill leachate were pH 7.4∼8.2, BOD 79∼450㎎/L, COD 998∼1460㎎/L, NH_3-N 1380∼3412㎎/L, T-P 2.6∼7.O㎎/L, color 890∼1992 unit, and heavy metals are a very small amount. 2. Either physio-chemical or biological treatment of Landfill leachate alone did not work well. So for the adequate treatment of leachate, it was necessary to deal with the physio-chemical pretreatment before biological treatment. And it was found that both electrolysis and ozone treatment are better pretreatments of leachate than others. 3. In this study, landfill leachate was effectively processed by two step : first by electrolysis pretreatment, and secondly by SBR treatment. Thus, the study showed considerable substrate removal of raw leachate, even though the rate of COD removal depended on HRT.
13.
1995.08
서비스 종료(열람 제한)
There has been an increased awareness of the need to confirm the chloroform exposure associated with using chlorinated household water. Ten of a 30-minute tub bath were normally taken by two volunteers in a bathroom of an apartment. Chloroform concentrations were measured in bathing water and bathroom air, and exhaled breath of the subjects prior to and after bathing. Bathing using chlorinated tap water resulted in a chloroform exposure and caused a body burden. Based on the difference of chloroform concentrations between breath samples collected prior to and after bathing, the chloroform body burden from a 30-minute bath was estimated to be about 8 to 26 folds higher than that prior to the bath. The mean water and bathroom air chloroform concentrations measured to evaluate the body burden were 9.4 ㎍/ℓ and 14.9 ㎍/㎥, respectively. The chloroform level of the bathroom air was 34 to 130 times higher than that of the living-room air. The relationship between the bathroom air and the corresponding breath chloroform concentrations were significant with p=0.03 and R^2=0.47.
14.
1995.08
서비스 종료(열람 제한)
A comparative study on the chemical compositions of precipitations from February 1993 to April 1993 in Sungnam city of Kyunggi province, Inchon city, Kangneung city of Kangwon province, and Chongwon-gun of Chungbuk province has been performed. The metal cation and anion concentrations were measured by atomic absorption spectrometer and ion liquid chromatography, respectively. pH/Ion meter and direct nesslerization method were used for the concentration measurements of H^+ and NH_4^+ ions, respectively. The quantitative orders of the cation and anion average concentrations, correlation coefficients between the ion concentrations, and pH values are used for chemical analysis on the environmental pollution and pollutant sources in the urban, surburban, seaside, and rural areas of the Korean Peninsula.
15.
1995.08
서비스 종료(열람 제한)
Continuous deodorization of malodorous sulfur compounds by Thiobacillus neapolitanus R-10 immobilized onto a polypropylene pellet was studied using a column reactor at 30℃. The maximum amounts of immobilized cells was 5.3 g/ℓ polypropylene with 5 × 7.5㎜ in pellet size, and the amounts of immobilized cells in the higher part of the column was as twice as in the lower part. The optimum pH and temperature for removal of dimethyl sulfide were 6.0 and 30℃, respectively. When 5-20 ㎕/ℓ of hydrogen sulfide and methylmercaptan were employed 98% of removal efficiency were achieved. In contrast, lower concentrations of dimethyl sulfide and dimethyldisulfide should be supplied to meet satisfactory deodorization efficiency. The immobilized cell column was successfully operated for the deodorization of mixture of sulfur compounds over 15 days without significant loss of initial activity achieving high efficiency.
