• 환경위생공학
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• 제12권1호
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• pp.69-75
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• 1997

Biological drinking water treatment is widely used in Europe for the removal of ammonia nitrogen and organics. During the last 16 years, the deterioration of the quality of surface waters used to produce drinking water has resulted in the widespread use of ozone-biological treatment in Korea. This study were conducted to determine the effect of media weight and preozonation on the biodegradability enhancement in biological fluidized bed(BFB) using Han river water. When the carbon weight was increased, $NH_{3}-N$ and DOC removal increased, but turbidity and SS removal decreased. To remove turbidity and SS, the bed depth in 40% expansion rate/total bed depth was very important. Preozonation of raw water was not effective in $NH_{3}-N$, but increased in biodegradable organic fraction about 10-30% with 0.425-0.85 mg $O_{3}/mg$ DOC.

• 환경위생공학
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• 제15권4호
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• pp.14-19
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• 2000

This study was carried out to get efficient of nutrient removal and wastage sludge production minimized effects on the treatment of slaughterhouse wastewater using aerobic curtain biological film contact process. As a results of biofilm attachment experiment aggravation of water quality due to excessive biofilm showed after every 15 days of operating times. The concentration of BOD and COD in the influent were 2500~3000mg/L and 1700~2100mg/L , respectively. The average BOD and CoD were 9mg/L and 17mg/L , respectively. The result of this experiment was wastage sludge did not almost generated and the removal efficiency of nutrients were kept equilibrium.

• 환경위생공학
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• 제16권1호
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• pp.40-46
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• 2001

Conventional membrane systems was difficult to treatment for pulp and paper mills waste warter. Technological advances in membrane filtration systems have created opportunity for pulp and paper mills to treat effluent streams in order to meet stricter environmental constraints. "Vibratory Shear Enhanced Processing(VSEP)" developed by new logic international makes if possible to filter effluent streams without the fouling problems exhibited by conventional membrane systems. Various kinds of waste water occurred to and paper mills experiment with "VSEP" set up conventional membrane. The results were as followes : Excepting ultra filter($0.1{\mu}\textrm{m}$ Teflon, C-100, G-50), Nano filter(NTR-7450, DS-5, PVD-1) and reverse osmosis(ACM-4) was treated with very excellent weight of treatment, electric conductivity, removal COD, TDS, turbidity.

• 환경위생공학
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• 제17권3호
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• pp.89-98
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• 2002

The changes of conventional clarification process and an increase in treatment cost are required to meet increasingly stringent regulations related to the treated water quality. Although many enhanced coagulations have introduced to improve organic matter removal, the results to remove color, nitrogen and phosphorus as well as organic material have not been very efficient yet. The removal of waste matters such as SS, organic matter, color and turbidity contained in dyeing wastewater was carried out by using the combination of calcium hydroxide and magnesium sulfate. The flocculation was investigated as a function of coagulant dose, pH, mixing time, settling time and coagulant addition modes such as the sequential addition of the two coagulants and the simultaneous addition of them. The flocculation by the combination of calcium hydroxide and magnesium sulfate was compared with that by aluminum sulfate. The mechanism of flocculation was investigated as well. About 84% of color in dyeing watewater was removed by flocculation with combination of calcium hydroxide and magnesium sulfate.

• 환경위생공학
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• 제9권2호
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• pp.110-119
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• 1994

The objective of the this study was to evaluate the effects of heavy metals on the sewage treatment process designed to remove organic material and nutrients using Water- hyacinth ( Eichhornia crassipes ). Batch experiments were carried out using domestic sewage spiked with different level of heavy metal mixtures ( Cd, Pb and Cu ). The specific growth rates of Water- hyacinth ranged from 0.0008 to 0.0015 1/day( operated at water temperatures of 22 ∼30$\circ $c ) and increased as the concentration of heavy metals decreased. The test result showed that the permissible maximum concentrations Cd, Pb and Cu for the growth of Water- hyacinth were 0.5, 1, and 6 mg/ℓ respectively. Under these maximum permissible heavy metal loads, removal rate of organic material, nitrogen and phosphorus were 85%,75% and 75% , respectively, during 40days of the test period.

• 환경위생공학
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• 제17권4호
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• pp.10-18
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• 2002

The changes of conventional clarification processe and an increase in treatment cost are required to meet increasingly stringent regulations related to the treated water quality. Although many enhanced coagulations have introduced to improve organic matter removal, the results to remove color, nitrogen and phosphorus as well as organic material have not been very efficient yet. In this context as new flocculation using calcium hydroxide and magnesum sulfate was carried out. The removal of waste matters such as SS, organic matter, COD, nitrogen and phosphorus contained in stock wastewater was carried out by using the combination of calcium hydroxide and magnesium sulfate. The flocculation was investigated as a function of coagulant dose, pH, mixing time, settling time and coagulant addition modes such as the sequential addition of the two coagulants and the simultaneous addition of them. The flocculation by the combination of calcium hydroxide and magnesium sulfate was compared with that by aluminum sulfate. The mechanism of flocculation was investigated as well. About 60% of COD in stock watewater was removed by flocculation with combination of calcium hydroxide and magnesium sulfate.

• 환경위생공학
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• 제12권2호
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• pp.29-35
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• 1997

Phenol, often discharged from petroleum and fine chemical industries is potential carcinogen and was classified into priority pollutant by EPA in USA. It causes serious environmental and health problem if discharged to the environment such as soil or aquifer. The removal efficiency of phenol and COD using Fenton treatment(Hydrogen Peroxide and Ferrous Sulfate) was observed and biodegradability (BOD$_{5}$/COD$_{cr}$) of reaction products were also examined. When 50 mg/l of phenol was treated by Fenton's Reagent(50 mg/l of hydrogen peroxide and 900 mg/l of ferrous sulfate), the removal efficiency of phenol and COD was 100% and 80% respectively in 10 minutes, which suggested this method can be used as actual phenol removal process. The initial biodegradability of 500 mg/l phenol solution was 0.7 but decreased as hydrogen peroxide was increased.

• 환경위생공학
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• 제12권3호
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• pp.95-102
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• 1997

The process which can stabilize water quality of treatment and improve nitrogen removal rate under the condition of high organic loading was developed by charging fibrous HBC media to single sludge nitrification-denitrification process. This process was operated easier, minimized the treatment cost, and shortened the retention time. To improve T-N removal rate, a part of nitrifing liquid at aerobic zone was recycled to anoxic zone by approximate internal recycle ratio. The experimental results are as follows ; T-N removal efficiency in the organic volumetric loading 0.14-0.19 kg/COD/m$^{3}$·d was obtained asmaxium of 85% at internal recycle ratio 2.5 and in more ratio than this it was decreased. Organic removal efficiency was about 91% under the overall experimental conditions and not influenced by recycle ratio.

• 환경위생공학
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• 제12권2호
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• pp.65-74
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• 1997

The purpose of this study was to investigate the removal effect and variation of contaminated water by various water treatment processes using sediment filter, activated carbon, photocatalysis, reverse osmosis, ultra violet sterilizer and ultra filtration. The removal effect of chloride and trace metal was low by activated carbon and ultra filter but high in reverse osmosis. The removal effect of bacteria and E. coli was low by activated carbon and membrane filter system using activated carbon but high in impregnated activated carbon. The removal effect of TCE was low in sand and ultra filter system as compared with activated carbon. Ultra filtration process was effective for purify agricultural water without E.coli. Reverse osmosis was effective to remove heavy metal and activated carbon was effective to remove halogenated organic chemical compound. The flux and the removal effect of COD in spiral wound ultrafilter were higher than the hollow fiber ultrafilter.

• 환경위생공학
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• 제13권3호
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• pp.30-36
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• 1998

A study on the color removal by irradiation of ${\gamma}-ray$ was carried out to reclaim the secondary effluent for the purpose of industrial water. Coagulation, ozone and ion exchange methods were compared. It could know that irradiation method was the most effective in color removal. The color was removed by 87.5% at 0.5 Mrad and it was increase with dose. High removal efficiency could be obtained in low pH and low concentration of $CO3^{-2}$. This process can be applied to the treatment of secondary effluent and is considered to be one of the most useful tertiary treatment.