• 상하수도학회지
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• 제19권5호
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• pp.537-546
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• 2005

This study was carried out to evaluate EPS and SMP variation of sludge and effluent in nitrification and denitrification process with zeolite addition, a possible reduction of effluent DOC by URC(Ultra Rapid Coagulation) process. As a biological wastewater treatment result, EPS formation of both aeration and anoxic sludges are not affect by SRT variation. However, EPS concentration of sludges is higher in aeration tank than in anoxic tank by 6~8 mg EPS/ g VSS. Linear relationship between SMP to DOC indicates that SMP of bulk solution contributes to most of the biological treatment effluent DOC. DOC and turbidity removal efficiency was more improved with URC process than in a conventional coagulation. For pretreatment of UF filtration DOC removal was advanced by URC process than only UF filtration.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 춘계학술대회 논문집
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• pp.241-246
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• 2004

본 연구는 강우에 기인한 연안역의 토사 및 영양염류 유출에 관한 현지관측과 대안[( 沖蠅石垣島 ) 오끼나와 이시가키섬]이며, 이를 통한 유출지형분석, 강우강도ㆍ조석과의 영향, 유출입자의 특성(탁도, 임도, 영양염류) 등을 확인하였다. 연안부의 토사 유출과 영양염류의 농도는 강우강도와 조수간만의 시간적 변화에 따라 지역적 차이를 보였으며, 하천유역 주변 토지 이용형태와 주변 식생의 분포비율에 따라 변화되어지고 있음을 확인할 수 있었다.

• 한국물환경학회지
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• 제24권3호
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• pp.306-310
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• 2008

Characteristics of microalgal growth was investigated using anaerobic effluent from two-phase animal waste digestor as substrate. Batch experiments were carried out to investigate the effect of the initial nitrogen and phosphorus concentrations on growth of Microcystis aeruginosa, Chlorella sp. and Euglena gracilis. In 400 times diluted anaerobic effluent (TN 3 mg/L), single cell growth of the Euglena gracilis population increased twice without delay, although Chlorella sp. and Microcystis aerugenos take over 144 hours. Similar appearance with single cell growth was observed in mixed cultures. However, microalgae population did not increase under condition of 10 times diluted influent (TP 3 mg/L) in both pure and mixed cultures, which was affected by high organic and nitrogen concentration. Logistic growth model successfully fitted to determine biokinetic parameters such as ${\lambda}$: lag time, ${\mu}m$: maximal specific growth rate, A: asymptote of growth.

• 한국환경과학회지
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• 제15권5호
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• pp.439-446
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• 2006

The effluent discharge standards of industrial wastewater has become more stringent since 2003. Many industrial wastewater treatment plants has been upgraded to advanced treatment facilities. There are high concentrations of nitrate(>200 mg/L) and ammonium(>50 mg/L) nitrogen in the acrylic fiber wastewater of H textile Co. Wastewater from acrylic fiber industry containing acrylonitrile, which may affect the subsequent biological treatment process. Manufacturing of acrylic fiber also produces shock loadings. Excessive acrylonitrile and polymer debris produced in the polymerization process was screened, coagulated with CaO and settled down. A preaeration system was added to treat this high pH effluent to remove volatile organic compound and ammonia nitrogen by the air stripping effect. it was found that nitrification rate was not sufficient in the Anoxic/Oxic(AO) process. One denitrification tank was converted to nitrification reactor to extend HRT of nitrification. Nitrification rate of ammonia nitrogen was promoted from 32% to 67% by this modification and effluent nitrogen concentration was well satisfied with the effluent standards since then.

• 한국항해항만학회지
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• 제29권1호
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• pp.113-118
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• 2005

본 연구는 강우에 기인한 연안역의 토사 및 영양염류 유출에 관한 현지관측과 대안[오끼나와 이시가키섬]이며, 이론 통한 유출지형분석 강우강도$\cdot$조석과의 영향, 유출입자의 특성(탁도, 입도, 영양염류) 등을 확인하였다. 연안부의 토사 유출과 영양 염류의 농도는 강우강도와 조수간만의 시간적 변화에 따라 지역적 차이를 보였으며, 하천유역 주변 토지 이용형태와 주변 식생의 분포비율에 따라 변화되어지고 있음을 확인할 수 있었다.

• 한국물환경학회지
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• 제33권4호
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• pp.481-486
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• 2017

This paper aims to evaluate the characteristics of direct and indirect effluents'toxicity level and difference between two test durations (24 h and 48 h) of test method. The proportion of the indirect effluent samples which exceeded the ecotoxicity permit limitations (TU 1 or TU 2) showed more than 2 times higher than that of direct effluent samples. However, effluent toxicity of Wastewater Treatment Plants (WTPs) indicated less than TU 1 regardless of influent toxicity. From this results, treatment process was thought to have a good efficiency. WTP Salinity was very similar between influent and effluent. This trend could be reconfirmed by the component ratio of ion concentration between them and $Na^+$, $SO_4^{2-}$, $C^-$ lions which have a greater percentage than other ions. In addition, in case of high salinity, toxicity value also showed high level. To judge from above results, indirect effluents which were exempted from application of ecotoxicity standards, may need a new effluent limitations regardless of the treatment efficiency of WTP. According to circumstances, effective countermeasure may need to restrain the discharge of salinity-contained effluents which came from indirect-effluent factories. Test duration comparative study indicated that 48 h results were higher toxicity (exceeding rate of ecotoxicity criteria) than 24 h by the 5 to 5.4 percentage. 24 h test duration seemed to be useful in case of rapid detection, whereas 48 h test method could be applied for reinforcement of ecotoxicity regulatory system.

• Journal of Radiation Protection and Research
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• 제48권2호
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• pp.77-83
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• 2023

Background: The purpose of this study is to purify uranium (U[VI])-contaminated soil-flushing effluent using the precipitation-distillation process for clearance. Precipitation and distillation are commonly used techniques for water treatment. We propose using a combination of these methods for the simple and effective removal of U(VI) ions from soil-flushing effluents. In addition, the U concentration (Bq/g) of solid waste generated in the proposed treatment process was analyzed to confirm whether it satisfies the clearance level. Materials and Methods: Uranium-contaminated soil was decontaminated by soil-flushing using 0.5 M sulfuric acid. The soil-flushing effluent was treated with sodium hydroxide powder to precipitate U(VI) ions, and the remaining U(VI) ions were removed by phosphate addition. The effluent from which U(VI) ions were removed was distilled for reuse as a soil-flushing eluent. Results and Discussion: The purification method using the precipitation-distillation process proposed in this study effectively removes U(VI) ions from U-contaminated soil-flushing effluent. In addition, most of the solid waste generated in the purification process satisfied the clearance level. Conclusion: The proposed purification process is considered to have potential as a soil-flushing effluent treatment method to reduce the amount of radioactive waste generated.

• 상하수도학회지
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• 제18권1호
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• pp.37-48
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• 2004

The purpose of this study was to evaluate adaptability of external carbon source using GPS-X program in pilot plant composed with 2-stage denitrification process. The result from analysis of pilot plant operation and GPS-X simulation showed that effluent concentration could be simulated similarly by modifying operation conditions, such as DO concentration, C/N ratio and other calibrated parameter. In order to satisfy the standard of the effluent water quality on T-N of 20mg/L, it required approximately 3.1 of C/N ratio and 50% of nitrogen removal efficiency when influent T-N is 36.9mg/L. To maintain the stable water quality of the receiving water, the effluent T-N concentration should be less than 10-15mg/L and the appropriate C/N ratio to remove nitrogen was 4.27-6.82. The analysis of sensitivity to kinetic coefficient and reaction constant showed that $Y_H$ and ${\mu}_{mAUT}$ were most sensitive to nitrate and ammonia nitrogen, relatively and sensitivity coefficient of their were 1.32, 1.98. It was concluded that as $Y_H$ decreased and ${\mu}_{mAUT}$ increased, the reaction rates of denitrification and nitrification increased and the removal efficiencies of $NO_3{^-}-N$ and $NH_4{^+}-N$ improved.

• Environmental Analysis Health and Toxicology
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• 제22권1호
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• pp.83-90
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• 2007

This study was investigated the effort of growth and gonadal development in olive flounder, Paralichthys olivaceus exposed to PCBs Effluent Allowance Concentration, 3.0 ppb in Korea. Total length, body weight and weight gam of fish were no significant differences between two treatments (control: T.L.-110.0 mm, T.W.-9.61 g: treatment: T.L.-112.8 mm, T.W.-9.68 g), however, weight gain of fish unexposed to PCBs wat observed to increase gradually from 100 days after hatching (30 days after treatment). In the indifferentiated gonad to the juvenile stage, the differentiation of the ovary occured at 60 days after hatching (20 days after treatment) and that of the testis occured at 70 days after hatching (30 days after treatment) in two groups. In the ovary, the oogonia and ovarian lamellar appeared 130 days after hatching (50 days after treatment). The spermatogonia and resticular lobule of the testis were observed at 130 days after hatching (50 days after treatment). Testicular cyst appeared 140 days after hatching (60 days After treatment). There was no difference on the development of ovary and testis. There was no obvious difference of sex ratios. Therefore, These results considerate that PCBs have any effect for growth and gonadal development, but a little act for early growth in olive flounder.

• 한국물환경학회지
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• 제20권1호
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• pp.24-31
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• 2004

This study was initiated to evaluate the efficiencies of DEPHANOX and Modified-DEPHANOX, which were devoloped to enhance nitrogen removal efficiency in municipal wastewater treatment. In the results, removal efficiency of organic matters was not affected much by increased loading rate of organic matters which is contained in influent. The nitrogen removal efficiencies according to the loading rate of influent TN was decreased drastically in conditions of over $0.2kg/m^3{\cdot}day$, which is T-N loading rate, and the DEPHANOX process was affected more sensitively than the M-DEPHANOX was. When the temperature was altered from $25^{\circ}C$ to $16^{\circ}C$ at HRT 6hrs, the removal efficiency of ammonia nitrogen was still over 90% and it was concluded that both DEPHANOX and M-DEPHANOX were strong enough to endure temperature variation. Moreover, both processes showed over 90% in ammonia removal efficiencies in over HRT 5hrs, so it was concluded that they were strong in HRT variation. M-DEPHANOX process showed a higher value than DEPHANOX did in T-N removal efficiency to the extent of 4~21 %, which resulted from differency of denitrification rates and the biosorption efficiency of organic matter in both processes. In the condition of HRT less than 4hrs, concentrations of ammonia nitrogen contained in effluents and nitrification reactors, might be sensitively affected by biosorption efficiency of organic matters in first separation tank. In the effect of effluent nitrate concentration in phosphorus removal, the more effluent nitrate concentration was decreased, the more phosphorus removal efficiency was increased. This result is related to the decrease of concentration of effluent nitrate which resulted from nitrification inhibition by decreased HRT.