• Environmental Analysis Health and Toxicology
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• 제19권4호
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• pp.375-382
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• 2004

This study was designed to investigate potential endocrine disrupting effects of several industrial wastewater effluents discharged from cosmetic, plaiting, paint, textile industry using EROD bioassay and E-Screen assay. The results of E-screen assay showed that textile industrial wastewater could act as a full agonist and cosmetics and plaiting industrial wastewater could act as a partial agonist. On the contrary, the wastewater discharged from paint industry did not show any estrogenic effect. Estrogenic activity in the effluents of cosmetic and paint industrial wastewater was lower than that in the influents indicating that the wastewater treatment process minimized the effects of discharges on water quality. Despite of these results, it was recognized that wastewater treatment was not always minimize toxic impact. In this study, increased estrogenic effect was observed in the effluents of plating and textile wastewater, and EROD activity was increased in the effluents of cosmetic and plating wastewater.

• 상하수도학회지
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• 제26권4호
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• pp.579-589
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• 2012

To reduce extensive energy costs of the internal recycling for the purpose of denitrification in the advanced wastewater treatment, a post-treatment process using an electro-coagulation to treat nitrate in the secondary effluents is evaluated in this study. Removals of phosphorus and organics in the secondary effluents by the electro-coagulation were also evaluated to propose an alternative advanced wastewatert treatment process. A series of experiments of the electro-coagulation were carried out with the following 4 different samples: synthetic solution containing nitrate only, synthetic solution containing nitrate as well as phosphorus, secondary effluents from activated sludge cultivated in laboratory, and secondary effluents from real wastewater treatment plants. Removals of nitrate and phosphorus in the synthetic solution were 30 and 97 % respectively, which verified the feasibility of the process. Removals of nitrate, phosphorus and COD in the secondary effluents from the cultivated sludge in laboratory were 49, 90 and 19 % respectively. Removal efficiency of the total nitrogen, nitrrate, phosphorus and COD in the secondary effluent from real wastewater treatment plant were 50, 61, 98 and 80 % respectively. The removal of the total nitrogen was less than the nitrate as expected, which is due to the formation of ammonia nitrogen in the cathode. But the proposed scheme could be an energy saving and alternative process for the advanced wastewater treatment if further studies for the process optimization are carried out.

• Journal of Ecology and Environment
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• 제41권11호
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• pp.318-327
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• 2017

Background: A typical sewage treatment plant is designed for organic and nutrient removal from municipal sewage water and not targeted to eliminate micropollutants such as pesticides, pharmaceuticals, and nano-sized metals which become a big concern for sustainable human and ecological system and are mainly discharged from sewage treatment plant. Therefore, despite contaminant removal by wastewater treatment processes, there are still remaining environmental risks by untreated pollutants in STP (sewage treatment plant) effluents. This study performed aquatic toxicity tests of raw wastewater and treated effluents in two sewage treatment plants to evaluate toxicity reduction by wastewater treatment process and analyze concentration of contaminants to reveal potential toxic factors in STP effluents. Methods: Water samples were collected from each treatment steps of two STPs, and acute and chronic toxicity tests were conducted following USEPA (United States Environmental Protection Agency) and OECD (Organization for Economic Cooperation and Development) guidelines. Endpoints were immobility for mortality and reproduction effect for estrogenicity. Results: Acute $EC_{50}s$ (median effective concentration) of influents for Seungki (SK) and Jungnang (JN) STPs are $54.13{\pm}32.64%$ and $30.38{\pm}24.96%$, respectively, and reduced to $96.49{\pm}7.84%$ and 100%. Acute toxicity reduction was clearly correlated with SS (suspended solids) concentration because of filter feeding characteristics of test organisms. Chronic toxicity tests revealed that lethal effect was reduced and low concentration of influents showed higher number of neonates. However, toxicity reduction was not related to nutrient removal. Fecundity effect positively increased in treated wastewater compared to that in raw wastewater, and no significant differences were observed compared to the control group in JN final effluent implying potential effects of estrogenic compounds in the STP effluents. Conclusions: Conventional wastewater treatment process reduced some organics and nutritional compounds from wastewater, and it results in toxicity reduction in lethal effect and positive reproductive effect but not showing correlation. Unknown estrogenic compounds could be a reason causing the increase of brood size. This study suggests that pharmaceutical residues and nanoparticles in STP effluents are one of the major micropollutants and underline as one of estrogenic effect factors.

• 한국물환경학회지
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• 제21권3호
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• pp.274-276
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• 2005

To investigate bioassay for toxic level evaluation of wastewater, toxic levels were checked influents and effluents of 6 wastewater discharge facilities with Daphnia magna and Vibrio fischeri. In view of test duration, D. magna is preferred at 48 hours. And it was judged to efficient that one of the two was choosen for toxicity test method (Daphnia test and Vibrio test). Analysis data for wastewater is average toxic level for influent more higher than effluent. And effluent toxic level is sharp decrease than effluents.

• 한국환경과학회지
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• 제20권7호
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• pp.811-818
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• 2011

Daphnia Magna Stratus has been widely accepted as useful species for estimating the toxicity of chemicals to aquatic invertebrate and recommended as species for the testing chemicals from the international guideline as well as Korean guideline. The study was performed for the acute toxicity test by using water flea(D. Magna) for effluents from several wastewater treatment plants and drainage canals in GyeongBuk area. Five heavy metals, 1,4-Dioxane and Perchlorate were tested. Most Toxicity Units(TU) of Industrial wastewater effluents were less than 1 which means effluent was not toxic to D. Magna. However, effluents containing 1,4-Dioxane and Perchlorate were significantly toxic to D. Magna. Therefore, facilities should reduce the 1,4-dioxane since new regulations will force them after the year of 2011.

• ALGAE
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• 제18권2호
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• pp.157-167
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• 2003

Effect of the effluent of the sewage and wastewater plants on the algal growth was investigated from the 19 plants located in the Nakdong river basin. Most of the samples showed high values of the algal growth potential (AGP) when they were mixed with natural river water at 20% of final concentration. At 20% of the mixing ratio, the mixed effluents of sewage and wastewater showed 3.5 and 1.8 times higher AGP than those of the natural river water. The higher AGP values are attributable to the high contents of phosphorus and ammonium in the effluent. The mixing ratio of effluents of the discharge/river flow was highest in the Kumho River (42.8%) followed by the middle of Nakdong River (22.7%), Kam Stream (13.9%), Byungsung Stream (13.3%), Yangsan Stream (7.9%), and Young River (5.4%). Comparison of the trophic state of the effluents with natural river water indicated that the effluents showed higher trophic values than natural water. Concentrations of total phosphorus, total nitrogen and conductivity in the effluents were 12.3, 4.9 and 5.3 times higher than the those found in natural river water respectively. The AGP values were highly related with the trophicity of the water especially on the concentrations of phosphate and ammonium. Toxicities of the treated sewage water, wastewater and livestock waste water tested by the luminescent bacteria, Vibrio fischerii were generally low.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2002년도 학술대회지
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• pp.455-458
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• 2002

Mixing zone characteristics of the wastewater effluents discharged from an ocean outfall have been investigated using an outfall mixing zone analysis method. This analysis was applied to Sokcho ocean outfall case and was used to simulate the concentration distribution of wastewater effluents. Hourly concentration distributions of outfall effluent discharges were averaged for the period of 15 days. The results show that near-field dilution was relatively high with the dilution of 130 for the winter season.

• 한국수산과학회지
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• 제47권6호
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• pp.1006-1013
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• 2014

Wastewater organic compounds, that is, nonylphenolic compounds (NPs) and fecal sterols, were measured in surface sediments from Busan Suyeong Estuary, where two wastewater treatment plants (WWTPs) are located, to assess contamination from municipal effluents. The NPs analyzed were nonylphenol, and nonylphenol mono- and di-ethoxylates, all synthetic endocrine disruptors. The fecal sterols analyzed were coprostanol (COP), cholestanol, and epicoprostanol. Concentrations of NPs in the sediments ranged from 146 to 3,723 ng/g, and those of COP ranged from 366 to 13,018 ng/g. Their detection in all of the sediments analyzed indicates widespread pollution by municipal effluents. The highest concentrations of NPs and COP were detected at stations close to outfalls of WWTPs. Their levels in sediments are categorized in the higher range of those previously reported in Korean coastal areas. Moreover, in comparison with screening values of NPs in the Netherlands, Norway, and Canada, more than 50% of the sampling stations exceeded the guidelines. This indicates that the estuary may be adversely influenced by municipal effluents.

• Journal of Microbiology and Biotechnology
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• 제3권1호
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• pp.19-23
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• 1993

Spirulina platensis NIES 39 was grown in effluents from a wastewater treatment plant utilizing activated sludge process at a pig farm to reduce pollutants and to produce feed resources. The addition of 2 g/l NaCl was required for the growth of S. platensis in the effluents with about 100 mg/l ammonia nitrogen concentration. The growth was stimulated by the addition of 2 g/l sodium bicarbonate and 4 mg/l ferrous sulfate. The microorganism grew well at pH 8~11, and the optimum pH for the growth was 10. The algal concentration of 1.1 g/l was attained after 8 days of growth at the optimum condition with the removal of 95% ammonia nitrogen and 34% phosphorus.

• 한국해양환경ㆍ에너지학회지
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• 제4권2호
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• pp.15-24
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• 2001

Huang 등[1996]이 제안한 해양방류 혼합구역에 대한 분석방법을 활용하여 마산만 해양방류 해역의 혼합구역에서 주변해수의 흐름과 밀도성층의 변화에 따른 혼합 희석에 의한 수중방류하수의 농도변화분포를 산정하였다. 방류해역에서 5월 중순부터 8월 중순까지 3개월 동안 연속 관측된 조류의 매 시간별 유향과 유속변화에 따른 혼합구역에서의 하수농도분포를 계산하고, 마산만 해수유동에 있어 가장 큰 요소인 조류의 변화를 고려하여 15일 간격으로 방류하수의 평균된 농도분포를 구하였다. 이 결과에 의하면 조류의 유속이 상대적으로 강했던 기간동안에는 혼합구역에서의 평균농도는 매우 낮았고, 유속이 약했던 기간에는 낮은 희석률로 인해 평균농도가 매우 높게 나타났다. 그리고 관측된 조류의 주 방향으로 인해 혼합구역이 방류해역의 서측 해안까지 확장됨을 나타내었으며, 이는 방류해역에서 조사된 퇴적물의 오염도 분포결과와도 잘 일치되었다.