• Asian-Australasian Journal of Animal Sciences
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• v.17 no.8
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• pp.1168-1176
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• 2004

Intensive animal industries create large volumes of nutrient rich effluent, which, if untreated, has the potential for substantial environmental degradation. Aquatic plants in aerobic lagoon systems have the potential to achieve inexpensive and efficient remediation of effluent, and to recover valuable nutrients that would otherwise be lost. Members of the family Lemnaceae (duckweeds) are widely used in lagoon systems, but despite their widespread use in the cleansing of sewage, only limited research has been conducted into their growth in highly eutrophic media, and little has been done to systematically distinguish between different types of media. This study examined the growth characteristics of duckweed in abattoir effluent, and explored possible ways of ameliorating the inhibitory factors to growth on this medium. A series of pot trials was conducted to test the tolerance of duckweed to abattoir effluent partially remediated by a sojourn in anaerobic fermentation ponds, both in its unmodified form, and after the addition of acid to manipulate pH, and the addition of bentonite. Unmodified abattoir effluent was highly toxic to duckweed, although duckweed remained viable and grew sub optimally in media with total ammonia nitrogen (TAN) concentrations of up to 100 mg/l. Duckweed also grew vigorously in effluent diluted 1:4 v/v, containing 56 mg TAN/L and also modified by addition of acid to decrease pH to 7 and by adding bentonite (0.5%).

• Journal of Korean Society on Water Environment
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• v.28 no.6
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• pp.804-812
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• 2012

This study contemplated domestic and other country's effluent limitation standards and suggested a methodology to establish technology-base limitation value. Current effluent limitation regulates industrial point sources discriminated by discharge flow rate and by regional distinction in Korea. Discharged $BOD_5$ load from large-scale plants(flow rate above $2,000\;m^3/day)$ exceeds 50% of overall industrial wastewater, which present rationale for discrimination based on plant size. However, regional distinction and pollutant- specific regulation might be insufficient to meet practical effectiveness of wastewater management policy, due to the nearly same limitation. Water quality data and treatment methods were investigated in hospital industry. And their distribution of effluent $BOD_5$ concentrations was statistically analyzed to suggest limitation value. Effluent $BOD_5$ concentrations showed lognormal distribution and $95^{th}$ percentile was corresponded to 87.9 mg/L, which could be suggested as tentative effluent limitation in hospital industry. The $95^{th}$ percentile of log-transformed distribution showed similar value of 86.5 mg/L. This study demonstrated reasonable methodology for establishing effluent limitation reflecting wastewater characteristic and treatment technology in separately categorized industry.

• Journal of Korean Society on Water Environment
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• v.29 no.2
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• pp.276-287
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• 2013

Domestic sewage contains increasingly more pharmaceuticals and personal care products (PPCPs), due to rising use of medicines, health supplement food and daily necessities. And various types of industrial wastewater from pollution sources in treatment areas could flow into the public sewerage treatment plants (PSTPs) in metropolitan areas. The conventional PSTPs are designed to treat suspended solids, biodegradable organics, nitrogen and phosphorous from residential and industrial areas and public facilities. However, toxic, conventional, and non-coventional pollutants from non-domestic sources that discharge into sewer system as well as domestic source with various chemicals could not be treated in the conventional PSTPs and discharged untreated to public basin. In this paper we aim to consider the establishment system of effluent standard of PSTPs in comparison with water quality standard of water environment and wastewater discharge regulation. And also we suggest the necessity of regulations on the pretreatment of industrial wastewater as part of efforts to improve water quality in sewerage systems and to protect public basin.

• Journal of Korean Society on Water Environment
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• v.26 no.3
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• pp.377-386
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• 2010

Introduction of TBELs into Korean environmental regulatory system for wastewater may require very careful considerations and appropriate modifications of the TBELs applied in US. The Korean regulations for wastewater are based on uniform regulatory criteria for wastewater effluent discharge and are quite different from the individual permit system in US. In addition, the toxic pollutants regulated in Korea are much less than those in US. Therefore, the effects of TBELs application on the pollutants reduction and the economic feasibility should be carefully assessed for different categories of wastewater sources. In this study, the applicability of TBELs for the industrial categories of Korea was discussed. The TBELs were derived for a sample category, the pulp paper paperboard manufacture, based on the previously reported analytical data from 52 facilities of the domestic pulp paper paperboard manufacture in Korea. It was suggested that the BAT effluent limitations were BOD 30 mg/L, $COD_{Mn}$ 40 mg/L, SS 40 mg/L, T-N 30 mg/L and T-P 4 mg/L and that the allowable effluent loads were $0.31{\sim}1.75kgCOD_{Mn}/ton$-products. Due to the limitation of insufficient data, there were difficult to obtain the important factors to derive more systematic and accurate limitation standards for the pollutants such as the 'Long Term Average (LTA)', the 'Product Normalized Discharge Flow (PNDF)', and the 'Variability Factor (VF)'. However, as the first trial of TBELs determination based on the all available analytical data reported, the procedure and the outcome of the study may provide valuable insight on application of TBELs in Korea.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.18 no.4
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• pp.329-337
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• 2006

A small hydro-power plant operated by cooling water discharged from the power plant is under construction. In this study, the flow characteristics of the effluent channel and the outfall coastal zone in which the facilities are constructed have been measured and analysed. The flow pattern is highly dependent on the effluent discharge and clearly classified as these typical areas; the upstream and downstream areas of the weir, and the outfall coastal zone. The discharge and the width of the channel in the upstream area of the weir are increased step by step, so the water level fluctuation is small. The flow overtopping the weir is rapidly changing and has highly vertical fluctuation patterns after hydraulic jump just below the weir. The flow pattern in the outfall zone is directed toward the seaward direction and the velocity is dominated by the tidal level fluctuation. The mean tidal range in this area is about 10% greater than that of the Tongyeong tidal gauging station and the wave effects are negligible because of the sheltering effects of this area.

• Journal of Environmental Health Sciences
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• v.41 no.5
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• pp.305-313
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• 2015

Objectives: The objective of this study is to identify toxicants causing acute toxicity in effluents from the aluminum rolling industry that violate the discharge limits in Korea. Methods: Whole effluent toxicity tests (WET) were conducted on effluent discharged from the aluminum rolling industry following the US EPA WET test methods. We collected effluent samples three times and evaluated acute toxicity by using Daphnia magna. We employed toxicity identification evaluation (TIE) procedures to identify toxicants causing toxicity in the effluent. Results: No specific chemical groups were identified in the seven different manipulations applied to the of wastewater effluent samples showing 1.3 toxic units (TU) according to the TIE phase I procedures. Water quality parameters for water hardness, electric conductivity and heavy metals (Mn) were 4,322 mg/l as $CaCO_3$, 11.39 mS/cm, and $5,551{\mu}g/l$, respectively. Considering water hardness and reference toxicity, high concentrations of Mn can be disqualified from the causative toxicants. Consequently, high ionic concentrations of $Na^+$(1,648 mg/l), $Ca^{2+}$(1,048 mg/l), $Mg^{2+}$(1,428 mg/l) and $SO_4{^{2-}}$(7,472 mg/l) were identified to be causative toxicants. Water hardness and electric conductivity exceed the $EC_{50}$ value obtained by biological toxicity tests using Daphnia magna. Conclusion: According to TIE procedures, high salt concentration is determined to be a major toxicant in the effluent of agro-industrial wastewater treatment plants receiving wastewater from the aluminum rolling industry.

• Journal of Environmental Science International
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• v.22 no.12
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• pp.1643-1650
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• 2013

This study investigated water quality of effluents and stream from the sewage treatment plants located at Gumi Complex 4, Gumi, and Wonpyeong in Gumi. Downstream region was found to increase the concentration of nutrients for sewage treatment plant effluent. Both phosphorus and nitrogen were accounted most as soluble form. In particular, the high ratio of dissolved effluent of sewage treatment plants were investigated. In the streams, Phosphorus concentration was high during rainy season and nitrogen concentration was high in the dry season. Sewage treatment plant effluent was relatively less microbial activity and nutrient concentrations were higher in the winter. TN/TP ratio was the highest in the upstream region and the lowest in the sewage treatment plant effluent. The effect of the nutrient matter from a discharge of a sewage treatment plant on rivers varied depending on the size of the river and the treatment plant. However, the influence of the concentration was greater than that of flowrate. Sewage treatment plant effluent loads phosphorus, nitrogen accounted for 8% and 6% respectively at the point N3 of the Nakdong river.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.1
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• pp.10-16
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• 2022

Interest in effluent treatment is currently increasing and the use of polymetric coagulants is considered as a pretreatment of physical filtration prior to effluent discharge to increase solids recovery. A jar test evaluated effluent treatment efficiency of polymeric coagulants for semi-recirculating aquaculture systems. The particle coagulation efficiency and distribution were evaluated at different polymer dosages in freshwater and seawater effluents. The polymer was added at 0.005-0.08 mL/g of total suspended solids (TSS) in the effluents. TSS in the supernatant after coagulation decreased with increasing polymer dose in the freshwater, while showing no corresponding changes with dose in the seawater. However, in all treatments for both effluents, the removal efficiency was above 90%, regardless of the dose in the tested range. Both the De Brouckere Mean Diameter (DBMD) and volumetric median diameter (VMD) were all above 100 ㎛ in the freshwater effluent. In the seawater effluent, the particle size appeared to be larger than that in freshwater, ranging from 400-1,000 ㎛ for both DBMD and VMD. Considering that the typical pore size of physical filtration in aquaculture is between 60 and 200 ㎛, the use of polymers is expected to improve the practicality of physical filtration for efficient treatment.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.247-253
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• 2004

As a large scale port development in coastal waters proceeds step by step and populations in the vicinity of port are getting increased, the issue on "how to dispose the treated municipal water and wastewater in harbor" brings peoples′ concern. The submarine outfall system discharges the primary or secondary treated effluent at the coastline or in deep water, or between these two. The effluent, which has a density similar to that of fresh water, rises to the sea surface forming plume or jet, together with entraining the surrounding sea water and becomes very dilute. We intended in this paper to investigate the impact on dilution of effluent and the behavior of flume under the conditions of the seasonal and spatial temperature variations, which have not been noticeable in designing effective marine outfall system. To predict and analyze the behaviour and dilution characteristics of plume not just with the effluent temperature, but also with the seasonal variation of temperature of surround water and tidal changes, CORMIX(Cornell Mixing Zone Expert System)-GI have been applied. The results should be used with caution in evaluation the mixing zone characteristics of discharged water. We hope to help for the effective operation of outfall system, probable outfall design, protection of water quality, and warm water discharges from a power plant, etc.

• Journal of Environmental Science International
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• v.15 no.5
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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.