• Journal of Korean Society on Water Environment
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• v.34 no.2
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• pp.226-233
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• 2018

Small-scale wastewater discharge facilities account for 98% of all workplaces, but in the generation and emission of major pollutants, they account for 27.5 % and 23.5 %, respectively. Since the proportion of the emission load of the small-scale workplace is not large, the national environmental policy has been established mainly around large-scale wastewater discharge facilities. However, in the case of specific hazardous substances in water, the amount of the discharge load of the small-scale wastewater discharge facility was 2.4 times higher than that of the generation load. Certain types of specific hazardous substances in water, which have a higher discharge load than large-scale wastewater discharge facilities, account for 24 ~ 32 %. There are also cases in which the discharge load from a small-scale discharge facility is more than four times higher, depending on the specific kind of water pollutant. As a result of inspections, the violation rate of the small-scale wastewater discharge facility among the total violations by facilities is 93.9 ~ 97.5 %. As a result, the ecotoxicity value of small-scale wastewater discharge facilities was high in most industries, and there was a fluctuation in the measured value. This indicates that the ecological integrity of the water system can be largely influenced by small-scale wastewater discharge facilities. Therefore, it is necessary to expand the environmental management of small-scale wastewater discharge facilities, and in some cases, the effect of the improvement in quality may be more significant than in the management of large-scale wastewater discharge facilities.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.5
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• pp.541-550
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• 2008

In this investigative study, the unit mass discharge for the major water quality parameters such as flowrate, SS, BOD, CODmn, CODcr, TN, TP from textile spinning/weaving industry nearby Nakdong river basin was estimated. To represent the respective industries, three companies from hundreds of textile spinning/weaving industries located in Nakdong river basin was carefully selected based on its manufacturing goods, flowrate and location for the estimation of unit mass discharge based on unit operation and process. There was a drastic decrease of unit mass discharge estimation between influents and effluents of water quality parameters, which represents the removal capacity of wastewater treatment plant. With the advent of new regulation on the imposed payment proportional to the total amount of pollutants discharge into the water body, the concept of cleaner production technology should be employed in the unit operation/process in wastewater treatment plant as well as textile manufacturing procedure to minimize the levy on the pollutants discharge. Unit mass discharge estimations of unit process (estimated in this study) in major water quality parameters (SS, BOD, COD, TN and TP) based on land were similar to those of composite process (estimated by National Institute of Environmental Research). But the unit mass discharge estimations of unit process in BOD and CODmn based on total sale were much higher than those of composite one while in SS, TN and TP similar to each other. For the detailed estimation of the imposed payment, unit mass estimation based on unit process should be further emphasized.

• Journal of Korean Society on Water Environment
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• v.36 no.6
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• pp.500-507
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• 2020

This study examined the wastewater at a livestock farm, and found that the dairy wastewater from the milking parlor had a lower concentration than the piggery wastewater, and that it was produced at a rate under 1.3 ㎥/day in a single farmhouse. The amount of dairy wastewater was determined based on the performance of the milking machine, the maintenance method of the milking parlor, and the amount of milk production allocated for each farmhouse, not by the area. The results confirmed that both dairy wastewater treatment processes, specifically those using Hanged Bio-Compactor (HBC) and Sequencing Batch Reactor (SBR), can fully satisfy the water quality standards of discharge. The dairy wastewater has a lower amount and concentration than piggery wastewater, meaning it is less valuable as liquid fertilizer, but it can be easily degraded using the conventional activated sludge process in a public sewage treatment plant. Therefore, discharging the dairy wastewater after individual treatment was expected to be a more reasonable method than consigning it to the centralized wastewater treatment plant. The effluent after the SBR process showed a lower degree of color than the HBC effluent, which was attributed to biological adsorption. In the case of the milking parlor in the livestock farm, the concentrations of the effluents obtained after HBC and SBR treatments both satisfied water quality standards for the discharge of public livestock wastewater treatment plants at 99% confidence intervals, and the concentrations of total nitrogen and phosphorous in untreated wastewater were even lower than the water quality standards of discharge. Therefore, we need to discuss strengthening the water quality standards to reduce environmental pollution.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.135-139
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• 2001

According to the requirement of cyanide precipitation-purification technology, adopt the acidized sulfate to precipitate cyanide. Studying the influence of acidity and the dosage of sulfate on precipitation rate of impurity ion in cyanide wastewater, and, on the basis of synthetic precipitation experiments, we obtain principle process of cyanide precipitation-purification to technology.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.759-762
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• 2008

A wastewater treatment plant located in coastal areas should be built considering the discharge of rainwater and treated water into the sea. The current Hagik Wastewater Treatment Plant in Incheon City was designed in the surface discharge method, which refers to discharging treated water directly into the sea. This method may cause hydrodynamic issues in a wastewater treatment plant because seawater enters an outfall riser when the level of discharged water is lower than the tidal level on a shore with high tidal range. In this study, a method for installing a weir in the discharge manhole was proposed in order to prevent seawater from entering the outfall riser of a wastewater treatment plant. Its feasibility was reviewed by calculating the hydrodynamic that had occurred due to the installation of the weir. As a result, seawater did not enter in the discharge manhole. Thus, even if the coast of Incheon City reaches the highest tidal level, treated water will be able to be properly discharged.

• Journal of Korean Society on Water Environment
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• v.36 no.5
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• pp.453-467
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• 2020

This study aimed to inventory the water pollutant discharge of wastewater from two facilities, one primary steel manufacturing facility and one petroleum refinery, both of which are located in Korea, and to identify ways to improve the wastewater treatment process through field investigation. Probability evaluation was used to inventory the substances in polluted water. The samples collected in this study included original wastewater, on processing wastewater, and treated water. The general description of wastewater occurrence, major sources, and treatment facilities were also investigated to obtain an integrated database of the pollutants created by different industrial categories. Based on our analysis of raw wastewater and final effluent, the detected pollutants were confirmed by analyzing their presence in the raw or supplemental materials, the potential of formation as byproducts, and the possibility of inclusion as impurities. The compounds detected for each category were screened via investigation of their possible sources and confirmed as the final water pollutant inventories. Thirty kinds of water pollutants were emitted by the primary steel manufacturing facility (reference in case A), including 14 specified hazardous water pollutants. The petroleum refinery (reference in case B) emitted 36 water pollutants, including 16 specified hazardous water pollutants.

• Journal of Korean Society of Water and Wastewater
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• v.14 no.3
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• pp.251-259
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• 2000

In this study, the urban runoff models, ILLUDAS model and SWMM, are analyzed the probable peak discharge and discharge using rainfall distribution by Huff's method at Bum-uh chun area in Taegu city. The probability rainfall and intensity is analyzed by Pearson-III type. The rainfall duration, 90 minutes, is determined by the critical duration computed the maximun peak discharge for some rainfall durations. The peak discharge according to Huff's rainfall distribution types compute in order of type 3, type 4, type2, and type 1, so Huff's 3 type is selected as an adequate rainfall distribution in Bum-uh chun basin. ILLUDAS model and SWMM are shown as good models in Bum-uh chun, but SWMM is computed higher peak discharge than ILLUDAS model, so SWMM is shown as the adequate urban runoff model for the design of interior drainage in urban basin.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.5
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• pp.581-590
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• 2013

A research was performed for zero discharge system of waste water which is produced from energy recovery process of waste and biomass. Leachate and all kinds of waste water should be separated and integrated into three categories in addition to converting existing leachate treatment facility into waste water treatment facility as well as introducing a management system of reverse osmosis membrane facility and bioreactor landfill. Following these conditions to better water treatment process, it was likely to produce over 3,000 tons of low-grade recycling water and 2,000 tons of high-grade recycling water per day when zero discharge system of waste water is applied starting from 2016. Economical efficiency was also surveyed in total treatment fee. Present system costs 18,129 million won per year, and suggested zero discharge system would cost 15,789 million won per year.

• Membrane and Water Treatment
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• v.13 no.1
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• pp.1-6
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• 2022

The regulations of the International Maritime Organization (IMO) have been steadily strengthened in ship emissions. Accordingly, there is a growing need for development of related technologies for the removal of contaminants that may occur during the treatment of SOx and NOx using a wet scrubber. However, this system also leads to wastewater production when the exhaust gas is scrubbed. In this research, we evaluated the performance of an ion selective resin process in accordance with scrubber wastewater discharge regulations, specifically nitrate discharge, by the IMO. Accelerated real and synthetic wastewater of wet scrubbers, contained high amounts of TDS with high nitrate, is used as feed water in lab scale systems. Furthermore, a pilot scale dissolved air flotation (DAF) using microbubble generator with ion exchange resin process was combined and developed in order to apply for the treatment of wet scrubber wastewater. The results of the present study revealed that operating conditions, such as resin property, bed volume (BV), and inlet wastewater flow rate, significantly affect the removal performance. Finally, through a pilot test, DAF with ion exchange resin process showed a noticeable improvement of the nitrate removal rate compared to the single DAF process.

• Applied Chemistry for Engineering
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• v.24 no.5
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• pp.544-550
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• 2013

This work investigated the environmental application of an underwater dielectric barrier discharge plasma reactor consisting of a porous hydrophobic ceramic tube to the decolorization of an azo dyeing wastewater. The reactive species generated by the plasma are mostly short-lived, which also need to be transferred to the wastewater right after the formation. Moreover, the gas-liquid interfacial area should be as large as possible to increase the decolorization rate. The arrangement of the present wastewater treatment system capable of immediately dispersing the plasmatic gas as tiny bubbles makes it possible to effectively decolorize the dyeing wastewater alongside consuming less amount of electrical energy. The effect of discharge power, gas flow rate, dissolved anion and initial dye concentration on the decolorization was examined with dry air for the creation of plasma and amaranth as an azo dye. At a gas flow rate of $1.5Lmin^{-1}$, the good contact between the plasmatic gas and the wastewater was achieved, resulting in rapid decolorization. For an initial dye concentration of $40.2{\mu}molL^{-1}$ (volume : 0.8 L; discharge power : 3.37 W), it took about 25 min to attain a decolorization efficiency of above 99%. Besides, the decolorization rate increased with decreasing the initial dye concentration or increasing the discharge power. The presence of chlorine anion appeared to slightly enhance the decolorization rate, whereas the effect of dissolved nitrate anion was negligible.