• Journal of Korean Society of Rural Planning
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• v.12 no.2 s.31
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• pp.57-64
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• 2006

The experiment was carried out to determine the distribution of total coliform the translocation of heavy metals and the salt accumulation in soils following the supply of ground water, the domestic wastewater and the ultraviolet treatment of domestic wastewater during the spinach and the chinese cabbage cultivation. There were not much changes in the Total-N, Total-P and cations in soils following the ultraviolet treatment of the domestic wastewater. However, the density of total coliform was dramatically reduced from 894MPN/100mL to 5MPN/100mL. The diagnosis of composition of soil after the harvest of chinese cabbages and spinach has shown that the concentration of Na$^+$ was 3-4 times higher in plot using domestic wastewater than in plot using ground water. When domestic wastewater and ground water were used in growing spinach md chinese cabbage at 50% each, the application of chemical fertilizers reduced about 25% to 50% compared to the criteria set down by the Rural Development Administration and there was not significant difference in terms of harvest. Using non-ultraviolet treatment of domestic wastewater directly on spinach and chinese cabbage has resulted in excessive density of total coliform at 25,000MPN/100mL. Even when ultraviolet treatment, the density was still high at 2,000MPN/100mL. The high density of total coliform even following ultraviolet treatment of domestic wastewater is considered to be caused by photo-reactivation of micro-organism. When reusing domestic wastewater, the application of sterilization such as ultraviolet, ultrasonic and electron-beam for public health and hygiene reasons may provide safe supply of agricultural water.

• Journal of Korean Society of Rural Planning
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• v.12 no.2 s.31
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• pp.49-56
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• 2006

The application of domestic wastewater on rice paddies results in the accumulation of sodium(Na$^+$) to the soil. Excessive concentration of sodium may cause the deterioration of the physical characteristics of the soil, change in the osmosis of the soil, destruction of soil aggregates as well as ion toxicity due to sodium accumulation. Using domestic wastewater as irrigation water should be preceded by measures to prevent or control the soil salinization caused by sodium. Agricultural reuse of domestic wastewater were found not to cause serious problems with food safety due to heavy metals. However, pre-treatment using ultraviolet or ozone is recommended to reduce the number of bacteria and gem and for public health reasons. Using domestic wastewater has shown that reducing the standard application of chemical fertilizers by as much as 50% reduced the harvesting index by only 10%. This study has shown that it is feasible to reuse domestic wastewater on rice paddies. In order to facilitate the application, it is deemed necessary to establish wastewater treatment technologies in the future, to review criteria for recycling domestic wastewater for agricultural purposes such as conditions of soil and cropping system and to resolve conflicts with farmers and public health issues.

• Journal of Korean Society on Water Environment
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• v.22 no.2
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• pp.333-341
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• 2006

The concept for the decolorization in biological dye wastewater treatment systems is based on anaerobic treatment, for the reductive cleavage of the dyes' azo linkages, in combination with aerobic treatment, for the degradation of the products from azo dye cleavage, aromatic amines. Batch tests were conducted to examine the conditions and the factors affecting biological treatment of dye wastewater. From the tests, the removal efficiencies of organics and colors of dyeing wastewater were improved to $COD_{Cr}$ 27% and color 9% by injecting 10% of the domestic wastewater as a cosubstrate, and $COD_{Cr}$ 30%, color 22% with 30% injection of domestic wastewater. Therefore it was proved that decolorization efficiency is demonstrated with domestic wastewater as a cosubstrate. The analysis of aromatic amines in wastewater showed that decolorization was achieved by cometabolism while aromatic amines were produced by cleavage of azo bonds under anaerobic conditions and these products were removed in an aerobic tank subsequently.

• Journal of Korean Society of Water and Wastewater
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• v.14 no.1
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• pp.45-53
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• 2000

The optimum operation of domestic wastewater treatment plant can give influence on operational cost and future expansion in Korea where has 93 operational domestic wastewater treatment plants. Also, the study on optimum operation can reduce operation cost and budget of municipalities whom have responsibility of wastewater treatment plant operation. In this study, 9 domestic wastewater treatment plants which can represent 93 plants in Korea have been selected and operational data are gathered. The collected data are inputted to computer simulator based on IAWQ's Activated Sludge Model No.1 and optimum operation methods are developed. Also, the electric power for aeration which has large portion of overall operation cost are calculated based on design and operation conditions and these are compared. In this study, it was found that design wastewater characteristics are 1.6 times higher than those of daily maximum except for E plant and that estimation methods for design wastewater characteristics have to be improved. Based on computer simulation, we found there is no need to operate all aeration tanks due to weak influent overall power for aeration can be reduced to about 43% of design one.

• Journal of Korean Society of Water and Wastewater
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• v.16 no.6
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• pp.679-685
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• 2002

The objective of this study was investigated for the microbial community structure and treatment performance of domestic wastewater in lab-scale submerged membrane bioreactor operated with anoxic-oxic cycles. Respiratory quinone profiles were applied as tools for identifying different bacterial populations. The cycle time program of bioreactor was control under anoxic/oxic of 60/90 minutes with an hydraulic retention time of 8.4 hrs. The average $COD_{Cr}$ removal efficiency of domestic wastewater was as high as 93%. The results showed complete nitrification of $NH_4^+$-N generated during oxic period and up to 50% of the total nitrogen could be denitrified. The dominant quinone types of suspended microorganisms in bioreactor were ubiquinone (UQ)-8, -10, followed by menaquinone (MK)-6, and MK-7 for anoxic period, but those for oxic period were UQ-8, MK-6, followed by UQ-10 and MK-7. The microbial diversities of bioreactor at anoxic and oxic periods, calculated based on the composition of all quinones were 10.4 and 12.2-11.8, respectively. The experimental results showed that the microbial community structure in the submerged membrane bioreactor treating domestic wastewater was slightly affected by intermittent aeration.

• Journal of Environmental Science International
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• v.16 no.2
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• pp.227-232
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• 2007

Water pollution in enclosed water bodies such as lake and river has become a serious problem over the world. Domestic wastewater is responsible for more than 60 % pollution load in public water area in Korea. Effluent of the treated domestic wastewater at low removal level is abundantly fed rivers and lakes and thus be an serious cause of lake pollution. Therefore, effective implement of domestic wastewater treatment in basin of lake and river must be prepared. The septic tank is one of the effective domestic wastewater treatment equipment and used in individual treatment for a unit of household, The purpose of septic tank as biological treatment system is simultaneously to remove BOD, T-N, T-P and reduce turbidity from influent. Accordingly, the appropriate control of functional microorganisms is important subject for the establishment of stability and economy of the biological treatment method. Especially, microanimals as a high-ranked microorganisms of food-chain are important, because microanimals control the other microorganisms especially various bacteria and effect on function of treatment. Therefore, it is necessary that functional predator like rotifers are attached in wastewater treatment process. In this study, the methods for attachment high density the rotifer to and improvement of transparency in the effluence by a dense rotifer was examined using laboratory scale biological treatment reactor simulated septic tank and real one.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.5
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• pp.603-610
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• 2013

According to industrialization, increased toxic chemicals discharge has been causing water pollution. Especially domestic sewage is a major source of water pollution. Sixty percent of the total wastewater discharged is domestic sewage. Self-purification capacity of rivers and streams is drastically reduced by the emission of domestic sewage, industrial wastewater and livestock wastewater. Although domestic sewage is managed by implementing standards and regulations, toxicity effect of domestic sewage to humans and the environment is not yet clearly understood. In this study, by using daphnia magna, the ecotoxicity of domestic swage was assessed. Cl, Cu, Pb, COD, T-N, DO, pH and residual chlorine were investigated as background concentrations. The experiments were conducted with water samples obtained from three local sewage treatment plants. The experiment results indicated that higher level of toxicity corresponds to the higher pollution concentrations. The higher level of combinations of background concentrations such as heavy metals leads to the worse ecotoxicity. Especially, the Cu concentration affects the TU value.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.5
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• pp.529-545
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• 2013

With the increasing concern on climate changes and energy shortage, anaerobic membrane bioreactors (AnMBR) become a promising alternative to aerobic processes for domestic wastewater treatment. Two major advantages of AnMBRs are energy production and sludge reduction. Recently, several different configurations of AnMBRs have been proved to produce high quality effluent at reasonable hydraulic retention time and ambient temperature. One of the major problems of the AnMBR is membrane fouling control, and some solutions are already suggested. Other problems to be solved before the full application of the AnMBR are recovery of dissolved methane, management of residual nutrients and sulfide. Considering the potential advantages and future technology development, AnMBR will become major domestic wastewater treatment process in near future.

• Korean Journal of Ecology and Environment
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• v.38 no.spc
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• pp.62-66
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• 2005

The distributions of fluorescent whitening agents (FWA) in the water of the Yasu River and their tributaries flowing into Lake Biwa (Japan) were surveyed on winter and summer. The FWA fluxes had linear correlation with the corrected resident population in catchments of the tributaries of Yasu River. Therefore, the FWAs in the rivers come from domestic wastewater, and those fluxes in the tributaries depended on the human population of their catchments. As an application of the FWA indicating domestic wastewater, we could assess seasonal changes in the sources of dissolved organic matter in the tributaries.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.129-129
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• 2021

Constructed wetlands (CW) are artificially developed wetlands that are used to control water pollution. In central India, the field application of CW started on the late 1990s but are mostly focused on wastewater treatment. In this paper, different existing and experimental studies on constructed wetlands were reviewed to be able to determine the current status of wetlands in India to identify the type of CW that is more suitable in managing a specific target pollutant and type of wastewater. Wetlands were categorized into three types: vertical flow, horizontal flow, and hybrid while the wastewater were classified as domestic and industrial. Based on the review, 80% of constructed wetlands are used for treating domestic wastewater while 20% are treating industrial wastewater. Inflow analysis showed that industrial wastewater in hybrid constructed wetland produced the highest average concentration for parameters like COD (2851 mg/L) and BOD (5715 mg/L) while the lowest concentration was TN (13.97 mg/L) found in municipal wastewater. In terms of removing nonpoint source pollutants, it was revealed that vertical flow constructed wetlands (VFCW) are more effective at removing TSS and BOD as compared to horizontal flow constructed wetlands (HFCW) and hybrid constructed wetlands (HCW). HCW were found to be capable of efficiently removing COD and TN. Meanwhile, HFCW showed the highest TP removal among all the types of wetlands. In addition, VFCW were more effective for domestic wastewater while HCW are more effective for treating industrial wastewater. Lastly, there is currently a need to conduct further research on constructed wetlands for industrial wastewater as well as stormwater treatment to be able to gather more data and improve wetland design, performance, and maintenance.