• Proceedings of the Korean Environmental Health Society Conference
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• 2005.06a
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• pp.406-409
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• 2005

Since 2003, Korean government has restricted landfill application of organic waste, which shares approximately 56% of total waste sludge from municipal and industrial wastewater treatment plants. In addition, enforcement of the ocean disposal prohibition law is effective from 2005. Organic sludge was composted for the purpose of converting to organic fertilizer. After moisture content was regulated with bulking agents aerobic treatment performed. When composting was conducted, commercial and activated microbe materials, identified from soil were seeded in sewage sludge. Carbon dioxide production was increased sharply after 24 hours. Temperature and pH of compost reached to $66.2^{\circ}C$ and 8. Heavy metals were lower than their regulatory limits, which enable it to utilize as organic fertilizer.

• Journal of environmental and Sanitary engineering
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• v.7 no.2
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• pp.1-10
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• 1992

Since 1960's along with industrialization and urbanization, economic growth has been . achieved, however, at the same time, environmental condition has been seriously deteriorated. . Currently, volume of wastewater has been increasing at annual rate of 7% in sewage and 20% in industrial wastewater. However, the nation's sewage treatment serves only 33% of the municipal wastewater as of 1991. Major portion of air pollutants comes from combustion of oil and coal which comprise 81% of total energy use and emission gases from motor vehicles increasing at an accelerated rate. It is known that Korea generates the highest amount of waste per capta. Nevertheless, it is not sufficient to reduce the volume of waste by means of resources recovery and recycling. Recognizing the importance of global environmental problems such as ozone layer depletion, global warming and acid rain, international society has been making various efforts since the 1972 Stockholm conference. In particular, it is expected that the Rio conference which has adopted the Rio declaration and Agenda 21 will form a crucial turning point of the emerging new world order after the Cold War confrontation. To cope with such issues as domestic pollution and global environmental problems, the fundamental national policy aims at harmonizing "environmental protection and sustainable development". The Ministry of Environment has recently set up a mid-term comprehensive plan which includes annual targets for environmental protection. According to the government plan, gradual improvement of various environmental conditions and specific measures to achieve them is planned in time frame. Additional sewage treatment plants will be constructed in urban areas with the target to treat 65% of the nation's municipal sewage by 1996. Supply of clean fuels such as LNG will also be expanded starting from large cities as a cleaner substitute energy for coal and oil. In parallel with expansion of LNG, emphasis will be placed on installation of stack monitoring system. Due to the relatively limited land, government's basic policy for solid waste treatment is to develop large scale landfill facilities rather than small sized ones. Thirty three regional areas have been designated for the purpose of waste management. For each of these regions, big scale landfill site is going to be developed. To increase the rate of waste recycling the government is planning to reinforce separate collection system and to provide industries with economic incentives. As a part of meeting the changing situation on global environmental problems after UNCED, and accommodation regulatory measures stipulated in the global environmental conventions and protocols, national policy will try to alter industrial and economic structure so as to mitigate the increasing trends of energy consumption, by encouraging energy conservation and efficiency. In this regard, more attention will be given to the policy on the development of the cleaner technology. Ultimately, these policies and programs will contribute greatly to improving the current state of national public health.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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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.

• Korean Journal of Environmental Agriculture
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• v.9 no.2
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• pp.121-131
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• 1990

Four crop plants, such as green onion(Allium ascalonicum L.), radish(Raphanus sativus L.), potato(Solanum tubersum L.) and chinese cabbage(Brassica pekinensis Rupr), were grown in greenhouses to determine the accumulations of Cd and Zn absorbed by the plants grown on soils treated with municipal sewage sludge of different levels of 0, 22.5, 45.0 and 90.0 ton $ha^{-1}$ as soil dry weight. The result was analyzed to be comparable to the heavy metal content in the plant tissues among the crop species and the statistical characteristics were investigated to determin a possible relationship between causes of increased contents of Cd and Zn in plants and in soils. The results were as follows : 1. The Cd and Zn content in experimental crop plants increased with increase in quantity of treatment sludge. 2. The Cd and Zn content in roots of all experimental plants increased with sludge treatment amount in soil, in the following order : green onion>potato>chinese cabbage>radish. 3. The Cd content in leaves of crop plants were high in this order : green onion>radish>potato>chinese cabbage, and the Zn content in leaves of crop plants was high in this order. : potato>radish>chinese cabbage>green onion. 4. Concentrations of Cd in potato tubers, radish roots and chinese cabbage leaves ranged from 0.03 to 0.12 ppm. 5. Concentrations of Cd and Zn in plant tissues grown in sludge treated soil of 90.0 ton $ha^{-1}$ were 1.2 to 10 times and 0.4 to 2.3 times higher as compared with those absorbed from sludge-free soil, respectively. 6. The accumulation rates of Cd and Zn in sludge-treated plant tissue were almost constant except for green onion roots.

• Journal of Wetlands Research
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• v.22 no.2
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• pp.92-99
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• 2020

Linked treatment refers to a system that relieves the burden of the business by linking high concentrations of wastewater such as human waste, manure, leachate, and other industrial wastewater to nearby municipal wastewater treatment plants(MWTPs). In 2018, 187 MWTPs, which are about 4.5% of the total domestic MWTPs, have implemented a linked treatment system, but local governments are having difficulties in operating sewage treatment due to lack of reasonable cost estimation standards. Therefore, we proposed an improvement plan to solve the problem in the calculation method that currently imposes linked wastewater. To this end, the effects and correlations of the linkage treatment system on the sewage treatment unit were analyzed, and among them, the main factors with the highest correlation were applied to the improvement plan. As a result, an improvement plan that improved three parts of the existing calculation method was presented, and the calculation method and the calculation case using the existing literature values were also presented. This can be used as a basis for future reference by local governments to implement linkage treatment, and to revise local sewerage ordinance and is believed to be helpful in operating a rational linkage system.

• Journal of Korean Society of Water and Wastewater
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• v.35 no.3
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• pp.205-225
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• 2021

Due to the large-scale production and use of synthetic chemicals in industralized countries, various chemicals are found in the aquatic environment, which are often termed as micropollutants. Effluents of municipal wastewater treatment plants (WWTPs) have been identified as one of the major sources of these micropollutants. In this article, the current status of occurrence and removal of micropollutants in WWTPs and their management policies and options in domestic and foregin countries were critically reviewed. A large number of pharmaceuticals, personal care products, and industrial chemicals are found in WWTPs' influent, and are only partially removed by current biological wastewater treatment processes. As a result, some micropollutants are present in WWTPs' effluents, which can negatively affect receiving water quality or drinking water source. To better understand and assess the potential risk of micropollutants, a systematic monitoring framework including advanced analytical tools such as high resolution mass spectrometry and bioanalytical methods is needed. Some Western European countries are taking proactive approach to controlling the micropollutants by upgrading WWTP with enahnced effluent treatment processes. While this enahnced WWTP effluent treatment appears to be a viable option for controlling micropollutant, its implementation requires careful consideration of the technical, economical, political, and cultural issues of all stakeholders.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.2
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• pp.98-103
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• 2004

Recently, a New Great Harbour Bridge between Mokpo City and Koha Island is planned to be built across Mokpo Inner Harbour, and Namak New Town is under construction adjacent to Mokpo. Citizels' concorn of and participation in 「Campaign for Shaping Mokpo into Beautiful Seaport」 are necessary to match the view of Mokpo harbour with natural scenery beautifully and with marine environment harmoniously. Citizens'ㄹ levels of consciousness of coastal and marine environment were ascertained through questionnaire surveys of local citizenry attitudes and opinions, and citizenry action plans for the conservation of coastal and marine environments around Mokpo harbour are suggested on the basis of the results of questionnaire surveys. Citizens' voluntary participations in local policy for the control of marine wastes production and in a campaign for the collections of marine debris and wastes around beaches and coastal areas are required. The operation of municipal sewage treatment plants is to be performed effectively and efficiently, and to be monitored and evaluated periodically by the general public, the local federation for environmental movement or NGO. The development and performance of marine environmental education programs and an enlightenment campaign for environment preservation are to be incessantly done in cooperation with local residents. Only when local government of Mokpo collects the public opinions and continues to shape Mokpo into international beautiful seaport in the direction of a reflex of public opinion, coastal and marine environment around Mokpo harbour can be kept in good condition with citizens' positive participation in citizenry long-term practical action plans for environment conservation.

• Journal of Korean Society on Water Environment
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• v.24 no.5
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• pp.618-625
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• 2008

Advanced Phase Isolation Ditch (APID) process was studied to develop economic retrofitting technology, for the plants where retrofitting of common activated sludge process is required. In this study, to evaluate the effluent BOD, SS, T-N, and T-P concentrations as process capable and stable parameters for treating municipal wastewater, a demonstration plant was installed and operated in the existing sewage treatment plant of P city. During this study, the average effluent BOD, SS, T-N, and T-P concentrations were 4.56, 5.20, 9.30, and 1.75 mg/L at the conventional mode and 3.95, 3.17, 7.65, and 1.18 mg/L at the modified mode. The modified mode (BOD: 3.69, SS: 3.19, T-N: 1.27, and T-P: 0.69) increased the process capability more than the conventional mode (BOD: 1.80, SS: 1.05, T-N: 2.17, and T-P: 0.15) in this study. If process capability over 1.0, this process is capable and stable to treat wastewater. Therefore, newly developed APID process with modified intermittent aeration mode can be one of the useful processes for stable organic matter and nutrients removal.

• Journal of Korean Society on Water Environment
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• v.25 no.6
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• pp.872-878
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• 2009

Advanced Phase Isolation Ditch (APID) process was studied to develop economic retrofitting technology, for the plants where retrofitting of common activated sludge process is required. In this study, to develop and apply the modified intermittently aeration mode as process control conditions for treating municipal wastewater, a demonstration plant was installed and operated in the existing sewage treatment plant of P city. During this study, the average effluent $BOD_5$, SS, T-N, and T-P concentrations were 6.3, 4.5, 10.0, and 1.3 mg/L. The modified mode decreased the nitrification capability more than the conventional mode in the application period. Nitrate in the anaerobic condition can have a negative effect on biological phosphorus removal. In the decreasing nitrate levels, the modified mode increased the biological ability of removal phosphorus more than the conventional mode in this study. Therefore, newly developed APID process with modified intermittent aeration mode can be one of the useful processes for stable organic matter and nutrients removal.

• Korean Journal of Microbiology
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• v.47 no.1
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• pp.38-49
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• 2011

Bioaerosols generated from wastewater treatment plants may create health risks for plant workers and nearby residents. To determine the levels of culturable airborne bacteria and fungi in bioaerosols, samples were seasonally collected above and near the aeration tanks of one feces-urine and three sewage treatment plants in Ulsan, Korea with an impaction-type sampler. In the feces-urine treatment plant, concentrations of heterotrophic bacteria were between $1.3({\pm}0.2){\times}10^3$ and $2.6({\pm}1.2){\times}10^4$ MPN/$m^3$ above the aeration tank and between $1.7({\pm}1.0){\times}10^2$ and $7.2({\pm}2.2){\times}10^3$ MPN/$m^3$ near the aeration tank. Coliform bacteria were detected both above and near the aeration tank. In cases of sewage treatment plant, the numbers of heterotrophic bacteria ranged from $1.9({\pm}1.2){\times}10^1$ to $1.8({\pm}1.2){\times}10^4$ MPN/$m^3$ above the aeration tank and from $5.0({\pm}2.8){\times}10^0$ to $6.6({\pm}2.0){\times}10^3$ MPN/$m^3$ near the aeration tank. At reference sites, the concentrations of heterotrophs in ambient air were measured between $7.0{\times}10^0$ and $2.7{\times}10^1$ MPN/$m^3$. When we isolated and tentatively identified heterotrophic bacteria, Pseudomonas luteola was the most dominant species in bioaerosols from wastewater treatment plants, whereas the most abundant one in reference samples was Micrococcus sp. When we measured fungal concentrations in bioaerosols, they were rather similar regardless of sampling locations and seasons, and such genera as Cladosporium, Alternaria, and Penicillium were commonly identified.