• Membrane and Water Treatment
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• v.6 no.1
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• pp.77-94
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• 2015

Ultrafiltration membranes have several advantages over conventional drinking-water treatment. However, this technology presents major limitations, such as irreversible fouling and low removal of natural organic matter. Fouling depends heavily on the raw-water quality as well as on the operating conditions of the process, including flux, permeate recovery, pre-treatment, chemical cleaning, and backwashing. Starting with the premise that the optimisation of operating variables can improve membrane performance, different experiments were conducted in a pilot plant located in Granada (Spain). Several combinations of permeate and backwashing flow rates, backwashing frequencies, and aeration flow rates were tested for low-quality water coming from Genil River with the following results: the effluent quality did not depend on the combination of operating conditions chosen; and the membrane was effective for the removal of microorganisms, turbidity and suspended solids but the yields for the removal of dissolved organic carbon were extremely low. In addition, the threshold transmembrane pressure (-0.7 bar) was reached within a few hours and it was difficult to recover due to the low efficiency of the chemical cleanings. Moreover, greater transmembrane pressure due to fouling also increased the energy consumption, and it was not possible to lower it without compromising the permeate recovery. Finally, the intensification of aeration contributed positively to lengthening the operation times but again raised energy consumption. In light of these findings, the feasibility of ultrafiltration as a single treatment is questioned for low-quality influents.

• Food Science and Preservation
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• v.19 no.3
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• pp.428-432
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• 2012

This study was carried out to investigate the effect of carbonated water on the yield, weight, length, thickness, and vitamin C and isoflavone contents of soybean sprouts cultivated for 6 days. 100 g Junjori cultivar soybeans were cultivated at $22{\pm}1^{\circ}C$ with carbonated water (pH 4.5) and drinking water (pH 7.8) for 6 days, respectively, after 6h presoaking treatment. The yield of the soybean sprouts cultivated with carbonated water for 6 days was 255.1 g, approximately 1.45 times higher than the 176.1 g soybean sprouts cultivated in drinking water. The weight and length of the soybean sprouts cultivated with carbonated water were 1.3 and 1.2 times higher, respectively, than those of the soybean sprouts cultivated with drinking water. The same can be said of the thickness of the carbonated- and drinking-water soybean sprouts. The vitamin C contents of the soybean sprouts cultivated with carbonated water was about two times (1.13 mg%) higher than those of the soybean sprouts cultivated with drinking water. The genistein and daidzeinin contents of the soybean sprouts cultivated for 6 days with carbonated water were higher than those of the soybean sprouts cultivated for 6 days with drinking water. The growth characteristics and contents of the useful components of the soybean sprouts were affected more by carbonated water than by drinking water.

• Korean Journal of Environmental Agriculture
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• v.14 no.3
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• pp.351-373
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• 1995

The objective of this paper is to present relevant information and data from domestic and foreign references and to propose legal standards on pesticide residues in order to mitigate the pesticide contamination in the water environment. Among 200 pesticide ingredients in use in Korea, items necessary for standard setting were selected and theoretical residue limits were computed. The results are summarized as follows. In advanced countries, drinking water standards are established on the basis of health index ADI and water intake, whereas standards for surface water are established temporarily on the basis of different parameters, inconsistent with different countries. Pesticide residue limits applicable in Korea were proposed for 24 pesticides in drinking water(health basis) and for 25 pesticides in surface water(ecotoxicological basis), as selected by risk priority. It was recommended to accumulate scientific data by persistent research efforts in order to maintain the justification of the pesticide residue limits in water and relevant research topics to be undertaken in future were proposed.

• Environmental Engineering Research
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• v.23 no.2
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• pp.136-142
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• 2018

The river water source of Saidabad Surface Water Treatment Plant at Dhaka, Bangladesh, is deteriorated too much to be treated by conventional treatment process due to excessive ammonia pollution. In order to improve the raw water quality before it enters into the main treatment chain, a pilot study was conducted for pre-treatment of the raw water. The objective is to investigate the rate of reduction of ammonia using the Meteor pilot, a biological pretreatment system, which is a laboratory scale Moving Bed Biofilm Reactor with a nominal volume of hundred liters, filled with 50 L of Meteor 660 media. The reduction of ammonia was quite significant on average 73%, while the reduction of COD was in a range from 20 to 60%. The Meteor pilot was able to treat and nitrify the raw water and produce an effluent that respects the guarantee of ammonia < $4.0mg\;NH_3-N/L$ when the raw water ammonia concentration was < $15mg\;NH_3-N/L$. The study identified operating parameters necessary to achieve the desired goal of adequate ammonia removal. The study results would benefit a range of systems across the country by providing guidance on the design and operation of a biological pre-treatment system for ammonia removal.

• Journal of Korea Water Resources Association
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• v.55 no.1
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• pp.11-21
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• 2022

The COVID-19 started to spread at early 2020 in South Korea and has been threatening our life in many aspects. Countermeasures such as social distancing to prevent COVID-19 spread have brought many changes in our society an human life. In this study, as a part of the COVID-19 pandemic management, drinking water usage change is analyzed to evaluate potential risks on water supply service. We collected hourly water use data of residential area in S city, which is a mid-size city in South Korea, before and after the COVID-19 pandemic. The collected data were analyzed to reveal the changes in total water consumption, water usage weight, and hourly water-demand pattern caused by the COVID-19 pandemic. The case study revealed the noticeable changes in water consumption caused by the COVID-19 pandemic and required more secured and adaptive operation of drinking water system under the pandemic situation caused by infectious disease.

• Environmental Analysis Health and Toxicology
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• v.10 no.1_2
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• pp.37-46
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• 1995

The purpose of this research is to estimate a safe environmental level of human exposure to thresholding-acting toxicants in drinking water and recommend the acceptable levels and management plans for maintaining good quality of drinking water' and protecting health hazard. This research has been funded as a national project for three years from 1992 to 1995. This study(the second year, 1993-1994) was conducted to monitor 39 species of noncarcinogenic chemicals such as volatile organic compounds(VOCs), polynuclear aromatic hydrocarbens(PAHs), pesticides and heavy metals of drinking water at some area in six cities of Korea, and evaluate health risk due to these chemicals through four main steps (hazard identification, exposure assessment, dose-response assessment and risk characterization) of risk assessment in drinking water. In hazard identification, 39 species of non-carcinogenic chemicals were identified by the US EPA classification system. In the step of exposure assessment, sampling of tap water from the public water supply system had been conducted from 1993 to 1994, and 39 chemicals were analyzed. Inclose-response assessment for non-carcinogens, reference doses(RfD) and lifetime health advisories(HAs) of lifetime acceptable levels were calculated. In risk characterization of detected chemicals, the hazard quotients of noncarcinogens were less than one except those of manganese and iron in D city.

• Journal of Korean Medical Science
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• v.33 no.46
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• pp.288.1-288.12
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• 2018

Background: Diarrheal and intestinal infectious disease caused by inadequate drinking water, sanitation, and hygiene (WASH) is not only a great concern in developing countries but also a problem in low-income populations and rural areas in developed countries. In this study, we assessed the exposure to inadequate WASH in Korea and estimated the burden of disease attributable to inadequate WASH. Methods: We used observational data on water supply, drinking water, sewage treatment rate, and hand washing to assess inadequate WASH conditions in Korea, and estimated the level of exposure in the entire population. The disease burden was estimated by applying the cause of death data from death registry and the morbidity data from the national health insurance to the population attributable fraction (PAF) for the disease caused by inappropriate WASH. Results: In 2013, 1.4% of the population were exposed to inadequate drinking water, and 1.0% were living in areas where sewerage was not connected. The frequency of handwashing with soap after contact with excreta was 23.5%. The PAF due to inadequate WASH as a cluster of risk factors was 0.353 (95% confidence interval [CI], 0.275-0.417), among which over 90% were attributable to hand hygiene factors that were significantly worse than those in American and European high-income countries. Conclusion: The level of hand hygiene in Korea has yet to be improved to the extent that it shows a significant difference compared to other high-income countries. Therefore, improving the current situation in Korea requires a continuous hand washing campaign and a program aimed at all people. In addition, continuous policy intervention for improvement of sewage treatment facilities in rural areas is required, and water quality control monitoring should be continuously carried out.

• Journal of Korean Society on Water Environment
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• v.22 no.6
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• pp.977-981
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• 2006

In order to improve water quality in drinking water sources, Ministry of Environment (MOE) was implemented total water pollution load management (TWPLM) in all the major river basins. From the experience of the application of TWPLM, we could find some problems relating the target watershed, standard operating procedure (SOP) of establishment and implementation plan, water quality and flow rate, design flow, water quality model, margin of safety (MOS), and estimation of wasteload were found. The authors were reviewed ongoing TWPLM and presented the improvement schemes for a successful TWPLM. For the application of these suggestions, further detailed studies should be done to implement TWPLM in the future.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2001.05a
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• pp.142-142
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• 2001

A national survey for enteric virus contamination in treated water and its source water was performed from March to November 1999. The water samples were subjected to virus filtration at the major water plants producing over 10$^5$ tons treated water per day. Twenty surveyed sites encompass most of heavily populated residential area except for Seoul and Pusan. (omitted)

• Advances in environmental research
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• v.2 no.2
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• pp.119-129
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• 2013

The study examined the effect of urbanization on the water quality of Nwaorie and Otamiri Rivers in Owerri metropolis, Imo State, South-East Nigeria. Water samples were collected from Nwaorie and Otamiri Rivers from four sampling stations up and down stream. Water parameters analyzed using standard procedures were: color, turbidity, temperature, pH, total hardness, total solids, metals (Iron and magnesium), anions (nitrate and ammonia) and Fecal coliform. Results showed increased levels of coloration, iron, ammonia, turbidity and fecal coliform which exceeded the World Health Organization (WHO) permissible limits for drinking water. Increase in these parameters indicated influx of industrial effluent from the nearby industries and indiscriminate disposal of wastes at the bank of the rivers. Application of ANOVA showed various degree of variation in pollutants levels between the two rivers and at different sampling points. River Nwaorie was observed to be more impacted than River Otamiri. High values of iron observed from the study could be deleterious to human health if the river water is consumed without treatment. The study, therefore, recommended proper waste management and disposal as well as effluent treatments in Owerri municipal against pollution of surface water.