• 한국환경농학회:학술대회논문집
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• 2009.07a
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• pp.344-344
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• 2009

• Journal of Environmental Health Sciences
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• v.31 no.3
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• pp.192-198
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• 2005

The occurrence of toxic cyanobacterial blooms has been reported worldwide and poses a threat to human health through drinking water exposure. The toxins they produce are highly water soluble and can leach into the water body. To eliminate any risk of drinking water exposure, removal of these toxins is essential before the water is consumed. Conventional water treatment techniques such as chlorination, if managed well, can be effectively used to remove some of these toxins, however, saxitoxin and its derivatives pose a problem. Little toxicological data are available to evaluate the real threat of these toxins.

• Membrane Journal
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• v.6 no.4
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• pp.189-195
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• 1996

It is concluded from this study that human consumption of very low TDS water does not leach minerals from the body that cause ill health effects because; -The human body's own control mechanism of homeostasis and internal body secretions keep tight controls on body fluid composition regardless of drinking water TDS for a normal person under normal csonditions. -The unofficial WHO document's proposed guideline of a 100m/l lower limit for drinking water due to mineral leaching and subsequent ill health was not found to be scientifically or physiologically credible. Leaching of minerals from the body is not officially recognized by WHO. -The experience of the U.S. Navy, Army, NASA and dommunity demonstrations do not support ill health symptoms caused by consumption of low TDS drinking water. -Millions of people regularly consume maturally occurring low TDS water without symptoms of ill health.

• Journal of Environmental Health Sciences
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• v.29 no.1
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• pp.8-15
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• 2003

In this study, chlorine dose at water storage tank was predicted to meet the recommended guideline for free chlorine residual in drinking water distribution system, using EPANET which is a computer program that performs extended Period simulation of hydraulic and water quality behavior within pressurized pipe networks. The results may be summarized as follows. The decay of chlorine residual by season varied considerably in the following order; in summer ($25^{\circ}C$) > spring and fall (15$^{\circ}C$) > winter (5$^{\circ}C$). For re-chlorination at water storage tank by season, season-varying chlorine dose was required at its maximum of 1.00 mg/l in summer and minimum of 0.40 mg/l in winter as free chlorine residual. The decay of chlorine residual through out the networks increased with water age spent by a parcel of water in the network except for some points with low water demand. In conclusion, the season-varying chlorine dose as well as the monitoring of water quality parameters at the some points which showed high decay of chlorine residual may be necessary to deliver the safe drinking water.

• Journal of the Korean GEO-environmental Society
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• v.16 no.1
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• pp.55-60
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• 2015

As the water supply system has been installed over the country, the management of drinking water could be easier and controlled by experts. This helps to supply safe water to public. However, in rural area, small scale water treatment systems or groundwater haves been used as drinking water supplier. The drinking water including groundwater contains various contaminants. Private or small scale water treatment system can be contaminated with heavy metals such as arsenic, selenium and strontium which are usually originated from natural source. Arsenic, selenium and strontium have been determined from the goundwater, small scale water treatment system in the Kyungpook area. The results have been compared with the Korean and international standards. The results were analyzed on the geological characteristics of the area. Among the total of 1,412 samples, 76 samples showed higher concentration of arsenic than WHO guideline and the Korean drinking water standard. Total 4 samples had higher contents of selenium than WHO guideline which was $10{\mu}g/L$. In the analysis of geological characteristics, arsenic was highly released from a few area and which are in order of biotite granodiorite > biotite granite > daegu formation. Selenium has been highly released from biotite granite > black shale > diluvium.

• Journal of Environmental Policy
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• v.5 no.2
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• pp.49-67
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• 2006

The radionuclides in drinking water have been regulated in many countries. In USA, the regulation has been revised for over 30 years since radionuclides have been regulated under Safe Drinking Water Act(SDWA) from 1974. Today, USEPA is finalizing maximum contaminant level goal(MCLG) of zero for radionuclides, maximum contaminant level(MCL) and alternative maximum contaminant level(AMCL) of 300pCi/L and 4,000pCi/L for radon respectively, MCLs of $30{\mu}g/L$ for uranium, and MCLs of 5pCi/L for combined radium 226 and 228. In Canada, Maximum Acceptable Concentration(MAC) value for uranium is $20{\mu}g/L$. WHO revised the guideline value of uranium and radon to $15{\mu}g/L$ and 100Bq/L in september 2004, respectively. On this survey, it has been found that international regulations for radionuclides in drinking water have been established and improved steadily on the knowledge basis from the past decades' studies.

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.45-48
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• 2000

Reverse osmosis filtration(RO) system and ultrafiltration(UF) system are principally use for domestic home drinking water treatment systems. The object of this study is to make a comparison between two systems in terms of theirs abilities to remove RNA coilphage QB as an indicator of pathogenic enteroviruses. The virus removal ratio of RO system was 99.999%, which was higher than EPA virus treatment guideline(99.99%). In the course of filtration, removal ratios of sediment filter, pre-carbon filter, reverse osmosis membrane and post-carbon filter were 75.000%, 93.208%, 99.997% and 99.999%, repectively. In case of UF system, virus removal ratio was 99.708%. Removal ratios of sediment filter, pre-carbon filter, post-carbon filter and ultrafiltration membration membrane were 71.038%, 91.530%, 98.283% and 99.708%, respecively, in UF steps. Therefore, RO system is more effective than UF system in virus removal.

• Journal of Korean Society on Water Environment
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• v.24 no.6
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• pp.701-708
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• 2008

As a countermeasure for reduction of corrosion in the delivery and distribution pipes used for tap water, materials for the pipelines in-houses and the effect of water quality on corrosivity of water pipelines were investigated in the distribution system of Han river. As the corrosion index at 6 water purification facilities of Han river, average Langelier Saturation Index (LI) of raw and finished water were -1.0 and -1.4 respectively and average Larson Index (LR) were 9.5 and 9.9, respectively. And also corrosion potential showed corrosivity in finished water (-431~-462 mV) as well as raw water (-426~-447 mV). This results indicate that tap water quality of han river have corrosivity. To understand the corrosivity effect in pipe material used for premise distribution system, water quality of stagnant tap water and tap water were analyzed and the differences between them were calculated. The difference concentration of iron, copper and zinc were $12.9{\mu}g/L$, $31.0{\mu}g/L$ and $45.0{\mu}g/L$ respectively in galvanized steel pipe for use more than 15 years and showed highest concentration. As a result, the control to corrosivity in the water pipelines, corrosivity control treatment in the water purification system can be applied. In advance it is necessary to monitor corrosivity of water quality using corrosive index because corrosivity may differ from the seasonal and regional characteristics and water chemicals dosage. For the future the guideline for corrosion index have to be established.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.5
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• pp.575-581
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• 2015

Although disinfection in drinking water treatment plants provides a safer water supply by inactivating pathogenic microorganisms, harmful disinfection by-products may be formed. In this study, the disinfectant, chlorine, was produced on-site from the electrolysis of salt (NaCl), and the by-products of the disinfection process, bromate and chlorate, were analyzed. The provisional guideline levels for bromate and chlorate in drinking water are $10{\mu}g/L$ and $700{\mu}g/L$, in Korea, respectively. Bromide salt was detected at concentrations ranging from 6.0 ~ 622 mg/kg. Bromate and chlorate were detected at concentrations ranging from non-detect (ND) ~ 45.3mg/L and 40.5 ~ 1,202 mg/L, respectively. When comparing the bromide concentration in the salt to the bromate concentration in the chlorine produced by salt electrolysis, the correlation of bromide to bromate concentration was 0.870 (active chlorine concentration from on-site production: 0.6-0.8%, n=40). The correlation of bromate concentration in the chlorine produced to that in the treated water was 0.866.

• Membrane and Water Treatment
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• v.7 no.4
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• pp.313-325
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• 2016

South Africa recognises piped water as the main source of safe drinking water supply. Remote areas do not have access to this resource and they rely solely on surface water for survival, which exposes them to waterborne diseases. Interim point of use solutions are not practiced due to their laboriousness and alteration of the taste. Bio-ultra low pressure driven membrane system has been noted to be able to produce stable fluxes after one week of operation; however, there is limited literature on South African waters. This study was conducted on three rivers namely; Umgeni, Umbilo and Tugela. Three laboratory systems were setup to evaluate the performance of the technology in terms of producing stable fluxes and water that is compliant with the WHO 2008 drinking water guideline with regards to turbidity, total coliforms and E.coli. The obtained flux rate trends were similar to those noted in literature where they are referred to as stable fluxes. However, when further comparing the obtained fluxes to the normal dead-end filtration curve, it was noted that both the Umbilo and Tugela Rivers responded similarly to a normal dead-end filtration curve. The Umgeni River was noted to produce flux rates which were higher than those obtainable under normal dead-end. It can be concluded that there was no stabilisation of flux noted. However, feed water with low E.coli and turbidity concentrations enhances the flux rates. The technology was noted to produce water of less than 1 NTU and 100% removal efficiency for E.coli and total coliforms.