• Journal of Life Science
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• v.20 no.7
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• pp.1073-1077
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• 2010

Fungi, including allergenic, pathogenic or toxigenic species, may have direct effects on human health, interfere with the disinfection process and maintenance of chlorine residual, and add to taste and odor problems. We surveyed distribution of waterborne fungi from raw water in Busan metropolitan city using the EPA standard method. According to the survey, conducted from March 2008 to October 2008, the number of fungi in raw water was high in September and low in April. Quantitative enumeration of fungi per 100 ml of raw water ranged from 5 to 64 CFU, and a higher number was detected in the Mulgum region compared to the Maeri region. Total fungi numbers highly correlated with pH, water temperature and total coliform in this area. Predominant fungi genera grown in medium were identified as Aspergillus, Penicillum, Histoplasma, Rhizopus, Trichophyton, Mucor and Sporthrix species. Aspergillus flavus and Penicillum notatum were particularly dominant in both areas. There were a total of 6 and 9 species detected in the Mulgum and Maeri regions respectively, and the number of species was more verified in the Maeri region than the Mulgum region.

• 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.22 no.6
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• pp.665-672
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• 2008

It is necessary to implement the management plan for the production of safe and high quality drinking water from lake Paldang. To set up the plan, the water quality items such as BOD, T-P, SS and coliform were monitored for ten years, 1997~2006, and the influence of raw water quality on the drinking water treatment process and the treated water quality was also evaluated from 2004 to 2006. In conclusion, water quality items such as turbidity(SS), T-P(eutrophication), pathogens(fecal coliforms, enterovirus, reovirus, giardia, cryptosporidium), DOC(precursor of disinfection by-products), and micro-pollutants(phthalates, VOCs, heavy metals) are should be managed to get safe and high quality drinking water from lake Paldang.

• Journal of Environmental Science International
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• v.22 no.4
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• pp.453-461
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• 2013

This study, changes in raw water quality is to indicate on the efficiency of ozone treatment of each pollutant as compared to derive the appropriate operating measures. The appropriate selection for injection rate of pre-ozone and did not inject pre-ozone assess changes in the water. When good water quality, you not injected of pre-ozone to evaluate the economic efficiency of electricity and put the most cost-effective ozone concentration were evaluated. Evaluation remove organic matter and chlorophyll-a concentration level in experiments with each factor of the water DOC> 2.5 mg/L, THMFP> 70 ${\mu}g/L$, Chl-a> 30 $mg/m^3$or less constant process, if you do not need to put pre-ozone showed little impact. It also does not put you in pre-ozone appropriate produce enough power rate savings was calculated as approximately 90 million won. Ability to remove organic materials and the ability to produce disinfection byproducts, and cost-effective decisions by considering the concentration of injection if pre-ozone 1 mg/L was investigated by the appropriate concentration of ozone injection.

• Journal of Korean Society on Water Environment
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• v.20 no.1
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• pp.55-62
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• 2004

This study was carried out to investigate the formation of DBPs(Disinfection By-products) such as trihalomethane(THMs) and haloacetic acid(HAAs) by chlorination in raw water and finished water of Water Treatment Plant(WTP). The formation of THMs was increased with the increase of pH and reaction time. HAAs was found as a high formation at a pH 7 and low formation at pH 9. THMFP(Trihalomethane Formation Potential) was the highest formation potential in raw water of Pu-1 and the lowest in raw water of Pa-1. In case of HAAFP(Haloacetic acid formation potential), So-1 showed the highest value, while Pa-1 showed the lowest value. It was investigated the relationship between HAAs and organic matters which were described as DOC(dissolved organic carbon) and $UV_{254}$. In both DOC and $UV_{254}$ versus HAAFP, Pu-1 showed the good correlation coefficients($r^2$) with 0.95 and 0.84, respectively. For three WTP investigated, DBPs(THMs + HAAs) was shown over the range of $42.00{\sim}49.36{\mu}g/L$. This result might be due to the different characteristic of organic matters in raw water and the difference of chlorine dosage for a water treatment.

• Korean journal of food and cookery science
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• v.23 no.4 s.100
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• pp.567-578
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• 2007

This study was designed to provide basic data for the application and practical use of vinegar disinfection for raw vegetable preparation in foodservice operations. The test materials were washed and disinfected by three different methods(tap water washing, chlorine water disinfection, vinegar disinfection) and stored at $3^{\circ}C$ and $10^{\circ}C$ for 7 days. Then, their microbiological qualities were compared. Total plate counts increased over the course of the storage period, and all samples, except in the case of tap water washing, remained under the permitted limit until the 7th day of storage. In particular, vinegar disinfection showed the lowest increase in total plate counts(2.35${\sim}$4.03 log CFU/g). While the total plate counts of chlorine and vinegar disinfection were within the 6.00 limit of microbiological safety, the tap water washing treatment passed the permitted limit. The psychrotrophic counts increased steadily over the course of the storage period, and increased least at $3^{\circ}C$, however, the tap water washing showed the most drastic increase, while vinegar disinfection yielded the smallest increase.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.6
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• pp.653-661
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• 2007

The Disinfectants/Disinfection By-products (D/DBP) Rule proposed by the US Environmental Protection Agency requires the implementation of enhanced coagulation as a control strategy for natural organic matter (NOM) removal and as a means of limiting the formation of all DBPs, i.e., not just the trihalomethanes and haloacetica acids. To control DBP formation, several best available technologies (BATs) were determined for removal of DBPs and DBP precursors. The enhanced coagulation is one of the BATs for DBP precursors removal. Treatment facilities that achieve a specified percent removal of total organic carbon (TOC) prior to the application of a continuous disinfectant or that achieve a residual TOC concentration < 2mg/L prior to the application of a continuous disinfectant are considered to be in compliance with enhanced coagulation. The enhanced coagulation was applied to raw water in Korea, the Han River. Raw water were examined and effects of different raw water qualities on enhanced coagulation were investigated. Three analyses were used for raw water characteristics, water quality measurement, molecular weight distributions, hydrophobic/hydrophilic fractionation. The Han River had the relatively low alkalinity and low organic carbon concentration. The results of molecular weight distributions showed significant portions of low molecular weight organics, which is very different from most water in USA. The alum doses for the required TOC removal guided from USEPA manual were quite low (i.e. 10~30 mg/L alum) for the water, probably due to the specific water quality of the Han River.

• Journal of Life Science
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• v.17 no.10
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• pp.1374-1380
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• 2007

The development of polymerase chain reaction (PCR) technology has the potential to solve for isolating pathogenic microorganisms from environmental samples than traditional plate counting methods. We have been detected pathogenic bacteria from raw water and water treatment process in Busan metropolitan city by PCR method. According to the result of survey from July 2004 to October 2005, 80 out of 92(87.0%) were positive for bacterial pathogens in raw water samples and positive rate of Shigella spp., Yersinia spp., Salmonella spp. and Legionella spp. were 46.2%, 40.7%, 17.6% and 9.9%, respectively. Pathogenic bacteria in raw water was mainly distributed through the lately Autumn to the winter and more highly detected Maeri than Mulgum region. During the period of survey in water treatment process, Shigella spp. was highly detected but all of bacterial pathogens were entirely removed after in post-ozonation step. These suggest that waters supplied in Busan metropolitan city may be safe against the pathogenic bacteria.

• Journal of the Korean Society of Marine Environment & Safety
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• v.2 no.1
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• pp.89-95
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• 1996

This paper describes a fuzzy controlled pre-chlorination technique for purifying the pulluted raw water in water purification lants. For the purpose of obtaining the high quality water, the appropriate pre-chlorine dosage rate has to be continuously adjusted according to a change in quality of a intake raw water, weather, solar nergy mount, temperature and etc. Therefore, the method of expressing an expert's empirical knowledge cumulated from his past carrier by fuzzy reasoning and the fuzzy controller design technique is necessary.In this paper fuzzy membership functions and rules accordingto emprircal knowledge and experimental field data were obtained, And also fuzzy cintriller design using four feedforward components for the determination of pre-chlorine dosage rate and four feedback ones for the compensation of its dosage rate with residual chlorine and its change rate, was executed.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.6
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• pp.699-705
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• 2007

In this study, the improvement of the operation condition and the water quality in water treatment plant by operating information system(OIS) was evaluated for Ansan water treatment plant. The average flow rate of raw water in the year 2005(after constructing the OIS) appeared 15.6 % lower than that in the year 2004(before constructing the OIS). The mean value(12.37 NTU) of raw water turbidity in the year 2005 remained constant, or nearly so with that(12.06 NTU) in the year 2004. The average dosing rates of coagulant appeared 12.06 mg/L in the year 2005 which was higher than 10.31 mg/L in the year 2004. Furthermore, the average turbidity concentration of fresh water in the year 2005 appcared slightly better than that in the year 2004. From $COD_{Mn}$ and BOD concentration of raw water, the water quality in the year 2005 were better than those in the year 2004. The average concentration of $KMnO_4$ in the year 2004 and the year 2005 was 2.95 mg/L and 1.25 mg/L, respectively, and the average concentration of THMs in the year 2004 and the year 2005 appeared 0.038 mg/L and 0.025 mg/L, respectively. Therefore, the fresh water quality in the year 2005 was better than that in the year 2004. In this study, it is considered that the operation of Ansan water treatment plant may be optimized by OIS, and thus the OIS may be very useful method to improve the water quality.