• Journal of Korean Society of Water and Wastewater
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• v.28 no.6
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• pp.725-733
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• 2014

16 water treatment plants(WTPs) in Jeju province were investigated to evaluate the corrosivity of tap water. In addition, the impacts of lime and carbon dioxide on LI changes at ES WTP were analyzed. The average of LI in Jeju tap was -1.78 which was similar to that of in-land multi-regional WTPs. The recommended process to improve LI of ES WTP which has high corrosivity(i.e., LI = -2.61) was to combine lime and carbon dioxide with the dosages of 20 mg/L and 5 mg/L respectively to meet LI of -1.0 ~ 0. pH was confirmed to be a major water quality parameter that determined LI based on the correlation results among LI and water quality parameters. Precaution on turbidity increase by lime addition should given to minimize particle breakthrough in the distribution system. Turbidity increase can be controlled by the addition of lime prior to filters.

• Journal of Environmental Health Sciences
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• v.19 no.3
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• pp.22-28
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• 1993

In order to investigate the hygienic chemical conditions of farm waters used as the potable and cleaning water for cow, we examined the pH, turbidity, KMnO$_4$ consumption, total hardness, chlorine, sulfate, NH$_3$-N, NO$_3$-N, lead, maganese, copper, zinc, fluoride and chrome for 78 farm waters around Kyunggi Province. Of 78 farm waters tested, average pH was 6.70+_0.06, turbidity 0.724 $\pm$ 0.081, KMnO$_4$ consumption 4.200 $\pm$ 0.256 mg/l, total hardness 107.46 $\pm$ 6.90 mg/l, NH$_3$-N 0.043 $\pm$ 0.037 mg/l, NO$_3$-N 8.096 $\pm$ 0.652 mg/l, chlorine 21.414 $\pm$ 2.187 mg/l, sulfate 12.737 $\pm$ 1.511 mg/l, lead 0.076 $\pm$ 0.001 mg/l, manganese 0.029 $\pm$ 0.004 mg/l, copper 0.018 $\pm$ 0.002 mg/l, zinc 0.055 $\pm$ 0.005 mg/l, chrome 0.048 $\pm$ 0.002 mg/l and fluorine 0.011 $\pm$ 0.001 mg/l. According to the geological characteristics, the concentrations of total hardness, NO$_3$-N, pH and chlorine in farm waters of Hwasung gun were higher than those in Yangpyung and Kwangju gun. In hygienic chemical items tested, there were high significanc among NO$_3$-N, total hardness, sulfate and chlorine. KMnO$_4$ consumption was significant with NH$_3$-N, sulfate and pH. But in heavy metals, there were significance between lead and copper, copper and chrome, and copper and fluorine.

• Journal of Korean Society of Water and Wastewater
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• v.17 no.4
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• pp.487-494
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• 2003

In this research, water qualities of river water and bank-filtrate were compared for six months including winter season. The location studied was Galjon area, the downstream of the Nakdong river. The well for bank-filtrate was installed 40 m apart from riverside. Main analytic results of bank-filtrate and river water were summarized as followings; the average concentrations in bank-filtrate were turbidity 0.8NTU, TN 0.4mg/l, $BOD_5$, 0.1mg/l, $KMnO_4$ consumption 1.6mg/l, heterotrophic bacteria 350cfu/ml, Fe 0.5mg/l, Mn 0.99mg/l while the average concentrations in river water were turbidity 6.1NTU, TN 3.9mg/l, $BOD_5$, 3.6mg/l, $KMnO_4$ consumption 11mg/l, heterotrophic bacteria 1,640cfu/ml, Fe 0.28mg/l, Mn 0.04mg/l. Water quality of bank-filtrate was mostly shown a good results than it of river water excepting Fe and Mn. In even basic constituents such as water temperature and pH, bank-filtrate was very settled while river water was extraordinary changable and high. In case of nitrogen, especially, total nitrogen of river water was 3.9mg/l while it of bank-filtrate was 0.4mg/l and its reduction was very high. The reason is that $NH^+_4-N$ among total nitrogen in the river water is nitrified and then denitrified in soil layer when it is pumped up as bank-filtrate. But Fe and Mn caused by the characteristics of soil was very high in bank-filtrate while Mn in river water was particularly very low and settled. As the distance between riverside and well was longer, concentration of Fe and Mn may be went up while its bacteria may be reduced.

• 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.

• KSBB Journal
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• v.16 no.4
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• pp.332-336
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• 2001

This paper is intended as an application of the biological rope media sedimentation tank using biodegradability of BAC(Biological activated carbon) to the drinking water treatment system for the removal of NOM. The removal of DOC(Dissolved organic carbon), UV absorbance(UV$\_$254/), and turbidity were evaluated under various operation condition of a biological rope media sedimentation tank such as raw water-media process (Media 1), ozonation-media process (Media 2), and ozonation-coagulation/sedimentation-media process (Media 3). The raw water had DOC concentration of 1.3∼3.4 mg/L, UV$\_$254/ of 0.027∼0.039 cm$\^$-1/, and turbidity of 0.3∼4.5 NTU, respectively. The average DOC concentration were 2.2 mg/L in media 1, 1.8 mg/L in media 2, and 1.3 mg/l in media 3 from raw water, respectively. On the other hand, the DOC concentration in conventional sedimentation tank was 1.5 mg/l. Higher removal of the DOC was noted in media 3 than media 1 and media 2. The UV$\_$254/ of the treated water were 0.037 cm$\^$-1/ in media 1, 0.027 cm$\^$-1/ in media 2, and 0.014 cm$\^$-1/ in media 3 from raw water, respectively The UV$\_$254/ in conventional sedimentation tank was 0.014 cm$\^$-1/ which is similar to that of media 3. Average turbidity of the treated water was 1.1 NTU in media 1, 0.9 NTU in media 2, and 0.5 NTU in media 3, respectively. It is expected that the biological rope media sedimentation tank is a good alternative over the conventional sedimentation process from these results.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.8
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• pp.1051-1056
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• 2006

Response surface methodology was used to investigate the quality of clarified mixed apple and carrot juices using ultrafitration. Apple and carrot juices were blended at the ratio of 1:3, 1:1, and 3:1. A three-variable, three-level central composite design was employed where the independent variables were the blend ratio, temperature and average transmembrane pressure (ATP). With increasing temperature and pressure, flux linearly increased regardless of blending ratio. Blend juice with 75% apple showed the highest soluble sugar and total sugar content in apple and carrot blend juices. Soluble solid contents were more affected by blending ratio than temperature and ATP. Total sugar contents were greatly affected by temperature; increasing temperature led to higher total sugar content up to $25^{\circ}C$. Higher carrot ratio led to higher vitamin C content. In general, higher acidity was achieved by higher apple content and acidity was increased with increasing temperature. Turbidity increased for all samples as APT increased, with the blending ratio of 1:1 (apple:carrot) showing the highest turbidity. Viscosity was greatly changed in the blending ratio of 3:1 (apple:carrot) juice. The polynomial models developed by RSM were satisfactory to describe the relationships between the studied factors and the responses. Analytical optimization gave $flux=0.216\;L/m^2.h$, soluble $solids=10.39^{\circ}Brix$, total sugar=71.32 mg/mL, vitamin C=315.18 mg%, acidity=7.78 mL, turbidity=0.017, and viscosity=1.44 cp, when using a $temperature=44.97^{\circ}C$, ATP=113.57 kPa, and blend ratio=28.50%.

• Journal of environmental and Sanitary engineering
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• v.5 no.1
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• pp.65-72
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• 1990

To study on the water quality of domestic purifier, twenty four samples of clean water by purifier and the raw water(tap water) were tested for biological and physico-chemical examination and were checked for style of purification and the period elapsed after changing of purification medium. The results were as follows; Biological and physico-chemical findings of raw water were not exceeded standard values. Average number of general bacteria,2.coli and pH in clean water were significantly higher than that of raw water(respectively, p<0.01), but mean contents of turbidity, chloride, nitrate and iron in clean water were significantly lower than that of raw water(respectively, p<0.01). In general count of bacteria and E.coli, a half of the clean water of ceramic filter and roverse osmosis style were exceeded standard values for drinking water. All of the pH of the ion exchange style clean water were exceeded standard values. But other findings were within standard values. In average bacterial counts and physico-chemical findings of clean water by purification style of purifier, clean water of ion exchange style purifier were lowest number of general bacteria and not detected in 2. coli. But other items were highest. The longer period elapsed after changing of purification medium were the higher contents of biological and physico-chemical findings of clean water.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.225-228
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• 2003

For the purpose of finding out the distributions of groundwater uses, the effect of facilities on the parameter and the correlations among measurements, various statistical analysis were carried out with the data of groundwater quality measurements from January to December in 2002. 1. The rates of groundwater for drinking water were 10.5% in Yangcheon-Gu, 10.2% in Kangdong-Gu, and 9.9% in Eunpyung-Gu. The rates of other uses of groundwater were shown to be 58.1%(786 wells) for civil defense emergency, 22.1%(299 wells) for contamination-concerning, 9.8%(133 wells) for water quality monitoring, consisting of 90% of all groundwater. 2. The 52.6% of groundwater for drinking were demonstrated to be appropriate while 91.9% for tither uses-domestic, industrial, agricultural uses- were shown to be proper. 3. For drinking water, the average values of colar, turbidity, NH3-N, F, and Fe were 11.216 degree, 2.138 NTU, 2.458mg/l, 0.212mg/1 and 0.507mg/1 respectively. 4. In cases of drinking water wells for emergency, the results of statistical analysis showed that building year of the wells, depth and pumping rate didn't affect on whether it was proper for that use or not. It were shown that there were linear correlations between depth and NO$_3$-N(-0.171) and F￣(0.332) while the correlation coefficients were 0.381 and -0.169 between the building year of well and depth and pumping rate respectively.

• Journal of Korean Society on Water Environment
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• v.16 no.4
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• pp.431-443
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• 2000

Water quality data from water treatment plants in Korea during 1994-1998 were investigated to find out the characteristics of their non compliance. The number of plants surveyed were approximately 600 and the number of samples were over 30,000. Ten parameters of water quality selected in this study and their non compliance % (inside parenthesis) were as follows: Heterotrophic plate count (0.14%), Total coliforms (0.08%), $NH_3$-N (0.29%), $NO_3$-N (0.14%), THMs (0.02%), Turbidity (0.11%), Residual chlorine (5.5%), $KMnO_4$ consumption (0.04%), Hardness (0.03%), pH (0.07%). These levels of non compliance were compared to those obtained from WIDB (Water Industry Database, 1996) of American Water Works Association. This study strongly supported that small water plants (<10,000 tons/day) were more vulnerable in meeting the regulation criteria of many water quality parameters such as Heterotrophic plate count. Total coliforms, $NO_3$-N, THMs, Turbidity, Residual chlorine, $KMnO_1$ consumption, Hardness and pH. The $NH_3$-N concentration was especially high in winter and its violation was frequently found in the specific areas such as the downstream of major rivers. The average THMs concentration was surprisingly low, indicating $13{\mu}g/L$ which is 43% of US. Accordingly, these characteristics must be reflected in establishing the effective management of water quality policy of drinking water in Korea.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.1
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• pp.39-50
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• 2017

In the coagulation/sedimentation (C/S) process of the water treatment process, the inflow of massive algal bloom causes many problems including fouling of filter media. This study was conducted to find out the way to remove the algae's harmful effects by addition of pre-treatment prior to C/S process. Many Jar-tests were conducted such as (1) ACF (Algae Coagulation Flotation) process using natural algae coagulant (Water $Health^{(R)}$), (2) ACF + C/S process and (3) C/S process with a variety of conditions using cultured algae. The average values of turbidity were (1) 0.42 NTU for ACF process, (2) 0.13 NTU for ACF + C/S process and (3) 0.25 NTU for C/S process. It was shown that the treatment efficiency of ACF process could get low turbidity results, and ACF + C/S process could achieve more efficient results than those of C/S process. Any negative effects of ACF process to the efficiency of C/S process were not observed in ACF + C/S process. In order to reduce the unfavorable effects of algae, it was found out that the introduction of ACF process in the forms of (1) ACF or (2) ACF + C/S could be one of the effective and alternative solutions.