• Journal of Sericultural and Entomological Science
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• v.29 no.2
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• pp.73-81
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• 1987

This investigation was carried cut to obtain the reeling water conditions in Korea. The analyzed items of water were pH, colority, turbidity, acidity, alkalinity, solids electric conductibity hardness and heavy metal ions. About 40% of the reeling water were found to be agreeable, 30% were acceptable provided with some quality control and the others were out of acceptable range mainly based on the M-alkalinity, acidity, pH and total hardness. It was found that there was a following relationship between total hardness and electric conductibity with the relative correlation coefficient r=0.9145. y=15.967+0.22774x Where x, y are electric conductivity and total hardness respectively.

• Textile Coloration and Finishing
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• v.16 no.1
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• pp.34-39
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• 2004

Dyeing properties of Glycyrrhizae Radix was investigated with silk fabrics. Dyeing water is a type of chalcone, it showed yellow in IR spectrum. K/S value showed high in following conditions; Glycyrrhizae Radix $200g/1\ell4 water, $80^{\circ}$ of dyeing temperature, 90 minute of dyeing time. Glycyrrhizae Radix dyeing water has higher K/S value in alkalinity(pH9) than in neutrality(pH7) or acidity(pH3) conditions. K/S value showed highest in pH5 premordant method of alkalinity dyeing water condition. The color of silk fabric dyed with Glycyrrhizae Radix is yellow. The change of color did not show by mordant treatment. K/S value showed higher in mordant treatment than nonmordant. Light fastness showed over 3 degree in nonmordant, premordant, simmordant(Al,Cu,Fe) and postmordant(Cu). Water fastness showed over 3 degree in dyeing water(pH3, pH5, pH7). Dry cleaning fastness showed over 3 degree in all dyeing methods. Washing fastness is showed in 2-3 degree; Al in nonmordant, premordant, simmordant and Cu in simmordant are 2-3 degree. Perspiration fastness is nearly 3-4 degree in premordant and simmordant. Perspiration fastness shows high in premordant, simmordant than postmordant. The fastness of light, water, dry cleaning, washing, perspiration shows better nonmordant, premordant, simmordant than postmordant method.

• Journal of Soil and Groundwater Environment
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• v.24 no.1
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• pp.10-16
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• 2019

Alkalinity is an essential parameter for understanding geochemical processes and calculating partial pressure of $CO_2$, dissolved inorganic carbon, and mineral saturation indices. The Gran Titration Method (GTM) is one of the most accurate methods for measuring the alkalinity in water samples. However, this method has not been widely employed in measuring groundwater alkalinity in Korea, probably due to inadequate and insufficient understanding of the method. In this regard, this article was prepared to introduce GTM and related know-hows learned from the authors' experiences in measuring alkalinity. This paper also introduces a MS Excel-based alkalinity calculator as a handy tool for GTM.

• The Journal of Engineering Geology
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• v.12 no.4
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• pp.439-457
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• 2002

Sping waters at 60 sites and groundwaters at 6 wells in Mts. Geumjeong and Baekyang area were investigated for measuring nine physicochemical components (temperature, pH, Eh, EC, TDS, DO, salinity, alkalinity and discharge rate). The pH of spring waters ranges from 5.06 to 8.38, alkalinity from 7.93 to 102.21 mg/ㅣ, electrical conductance from 9.5 to $270{\;}\mu\textrm{s}/cm$, Eh from 64.2 to 685.9 mV, DO from 4.57 to 12.13 mg/l, and the discharge rate from 4.26 to 182.2 ml/s. General statistics was carried out to analyze statistical characteristics of those components. To compare the components with one another, regression analyses were carried out. And the components of spring waters were compared to those of groundwaters. Kriging was used to estimate the spatial variation of DO, pH, Eh, EC, alkalinity and discharge rate in the study area. The kriged isopleth maps were made using normalized kriged values to find anomalies of the physicochemical components and to compare anomalies of different components.

• Corrosion Science and Technology
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• v.3 no.6
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• pp.245-250
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• 2004

A series of classical G109 type concrete specimens was exposed to cyclic wet and dry ponding with 15 w/o NaCl solution for approximately five years. Mix design variables included 1) three cement alkalinities (EqA of 0.97, 0.52, and 0.36) and 2) three water-cement ratios (0.50, 0.41, and 0.37). To determine the corrosion initiation time, corrosion potential and macro-cell current between top and bottom bars were monitored. Subsequent to corrosion initiation, specimens were autopsied and visually inspected. Concrete powder samples were collected from top rebar trace and chloride concentration was measured. Also, time-to-corrosion, $T_i$, for specimens of the individual mix designs was represented using Weibull analysis. Time-to-corrosion was a distributed parameter; and because of this, corrosion initiation of four identical specimens for each mix varied, often over a relatively wide range. Specimens fabricated using the lowest water cement ratio and the highest alkalinity cement exhibited the longest time-to-corrosion initiation and the highest chloride threshold levels. Time-to-corrosion did not increase monotonically with cement alkalinity, however, presumably as a consequence of relatively high $Cl^-$ binding in the lower pore water pH range. The chloride threshold level, $Cl_{th}$, increased with increasing $T_i$ and, consequently, was greatest for the highest cement alkalinity specimens.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.3
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• pp.53-60
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• 2011

As Construction & Demolition(C&D) debris increase every year, a system has enforced for recycled aggregate made out of C&D debris, then recycled aggregate usage increased in construction field. But as environmental problem by alkalinity of recycled aggregate occurred, the study for lowering alkalinity of recycled aggregate is needed. In this study we made alkalinity reducing facility and installed in the C&D debris midterm-treat field. Then we certified effect of lowering alkalinity and quality of recycled aggregates before and after carbonation. As a result, the most effective carbonation condition is 30seconds in carbonation time, -50~100 kPa of reaction pressure with change of 3cycles. This condition made pH 9.33~9.8 of recycled aggregate possible. The quality of recycled aggregate after carbonation was better than before carbonation in terms of plasticity index, modified CBR, abrasion loss, sand equivalent, liquid limit, size distribution, density and water absorption.

• Journal of Environmental Health Sciences
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• v.19 no.2
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• pp.1-9
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• 1993

In public water supply systems, Alum and/or PAC being used as a coagulant. It is well known that their use increased frequently the concentration of residual aluminum in filtered water upon operating conditions. This study was conducted to find the optimum conditions that both the concentration of residual aluminum and turbidity are minimized by changing such factors as pH, temperature, alum dosage, mixing rate, alkalinity and hardness. The results can be summarized as follows: The pH values for the minimum concentration of residual aluminum and turbidity as a given experimental condition were found at pH 6 and pH 7 respectively, the apparent clarity was best at pH 8. The floc settling rate was the greatest at pH 6.5, but the turbidity was high at the same condition. The more alum dosage, the higher the concentration of residual aluminum. However the alum dosage less than 15 mg/l tend to decrease in turbidity. Restabilization and enmeshment occurred near 15 mg/l and 20 mg/l of alum dose respectively. With the increase of mixing rate (rapid and slow), the concentration of residual aluminum and turbidity are increased and the same trend was found in increment of mixing time. At low water temperature, the concentration of residual aluminum was decreased, but turbidity was increased. It was confirmed that alkalinity had an effect on the coagulation efficiency, but hardness did not.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.4
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• pp.294-300
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• 2013

In this study, major parameter of partial nitritation was investigated for the stable operation. In order to establish partial nitritation system, prevailing parameters such as temperature, BA (bicarbonate alkalinity) and pH were evaluated. As a result, it is inferred that appropriate bicarbonate alkalinity ratio (mg $NaHCO_3{\cdot}L^{-1}/mg$ Inf. $NH_4{^+}-N{\cdot}L^{-1}$) drives stable 50% partial nitritation at $32^{\circ}C$ and ambient temperature, respectively. Alkalinity ratio was proposed as new strategy for 50% partial nitritation without pH control in both temperature regimes. Because of the results, it was added amound of BA required only for 50% nitritation to inhibit nitratation. The effluent $NO_2{^-}-N/NH_4{^+}-N$ ratio reached almost 100% when initial bicarbonate alkalinity ratios (mg $NaHCO_3{\cdot}L^{-1}/mg$ Inf. $NH_4{^+}-N{\cdot}L^{-1}$) were 6.8 (R1) and 6.7 (R2), respectively. Polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) results demonstrated that AOB was the dominant nitrifying bacteria and NOB was negligible after adopting process control.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.3
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• pp.162-167
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• 2012

The removal of orthophosphate ions from aqueous solutions by the anion exchange resin in the form of $Cl^-$ ion was investigated to elucidate the ion exchange mechanism which depends on the forms of orhthophoshate ions. In addition, the effects of alkalinity and other common anions were studied. The results showed that the orhthophosphate ions with the oxidation state of 2 and 3 ($HPO{_4}^{2-}$ and $PO{_4}^{3-}$) were effectively removed by the anion exchange resin, whereas the part of the $H_2PO_4{^-}$ ion passed through the ion exchange column. This suggested that the affinity of $H_2PO_4{^-}$ to the ion exchange resin was comparable with that of $Cl^-$ ion. In all cases, the effluent pHs have shown to be much lower than the calculated values, indicating that more $Cl^-$ ions than the orthophosphate equivalents in the influent were eluded. As the alkalinity increases, the decrease in pH was minimized. When the alkalinity was 100 mg/L ($CaCO_3$) or greater, 100 mg/L orthophosphate ions including $H_2PO_4{^-}$ were completely removed. The common anions such as $SO{_4}^{2-}$ and $NO_3{^-}$ were also removed by the anion exchange resin, and thus decreased the ion exchange capacity for the removal of orthophosphate.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.4
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• pp.362-368
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• 2005

The pH, alkalinity and calcium hardness could be adjusted by $CO_2$, $Ca(OH)_2$, and $Na_2CO_3$ addition in the water treatment process for corrosion protection of the water pipes. This research was performed to investigate the effect on the variation of water quality on the unit process by addition $CO_2$, $Ca(OH)_2$, and $Na_2CO_3$ in water treatment process. Carbon dioxide and lime were added before the coagulation basin and soda ash was added after the BAC process. pH and aklainity were increased at coagulation basin then after the water qualities had sustained similiarly to BAC process. There was no effect on turbidity and DOC removal efficiency during experimental period by addition\ $CO_2$, $Ca(OH)_2$, and $Na_2CO_3$ solution was added into clear well, the last process for optimum control of CCPP and is used mainly to control pH and alkalinity. In this research, average pH, alkalinity, and calcium hardness in treated water were 8.39, 61.4 mg/L as $CaCO_3$, 59.4 mg/L as $CaCO_3$, respectively and CCPP of treated water was higher than 29.5 mg/L to BAC process water, so adjusted water was expected to prevent internal corrosion of water pipe.