• Preventive Nutrition and Food Science
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• v.21 no.2
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• pp.147-154
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• 2016

In this study, the effects of a pre-filter system and electrolysis system on the safe and efficient reuse of brine in the cabbage salting process were investigated. First, sediment filter-electrolyzed brine (SF-EB) was selected as brine for reuse. Then, we evaluated the quality and microbiological properties of SF-EB and Chinese cabbage salted with SF-EB. The salinity (9.4%) and pH (4.63) of SF-EB were similar to those of control brine (CB). SF-EB turbidity was decreased (from 0.112 to 0.062) and SF-EB residual chlorine (15.86 ppm) was higher than CB residual chlorine (0.31 ppm), and bacteria were not detected. Salinity (2.0%), pH (6.21), residual chlorine (0.39 ppm), chromaticity, hardness, and chewiness of cabbage salted with SF-EB were similar to those of cabbage salted with CB. The total bacterial count in cabbage salted with CB was increased as the number of reuses increased (from 6.55 to 8.30 log CFU/g), whereas bacteria in cabbage salted with SF-EB was decreased (from 6.55 to 5.21 log CFU/g). These results show that SF-EB improved the reusability of brine by removing contaminated materials and by sterilization.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.4
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• pp.329-338
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• 2017

The problem of disposal of brine due to increased MD/RO desalination plant has recently become a big social issue. The chlor-alkali process through electrolysis of brine has been studied as a method to overcome this problem. In order to increase the electrolysis efficiency, a pretreatment process for removal of hard substances must be preceded. In this study, we investigated the mechanism of removal of hardness through chemical precipitation. As a result, Ca was greatly influenced by addition of $Na_2CO_3$, and Mg was strongly influenced by pH. Also, the addition of NaOH and $Na_2CO_3$ enabled simultaneous removal of Ca and Mg, and showed a removal efficiency of 99.9% or more. Finally, the residual concentrations of Ca and Mg in the brine after the reaction were 0.14 and 0.13 mg/L, respectively. Saturation index was calculated using Visual MINTEQ 3.1, and solid phase analysis of the precipitate was performed by FE-SEM and PXRD analysis. It was confirmed that precipitate formed by the formation of calcite and brucite.

• Resources Recycling
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• v.33 no.2
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• pp.16-23
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• 2024

The electrolysis for extracting magnesium from seawater or brine primarily involves recovery of magnesium via precipitation as the form of magnesium hydroxide. The technology is classified into cation-exchange membranes (CEM), anion-exchange (AEM) membranes, electrodialysis, and membraneless methods. Recent research has focused on enhancing the efficiency and selectivity of magnesium recovery from seawater or brine containing magnesium, with expectations of effective magnesium recovery even with normal seawater. In a future, the optimization of the selective and efficient recovery of magnesium and various valuable substances through long-term operation of scaled-up systems is crucial with enhancing economic and environmental viability. It is essential to realistically estimate operational costs considering the membrane's lifespan and replacement cycle. Also, detailed and practical process models should be developed based on monitoring data on various factors.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.1
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• pp.109-113
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• 2016

Techno-economic evaluation of Non-Capture $CO_2$ Utilization (NCCU) technology for the production of high-value-added products using greenhouse gas ($CO_2$) was performed. The general scheme of NCCU process is composed of $CO_2$ carbonation and brine electrolysis process. Through a carbonation reaction with sodium hydroxide that is generated from brine electrolysis and $CO_2$ of the flue gas, it is possible to get high-value-added products such as sodium bicarbonate, sodium hydroxide, hydrogen & chloride and also to reduce the $CO_2$ emission simultaneously. For the techno-economic study on NCCU technology, continuous operation of bench-scale facility which could treat $2kgCO_2/day$ was performed. and based on the key performance data evaluated, the economic evaluation analysis targeted on the commercial chemical plant, which could treat 6 tons $CO_2$ per day, was performed using the net present value (NPV) metrics. The results showed that the net profit obtained during the whole plant operation was about 7,890 mKRW (million Korean Won) on NPV metrics and annual $CO_2$ reduction was estimated as about $2,000tCO_2$. Also it was found that the energy consumption of brine electrolysis is one of the key factors which affect the plant operation cost (ex. electricity consumption) and the net profit of the plant. Based on these results, it could be deduced that NCCU technology of this study could be one of the cost-effective $CO_2$ utilization technology options.

• Journal of the Korean Electrochemical Society
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• v.5 no.1
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• pp.7-12
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• 2002

The gas diffusion electrodes as oxygen cathodes f3r the brine electrolysis process were investigated. The gas diffusion electrode consists of a reaction layer, a gas diffusion layer, and a current distributor. The reaction layer was made from hydrophilic carbon black, hydrophobic carbon black, PTFE(polyterafluoroethylene), and Ag catalyst loaded by the silver mirror reaction or impregnation method. The gas diffusion layer was made from hydrophobic carbon black and PTFE, and Ni mesh was used as the current distributor in the reaction layer. The result that the gas diffusion electrode $(10wt\%\;Ag\;catalyst\;and\;20wt\%\;binder)$ manufactured by applying impregnation method to the carbon black f3r reaction layer showed the better performance was obtained from experiments. From the half-cell test, the measured overpotential of this oxygen cathode was about 700mV, And through the electrolysis experiment under the condition of $80^{\circ}C,\;32wt\%$ NaOH, and $300mA/cm^2$, the electrolysis voltage of this electrode was about 2.2 V, The gas diffusion electrodes manufactured in the present research were capable of continuous operations for three months.

• Journal of Environmental Health Sciences
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• v.32 no.2 s.89
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• pp.171-178
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• 2006

The objectives of this study were to investigate the formation of trihalomethanes(THMs) and to compare the concentration level of THMs of swimming pools water by different disinfection methods such as chlorine, ozone-chlorine, and salt brine electrolysis generator (SBEG). The concentration of chloroform was the highest in the chlorine system, and the SBEG was the highest in the production of bromodichloromethane (BDCM), dibromochloromethane (DBCM) and bromoform. The average concentration of total trihalomethanes (TTHMs) in three disinfection systems were $64.5{\pm}27.4mg/l(SBEG),\;43.8{\pm}22.3mg/l(chlorine)$, and $30.6{\pm}16.1mg/l(ozone-chlorine)$, respectively. In chlorine and ozone-chlorine disinfection system, chloroform concentration was highest, followed by BDCN, then DBCM. In the SBEG, TTHMs was composed of 42% of chloroform, 28.9% of bromoform, 15.1% of BDCM and 14% of DBCM, respectively. The strongest correlation was obtained in the levels of chloroform and TTHMs in chlorine, and ozone-chlorine disinfection systems from both indoor and outdoor swimming pools ($r=0.989{\sim}0.999$, p<0.01). In the SBEG, the levels of BDCM and TTHMs showed a good correlation (r=0.913, p<0.01). In chlorine and ozone-chlorine disinfection systems at indoor swimming pools, pH, TOC and $KMnO_4$ consumption showed strong correlation with chloroform and TTHMs concentrations (p<0.01). In the SBEG, pH and TOC were also strongly correlated with chloroform (p<0.01). pH and TTHMs were correlated as well (p<0.05).

• Korean Chemical Engineering Research
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• v.49 no.6
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• pp.810-815
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• 2011

Concentrated water discharged from seawater desalination process contains a high concentration of $Na^+$ ion. Electrolysis was applied to synthesize NaOH solution from the highly concentrated NaCl solution. The effect of various operating parameters of composited laboratory-scale chlor-alkali (CA) membrane cell was investigated. The operating parameters such as membrane types (CIMS and Nafion membranes), pretreatment of the membrane, flow rate (73 mL/min~200 mL/min), initial $Na^+$ ion concentration (1.5 M, 3M and 5 M) and current (1.5A and 2A) were evaluated. It was observed that synthesis efficiency of NaOH solution with CIMS membrane was higher than that with Nafion membrane, but the durability of CIMS membrane on $Cl_2$ gas was poor. The synthesis efficiency of NaOH solution increased with increasing initial $Na^+$ ion concentration and current, while the efficiency decreased with increasing flow rate using Nafion membrane.