• Journal of Korean Society of Water and Wastewater
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• v.38 no.1
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• pp.1-15
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• 2024

Occurrence of process environment changes, such as influent load variances and process condition changes, can reduce treatment efficiency, increasing effluent water quality. In order to prevent exceeding effluent standards, it is necessary to manage effluent water quality based on process operation data including influent and process condition before exceeding occur. Accordingly, the development of the effluent water quality prediction system and the application of technology to wastewater treatment processes are getting attention. Therefore, in this study, through the multi-channel measuring instruments in the bio-reactor and smart multi-item water quality sensors (location in bio-reactor influent/effluent) were installed in The Seonam water recycling center #2 treatment plant series 3, it was collected water quality data centering around COD, T-N. Using the collected data, the artificial intelligence-based effluent quality prediction model was developed, and relative errors were compared with effluent TMS measurement data. Through relative error comparison, the applicability of the artificial intelligence-based effluent water quality prediction model in wastewater treatment process was reviewed.

• Rapid Communication in Photoscience
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• v.2 no.2
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• pp.42-45
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• 2013

Natural photosynthesis utilizes solar energy to convert carbon dioxide and water to energy-rich carbohydrates. Substantial use of sunlight to meet world energy demands requires energy storage in useful fuels via chemical bonds because sunlight is intermittent. Artificial photosynthesis research focuses the fundamental natural process to design solar energy conversion systems. Nicotinamide adenine dinucleotide ($NAD^+$) and $NADP^+$ are ubiquitous as electron transporters in biological systems. Enzymatic, chemical, and electrochemical methods have been reported for NADH regeneration. As photochemical systems, visible light-driven catalytic activity of NADH regeneration was carried out using platinum nanoparticles, molecular rhodium and cobalt complexes in the presence of triethanolamine as a sacrificial electron donor. Pt nanoparticles showed photochemical NADH regeneration activity without additional visible light collector molecules, demonstrating that both photoactivating and catalytic activities exist together in Pt nanoparticles. The NADH regeneration of the Pt nanoparticle system was not interfered with the reduction of $O_2$. Molecular cobalt complexes containing dimethylglyoxime ligands also transfer their hydrides to $NAD^+$ with photoactivation of eosin Y in the presence of TEOA. In this photocatalytic reaction, the $NAD^+$ reduction process competed with a proton reduction.

• Journal of Environmental Science International
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• v.12 no.8
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• pp.841-846
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• 2003

The ecosystem model was applied to estimate the regional distribution of the net production(or consumption) of phytoplankton and the net uptake(or regeneration) rate of nutrients in Masan Bay for scenario analysis to find a proper management plan. At the surface level, net production of phytoplankton is 200 mgC/㎡/day at the entrance of the bay, and 400∼1000 mgC/㎡/day at the center of the bay. The inner area of the bay showed more than 2000 mgC/㎡/day. All areas of the bottom level have a net consumption, with the center of the bottom level showing more than 600 mgC/㎡/day. For dissolved inorganic nitrogen, the results showed a net uptake rate of 100∼900 mg/㎡/day at the surface level. It showed that the net regeneration is above 50 mg/㎡/day at the bottom level. For dissolved inorganic phosphorus, the net uptake rate showed 10.0∼80.0 mg/㎡/day at the surface level, and the regeneration rate showed 0∼20.5 mg/㎡/day at the bottom level. Therefore, in order to control the water quality in Masan Bay, it is important to consider the re-supplement of nutrients regenerated in the water column.

• Journal of Wellbeing Management and Applied Psychology
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• v.4 no.2
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• pp.19-25
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• 2021

Purpose: The purpose of this study is to reduce odor complaints by identifying problems with odor management at the site of the water regeneration center and researching odor management methods. Due to the high population density of Korea, sewage treatment facilities are adjacent to residential and industrial areas. According to previous studies, the main malodor-emitting facilities of sewage treatment facilities were preliminary treatment facilities (2,220 times), sedimentation basins (4,628 times), and sludge treatment facilities (9,616 times). Research design, data and methodology: Compound malodors and designated malodor-producing substances were collected from five site boundaries of the water regeneration center and analyzed according to the official methods to test malodor, and a total of two times (August and September 2020) were conducted. Results: As a result of the measurement, in the green area in front of the center office, compound malodors were detected at a maximum of 8 times and at least 3 times during the dawn time. As for the designated malodor-producing substances, 0.1ppm of ammonia was detected in the green area in front of the center office and the park golf course. This is within 15 times the maximum allowable emission level of compound malodors and within 1ppm of the maximum allowable emission level of ammonia. Conclusions: Even if the dilution rate of the compound malodors did not exceed the maximum allowable emission level, the odor could be recognized, and more research is needed in the future to establish effective reduction measures according to the subjective and individual and seasonal odor characteristics.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.2
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• pp.39-44
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• 2023

This study was conducted to analyze problems related to non-water-soluble sanitary products during the treatment of water regeneration centers in E.T.F. and S.T.F. at a time when the demand and supply of non-water-soluble sanitary products are increasing. As a result, the improvement plan of the W.R.C. should focus on pretreatment facilities. When replacing facilities in the future, various dust removers suitable for the facility's reality will be installed in the pretreatment of S.T.F., and it is proposed to link a bar-racks screen with a comprehensive treatment device or install a comprehensive treatment device for impurities alone in the pretreatment of E.T.F.. In addition, a microscreen screen must be installed on the front end of the excretory treatment unit. to separate non-water-soluble materials, and it is necessary to secure a maintenance space for the excretory treatment unit.

• Journal of Korean Society of Water and Wastewater
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• v.34 no.5
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• pp.323-334
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• 2020

Adsorption by granule activated carbon(GAC) is recognized as an efficient method for the removal of perfluorinated compounds(PFCs) in water, while the poor regeneration and exchange cycles of granule active carbon make it difficult to sustain adsorption capacity for PFCs. In this study, the behavior of PFCs in the effluent of wastewater treatment plant (S), the raw water and the effluents of drinking water treatment plants (M1 and M2) located in Nakdong river waegwan watershed was monitored. Optimal regeneration and exchange cycles was also investigated in drinking water treatment plants and lab-scale adsorption tower for stable PFCs removal. The mean effluent concentration of PFCs was 0.044 0.04 PFHxS g/L, 0.000 0.00 PFOS g/L, 0.037 0.011 PFOA g/L, for S wastewater treatment plant, 0.023 0.073 PFHxS g/L, 0.000 0.00 PFOS g/L, 0.013 0.008 PFOA g/L for M1 drinking water treatment plant and 0.023 0.073 PFHxS g/L, 0.000 0.01 PFOS g/L, 0.011 0.009 PFOA g/L for M2 drinking water treatment plant. The adsorption breakthrough behaviors of PFCs in GAC of drinking water treatment plant and lab-scale adsorption tower indicated that reactivating carbon 3 times per year suggested to achieve and maintain good removal of PFASs. Considering the results of mass balance, the adsorption amount of PFCs was improved by using GAC with high-specific surface area (2,500㎡/g), so that the regeneration cycle might be increased from 4 months to 10 months even if powdered activated carbon(PAC) could be alternatives. This study provides useful insights into the removal of PFCs in drinking water treatment plant.

• Journal of Radiation Protection and Research
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• v.22 no.3
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• pp.195-205
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• 1997

This paper is to assess the effect of Adaptagen as a radioprotector in which main component is alkaloid fraction of ginseng. Evaluation was made in vitro and in vivo study with NIGP(S) mouse by the measurement of regeneration of jejunal crypt cell and micronucleus assay to analyze radioprotective effect of ginseng alkaloid fraction in comparison with that of water fraction after whole body irradiation. The results were as follows, 1. The degree of radiation damage of mouse jejunal crypt cell was diminished in both of alkaloid and water fraction groups compared to control group but more in alkaloid fraction group than water fraction group. Regeneration of mouse jejunal crypt cell was higher both in alkaloid and water fraction groups than control group. 3. In vitro study, frequency of micronucleus was diminished in tendency for the treated groups than control group but statistically insignificant. 4. In vitro study, frequency of micronucleus was diminished in both alkaloid and water fraction groups compared to control group but more in alkaloid fraction group than water fraction group.

• Korean Chemical Engineering Research
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• v.48 no.2
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• pp.253-258
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• 2010

In the field of the $CO_2$ absorption process using aqueous ammonia, the effects of regeneration pressure and temperature on $CO_2$ absorption performances of the aqueous ammonia were investigated. The absorbents were prepared by dissolving ammonium carbonate solid in water to grant the resulted solution 0.5 $CO_2$ loading ($mol\;CO_2/mol\;NH_3$) and various ammonia concentration (14, 20, 26 and 32 wt%). As-prepared absorbents were regenerated at high pressure and temperature (over $120^{\circ}C$ and 6 bar) before the absorption test. The absorption test was carried out by injecting the simulated gas that contains 12 vol% of $CO_2$ into a bubbling reactor. The introduction of 26 wt% of the ammonia concentration for $CO_2$ absorption test resulted in the higher absorption capacities than other experimental conditions. In particular, when the absorbents with 26 wt% of the ammonia were regenerated at $150^{\circ}C$ and 14 bar, the highest absorption capacity, $45ml\;CO_2/g$, was obtained. According to the analysis of absorbents using acid-base titration, the ammonia loss during the regeneration of the absorbents with a fixed ammonia concentration decreased as the regeneration pressure increased, while it increased as the regeneration temperature increased. In the condition of fixed regeneration pressure and temperature, as expected, the ammonia loss increased as the ammonia concentration increased. The measured $CO_2$ loadings and ammonia concentrations of absorbents were compared to the values calculated by Electrolyte NRTL model in Aspen Plus.

• KIEAE Journal
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• v.10 no.5
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• pp.13-22
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• 2010

The old city centers of local metropolitans have lost their functions as CBD in korea. Those old city centers have an only role as a gate connected to the new CBD. This study aims to present regeneration stratigies of old city centers through Osaka case study. This research has been focused on the physical and environmental factors in urban regeneration. There are 4 strategies for old city centers. First, the strategy to attract people to the old city centers is high-density and mixed-use development having functions like shopping, entertainment, residence. This kind of development makes local metropolitan cities compact cities to protect urban sprawl. Second, strategy to give old city centers an identity is to conserve traditional culture and structures and to revitalize retail market. Third is to make pedestrian-friendly street system. Osaka ism't pedestrian friendly but remodelling the connect the pedestrian path to the culture facilities. Fourth is to have water and green environment. Green space is the strong factor that pull people to old city centers.

• Plant Biotechnology Reports
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• v.2 no.1
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• pp.87-92
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• 2008

An improved protocol for high frequency plant regeneration via somatic embryogenesis from zygotic embryo-derived cell suspension cultures of watershield (Brasenia schreberi) was developed. Zygotic embryos formed pale-yellow globular structures and white friable callus at a frequency of 80% when cultured on halfstrength MS medium supplemented with $0.3mg\;l^{-1}$ 2,4-D. However, the frequency of formation of pale-yellow globular structures and white friable callus decreased slightly with increasing concentrations of 2,4-D up to $3mg\;l^{-1}$, where the frequency reached ~50% of the control. Cell suspension cultures from zygotic embryoderived white friable callus were established using half-strength MS medium supplemented with $0.3mg\;l^{-1}$ 2,4-D. Upon plating of cell aggregates on half-strength MS basal medium, approximately 8.3% gave rise to somatic embryos and developed into plantlets. However, the frequency of plantlet development from cell aggregates was sharply increased (by up to 55%) when activated charcoal and zeatin were applied. Regenerated plantlets were successfully transplanted to potting soil and grown to normal plants in a growth chamber. The distinctive feature of this study is the establishment of a high frequency plant regeneration system via somatic embryogenesis from zygotic embryo-derived cell suspension cultures of water-shield, which has not been previously reported. The protocol for plant regeneration of watershield through somatic embryogenesis could be useful for the mass propagation and transformation of selected elite lines.