• Journal of Korean Society of Water and Wastewater
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• v.19 no.3
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• pp.323-329
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• 2005

Advanced processes such as ozonation or activated carbon filtration (ACF) in water treatment plants have been used in Korea since 1994. At present, seventeen drinking water treatment plants are currently operating. This survey compares the treatment performance of advanced processes in eight plants which have comparable water quality data. The three parameters (DOC, $UV_{254}$, and $KMnO_4$ consumption) of water quality were selected as an indicator of treatment efficiency. The treatment efficiency of ozonation and ACF processes was found to vary with large deviations in each plant. Treatment efficiency of DOC, $UV_{254}$, and $KMnO_4$ consumption by post ozonation ranged from 3 to 11%, 6 to 33%, and 12 to 28% respectively. On the other hand, for ACF, treatment efficiency of DOC, $UV_{254}$, and $KMnO_4$ consumption ranged from 7 to 38%, 8 to 48%, and 16 to 66% respectively. These large deviations indicate the advanced processes of water treatment plants to be further optimized.

• Membrane and Water Treatment
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• v.3 no.3
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• pp.181-200
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• 2012

At present water crisis is not an issue of scarcity, but of access. There is a growing recognition of the need for increased access to clean water (drinkable, agricultural, industrial use). An encouraging number of innovative technologies, systems, components, processes are emerging for water-treatment, including new filtration and disinfectant technologies, and removal of organics from water. In the past decade many methods have been developed. The most important membrane-based water technologies include reverse osmosis (RO), ultrafiltration (UF), microfiltration (MF), and nanofiltration. Beside membrane based water-treatment processes, other techniques such as advanced oxidation process (AOP) have also been developed. Some unconventional water treatment technology such as magnetic treatment is also being developed.

• Journal of Environmental Science International
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• v.21 no.7
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• pp.837-843
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• 2012

The aims of this study were to investigated the occurrence of caffeine and carbamazepine in Nakdong river basin (8 mainstreams and 2 tributaries) and the behavior of caffeine and carbamazepine under drinking water treatment processes (conventional and advanced processes). The examination results showed that caffeine was detected at all sampling sites (5.4~558.5 ng/L), but carbamazepine was detected at five sampling sites (5.1~79.4 ng/L). The highest concentration level of caffeine and carbamazepine in the mainstream and tributaries in Nakdong river were Goryeong and Jinchun-cheon, respectively. These pharmaceutical products were completely removed when they were subject to conventional plus advanced processes of drinking water treatment processes. Conventional processes of coagulation, sedimentation and sand-filtration were not effective for their removal, while advanced processes of ozonation and biological activated carbon (BAC) filtration were effective. Among these pharmaceuticals, carbamazeoine was more subject to ozonation than caffeine.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.5
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• pp.511-516
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• 2008

Since 1989, Advanced drinking water treatment processes began to build in Korea, especially the water treatment plants around the Nak-dong river stream due to sequential pollutant accidents. Moreover, Advanced drinking water treatment processes, ozone and GAC, are again to be built in water treatment plants around Han-river stream to control taste and odor, micro pollutants. However, there are still a lot of discussion to decide the processes to apply for advanced treatment. Thus there are still need to understand clearly on the cost evaluation of each advanced treatment processes. The cost evaluation was accomplished based on the data of six water treatment plants which are currently being either operating or constructing. Exceptionally, PAC(Powdered Activated Carbon) process was evaluated with cost estimation from construction company. The capital cost per unit volume of ozone process was significantly decreased as the treatment capacity increased. The capital cost was in the order of GAC, ozone and GAC. The operation cost decreased in the order of PAC, GAC and ozone. The total cost considering present value shows that ozone process covers 84% of ozone and GAC process for $30,000m^3/d$ capacity while it covers less than 35% for over 140 thousands $m^3/d$ capacity. Comparing GAC only, and ozone/GAC process, ozone/GAC process is more cost effective for high capacity water treatment plant.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.4
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• pp.395-407
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• 2007

Disinfection by-products(DBPs) are formed through the reaction between chlorine and natural organic matter(NOM) in water treatment. For reducing the formation of chlorinated DBPs in the drinking water treatment, there is a need to evaluate the behavior of NOM fractions and the occurrence of DBPs for each fraction. Among the six fractions of NOM, the removal of HPOA and HPIN got accomplished through coagulation and sedimentation processes. Advanced water treatment processes were found to be most significant to remove the HPOA and HPON. It was found that HPOA made the most THMFP level than any other fractions and HPIA and HPOA formed higher HAAFP. The fraction of NOM with MW less than 1k Da was 32.5~54.3% in intake raw water. Mostly the organic matter with MW more than 1k Da was removed through coagulation and sedimentation in the drinking water treatment processes. In case of advanced water treatment processes, the organic matter with MW 1k~100k Da decreased by means of ozone oxidation for high molecular weight substances. As the result low molecular organic matter increased. In the BAC and GAC processes, the organic matter with MW less than 100k Da decreased.

• Environmental Engineering Research
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• v.21 no.4
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• pp.319-332
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• 2016

Micropollutants are often discharged to surface waters through untreated wastewater from sewage treatment plants and wastewater treatment plants. The presence of micropollutants in surface waters is a serious concern because surface water is usually provided to water treatment plants (WTP) to produce drinking water. Many micropollutants can withstand conventional WTP systems and stay in tap water. In particular, pharmaceuticals and endocrine disruptors are examples of micropollutants that are detected at the drinking water, ppb, or even ppb level. A variety of techniques and processes, especially advanced oxidation processes, have been applied to remove micropollutants from water to control drinking water contamination. This paper reviews recent researches on the occurrence and removal of micropollutants in the aquatic environments and during water treatment processes.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.4
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• pp.419-424
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• 2007

According to increase of consumer's desire for clean tap water, advanced treatment processes include with membrane, ozone, and granular activated carbon(GAC) were introduced. In order to evaluate the effect of advanced treatment processes for residual chlorine decay and trihalomethane(THM) formation in water distribution system, dissolved organic matter(DOC) removal of each advanced treatment process was investigated. The residual chlorine decay and THM formation using bottle tests were also evaluated. $UV_{254}$ removal in all advanced treatment was better than DOC removal. Especially, DOC by ozone treated was removed as 4% in contrast with sand filtered water, but $UV_{254}$ was removed about 17%. This result might be due to convert from hydrophobic DOC to hydrophilic DOC by ozonation. Ozone/GAC process was most effective process for DOC removal. The residual chlorine decay constants in treated water by sand filtration, ozonation, GAC adsorption, and ozone/GAC processes were 0.0230, 0.0307, 0.0117 and 0.0098 $hr^{-1}$, respectively. The sand filtered water was produced 81.8 ${\mu}g/L$ of THM after 190 hours of reaction time, as the treated water by ozone, GAC, and Ozone/GAC was less produced 6.0, 26.2, 30.3% in contrast with sand filtered water, respectively. Consequently, the durability of residual chlorine and reduction of THM formation were improved by advanced treatment processes.

• Proceedings of the Korea Water Resources Association Conference
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• 1996.05a
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• pp.631-647
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• 1996

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.406-415
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• 2018

Here, as-synthesized $Fe_3O_4$ nanoparticles were incorporated into the zeolitic imidazolate framework (ZIF-8) lattice to activate sodium percarbonate (SPC) for degradation of methylene blue (MB). The reaction rate constant of $Fe_3O_4@ZIF-8/SPC$ process ($0.0632min^{-1}$) at acidic conditions (pH = 3) was more than six times that of the $Fe_3O_4/SPC$ system ($0.009min^{-1}$). Decreasing the solute concentration, along with increasing SPC concentration and $Fe_3O_4@ZIF-8$ nanocomposite (NC) dosage, favored the catalytic degradation of MB. The $Fe_3O_4@ZIF-8$ NC after fifteen consecutive treatment processes showed the excellent stability with a negligible drop in the efficiency of the system (<10%). The reaction pathway was obtained via GC-MS analysis.

• Journal of Korean Society on Water Environment
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• v.25 no.2
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• pp.329-334
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• 2009

Bacterial numbers, such as endospore-formers, and treatment efficiencies were investigated for Rotating Activated Bacillus Contactors (RABC) and other advanced wastewater treatment processes including anaerobic-anoxic-oxic (A2O), sequencing batch reactor (SBR) and biological aerated filter (BAF). Endospore-forming bacterial numbers in the RABC showed 129-fold higher levels than those of the existing advanced systems. RABC process demonstrated the highest bacterial numbers in its bioreactors (paired t-test, p<0.01). RBC biofilms and aeration tanks of the RABC system showed 131- and 476-fold higher than other existing advanced processes, respectively. Mean treatment efficiencies of the existing systems were 83.5% for chemical oxygen demand (COD), 59.1% for total nitrogen (TN) and 76.8% for total phosphorus (TP). However, RABC process removed 96.9% for COD, 96.9% for TN and 91.9% for TP for highly concentrated food wastewater (COD>1,500 mg/L, TN>150 mg/L, TP>50 mg/L). Treatment efficiency was significantly reduced when the numbers of Bacillus genus in the bioreactors decreased below $10^6CFU/mL$. The automated RABC (A-RABC), in which dissolved oxygen concentrations are automatically controlled, showed higher treatment efficiencies compared to the RABC process. The RABC system maintained sufficient bacterial numbers for the effective treatment of highly concentrated food wastewater. Moreover, final effluent was in agreement to water quality standards.