• Journal of Environmental Health Sciences
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• v.40 no.4
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• pp.322-329
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• 2014

Objectives: The purpose of this study was to investigate the effect of BIO-CLOD on advanced wastewater treatment for enhanced removal efficiency and meeting the stringent discharge water requirements of wastewater treatment plants. Methods: Two experimental apparatuses consisting of anaerobic, anoxic and aeration tanks were operated. One included a BIO-CLOD cultivation tank. Organic and nutrient parameters and removal efficiency were analyzed by pH, BOD, CODcr, SS, T-N and T-P. Results: The average removal efficiencies of BOD, COD and SS from the apparatus with BIO-CLOD tank installation were 95.5%, 88.6% and 92.9%, respectively, and these were higher than the results from the apparatus without BIO-CLOD. The average TP removal efficiency with BIO-CLOD tank marked 56.0%, higher than the 47.3% from the apparatus without one. BIO-CLOD showed a higher performance for TN removal at 49.6%, compared to the result without BIO-CLOD of 34.3% Conclusion: By reaction with BIO-CLOD, ammonia removal was effective in the aeration tank, as was phosphorus release in the anaerobic tank. Phosphorus luxury uptake and nitrification in aeration tank proceeded smoothly. The application of BIO-CLOD can improve the decrease of odor and settleability of activated sludge in a wastewater treatment plant, as well as increase the removal efficiency of organic and nutrient materials in water.

• Membrane Journal
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• v.18 no.4
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• pp.325-335
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• 2008

In this study, we used multi-channels ceramic membrane having larger permeate volume per unit time rather than tubular membrane. The hybrid process for advanced drinking water treatment was composed of granular activated carbons (GAC) packing between module inside and outside of multi-channels microfiltration membrane. Instead of natural organic matters (NOM) and fine inorganic particles in natural water source, modified solution was prepared with humic acid and kaolin. Kaolin concentration was fixed at 30mg/L and humic acid was changed as $2{\sim}10\;mg/L$ to inspect effect of organic matters. As a result, both resistance of membrane fouling ($R_f$) and permeate flux (J) were highly influenced by concentration of humic acid. Also, in result of water-back-flushing period (FT) effect, the shorter FT was the more effective to reduce membrane fouling and to enhance permeate flux because of frequent water-back-flushing. However, the optimal FT condition was 8 min when operating costs were considered. Then, the hybrid process using multi-channels ceramic membrane and GAC was applied to lake water treatment. As a result, average treatment efficiencies in our experiment using the hybrid process were 98.02% for turbidity, 75.64% for $UV_{254}$ absorbance, 7.18% for TDS and 84.73% for $COD_{Mn}$.

• Journal of environmental and Sanitary engineering
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• v.22 no.4
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• pp.119-130
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• 2007

Sea food wastewater including high concentration of organics and nutrients is hard to treat stably by established traditional activated sludge process. This research is aimed to obey more and more of strengthened the law and to secure stable effluents by using advanced treatment process applied membrane filter in aeration tank for treatment of wastewater from marine products. It must maintain pH of influent over 6.0 to keep up stably biological sludge of advanced treatment process. At 38hr of HRT, removal rates of TBOD and TCOD were 99.9% and 99.4% respectively and TSS also removed with high efficiency. Most organics in the effluent was constituted with soluble type materials, it caused that membrane filter installed aeration tank should remove minute suspended particles. The reactor was operated well to get stable treatment results for operation period, in spite of high loading of organics like that $0.67{\sim}1.67\;kgTBOD/m^3/day$ of organics loading and $0.10{\sim}0.21\;kgBOD_5/kgMLSS/day$ of F/M ratio. At $36{\sim}48hr$ of HRT, removal rates of T-N and T-P were $89.7{\sim}90.7%\;and\;91.5{\sim}96.0%$ respectively. It means this treatment process also work to remove nutrients of high concentration. Upon investigation of advanced treatment's operation factors, optimum SRT was about 30days and average SNR that showed tendency to increase according to increase water temperature was calculated 0.014 gN/g MLVSS/d. SDNR was risen in conformity to increase F/M ratio of Non-aeration tank and investigated as $0.038{\sim}0.051\;gN/gMLVSS/d$.

• Journal of Environmental Science International
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• v.10 no.6
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• pp.393-399
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• 2001

This study was carried out to evaluate the pollutant removal efficiencies of the advanced drinking water treatment using ozonation. for raw water, Nakdong River was used. By conducting batch ozonation test, the following results were obtained. when ozone dosage of 5mg/$\ell$was used, preozonation of raw water reduced turbidity, KMnO$_4$consumption, DOC(dissolved organic carbon), UV254 absorbance, THMFP(trihalomethane formation potential) as much as 3.9NTU, 5.5mg/$\ell$, 1.15mg/$\ell$, 0.112 and 0.065mg/$\ell$, respectively. In case of postozonation of sand filtered water, water quality was also improved with decrease in turbidity, KMnO$_4$consumption, DOC, UV254 absorbance and THMFP at the amount of 0.08NTU, 2.6mg/$\ell$, 0.88mg/$\ell$, 0.042 and 0.018mg/$\ell$, respectively. On the other hand, contents of dissolved oxygen increased at the level of 1.3mg/$\ell$ after preozonation process and 1.0mg/$\ell$ after postozonation process. The effect of ozone dosage was higher than that of its contact time for the removal of the pollutants.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.6
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• pp.529-537
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• 2017

Membrane filtration process is an advanced water treatment technology that has excellently removes turbidity and microorganisms. However, it is known that it has problems such as low economic efficiency and the operating stability. Therefore, this study was to evaluate on the economical feasibility and operational stability comparison of membrane and sand filtration process in Im-sil drinking water treatment plant. For the economic analysis of each process, the electricity cost and chemical consumption were compared. In the case of electric power consumption, electricity cost is $68.67KRW/m^3$ for sand filtration and $79.98KRW/m^3$ for membrane filtration, respectively. Therefore, membrane filtration process was about 16% higher than sand filtration process of electricity cost. While, the coagulant usage in the membrane filtration process was 43% lower than the sand filtration process. Thus, comparing the operation costs of the two processes, there is no significant difference in the operating cost of the membrane filtration process and the sand filtration process as $85.94KRW/m^3$ and $79.71KRW/m^3$ respectively (the sum of electricity and chemical cost). As a result of operating the membrane filtration process for 3 years including the winter season and the high turbidity period, the filtrated water turbidity was stable to less than 0.025 NTU irrespective of changes in the turbidity of raw water. And the CIP(Clean In Place) cycle turned out to be more than 1 year. Based on the results of this study, the membrane filtration process showed high performance of water quality, and it was also determined to have the economics and operation stability.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.2
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• pp.155-163
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• 2015

Many advanced treatment processes have been introduced to WTPs, however, the consumer confidence on tap water is still low and the percentage of drinking water directly from the tap is less than 2 %. One of the methods to improve the credibility of tap water is to introduce a drinking water certification system. By introducing the system, water treatment processes can be optimized, which in turn, can significantly improve drinking water quality. In this paper, 6 water quality parameters(i.e., turbidity, CT, residual chlorine, geosmin, 2-MIB, Mn) which have significant influences on tap water quality and consumer confidence were identified, and their recommended guidelines were proposed. 3-Star or 5-Star certification can be awarded to the WTPs which have met the certification criteria. The drinking water certification system can be carried out as a voluntary program among drinking water suppliers.

• Journal of Advanced Marine Engineering and Technology
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• v.15 no.3
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• pp.57-65
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• 1991

The quenching of steels by water is one of the important problems in engineering for the applications of heat treatment or continuous casting process, but the fundamental researches by the theoretical approaches have not been satisfactorily improved yet. The very rapid cooling problems by the thermal conduction including the latent heat of phase transformation in steel and the transient boiling heat transfer of water on the surface of the steel covering from $850^{\circ}C$ to $20^{\circ}C$ are the key problems of heat treatment. The present quenching experiments are performed for the cylindrical specimens of carbon steel, S45C of diameters (12-30). Nonlinear transient heat conduction and transient boiling heat transfer problem of water on the surface of specimens is analyzed by the numerical method of inverse heat conduction problem. The conditions for the calculation are that the initial temperature of specimens is $820^{\circ}C$ and the cooling water in bath are $20^{\circ}C$,$40^{\circ}C$,$60^{\circ}C$,$80^{\circ}C$,$95^{\circ}C$ with no agitation.

• Journal of Environmental Science International
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• v.25 no.9
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• pp.1233-1239
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• 2016

This study aimed to evaluate changes in the TN and TP removal efficiencies, depending on whether or not a settling process is applied, in a sequencing batch reactor (SBR) process with a membrane bioreactor (MBR). Nutrient removal was considered in terms of developing an advanced water treatment system for ships in accordance with water quality standards set forth by 227(64). For these purposes, the TN and TP concentrations in the inflow and outflow water were measured to calculate the TN and TP removal efficiencies, depending on whether or not a settling process was used. Water discharged from a bathroom, which was constructed for the experiment, was used as the raw water. The experiment that included a settling process was conducted twice, and the operating conditions were: aeration for 90 min, settling for 30 min, agitation for 15 min, and settling for 15 min for one experiment; and aeration for 150 min, settling for 45 min, agitation for 15 min, and settling for 15 min in the other. Operating conditions for the experiment that did not include a settling process were: aeration for 180 min and agitation for 60 min. The concentration of the mixed liquor suspended solids (MLSS) in the reactor was 3,500 mg/L, while the aeration rate was 121 L/min and the water production rate was 1.5 L/min. For the two experiments where a settling process was applied, the average TN removal efficiencies were 44.39% and 41.05%, and the average TP removal efficiencies were 47.85% and 46.04%. For the experiment in which a settling process was not applied, the average TN removal efficiency was 65.51%, and the average TP removal efficiency was 52.51%. Although the final nutrient levels did not satisfy the water quality standards of MEPC 227(64), the TN and TP removal efficiencies were higher when a settling process was not applied.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.6
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• pp.861-867
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• 2011

Wastewater from crude oil reserve base usually contains large amount of non-biodegradable contaminants. The conventional wastewater treatment progress can hardly meet the regulation of wastewater effluent quality. This study investigated the removal of non-biodegradable organic contaminants in wastewater from crude oil reserve base using a pulse UV treatment. The modified process incorporating pulse UV process was set up to treat the wastewater from crude oil reserve base. The treatment process is composed with coagulation and flocculation, micro-bubble flotation, sand filter, pulse UV system, and GAC filter. The results show CODMn was effectively removed by the process with pulse UV system and it can meet the wastewater effluent regulation. The single effect of pulse UV process in CODMn removal was not significant(9~15% based on sand filtered effluent), however with the subsequent activated carbon filter the removal ratio CODMn was increased up to 28% compared to the process without pulse UV syetem.

• Journal of Environmental Science International
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• v.11 no.12
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• pp.1267-1274
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• 2002

This study was carried out to evaluate the pollutant removal efficiencies of the advanced drinking water treatment using ozonation process. For raw water, Nakdong River was used. By conducting batch test of ozonation, the following results were obtained. When ozone dosage of $5 mg/{\ell}$ was used, ozone transfer and utilization efficiencies of the ozonation were 94 to 92%, respectively. Removal efficiencies of single VOC compound or mixed VOC compounds in the raw water were 80% to 90% by the ozonation with $2 mg/{\ell}$ dosage and 10 minutes contact time. Removal efficiencies of ABS by the ozonation with $1 mg/{\ell}$, $3 mg/{\ell}$ dosage and 20 minutes contact time were 83% to 96%, respectively. Almost 67% of chlorophyll-a at the concentration of $38.4\mu\textrm{g}/{\ell}$ was removed by ozonation at ozone dosage of $1 mg/{\ell}$ for 20 min. Considering the efficiency of ozone utilization and water treatment, the most effective ozonation could be obtained with high ozone dosage and short contact time.