• Journal of Environmental Science International
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• v.25 no.8
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• pp.1155-1163
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• 2016

The treatment efficiencies of domestic sewage treatment processes were analysed and assessed to suggest and design a suitable technology for coal seam gas (CSG) water treatment. Two sewage treatment plants (S and G in Busan) were selected. The former operates with standard activated sludge and modified Ludzak Ettinger processes while the later uses the combination of $A_2/O$ and gravity fiber filtration. For both plants, the concentrations of BOD, $COD_{Mn}$, T-N and T-P were about 5.0, 19.0, 5.0, 11.0 and 1.0 ppm, respectively, which satisfy the discharge standards. Therefore, although sewage treatment processes seems to be applicable for CSG water treatment, additional processes to remove total dissolved solids and ionic compounds (i.e. bicarbonate) need to be introduced to produce fit-for-purpose water resources for beneficial use (in accordance with Water ACT 2013). This, for the CSG treatment process design, it is necessary to align the operating conditions with merging methods of combinable unit technology obtained from sewage treatment processes.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2008.11a
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• pp.510-514
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• 2008

본 연구에서는 전극의 특성에 따른 돈사유래 축산폐수의 ECO 공법에 의한 처리특성을 평가하기 위해 ECO 시스템 모듈내 Fe-Fe 및 Al-Al 계열의 용해성 전극과 Al-SUS, Ir-SUS 등 불용성 전극을 대상으로 5$\sim$20mA/cm$^2$의 전류밀도하에서 축산폐수내 유기물 및 영양염류의 제거특성을 평가하여 다음과 같은 결론을 얻을 수 있었다. 1. 전기응집산화에 의한 축산폐수의 처리시 수중 유기물질 및 영양염류의 제거효율은 전류밀도의 증가에 비례하여 증가한다. 2. 불용성 전극조합 및 불용성-용해성 전극조합은 전류밀도가 높을수록 수중 유기물 및 오염물질 제거효율이 안정되고, 용해성 전극은 15mA/cm$^2$ 이하의 저 전류밀도의 조건하에서 전류밀도의 증가에 따라 안정된 제거효율 향상을 기대할 수 있다. 3. 불용성전극 조합인 Ir-SUS 전극조합을 사용하여 축산폐수를 처리할 경우 COD$_{Mn}$ 제거효율을 약 10% 향상시킬 수 있으며, TN 20mA/cm$^2$에서 Al-Al 전극조합과 TP 15mA/cm$^2$ 이하에서 Fe-Fe 전극조합은 제거효율이 저하되는 경향이 나타난다.

• Journal of Korean Society on Water Environment
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• v.23 no.5
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• pp.756-760
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• 2007

Most of the sewage treatment plants in Korea are being operated by using the conventional activated sludge process. Recently, as the water criteria have been strict with regard to such main culprits of eutrophication, the existing sewage treatment plants are obliged to upgrade their treatment technology to meet the criteria. Under such circumstances, this study was aimed at analyzing the conditions of an existing sewage treatment plants in Korea, and thereupon, test its treatment performance for the actual sewage water by operating a pilot plant. When the pilot plant was operated with the NPR process at the capacity of $30m^3/day$, the average contents of BOD, $COD_{Mn}$, SS, T-N and T-P in the effluents were 7.0 mg/L, 9.7 mg/L, 5.1 mg/L, 8.0 mg/L and 0.23 mg/L, respectively, which were very stable in general. Accordingly, if the NPR process used for this pilot plant to upgrade the treatment technology for the sewage treatment plat could be adopted, the effluent water quality criteria effective beginning from 2008 would be met.

• Textile Coloration and Finishing
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• v.12 no.1
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• pp.25-31
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• 2000

In order to decolorize disperse dyes by using biological treatment process, a strain which has potential ability to degrade disperse dyes was isolated from natural system. To increase the removal efficiency of decolorization in the aqueous solutions, the optimal condition of decolorization by this strain was investigated, and continuous plant test was also developed. The optimal culture conditions of temperature and pH were found to be 4$0^{\circ}C$ and 8.5~9, respectively. When yeast extract was mixed with polypeptone at the mixing ratio of 1:1 as a nitrogen source, decolorization efficiency was highest(93%) among the nitrogen sources. The strain to be screened was excellent to adjust to pH, and it seems to be have ability to control pH needed to growth. The optimal culture conditions in concentration of $MgSO_4\cdot{7H}_2O$ and $KH_2PO_4$ were 0.1%(w/v) and 0.2%(w/v). The result of continuous plant process using wastewater was as following : $COD_{Mn}$ removal efficiency was over than 50%, and this strain was very excellent in decolorization-efficiency for the wastewater of Taegu dyeing complex.

• 한국해양학회지
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• v.6 no.2
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• pp.63-77
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• 1971

An year-long survey of chemical water quality for Lake Eui-am in Kang-won Province, Korea, was conducted from June 1970 to May 1971 to study the water quality and seasonal variations of productivities in relation to selected physical and chemical environmental factors. A monthly series of water samples were taken at the deepest basin of 18m depth of the lake. Water quality parameters determined were water temperature, Secchi disc reading(transparency), pH, O$\_$2/, CO$\_$2/, alkalinity, acidity, Cl, hardness, Ca, Mg, total residue, total ignitious residue, COD, BOD$\_$5/, nutrients, total-Fe, soluble Fe, Mn and Cu. On the whole, the results indicate that the chemical water quality of Lake Eui-am is high, and vary with season. The lake water is characterized that higher levels of dissolved oxygen(8.6 ml/L in mean of whole water) or percent saturation of dissolved oxygen(114%), and of nitrate nitrogen (523 $\mu\textrm{g}$/L). On the other hand, CO$\_$2/(9.6ppm), chlorides(3.5ppm), Ca(7.7ppm) Mg(2.2ppm), hardness(28.5ppm), silica(2.4ppm) and BOD$\_$5/(1.08ppm) are quite low. In terms of nutrient levels, the lake water exhibit slight signs of eutrophication. The high values for nitrate nitrogen, soluble iron and Cu of the lake water suggest that there are some imputs such as domestic and industrial discharges to the lake.

• Korean Membrane Journal
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• v.8 no.1
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• pp.50-57
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• 2006

We treated lake water by ceramic ultrafiltration membranes and found the optimal backflushing period and trans-membrane pressure (TMP) of periodic water-backflushing system. The optimal filtration time interval at fixed BT = 3 sec was 30 for A002 membrane in all viewpoints of $J/J_0,\;R_f$, and $V_T$, and we could acquire the highest $V_T$ value in the membranes used here. However, the highest $V_T$ was acquired at FT = 60 sec for M9, and at FT = 90 sec for C005 membrane. Then the lower TMP reduced the membrane fouling during filtration of lake water, and could maintain the higher permeate flux compared with the initial flux. However, the largest value $V_T$ could be obtained at the highest TMP condition for M9 membrane at fixed FT = 60 sec and BT = 3 sec. The quality of treated water in our UF ceramic system was Turbidity = $0.20{\sim}4.88NTU$, $COD_{Mn} = 0.00{\sim}2.58 mg/L$, $TDS = l8{\sim}71 mg/L$, and $NH_3-N = 0.004{\sim}1.689 mg/L$.

• Microbiology and Biotechnology Letters
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• v.27 no.2
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• pp.166-171
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• 1999

This study was conducted to investigate the removal rate of nitrogen and phosphorus, and lipid production from a swine wastewater by Botryococcus braunii UTEX 572 in an outdoor photobioreactor. B. braunii successfully predominated in competition with bacteria and other algae, especially Oscillatoria, which were grown spontaneously in a secondary-treated swine wastewater, under the conditions of incubation temperature at $25^{\circ}C$ and increased inoculum amount at 287mg/l. There was a significant relationship between dry weight of B. braunii and absorbance of culture solution at 680mn(r2=0.967), suggesting that the latter is as good as the former commonly used for the measurement of algal biomass which is considerably time-consuming. The removal rates of COD, TOC, total nitrogen, and total phosphorus from the swine wastewater were 33.2$\pm$2.6% and 32.8$\pm$3.2, respectively, which showing no different between them. These results suggested that the mass cultivation of B. braunii in an outdoor photobioreactor could be used for the advanced treatment of swine wastewater and lipid production.

• The Journal of Engineering Geology
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• v.24 no.4
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• pp.463-471
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• 2014

This paper considers the effect of rainfall on non-point source (NPS) pollutant loads. The impact of runoff on the occurrence of NPS pollutants was found to be influenced by rainfall amount, rainfall intensity, and the number of antecedent dry days (ADD), both independently and in combination. The close correlation ($R^2$ = 0.9920) between rainfall and runoff amounts was demonstrated at the study site (a flower farm) over the period between January 2011 and December 2013. The relationships among pollutant levels, runoff, and rainfall was not satisfactory results except for the Biochemical Oxygen Demand ($BOD_5$). The correlation coefficients between $BOD_5$, and both runoff and rainfall, were greater than 0.92. However, the relationships of other pollutants, such as Suspended Solid (SS), Chemical Oxygen Demand ($COD_{Mn}$), Total Nitrogen (TN), and Total Phosphorus (TP), with runoff and rainfall had correlation coefficients of less than 0.70. The roles of rainfall was different from rainfall categories on the occurrence of runoff. Instantaneous rainfall intensity was a principle factor on the occurrence of runoff following light rainfall events (total ${\leq}30mm$). For rainfall of intermediate intensity (total precipitation 31-50 mm), the combined effect of both average rainfall intensity and ADD was found to influence runoff generation. We conclude that the control of NPS pollutants with the reflection of the climate change that makes the remarkable effect of amounts and forms on the rainfall and runoff.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.4
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• pp.361-367
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• 2016

Pollutants removal and disinfection effect of secondary effluent from final settling tank of sewage treatment plant of W city were investigated in Loop Reactor using ordinary granular activated carbon(GAC) and GAC coated with silver nanoparticles. The results showed that the removal efficiency of $COD_{Mn}$, T-N and T-P using GAC with silver nanoparticles were higher than using the ordinary GAC. The removal efficiency of T-P using GAC with silver nanoparticles is 45.4% and that of T-P using ordinary GAC is 30.9% in the same case of the input amount of 20 g/L of GAC. The total califorms is reduced according to increasing input amount of GAC with silver nanoparticles and ordinary GAC. The disinfection efficiency of total coliforms in case of GAC with silver nanoparticles is much higher than that in case of ordinary GAC. For all experiments using the silver nanoparticles, the total coliforms is under 26 cfu/mL and this shows very excellent disinfection effect.

• Korean Membrane Journal
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• v.10 no.1
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• pp.33-38
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• 2008

In this study periodic water-back-flushing using permeate water was performed to minimize membrane fouling and to enhance permeate flux in tubular ceramic micro filtration system for Gongji stream water treatment in Chuncheon city. The filtration time (FT) 2 min with periodic 6 sec water-back-flushing showed the highest value of dimensionless permeate flux ($J/J_0$), and the lowest value of resistance of membrane fouling ($R_f$), and we acquired the highest total permeate volume ($V_T$) of 7.44L. Also in the results of BT effect at fixed FT 10 min, BT (back-flushing time) 20 sec showed the lowest value of $R_f$ and the highest value of $J/J_0$, and we could be obtained the highest $V_T$ of 8.04 L. Consequently FT 10 min and BT 20 sec could be the optimal condition in Gongji stream water treatment. Then the average rejection rates of pollutants by our tubular ceramic MF system were 93.8% for Turbidity, 20.7% for $COD_{Mn}$, 39.2% for $NH_3$-N and 31.5% for T-P.