• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.2
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• pp.73-78
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• 2007

The suitability of a flexible fiber filter for removing suspended solid (SS) in a recirculating aquaculture system was evaluated. This study focused on variation in the performance with a change in filtering time, influent water quality, and filtering mode duration. The particle distribution diagram of the filter effluent showed that the number of particles bigger than $5-8{\mu}m$ decreased dramatically, and the removal efficiency exceeded 80%. Although the removal efficiencies of SS and chemical oxygen demand (COD) were dependent on the quality of the influent, the SS and COD concentrations of the effluent were not affected by the influent concentrations. This was despite the deterioration if water quality after feeding in the rearing tank. The performance of the filter was not affected by the filtering mode duration, feeding conditions, or filtering time. The SS concentration and turbidity of the recirculating-type rearing tank were 30% and 50% lower, respectively, than of the a non-recirculating-type rearing tank under the same operating conditions. The flexible fiber filter was applicable to a recirculating aquaculture system that uses plenty of seawater, based on its low filtering resistance $(2kg_f/cm^2)$, high flux $(330m^3/m^2/hr)$, and high fine particle removal efficiency (80%, $5-8{\mu}m$).

• Environmental Engineering Research
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• v.19 no.4
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• pp.387-393
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• 2014

The purpose of this study is to evaluate integrated anaerobic hydrogen fermentation and membrane bioreactor (MBR) for on-site domestic wastewater treatment and resource recovery. A synthetic wastewater (COD 17,000 mg/L) was used as artificial brown water which will be discharged from urine diversion toilet and fed into a continuous stirred tank reactor (CSTR) type anaerobic reactor with inclined plate. The effluent of anaerobic reactor mixed with real household grey water (COD 700 mg/L) was further treated by MBR for reuse. An optimum condition maintained in anaerobic reactor was HRT of 8 hrs, pH 5.5, SRT of 5 days and temperature of $37^{\circ}C$. COD removal of 98% was achieved from the overall system. Total gas production rate and hydrogen content was 4.6 L/day and 52.4% respectively. COD mass balance described the COD distribution in the system via reactor byproducts and effluent COD concentration. The results of this study asserts that, anaerobic hydrogen fermentation combined with MBR is a potent system in stabilizing waste strength and clean hydrogen recovery which could be implemented for onsite domestic wastewater treatment and reuse.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.4
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• pp.439-444
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• 2013

Excessive phosphorus in aquatic systems causes algal bloom resulting in eutrophication, DO depletion, decline in recreational value of water and foul tastes. To treat wastewater containing phosphorus including effluent of wastewater treatment plant, the continuous experiments were performed by using electrochemical way. The spherical ZVI and silica sand which act as physical filter are packed at appropriate volume ratio of 1:2. Electric potential is applied externally which can be changed as per the operational requirement. The results indicate that optimum hydraulic retention time of 36 minutes (10 mL/min at 1 L reactor) was required to meet the effluent standards. Lower concentrations of phosphorus (<10 mg/L as phosphate) were removed by precipitation by contact with iron. Thus, additional electric potential was not required. In order to remove high concentration phosphorus around 150 mg/L as phosphate, external electric potential of 600 V was applied to the reactor.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.3-6
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• 2001

Various Parameters such as stream velocities, discharges, and dispersion coefficients of dissolved solutes were estimated by fitting 1-D nonreactive solute transport model to the time-series chemistry data. This study was done for the reaches of Mankyung River lower than the Jeonju Wastewater Treatment Plant (Jeonju WTP). Korea. Concentrations of inorganic chemicals in the stream waters are strongly influenced by mixing with the chemically distinct effluent from Jeonju WTP. Sulfate, EC. and the total major cation were proved to be nearly conservative in the study area front their relationships with chloride, the conservative chemical species. The solute transport model was constrained to the time-series concentrations for these 4 conservative species. The variations of concentration and discharge of Jeonju WTP were used as input parameters, and the stream velocities, dispersion coefficients, and concentrations and discharges of some inflows were optimized. The differences between the observed arid simulated values for alkalinities and nitrates are inversely correlated and show diurnal fluctuations, indicating the photosynthesis. The parameters obtained front this mode] range from 550 to 774 kcmd (stream discharge at the outlet of the study area), from 0.06 to 0.10 m/sec (flow velocity), and from 0.7 to 6.4 m$^2$/sec (dispersion coefficient). The history of Jeonju WTP discharge was well predicted when optimized, indicating the validity of the model results.

• The Korean Journal of Ecology
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• v.25 no.1
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• pp.63-70
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• 2002

This study examined the changes of water quality in relation to distribution of hydrophytes, and the purification capacity of Zizania latifolia to improve the effluent from Munpyeong stream from March 1997 to December 1999. While the concentration of nitrogen and phosphorous in water were increased during the farming season, those decreased, during the streaming down to paddy and drainage areas. In investigated sites, the Z. latifolia was dominant community according to the development of the natural wetlands. Furthermore, it formed a large community owing to its high adaptability to environmental changes in the agriculture lands. In September, the leaves productivity of the Z. latifolia were 4,032g D.W/$m^2$and roots were 7,680gD.W/$m^2$. The purification capacity of the Z. latifolia for NH$_3$-N, $No_3$-N, and PO$_4$-P were 13.41, 17.07, and 4.58 respectively during 5 days. The results suggested that it needs to establish wetlands vegetated by hydrophytes to improve the water quality of the effluent from agricultural lands.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.520-523
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• 2000

Phenol and other phenolic compounds are common constituents of aqueous effluents from processes such as polymeric resin production, oil refining and cokeing plants. Phenol is a both toxic and lethal of fish at relatively low concentrations e.g. 5-25 mg/L and imparts objectionable tastes to drinking water at far lower concentration. Therefore, the treatment of phenol effluent is important. Among the various techniques of phenol wastewater treatment, microbial teratment is a popular process. The breakdown of phenols by microorganisms has recived considerable attention, because of its biochemical interest and its industrial importance in effluent treatment. This research was performed to investigate the dynamics of microbial community, biofilm growth and the comparison of phenol removal efficiency by RBC (Rotating Biological Contactor) using Rhodococcus sp. EL-GT The experiment was carried out at rotating speed of 10ppm and hydraulic retention time of 7 hours. As time passed, phenol removal efficiency was gained highly. The RBC using Rhodococcus sp. EL-GT completely degraded 15 mM.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.3
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• pp.335-341
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• 2016

Various studies have forwarded an outstanding wastewater effluent treatment systems toward securing sustainable supply of water sources. In this paper, a broad overview of the performance of MF membrane as pretreatment option for wastewater reuse will be presented based on the literature survey and experiments conducted over the wastewater reuse pilot plant. The pilot plant was operated with a continuous data acquisition for about 300days under various chemical enhanced backwash (CEB) system with subsequent treated water quality analysis. Accordingly, assessment of the effluent revealed that the pretreated water is suitable enough to be used as an input for Reverse Osmosis (RO) unit and significant effect of CEB and concentration of NaOCl is also conceived from the analysis. Moreover, it's also observed that the application of various CEB condition over long operational hours induced a constant declination of overall performance of MF membrane.

• Journal of Korean Society on Water Environment
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• v.21 no.2
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• pp.196-204
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• 2005

The objective of this study is to evaluate the possibility to apply pre-ozone and membrane system for drinking water. This system is improved in fouling control by pre-ozone system. It is composed of ultrafiltration hollow fiber type membrane and ozone reactor. The result of this study is that the flux is increased about 10.7% and decreased in TMP by the pre-ozone. Also, backwashing pressure decreased about 18%. The optimum concentration of residual ozone is 0.3~0.5 ppm. During the period, the recovery ratio of this system was turned out to be 90% as the flowrate of effluent is $67.1m^3/day$. When the TMP and backwashing pressure was $0.85kg/cm^2$ and $1.10kg/cm^2$, this system was stable without sudden fouling. Finally, the quality of effluent is satisfied the guidelines for potable water quality such as turbidity, color, E.coli, Mn, Al, Fe and so on.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.4
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• pp.431-438
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• 2009

The purpose of this study was to evaluate the performances of zero-valent iron (ZVI) combined SBR (Z-SBR) process in decolorization and organic removal of synthetic dye wastewater. The batch test for optimizing the operation parameters of ZVI column showed that the appropriate EBCT was around 11 min and the pH of the dye wastewater was below 7.0. During the step increase of influent color unit from 300 to 1,000cu, about 53 to 79% decolorization efficiency could be achieved in control SBR (C-SBR, without ZVI column), which resulted from destroying azo bond of synthetic dye in anaerobic condition. For the same influent color loading, Z-SBR showed always higher decolorization efficiency than C-SBR with an aid of ZVI reducing power. The TCOD concentration in Z-SBR effluent was 20-30mg/L lower than C-SBR effluent although the TCOD before and after ZVI column was nearly same. It means that breakdown of azo bond by ZVI reducing power could increase biodegradability of synthetic dye wastewater.

• Journal of Korean Society on Water Environment
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• v.22 no.1
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• pp.59-65
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• 2006

The effluent limitations for individual industry based on the best available technology economically achievable (BAT) have been required to achieve effective regulation. BAT assessment criteria that are suitable for the circumstances of Korean industry were developed in the previous study. The criteria were applied to determine the BAT for petrochemical basic compound manufacturing (PBCM) and plastics and synthetic resins manufacturing (PSRM) industry. Wastewater discharged from the each category contains high concentration of COD and toluene. Eighteen sites were surveyed and wastewater qualities were analyzed. Six and two different technologies were applied to the PBCM and PSRM industry for the end-of-pipe treatment process, respectively. The technology candidates were evaluated in terms of environmental impacts, economically achievability, treatment performance and economical reasonability. As the result, the technology options: typical activated-sludge process + sand filtration + activated carbon adsorption (PBCM) and wet oxidation + chemical precipitation + typical activated-sludge process + chemical precipitation (PSRM) were selected as the BAT for each industry.