• Membrane and Water Treatment
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• v.5 no.1
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• pp.15-29
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• 2014

Reverse Osmosis (RO) desalination has gained wide and increasing acceptance around the world as a straightforward undertaking to alleviate the alarming water crisis. An enhanced monitoring of the quality of the water feeding in seawater RO (SWRO) plant through the application of an effective pretreatment option is one of the keys to the success of RO technology in desalination plants. Over the past 10 years, advances in ultrafiltration (UF) membrane technologies in application for water and wastewater treatment have prompted an impetus for using membrane pretreatment in seawater desalination plants. By integrating SWRO plant with UF pretreatment, the rate of membrane fouling can be significantly reduced and thus extend the life of RO membrane. With the growing importance and significant advances attained in UF pretreatment, this review presents an overview of UF pretreatment in SWRO plants. The advantages offered by UF as an alternative of pretreatment option are compared to the existing conventionally used technologies. The current progress made in the integration of SWRO with UF pretreatment is also highlighted. Finally, the recent advances pursued in UF technology is reviewed in order to provide an insight and hence path the way for the future development of this technology.

• Membrane and Water Treatment
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• v.11 no.4
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• pp.313-321
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• 2020

ACF preparation from different materials and its application in constructed wetlands for wastewater treatment has been focused in environmental field. Different materials have been used to prepare ACF around the world. This study aims to prepare, characterize and use of ACF from loofah for removal of Tetracycline from water through composite vertical flow constructed wetlands. ACF was prepared and it was tested for characterization, later it was used for removal of Tetracycline from water through composite vertical flow constructed wetlands. In composite vertical flow constructed wetlands, three HRTs were set according to the experiment, 1D, 2D, and 3D is individually. Samples were transported immediately from collection point to laboratory for analyzing. Samples were measured for Tetracycline (TC), Total Phosphorus (TP), and Total nitrogen and COD. Tetracycline absorbance with respective 356nm was obtained good and HRT is important factor. Results show that composite vertical flow constructed wetlands with ACF from luffa is best option and it is recommended to study further deep analysis.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.5
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• pp.65-77
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• 2014

The ecosystem of Jaemin stream, flowing into the center of Gongju-si, had been damaged by low water quality and lack of water quantity of the steam. However, after applying the SSB (Sustainable Structured wetland Biotop) system to the flood plain and the upstream of Jaemin stream, the efficiency of ecological water purification and ecological restoration are as follows. Through the constant maintenance and monitoring from year 2009 to year 2013 after restorative design and construction the average influent concentration of BOD5 was 4.2 mg/L, and the average effluent concentration was 1.8 mg/L, reaching ecological water purification rate of 57%. As for the T-N, the average influent concentration was 9.983 mg/L, and the average effluent concentration was 6.303 mg/L, showing the rate of 37%. For the T-P, the average influent concentration was 0.198 mg/L, and the average effluent concentration was 0.098 mg/L, being the rate of 51%. The vegetation of Jaemin stream monitored for 2 years after the restoration was composed of 51 species in 28 families which show high ratio of planted native species. As for the animals in the site, 5 species in 3 families of reptiles and amphibians, 34 species of 23 families of birds, and 3 species in 2 families of mammals were monitored, indicating that the bio-diversity of the site has improved, as well.

• Journal of Korean Society of Water Science and Technology
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• v.26 no.6
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• pp.3-12
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• 2018

The objective of this study was to evaluate the radius of influence of effluent of water treatment system developed for the purpose of improvement of reservoir water quality using fluorescent dye (Rhodamine-WT) tracer experiment and 3-D numerical model. The tracer experiment was carried out in a medium-sized agricultural reservoir with a storage capacity of $227,000m^3$ and an average depth of 1.6 m. A guideline with a total length of 160 m was installed at intervals of 10 m in the horizontal direction from the discharge part, and a Rhodamine measurement sensor (YSI 6130, measurement range $0-200{\mu}g/L$) was used to measure concentration changes in time, distance, and depth. Experimental design was established in advance through Jet theory and the diffusion process was simulated using ELCOM, a three dimensional hydraulic dynamics model. As a result of the study, the direct effect radius of the jet emitted from the applied water treatment system was about 50-70 m, and the radius of physical effect by the advection diffusion was judged to be 100-120 m. The numerical simulations of effluent advection-diffusion of the water treatment system using ELCOM showed very similar results to those of the impact radius analysis using the tracer experiment and jet flow empirical equations. The results provide valuable information on the spatial extent of the water quality improvement devices installed in the reservoir and the facility layout design.

• Journal of the Korean Wood Science and Technology
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• v.22 no.4
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• pp.13-18
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• 1994

Sapwood samples of pitch pine were treated with disodium octaborate alone by dip-diffusion, or in combination with water-repellent preservative(WRP) and methyl metacrylate(MMA). Treated samples were subjected to an accelerated leaching test for determining the improvement of leaching resistance and to soft rot and mold tests for evaluating the increase in bioefficacy, due to the addition of WRP and MMA applied as a second treatment. The addition of WRP and MMA retarded leaching of boron to some extent from treated samples and this retardation can be explained by improved water repellency of WRP and MMA treated samples. Borate /WRP and borate /MMA systems will not qualify borate treated wood for ground and fresh water contact use but may improve performance of borate treated wood in above-ground applications not subjected to continuous wetting conditions. Bioefficacy against soft rot fungi and mold fungi was improved by a second treatment with WRP. However, improvement in the performance of borate /MMA systems was not observed. Considering improvement in both resistance of leaching and bioefficacy against micro fungi by the treatment of WRP and MMA, simultaneously, the dual treatment of borate treated wood by MMA containing co-biocides might be believed as an ideal treatment system.

• Journal of Wetlands Research
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• v.22 no.4
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• pp.321-327
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• 2020

Recently The amount of wastewater and linked wastewater is being increased every year due to industrial development, population growth, and improvement in living standards. Linked wastewater shows the feature-low flow rate and high concentration. Therefore, it has been shown that it has a great impact on the operation of the sewage treatment plant and costs a lot for treating linked wastewater. In this study, a scenario with low increase of water quality when the total amount of the inflow of linked wastewater was entered into individual reactors is obtained. According to the result of modeling, The effluent water quality get the least increment once the water was introduced into the influent and anoxic tank. We generated the various scenarios Based on these results. scenarios are varying according to inflow from linked waste water's distribution ration. As a result of modeling through various scenarios, it was found that the increment of TN and TP were at the least when the inflow of linked water was distributed with ratio between sewage (80%) and oxygen-free tank (20%).

• Journal of Korean Society of Environmental Engineers
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• v.28 no.11
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• pp.1162-1167
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• 2006

The discharge of ballast water from the marine vessel without proper treatment causes the ecological disruption. Therefore, International Marine Organization(IMO) has the plan to force the proper treatment of ballast water before its discharge to open sea. To satisfy the IMO's criteria, several processes such as filtration, UV irradiation, and ozonation etc., were introduced. Since the disinfection of ballast water should be conducted within very short hydrolic retention time, electrochemical treatment can be a promissing process. The DSA(dimensional stable anode) electrode for the electrochemical treatment was prepared by thermal deposition method. The disinfection rate of microorganisms increased with the increasing current density and reaction time under low pH condition. The morphology of sterilized microorganisms was shown by SEM and Microscopy.

• Journal of Korean Society on Water Environment
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• v.28 no.4
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• pp.608-614
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• 2012

The effluent limitation of industrial wastewater is based on uniform regulatory criteria for effluent discharge facilities of all in Korea. But, an individual effluent limitation on each effluent discharge facility is widely applicable for regulation of industrial wastewater in US.EPA. To decide an individual effluent limitation, TBEL (Technology-based effluent limitation) and WQBEL (Water quality-based effluent limitation) are used. TBEL is based on the capability of a treatment technology to reduce the pollutants. WQBEL is based on ambient water quality standards. In this study, TBEL were derived for the pulp, paper and paper board manufacturing based on best practicable control technology currently available. It was suggested that effluent limitations were $BOD_5$ 4.7 mg/L, $COD_{Mn}$ 44.3 mg/L, SS 13.2 mg/L, TN 1.4 mg/L, TP 0.15 mg/L and best practicable control technology currently available (BPT) was neutralization, activated sludge treatment and coagulation and sedimentation for the pulp, paper and paper board manufacturing.

• Macromolecular Research
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• v.17 no.9
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• pp.666-671
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• 2009

Water repellent elastomeric surfaces were fabricated successfully on SBS/MWNT nanocomposites films using the breath figure method and subsequent thermal treatment. The uniformly dispersed CNTs were found to play significant roles in tuning the size and ordering of the macroporous morphology at the nanocomposite surface as well as enhancing the mechanical properties of nanocomposites. In particular, the CNTs dispersed in a nanocomposite solution retarded the coarsening process of aqueous droplets during the breath figure process and decreased the pore size in the finally fabricated film. The water contact angle measurement showed that the double-scale structure comprised of self-organized macropores and surface the roughness induced by a thermal treatment produced a highly water-repellent nanocomposite surface.

• Journal of Korean Society on Water Environment
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• v.20 no.5
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• pp.466-472
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• 2004

Red mud is formed as a waste during bauxite refining known as Bayer's process. Its main constituents are iron, aluminium, sodium and silica. The disposal of large quantities of wasted red mud causes a serious ecological problem. In this study, the red mud wasted from the bauxite refinery was studied for phosphate removal from aqueous solution according to activation methods. The influence of heat treatment, and neutralization with sea water and acid treatment level for the optimum conditions for phosphate removal have been determined. Heat treatment combined with acid treatment is most suitable for the removal of phosphate from aqueous solution. The optimal condition was activated with 1 N HCl solution after heating in $600^{\circ}C$ during 4 hours. Acid and heat treatment causes sodalite compounds which hinder the phosphate adsorption to leach out. The adsorption data obtained followed a first-order rate expression and fitted well with the Freundlich Isotherm well.