• Clean Technology
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• v.23 no.1
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• pp.34-41
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• 2017

The scrubber wastewater should be replaced frequently to maintain efficiency. Most chemical companies consign scrubber wastewater, because there are no wastewater treatment facilities. So scrubber wastewater is not frequently replaced because of high treatment cost. For this reason, the most scrubber exhaust gas exceeds the odor emission limit or has a phenomenon that the odor intensity of exhaust gas becomes higher. Therefore we have developed a scrubber wastewater cleaning system consisting of filtration and adsorption processes. The scrubber wastewater cleaning system was applied two chemical companies. We evaluated the water quality and odor reduction effect before and after system application. As a result, scrubber wastewater quality improved by 50% or more, odor reduction efficiency of scrubber exhaust gas improved by 20% or more. And the total operating costs of the scrubber could be reduced by 40% or more.

• Membrane and Water Treatment
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• v.13 no.1
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• pp.1-6
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• 2022

The regulations of the International Maritime Organization (IMO) have been steadily strengthened in ship emissions. Accordingly, there is a growing need for development of related technologies for the removal of contaminants that may occur during the treatment of SOx and NOx using a wet scrubber. However, this system also leads to wastewater production when the exhaust gas is scrubbed. In this research, we evaluated the performance of an ion selective resin process in accordance with scrubber wastewater discharge regulations, specifically nitrate discharge, by the IMO. Accelerated real and synthetic wastewater of wet scrubbers, contained high amounts of TDS with high nitrate, is used as feed water in lab scale systems. Furthermore, a pilot scale dissolved air flotation (DAF) using microbubble generator with ion exchange resin process was combined and developed in order to apply for the treatment of wet scrubber wastewater. The results of the present study revealed that operating conditions, such as resin property, bed volume (BV), and inlet wastewater flow rate, significantly affect the removal performance. Finally, through a pilot test, DAF with ion exchange resin process showed a noticeable improvement of the nitrate removal rate compared to the single DAF process.

• Environmental Engineering Research
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• v.20 no.2
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• pp.199-204
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• 2015

In this study, a novel phosphorus removal filter made of brass scrubber with higher porosity of over 96% was fabricated and evaluated. The brass scrubber was surface-modified to form copper hydroxide on the surface of the brass, which could be a phosphate removal filter for advanced wastewater treatment because the phosphates could be removed by the ion exchange with hydroxyl ions of copper hydroxide. The evaluation of phosphate removal was performed under the conditions of the batch type in wastewater and continuous type through filters. Filter recycling was also evaluated with retreatment of the surface modification process. The phosphate was rapidly removed within a very shorter contact time by the surface-modified brass scrubber filter, and the phosphate mass of 1.57 mg was removed per gram of the filter. The possibility of this surface-modified brass scrubber filter for phosphorus removal was shown without undesirable sludge production of existing chemical phosphorus removal techniques, and we feel that it would be very meaningful as a new wastewater treatment.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.4
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• pp.399-404
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• 2021

From 1 January 2020, the limit for Sulphur in fuel oil used on board ships operating outside designated emission control areas will be reduced to 0.5 %. This regulation by international maritime organization (IMO) is able to significantly reduce the amount of Sulphur oxides (SOx) discharging from ships and should have environmental advantages and health for all over the world. To meet the regulation, in these days, wet scrubber system is being actively developed. However, this process leads to make washing wastewater. In this study, we evaluated ion exchange resin system in accordance with scrubber wastewater discharge regulation by IMO. Theoretical wastewater used as feed solution of lab scale water treatment systems. The results revealed that nitrate ion was removed selectively in spite of high TDS wash wastewater solution depending on ion exchange resin property. Moreover, it was possible to improve efficiency of the system by optimizing operating conditions.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.10
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• pp.702-708
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• 2012

Tetrafluoromethane ($CF_4$) has been used as etching and Chemical Vapor Deposition (CVD) gases for semiconductor manufacturing processes. These gases need to be removed efficiently because of their strong absorption of infrared radiation and long atmospheric lifetimes which cause the global warming effect. Also, the wastewater including the fluorine is caused by of the ground water pollution. Long-term consumption of water containing excessive fluoride can lead to fluorosis of the teeth and bones. The wastewater including the fluorine among the by-product which is generated by using the waterjet plasma after destroying $CF_4$ by HF is generated. The system which can remove the hydrogen fluoride among the wastewater by using the electrocoagulation using this wastewater the aluminum electrode was developed. The operating condition such as initial pH, electrocoagulation time, wastewater flow rate, current density were investigated experimentally using a electrocoagulation. Through the parametric studies, the highest hydrogen fluoride destruction of 85% was achieved at 3.5 initial pH, 10 min electrocoagulation time, 10 mL/min wastewater flow rate and $159A/m^2$ current density.

• Prospectives of Industrial Chemistry
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• v.22 no.5
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• pp.14-24
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• 2019

전 세계적인 기후변화로 인하여 선박 내 이용되는 물과 관련된 배출 규제도 매년 강화되고 있는 추세이다. 심해지는 규제를 만족하기 위하여 다양한 선박용 수처리 기술이 개발되고 있으며, 고도화 연구가 활발히 진행되고 있다. 본 연구에서는 선박 내에서 이루어지는 수처리 공정인 선박 평형수(ballast water)처리, 조수기(fresh water generator)를 통한 선박 내 용수 공급, 대기오염 저감을 위한 스크러버(wet scrubber) 폐세정수 처리 공정과 관련된 국제해사기구(international maritime organication, IMO)와 같은 국제적인 규제 및 특정지역과 연안에 위치한 주정부 기관의 규제 현황에 대해 문헌조사를 통해 정리하였다. 이를 바탕으로 다양한 선박 내 수자원 활용과 규제에 부합하기 위해 적용되고 있는 관련 수처리 기술을 용도별로 정리하였으며, 현재 기존기술의 효율 개선 및 신기술 도입과 관련된 연구 현황을 정리하였다. 이러한 선박 내 수처리 현황 및 향후 적용될 기술개발연구를 바탕으로 지속가능한 해양환경 조성 및 기후변화 대응이 가능할 것으로 기대된다.

• Microbiology and Biotechnology Letters
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• v.32 no.3
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• pp.265-270
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• 2004

To select a promising technologies for removal of odorous gases emitted from a wastewater pump station, four methods such as activated carbon (A/C) adsorption, chemical absorption (acid and alkali scrubber), and two biofilters (polyurethane (PU) and worm cast) were investigated. The average odor removal efficiencies in the PU biofilter and A/C column was over 98%, but in a worm cast biofilter and chemical absorption were below 60-80%. The removal efficiency of PU biofilter was very stable (about 98-99%) in the range of retention times of 4-36s, and a maximum elimination capacity was $1.6${\times}$10^{ 7}$ $OUm^{-3}$$h^{-1}$ Deodorization costs for an activated carbon adsorption and a biofiltration method were investigated. With increasing odor intensity, the operating cost of the A/C column increased linearly, but the operating cost of the biofilteration increased slightly. The capital cost in a biofilter is about two times higher than that in an A/C column, but the operating cost is very lower than that of in A/C column. In conclusion, the biofiltration was evaluated one of the most promising technologies to control odor in a wastewater pump station.

• Resources Recycling
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• v.10 no.5
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• pp.36-43
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• 2001

The chlorine component in fly ash from municipal solid waste incineration ash was removed by water washing for the purpose of recycling fly ash as a raw material of ordinary portland cement. The samples were a different kind of 리y ashes using $Ca(OH)_2$and NaOH as media of wet scrubber for flue gas cleaning. The content of soluble salts of fly ash using $Ca(OH)_2$and NaOH was 32.8%, 50.1% and the content of chlorine component, 22.9% and 26.0% respectively, which was KCl, NaCl, CaC1OH mainly. When each fly ash was washed using water under conditions of a agitation speed of 300 rpm, a liquid to solid ratio of 10, most soluble salts in fly ash were dissolved within 30 minutes and the content of chlorine component in ash was diminished to the content of 4.4%, 2.O% at $20^{\circ}C$ and 1.7%, 0.8% at $50^{\circ}C$ respectively. And the main compound of residual chlorine component in ash after water washing was friedel`s salt ($3CaO.A1_2$$O_3$.$CaCl_2$.$10H2$O). From analysis results of water quality for wastewater by water washing, the components exceeding discharged wastewater standard were only Pb and Cd. But As pH was controlled to 10 with addition of $CO_2$(g) or $Na_2$$_CO3$in water, the concentration of heavy metals such as Pb and Cd was also under discharged wastewater standard.

• Journal of Wetlands Research
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• v.18 no.3
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• pp.286-291
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• 2016

This study was carried out to evaluate the feasibility of air-stripping by DIWS(Dip Injection Wet Scrubber) system on high concentration of ammonia wastewater more than 10,000 mg/L. In the case of changing temperature from $30^{\circ}C$ to $70^{\circ}C$ maintaining pH 12.5 within the 72 hours, the removal efficiency of T-N by the present treatment plant was increased to 90.5% which was initially kept 70.3%. Although the high concentration of T-N with 9,120~12,955 mg/L was treated by micro-bubble through DIWS system maintaining the temperature of $30^{\circ}C$ within the 20 hours, the removal efficiency of T-N reached 91.9%, which indicated the possibility of air-stripping.

• Journal of the Korean Applied Science and Technology
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• v.34 no.2
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• pp.210-216
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• 2017

Recovery of low level nitric acid and sulfuric acid ions, which were contained in wastewater of a wet scrubber for de-NOx and de-SOx from ship engines, was attempted as fertilizing materials. This study utilized a selective extraction method using four organic solvents to precipitate the solid salts of ammonium nitrate and ammonium sulfate. The IR analysis showed almost same composition of the extracted ammonium salts with a commercial product, and recovery rate of nitrogen and sulfuric ions was 89% and 80% respectively. It was found that the selectivity and solubility consequently could be the crucial factors to recover the low level ions from the waste scrubbing water.