서울 초등학교 교실의 PM_2.5 및 PM₁₀ 제거를 위한 학교용 공기청정기 실증

한방우,홍기정,신동호,김학준,김용진,김상복,김상우,황청하,노광철,Han, Bangwoo,Hong, Keejung,Shin, Dongho,Kim, Hakjoon,Kim, Yongjin,Kim, Sangbok,Kim, Sangwoo,Hwang, Cheongha,Noh, Kwangchul 한국입자에어로졸학회 2019 Particle and Aerosol Research Vol.15 No.2

It is important to control fine particles in children care centers, elementary schools, elderly care facilities and so on where vulnerable children and the aged stay during most of their time. This study has investigated $PM_{2.5}$ and $PM_{10}$ concentrations in two classrooms equipped with an air cleaner and two air cleaners, respectively and they were compared to those in a classroom without an air cleaner as well as those outdoors. Eight air cleaners which have various clean air delivery rates (CADRs) between 9.9 and $21.3m^3/min$ were tested in classrooms in two elementary schools in Seoul. Average $PM_{2.5}$ and $PM_{10}$ were $7.3{\pm}0.7$ and $45.5{\pm}4.1{\mu}g/m^3$ in classrooms equipped with an air cleaner and $4.2{\pm}0.6$ and $24.6{\pm}2.5{\mu}g/m^3$ in classrooms with two air cleaners, whereas they were $22.1{\pm}2.6$ and $109.1{\pm}9.6{\mu}g/m^3$ in classrooms without an air cleaner and $36.9{\pm}5.1$ and $74.1{\pm}10.6{\mu}g/m^3$ outdoors, respectively. $PM_{2.5}$ in classrooms could be reduced effectively by using an air cleaner or two air cleaners, because $PM_{2.5}$ was mainly infiltrated from outdoors, however $PM_{10}$ could not because $PM_{10}$ was mainly caused indoors by students' activities. Air cleaners were more effective for removal of $PM_{2.5}$ and $PM_{10}$ in classrooms with a high airtightness than those in classrooms with a relatively low one. Average $CO_2$ in classrooms was about 1500 to 2000 ppm for class hours dependent on the student number per a classroom, which was about 1.5 to 2 times higher than the standard, regardless of the use of air cleaner.

탄소섬유 시트 방전극의 입자 크기 별 집진 특성 및 공기청정기로의 응용

신동호,우창규,홍기정,김학준,김용진,한방우,shin, Dongho,Woo, Chang Gyu,Hong, Keejung,Kim, Hak-Joon,Kim, Yong-Jin,Han, Bangwoo 한국입자에어로졸학회 2018 Particle and Aerosol Research Vol.14 No.3

The market for improving the indoor air quality is continuously increasing, and air cleaners are the representative products. As interest in indoor air quality increases, so are the ultrafine particle which are harmful to the human body. Despite its many advantages, electrostatic precipitators are less used in indoor air due to ozone production. In this study, the carbon fiber sheet was applied to the discharge electrode and compared with the conventional tungsten wire discharge electrode. The particle collection efficiency and the amount of ozone generation were measured for 10-100 nm particles. Furthermore, it was applied to commercial air purifier with electrostatic precipitator to compare particle removal performance. The carbon fiber sheet type discharge electrode generates a small amount of ozone, and thus it can be applied to improve indoor air quality.

화력발전소 굴뚝 미세먼지 측정을 위해 개발한 이젝터-다공튜브 희석장치의 희석비 검증

신동호,김영훈,서현수,홍기정,김학준,김용진,한방우,이가영,천성남,황정호,Shin, Dongho,Kim, Young-Hoon,Hong, Keejung,Kim, Hak-Joon,Kim, Yong-Jin,Han, Bangwoo,Lee, Ga-Young,Chun, Sung-Nam,Hwang, Jungho 한국입자에어로졸학회 2019 Particle and Aerosol Research Vol.15 No.3

The exhaust emissions from coal-fired power plants have received much attention because coal-fired power plants are the one of the largest sources of particulate matter (PM) emissions in South Korea. To measure the PM10 and PM2.5, we developed the novel diluter which is comprised of ejector and porous tube in series. The dilution ratio must be defined to calculate particle concentrations of the sampled air as well as to probe match for the isokinetic sampling. For this reason, we verified the dilution ratio of the developed diluter by the flow rate, numerical solution, gas concentration and particle concentration. The ejector-supplied flow rates were 10-50 L/min and the porous tube-supplied flow rates were 30, 50 L/min in this study. All methods above showed similar dilution ratios to each other within 10 % error rate. The dilution ratio was confirmed by comparing mass concentrations before and after the dilution process.

나노펄스 플라즈마를 이용한 탈황 시스템의 H₂O 및 NH₃, 펄스 인가전압에 따른 입자변환 분석

김영훈,신동호,이건희,홍기정,김학준,김용진,한방우,황정호,Kim, Younghun,Shin, Dongho,Lee, Gunhee,Hong, Keejung,Kim, Hak-Joon,Kim, Yong-Jin,Han, Bangwoo,Hwang, Jungho 한국입자에어로졸학회 2020 Particle and Aerosol Research Vol.16 No.1

Nano-pulse plasma technology has great potential as the process simplicity, high efficiency and low energy consumption for SO₂ removal. The research on the gas-to-particle conversion is required to achieve higher efficiency of SO₂ gas removal. Thus, we studied the effect of the relative humidity, NH₃ concentration and applied voltage of the nano-pulse plasma system in the gas to particle conversion of SO₂. The particles from the conversions were increased from 10 to 100 nm in diameter as relative humidity, NH₃ concentration, applied voltage increases. With these results, nano-pulse plasma system can be used to more efficient removal of SO₂ gas by controlling above parameters.

습식-펄스방전 복합시스템의 황산화물 및 질소산화물 제거성능 특성

박현진,이환영,박문례,노학재,유정구,한방우,홍기정,Park, Hyunjin,Lee, Whanyoung,Park, Munlye,Noh, Hakjae,You, Junggu,Han, Bangwoo,Hong, Keejung 한국입자에어로졸학회 2019 Particle and Aerosol Research Vol.15 No.1

Current desulfurization and denitrification technologies have reached a considerable level in terms of reduction efficiency. However, when compared with the simultaneous reduction technology, the individual reduction technologies have issues such as economic disadvantages due to the difficulty to scale-up apparatus, secondary pollution from wastewater/waste during the treatment process, requirement of large facilities for post-treatment, and increased installation costs. Therefore, it is necessary to enable practical application of simultaneous SOx and NOx treatment technologies to remove two or more contaminants in one process. The present study analyzes a technology capable of maintaining simultaneous treatment of SOx and NOx even at low temperatures due to the electrochemically generated strong oxidation of the wet-pulse complex system. This system also reduces unreacted residual gas and secondary products through the wet scrubbing process. It addresses common problems of the existing fuel gas treatment methods such as SDR, SCR, and activated carbon adsorption (i.e., low treatment efficiency, expensive maintenance cost, large installation area, and energy loss). Experiments were performed with varying variables such as pulse voltage, reaction temperature, chemicals and additives ratios, liquid/gas ratio, structure of the aeration cleaning nozzle, and gas inlet concentration. The performance of individual and complex processes using the wet-pulse discharge reaction were analyzed and compared.

역삼투, 이온교환, 축전식 탈염 공정의 보론 제거 성능 분석

김유창(Yu Chang Kim),임성일(Sungil Lim),한방우(Bangwoo Han),김상복(Sang Bok Kim),박인용(Inyong Park),이건희(Gunhee Lee),박대훈(Dae Hoon Park),홍기정(Keejung Hong) 대한환경공학회 2021 대한환경공학회지 Vol.43 No.10

목적: 본 연구는 기수용 역삼투, 이온교환, 축전식 탈염 공정의 보론 제거 성능을 비교 분석하기 위해서 수행하였다. 역삼투식 해수담수화 공정에서는 본처리 공정인 역삼투 공정의 투과수내에 있는 보론을 추가적으로 더 제거해야 한다. 따라서, 세 공정의 보론 제거 성능과 에너지 소비량을 실험적으로 분석하여 상호 비교하였으며, 이를 통해 이 공정들이 해수담수화 공정의 생산수를 추가 처리하는 2nd pass (2차 통과) 공정으로 사용이 가능한지 여부를 분석하였다. 방법: 실험에 사용할 원수는 NaCl과 B(OH)₃를 이용하여 제조하여 사용하였으며, 역삼투 공정과 이온교환 공정은 소형 파일럿 규모(생산수량 1 m³/hr 이상), 축전식 탈염 공정은 벤치 규모(2.5 L/min 이상)의 시스템을 실험에 사용하였다. 각 공정의 원수와 처리수의 보론 농도를 Azomethine-H 방법으로 분석하였으며, 시스템의 소비 전력을 전력 분석기로 측정하여 에너지 소비량을 분석하였다. 결과 및 토의: 공정마다 보론을 제거하기 위한 운전조건이 다르다. 역삼투 공정의 경우 원수의 pH를 충분히 올려야 제거율이 좋아지며, 이온교환 공정의 경우 보론 선택성 수지(resin)의 흡착용량을 고려하여 파과점(breakthrough point) 이내에서 운전하여야 하며, 축전식 탈염 공정의 경우 보론이 다른 이온과 혼합되어 있으면 전극에 의한 이온 선택성 때문에 연속식 흐름을 갖는 시스템으로는 처리가 어려웠다. 각 공정의 에너지 소비는 가압형 공정인 기수용 역삼투 공정이 가장 컸으며, 축전식 탈염 공정도 탄소전극이 소비하는 전기량이 적지 않았다. 최근 역삼투와 축전식 탈염 공정이 관심을 많이 받는 것은 사실이지만 실제 보론 제거 성능이나 에너지 소비 측면에서는 보론 선택성 수지를 이용하는 이온교환 공정이 우수한 성능을 보이는 것으로 분석되었다. 결론: 이온교환 공정은 재생용 약품 폐수가 발생하고 운전이 쉽지 않다는 단점이 있다. 하지만 보론 제거와 에너지 소비 측면에서는 이온교환 공정이 기수용 역삼투와 축전식 탈염 공정보다 좋은 성능을 보였다. 물론 생산수의 사용처, 환경 및 에너지, 타 공정과의 연계성, 하이브리드 구성 등 다양한 측면에서 고려할 필요가 있다. Objectives : This article provides a comparative analysis of boron removal for brackish water reverse osmosis (BWRO), boron selective ion exchange (IX), or capacitive deionization (CDI) processes. Permeate of 1st-Pass RO process has to be post-treated for additional boron removal. Hence, we experimentally analyzed the performance of boron removal and specific energy consumption (SEC) of three aforementioned processes and investigated whether the processes are suitable for 2nd pass process of RO desalination. Methods : Raw feed water was prepared using NaCl and B(OH)₃. Semi-pilot scale RO and IX systems (over 1m³/hr capacity) and bench scale CDI system (over 2.5 L/min) were tested for performance comparison. Boron concentration was measured using Azomethine-H method for feed and product water. Energy consumption was monitored by using power quality analyzer. Results and Discussion : Each process has its own operating conditions. The RO process required high pH of feed water for high boron removal rate, the IX process was operated below breakthrough point considering adsorption capacity of boron selective resin, and the CDI process didn’t remove boron because chloride ion has higher ion selectivity for carbon electrode than boron. In terms of SEC, the pressure-driven RO process showed the highest SEC among three processes. The CDI process based on electrical adsorption of carbon electrode showed a considerable energy consumption as well. On the other hand, the IX process was operated at low energy consumption because its removal is just based on adsorption-desorption mechanism. Conclusions : The RO and CDI processes have received a lot of attention as leading and emerging technology while the IX process was regarded as a stubborn process because of regeneration of resin and its several segmentalized steps. However, we found that the IX process has a better performance for boron removal and energy consumption.