전자산업에서 발생되는 유해 산 폐액 중 구리의 회수

권기홍(Gi-Hong Kwon),남창모(Chang-Mo Nam),김동원(Dong-Won Kim),성병주(Byung-Joo Sung) 한국환경관리학회 2008 環境管理學會誌 Vol.14 No.3

전자산업에서 발생되는 유해 폐산의 재활용은 환원ㆍ산화, 정제, 여과 과정을 거쳐 환원공정에서는 구리를, 최종공정에서는 염화제이철(FeCl₃) 을 회수하고 있으나, 환원과정에서 얻어진 구리의 경우 순도가 낮아 제 가격을 받지 못하고 있는 실정이다. 따라서 본 연구는 폐산의 재활용공정 중 환원과정에서 얻어진 구리의 회수율 증대를 위한 연구를 수행한 결과 다음과 같은 결론을 얻었다. 구리 회수율 중대를 위한 방법으로 수세척을 이용하고 세척회수 2회, 구리 slurry와 세척액량의 비 30 : 100, 세척 및 침전시간 각각 30분, 세척조 하부 blowing하는 조건으로 운전한 결과 구리 순도율(수분 포함)은 세척 전에는 평균 62.8%였으나 세척 후에는 평균 80.4%로 약 18%의 순도가 향상된 것으로 확인할 수 있었으며, 세척과정에서 발생된 세척액의 성분분석 결과 농도는 낮지만 Cr, Pb 등의 중금속물질이 포함되어 있어 적정한 처리가 필요할 것으로 판단된다. 결론적으로 기존의 공정에서 세척 회수, 구리 slurry와 세척액량의 비, 세척 및 침전 시간의 적절한 조합으로 충분히 회수율을 높일 수 있음을 확인하였다. Hazardous acid wastewater generated at electronic industries can be recycled and reused after going through the procedures of reduction, oxidization, purification and filtration, Then, the Cu can be recovered in the reduction process and the iron chloride (FeCl₃) in the final process, respectively. Because the recovered Cu has a very low degree of purity, however, its fair and reasonable price can not be established. This study was performed to improve the recovery of Cu in the reduction process during the recycling and reuse of acid wastewater. The result of this study is summarized as follows. Water washing was used as a method to improve the Cu recovery with the following conditions: Twice washing recovery, the ratio of Cu slurry to washing solution: 30:100, washing and precipitation time: each 30 minutes, and blowing under the washing bath. Then, it was shown that the average purity degree of recovered Cu(including water) accounted for 62.7% before washing, and 80.4% after washing. There was the increase of approximately 18% in the Cu purity. When chemicals of washing solution were analysed after washing, the findings showed that such heavy metals as Cr and Pb were contained in very low concentration. It seems that they have to be treated in a proper way. In conclusion, the finding showed that it should be possible to improve the recovery by properly combining the existing procedure with these conditions: Washing times, ratio of Cu slurry to washing solution, washing and precipitation time.

Multibody Dynamic Analysis of a Washing Machine with a Rapid Change of Mass during Dehydration

장진석,진재훈,정혜영,박진홍,이재욱,유완석 한국정밀공학회 2016 International Journal of Precision Engineering and Vol.17 No.1

Dehydration is one of the main processes while laundering clothes. The distribution of clothes may not be uniform and can cause an unbalanced mass distribution in washing machines. Recently, many clothes are being made with waterproof materials, which can hold and release water suddenly, causing unusual vibrations during the dehydration process. The purpose of this study was to analyze the vibration of a washing machine during the dehydration process with a rapid decrease of unbalanced liquid mass and to find a design solution for reducing vibrations. A washing machine system rotating on the vertical axis was modeled using ADAMS. A multibody dynamic model was established using experimental data of several components obtained using an MTS test machine. To validate the dynamic model, a comparison of the simulation and experiment of a washing machine during the dehydration process was carried out. For simulating the effects of a rapid decrease of unbalanced liquid, constraint equations were deactivated through several steps with rapidly decreasing time. Higher preload on the upper and lower pivot connectors can help in decreasing the vibration, and in analyzing the dynamic behavior of the washing machine. For decreasing vibration, a pre-load tool was applied in the dynamic model. Effects of pre-load were analyzed by experimental simulation.

Gas Chromatograph-Ion Mobility Spectrometer 전자코를 이용한 워시드 가공 커피와 내추럴 가공 커피의 향기 특성에 대한 연구

문상윤(Sang-Yoon Moon),김미리(Mee-Ree Kim) 한국식품영양과학회 2020 한국식품영양과학회지 Vol.49 No.8

본 연구에서는 가공방식에 따라 커피 향기 특성의 차이가 있는지를 확인하기 위해 GC-IMS 전자코를 이용하여 국내에서 워시드 가공 커피와 내추럴 가공 커피로 동시에 많이 유통되고 있는 아라비카종의 에티오피아산 3개 지역의 커피를 사용하여 향기 특성을 비교・분석하였다. GC-IMS 전자코에 의해 검출된 향기 성분의 주성분을 분석한 결과 워시드 가공 커피와 내추럴 가공 커피의 향기 패턴은 뚜렷이 구분되었다. 에티오피아산 커피에서 가장 강하게 감지된 성분은 4-ethenylcyclohexene, isopentyl propanoate, cis-3-hexenol, 2-methyl propyl acetate였다. 또한, methoxybenzene 성분은 워시드 가공 커피에서 뚜렷이 감지되었고, methyl isobutyl ketone, butanal 성분은 내추럴 가공커피에서 뚜렷이 감지되었다. 이를 통해 워시드 가공방식과 내추럴 가공방식의 커피를 로스팅된 커피원두 상태로도 확인이 가능함을 확인하였고, 커피 로스터가 부각하고자 하는 향을 위한 커피 생두를 선택할 때 참고자료로 활용할 수 있을 것으로 사료된다. This study examined the characteristics of the aroma components of washed-processed and natural-processed coffee. A GC-IMS electronic nose was used to compare the aroma content of three processed and three natural processed coffees produced in the same country. An analysis of the main components of the aroma components detected by GC-IMS electronic nose and the aroma pattern of the washed and natural processed coffee were distinguished. Four common ingredients were detected because it was produced in the same country. On the other hand, methoxybenzene was detected in the washed coffee, whereas methyl isobutyl ketone and butanal were detected in the natural processed coffee. The results revealed a difference in the characteristics of coffee aroma depending on the processing method, even if it is coffee from the same country of origin. The coffee from the washed processing method and the natural processing method can be checked even with roasted coffee beans.

Evaluation of Changes in Ion Exchange Resin Performance According to Water Treatment Process Operation

Jae Kyung Lee 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.2

Korea Atomic Energy Research Institute’s Post Irradiated Examination Facility safely stores spent nuclear fuel using a wet storage method to conduct research. Here, in order to remove the radioactivity released into the water, the stored water is passed through an ion exchange resin tower, and the radionuclides are exchanged with the bead-shaped ion exchange resin filled inside to lower the radioactivity concentration. At this time, because the stored water passes in one direction, clogging of the ion exchange resin occurs. If this phenomenon continues, the flow rate of the water treatment process decreases and operation efficiency decreases, so a backwashing process is necessary to re-mix the ion exchange resin and secure the flow rate again. In this study, the flow rate reduction trend according to the lifespan of the ion exchange resin and the flow rate recovery according to the backwash process operation amount were analyzed. The flow rate reduction trend of the ion exchange process was analyzed immediately after the backwashing process was started. In addition, the amount of flow recovery according to the backwash process operation amount was evaluated by the amount of waste generated during the backwash process and the number of days of operation until the backwash process was needed again. As a result, the flow rate of the ion exchange process decreased rapidly right after the backwash process until the position of the ion exchange resins was stabilized, and then stabilized. After that, it gradually decreased and reached the point where the backwash process was necessary. However, the decline trend was analyzed to be the same regardless of the lifespan of the ion exchange resin. In addition, the amount of waste generated during the operation of the backwash process was increased in the order of 400 L, 600 L, 1,100 L, 1,400 L, 3,500 L, and 4,200 L to increase the amount of operation of the backwash process. As a result, the number of days of ion exchange resin operation was 285 days, 338 days, and 342 days, was analyzed as 422 days, 322 days, and 720 days. Based on this study, it was confirmed that the flow rate reduction trend is the same regardless of the lifespan of the ion exchange resin, and as the backwash process operation increases, the number of days the ion exchange process can be operated increases, but there is a turning point where the waste treatment cost exceeds the number of days of operation.

딸기의 세척 및 가공 과정에 따른 농약 잔류량 변화

곽세연,이상협,정혜린,남애지,Aniruddha Sarker,김효영,임채욱,조현정,김장억 한국환경농학회 2019 한국환경농학회지 Vol.38 No.4

BACKGROUND: As the demand for strawberries increases, people are paying attention to food safety in strawberry, especially pesticide residues. To remove the pesticides from strawberry, various washing and processing technique in households are additionally required. METHODS AND RESULTS: Strawberries were washed with water, detergent, alcohol, and ultrasonication and processed to strawberry jam. The mean reduction efficiency according to the washing solvent and method was found to be higher in the order of detergent (42.5%) > alcohol (41.7%) > water (41.3%) > ultrasoniation with alcohol (40.2%) > ultrasoniation with water (38.6%) > ultrasoniation with detergent (36.9%), but there was no significant difference among the treatments. The residue levels of pesticides during processing to jam decreased by 11.9-94.4% for etoxazole, fluopyram, procymidone, spiromesifen, and prochloraz, while the other pesticides were concentrated by boiling, or rather increased by 11.8-40.2%. However, when the residue levels were converted to residual amounts in consideration of the change in weight after processing, the residual amounts of the tested pesticides were reduced by 59.8-98.4% during processing. The processing factor (PF) were different for each pesticide, but PFs were < 1 for all washing solvents and methods, and 0.06-1.40 when processed into jam. CONCLUSION: To ensure the consumption of pesticidefree strawberry, the most efficient washing method is to immerse the strawberry in fresh water for few minutes, followed by rinsing them under running water.

에너지 절감형 염색기용 직접냉각수세장치에 대한 연구

한승철(Han, Seung-Chul),김진호(Kim, Jin-Ho),김제훈(Kim, Je-Hoon),이성규(Lee, Sung-Kyu) 한국산학기술학회 2012 한국산학기술학회논문지 Vol.13 No.2

최근 국내 섬유산업의 생산량이 증가함에 따라 섬유산업에서 에너지 소비는 계속 증가되고 있는 실정이다. 기존의 염색기는 고온·고압의 특성을 가지고 있기 때문에 염색 후 냉각을 하기 위하여 열교환기를 통한 간접냉각방 식을 채택하고 있다. 이러한 간접냉각방식은 물의 소모량이 많으며 작업 시간 또한 오래 걸리는 문제점이 있고 냉각 시 염액의 고착으로 인해 냉각 후 환원세정 및 수세를 수차례 하므로 에너지가 많이 소비된다. 따라서 본 논문에서는 고온·고압 액류 염색기의 열교환기에 의한 간접냉각방식을 염색기내에 냉수를 직접 공급하는 직접냉각방식으로 대 체하기 위한 장치를 개발하여 기존의 염색기에 적용하여 냉각과 동시에 환원세정공정을 생략하고 수세공정을 단축시 키면서 전공정을 마무리함으로써 전체 작업공정을 줄이고 에너지 소비를 절감하는 등의 생산성을 획기적으로 향상시 킬 수 있는 직접냉각수세장치를 제안하며, 시제작품을 제작하고, 실제 염색기에 적용하여 기존의 간접 냉각 방식의 염색기와 성능, 자원 및 에너지 절감율을 비교하였다. 또한 시제작품을 적용한 염색기의 염색성 실험을 하였다. Due to increase in production of the domestic textile industry, energy consumption in textile industry is still growing. Traditional dyeing machine has high temperature and pressure. Accordingly, it uses an indirect cooling system that utilize a heat exchanger to cool after the dyeing. However, this indirect cooling system consumes a great deal of water, takes prolonged periods of time to process and, most importantly, because of the condensing of the dye at the cooling stage requires further energy in reduction cleaning and washing process. Therefore, in this paper, we propose a direct cooling washing machine that replaces the traditional indirect cooling system to provide coolant into the dyeing machine. The newly proposed direct cooling washing machine will still use parts of the traditional dying but will be able to skip the cooling as well as the reduction cleaning and washing process, resulting in less processing time and lower energy consumption. Also, we made a prototype. The prototype was applied to dyeing machine to test the direct cooling washing machine's ability and dyeing property. Additionally, we compared indirect cooling washing machine with direct cooling washing machine about ability, material and energy saving assessment.

유기물 제어를 통해 분리막의 fouling을 저감시키는 MBR 공정개발

이한슬 ( Hanseul Lee ),김진수 ( Jinsu Kim ),심재훈 ( Jaehoon Shim ),강민구 ( Minkoo Kang ),김성근 ( Sungkeun Kim ),이상일 ( Sangill Lee ) 한국수처리학회 2015 한국수처리학회지 Vol.23 No.4

The process which apply the Membrane bioreactors(MBRs) provide many advantages over conventional treatment so that process with MBR is being applied for industrial wastewater treatment. However, membrane fouling is main obstacle for application of MBRs because it reduces washing-cycle and productivity. The bio- fouling caused by EPS, NOM, pore size, HRT, etc. In this study, MLE(modified Ludzack-Ettinger) process with adding an aerobic reactor(M2) process operated to control bio-fouling feasibly in MBRs. As install an oxic unit in MLE, COD removal efficiency was more excellent than existing MLE process. Also, the total amount of extracellular polymeric substance(EPS) extracted from M2 reactor was lower concentration than M1. Controlling the EPS, M2 process washing cycle was longer than M1 about a week. It showed that, bio-fouling is influenced by the concentration of EPS and adding an oxic unit to MLE is very effective to control the bio-fouling.

판상엽 스크류 프레스 공정 특성 평가

성용주,한영림,김근수,이문수,하인호,이기열,전은순,송태원,Sung Yong-Joo,Han Young-Lim,Kim Geun-Su,Rhee Moon-Soo,Ha In-Ho,Lee Ki-Yeul,Chun Eun-Soon,Song Tae-Won 한국연초학회 2006 한국연초학회지 Vol.28 No.1

The papermaking process for a reconstituted tobacco sheet (RECON) has been preferred more because of the various merits such as a wide range of Recon products with better quality. The screw press is one of the very important process in RECON making process which divides the mixed raw materials into the soluble material and the insoluble material and could greatly affect the productivity and product quality. In this study, the characteristics of the screw press process in a Recon making mill were evaluated for two different RECON products. Three different efficiency index were proposed for the more detailed analysis of the screw press process. The result showed that the difference in the raw material might result in the difference in the efficiency and the properties of the extracts and the filter cake, especially in the HWS. The washing technique which applied in this experiment showed the amount of residual HWS in the fiber portion were not much changed by the each steps of the screw press.

The Removal of Petroleum Hydrocarbon from Fine Soil in Soil Washing Water using Advanced Oxidation Processes

Jang, Gwan-Soon 한국토양비료학회 2014 한국토양비료학회지 Vol.47 No.5

This study was performed to test the applicability of the ozone/hydroxy radical reaction system, which applied advanced oxidation processes, to remove total petroleum hydrocarbon (TPH) from the fine soil in washing water of the soil washing process. Removal efficiency was tested on 40 L of washing water in a pilot reaction tank. Fine soil contaminated with $800mg\;kg^{-1}$ TPH was prepared at 5% and 10% suspended solids. Testing conditions included ozone/hydroxy radical flow rates of 40, 80, and $120L\;min^{-1}$, and processing time of 2 to 12 hours. The removal efficiency of petroleum hydrocarbon from water waster by ozone/hydroxy radical was increased with higher flow rates and lower percentages of suspended solids. Optimal efficiency was achieved at $80L\;min^{-1}$ flow rate for 4 hours for the 5% suspended solids, and $120L\;min^{-1}$ for 6 hours for the 10% suspended solids. These results verified the efficiency of hydroxy radical in removing TPH and the applicability of the ozone/hydroxy radical reaction system in the field.

The Removal of Petroleum Hydrocarbon from Fine Soil in Soil Washing Water using Advanced Oxidation Processes

장관순 한국토양비료학회 2014 한국토양비료학회지 Vol.47 No.5

This study was performed to test the applicability of the ozone/hydroxy radical reaction system, which appliedadvanced oxidation processes, to remove total petroleum hydrocarbon (TPH) from the fine soil in washingwater of the soil washing process. Removal efficiency was tested on 40 L of washing water in a pilot reactiontank. Fine soil contaminated with 800 mg kg-1 TPH was prepared at 5% and 10% suspended solids. Testingconditions included ozone/hydroxy radical flow rates of 40, 80, and 120 L min-1, and processing time of 2 to12 hours. The removal efficiency of petroleum hydrocarbon from water waster by ozone/hydroxy radical wasincreased with higher flow rates and lower percentages of suspended solids. Optimal efficiency was achievedat 80 L min-1 flow rate for 4 hours for the 5% suspended solids, and 120 L min-1 for 6 hours for the 10%suspended solids. These results verified the efficiency of hydroxy radical in removing TPH and theapplicability of the ozone/hydroxy radical reaction system in the field.