Acute toxicity assessment of camphor in biopesticides by using Daphnia magna and Danio rerio

임은채,김현조,김성준 환경독성보건학회 2014 환경독성보건학회지 Vol.29 No.-

Objectives An ecofriendly alternative to chemical pesticides is bio-pesticides, which arederived from natural sources. The interest in bio-pesticides is based on the disadvantagesassociated with chemical pesticides. Methods We conducted acute toxicity assessments of camphor, a major component ofbio-pesticides, by using Daphnia magna (D. magna) as well as assessed the morphologicalabnormalities that occurred in Danio rerio (D. rerio) embryos. Results The median effective concentration of camphor on D. magna after 48 hourswas 395.0 μM, and the median lethal concentration on D. rerio embryos after 96 hourswas 838.6 μM. The no observed effect concentration and predicted no effect concentrationof camphor on D. magna, which was more sensitive than D. rerio, were calculatedas 55.2 μM and 3.95 μM, respectively. Morphological abnormalities in D. rerio embryosexposed to camphor increased over time. Coagulation, delayed hatching, yolk sac edema,pericardial edema, and pigmentation of embryos mainly appeared between 24 and48 hours. Further, symptoms of scoliosis and head edema occurred after 72 hours. Inaddition, bent tails, ocular defects and collapsed symptoms of fertilized embryonic tissuewere observed after 96 hours. Conclusions The camphor toxicity results suggest that continuous observations on theecosystem are necessary to monitor toxicity in areas where biological pesticides containingcamphor are sprayed.

Acute Toxicity Assessment of New Algicides of Thiazolidinediones Derivatives, TD53 and TD49, Using Ulva pertusa Kjellman

임은채,박인택,한효경,김시욱,조훈,김성준 환경독성보건학회 2010 환경독성보건학회지 Vol.25 No.4

Objectives : This study was aimed to examine the acute toxicity assessment of two new algicides, thiazolidinediones derivatives (TD53 and TD49), which were synthesized to selectively control red tide, to the marine ecosystem. Methods : The assessment employed by a new method using Ulva pertusa Kjellman which has been recently accepted as a standard method of ISO. The toxicity was assessed by calculating the EC50 (Effective Concentration of 50%), NOEC (No Observed Effect Concentration) and PNEC (Predicted No Effect Concentration)using acute toxicity data obtained from exposure experiments. EC50 value of TD49 and TD53 was examined by 96-hrs exposure together with Solutol as a TD49 dispersing agent and DMSO as a TD53 solvent. Results : EC50 value of TD53 was 1.65 μM. From the results, values of NOEC and PNEC were calculated to be 0.63 μM and 1.65 nM, respectively. DMSO under the range of 0~10 μM, which is same solvent concentration used in examining TD53, showed no toxic effect. EC50 value of TD49 was 0.18μM and that of Solutol was 1.70 μM. NOEC and PNEC of TD49 were 0.08 μM and 0.18 nM, respectively and those for Solutol were 1.25 μM and 1.25 nM, respectively. Conclusions : From the values of NOEC, PNEC of TD53 and TD49, TD49 showed 9 times stronger toxicity than TD53. On the other hand, DMSO showed no toxicity on the Ulva pertusa Kjellman, but Solutol was found to be a considerable toxicity by itself.

Acute toxicity assessment of Osthol content in bio-pesticides using two aquatic organisms

임은채,김현조,김성준 환경독성보건학회 2014 환경독성보건학회지 Vol.29 No.-

Objectives This study focused on the assessment of acute toxicity caused by Osthol, amajor component of environment-friendly biological pesticides, by using two aquatic organisms. Methods The assessment of acute toxicity caused by Osthol was conducted in Daphniamagna and by examining the morphological abnormalities in Danio rerio embryos. Results The median effective concentration value of Osthol in D. magna 48 hours afterinoculation was 19.3 μM. The median lethal concentration of D. rerio embryo at 96hours was 30.6 μM. No observed effect concentration and predicted no effect concentrationvalues of Osthol in D. magna and D. rerio were calculated as 5.4 and 0.19 μM,respectively. There was an increase in the morphological abnormalities in D. rerio embryodue to Osthol over time. Coagulation, delayed hatching, yolk sac edema, pericardialedema, and pigmentation were observed in embryos at 24–48 hours. Symptoms of scoliosisand head edema occurred after 72 hours. In addition, bent tails, ocular defects,and symptoms of collapse were observed in fertilized embryo tissue within 96 hours. Ocular defects and pigmentation were the additional symptoms observed in this study. Conclusions Because Osthol showed considerable toxicity levels continuous toxicity evaluationin agro-ecosystems is necessary when bio-pesticides containing Osthol are used.

퇴적물 공극수의 Cd 제거를 위한 우분 바이오차의 적용

임은채,이재인,박성직 한국퇴적환경준설학회 2023 한국환경준설학회 학술대회논문집 Vol.2023 No.5

카드뮴(Cd)은 독성 중금속으로 자연에서 분해되지 않아 먹이사슬을 통해 인체에 유입될 수 있다. Cd이 인체에 축적될 경우 면역계와 호흡계 등에 손상을 유발한다. Cd은 많은 산업 공정 및 작업에서 사용된다. 산업 활동에 의해 발생된 폐수에는 고농도의 Cd이 포함되어 있다. 고농도의 Cd 폐수는 수역에 유입되어 퇴적물 공극수에 축적된다. 퇴적물 내에 축적된 Cd은 자연이나 인위적 활동에 의해 교란될 때 다시 수계로 방출되는 경향을 가진다. Cd의 방출을 막기 위한 처리 방법으로는 현장 피복 처리 방법이 있다. 현장 피복 처리 방법은 오염된 퇴적물의 표면을 피복재로 덮어서 처리하는 방법이다. 퇴적물과 수층 사이의 피복재를 통해 저서 유기체와 퇴적물을 격리시키고, 퇴적물의 재부유를 방지하여 퇴적물을 안정화하는 이점이 있다. 또한, 퇴적물의 이동이 불필요하여 준설에 대한 비용이 요구되지 않아 적은 비용으로도 중금속으로 오염된 퇴적물 정화가 가능하다. 현장 피복 방법의 더 높은 처리효율을 위해 흡착 소재를 함께 사용하기도 한다. 흡착은 저렴한 비용, 높은 제거 효율, 쉬운 유지 관리, 간단한 설계를 장점으로 하는 오염물질 제거 공정이다. 바이오차는 다공성 구조를 특징으로 하여 높은 표면적을 가지며, 저비용의 공급원료를 사용할 수 있어 많은 관심을 받는 흡착 소재이다. 우분을 활용한 바이오차는 폐기물을 활용하기 때문에 경제적이고, 높은 회분 함량과 양이온 교환 용량을 갖는 것이 특징이다. 본 연구에서는 Cd으로 오염된 퇴적물을 효과적으로 처리하기 위한 피복 소재로 우분 바이오차의 사용 가능성을 평가하였다. 우분 바이오차는 Cd 제거에 효과적인 흡착 성능을 보이며, 피복 소재로써 적합한 것으로 판단된다.

열분해된 굴 폐각을 이용한 암모니아 고정화

임은채,이재인,박성직 한국퇴적환경준설학회(구 한국환경준설학회) 2022 한국환경준설학회 학술대회논문집 Vol.2022 No.11

수성 환경에서의 암모니아는 일반적으로 암모늄(NH4+)의 형태로 존재한다. 암모늄과 같은 영양소의 자연 수계로의 배출 증가는 부영양화에 크게 기여한다. 영양소의 해로운 영향에 대한 인식과 이해가 높아짐에 따라 폐수 처리 시설 및 기타 점오염원 기여자로부터 영양소 배출을 제한하는 엄격한 법률이 도입되었으며, 영양소의 효율적인 제거가 필요하다. 수역에서의 암모늄 제거로 널리 사용되는 공정은 생물학적 처리이다. 생물학적 처리의 효율성에도 불구하고 넓은 반응기 부피 필요와 반응 과정이 느리기 때문에 많은 자본을 필요로 한다. 기존의 생물학적 공정을 대체하는 효과적인 공정의 개발은 매우 중요한 실정이다. 퇴적물 내에 존재하는 암모늄을 제거하기 위해 현장에서 일반적으로 사용되는 현장 피복 기술은 저 비용으로 즉각적인 제거 효율을 나타낸다. 피복 기술을 통한 오염물질의 높은 제거 효율을 위해서는 우수한 흡착제가 필요하다. 흡착 공정은 저가의 비용으로 높은 제거 효율을 가지며, 유지 및 관리가 용이하기 때문에 수중의 오염물 제거에 널리 사용되는 공정이다. 암모늄을 흡착공정으로 제거하기 위해 사용되는 흡착제로는 활성탄, 이온 교환수지, 아타풀자이트, biochar 등이 연구되고 있다. 본 연구에서 천연 흡착제로 굴 폐각을 사용하였고, 무산소 조건에서 다양한 열분해 온도 조건에 따라 제조하였다. 다양한 열분해 온도 조건에서 제조된 굴 폐각과 90 m/L의 암모니아 용액을 반응시켰다. 0-500°C 범위의 열분해 온도에서는 암모니아 흡착량이 나타나지 않았지만, 600°C에서부터 암모니아 흡착량이 나타나기 시작했다. 800°C와 900°C에서 열분해된 굴 폐각이 다른 열분해 온도 조건보다 수중에 존재하는 암모니아에 대한 높은 제거 효율을 보였다. 열분해된 굴 폐각은 수중에 존재하는 암모니아 제거에 대한 가능성을 보였으며, 녹색 흡착제로써 적용이 가능하다고 판단된다.

신규 살조물질인 Thiazolidinedione 유도체 (TD49)의 해양생태계에 대한 급성독성평가

임은채(Eun-Chae Yim),신준재(Jun-Jae Shin),박인택(In-Taek Park),한효경(Hyo-Kyung Han),김시욱(Si-Wouk Kim),조훈(Hoon Cho),김성준(Seong-Jun Kim) 한국생물공학회 2010 KSBB Journal Vol.25 No.6

A thiazolidinedione derivative, TD49 with the highly selective algicide to red tide was newly synthesized and its acute toxicity was examined in order to evaluate the effect on aquatic ecosystems of coast. Major three species having important role in the food chain of marine ecosystem, such as Skeletonema costatum of microalgae, Daphnia magna of crustacea, Paralichthys olivaceus of flatfish fingerling were employed for the acute toxicity assessment. EC50 or LC50 as the assessment criterion was investigated to each specie, and NOEC (No Observed Effect Concentration) and PNEC (Predicted No Effect Concentration) from most sensitive specie to toxicity of TD49 were further calculated. EC50 of S. costatum in 96-hour, EC50 of D. magna in 48-hour, and LC50 of P. olivaceus in 72-hour for TD49 were 0.34 μM, 0.68 μM, and 0.58 μM, respectively. NOEC from the results of S. costatum was estimated to be 0.20 μM and PNEC was estimated as 3.40 nM by applying factor value of 100 to EC50 0.34 μM of S. costatum. In addition, it was revealed that Solutol used as the dispersing agent of TD49 had very little toxic influence under the concentration range of 0~0.4 μM used in TD49 toxicity experiment. Although the estimated concentration of TD49 that will be sprayed onto the coastal field for the algicide is higher than NOEC value, it is considered that the spraying concentration would not be a considerable problem due to a dilution effect by tide at the opened coast.

Graphene의 물리적 분산과 화학적 표면 개질 연구

임은채 ( Eun Chae Yim ),김성준 ( Seong Jun Kim ) 한국화학공학회 2015 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.53 No.6

Graphene has a wide spectrum on its application field due to various and excellent physical properties. However, it is very difficult to apply that graphene exists as lump or fold condition in general organic solvents. Besides, graphene was difficult to maintain as uniform condition due to chemical inert and distributions with various size and shapes. Therefore, this study was focused to study dispersion and modifying methods of aggregated graphene. The dispersion methods contain as follow: i) physical milling using glass bead, ii) co-treatment of glass bead and ultrasonic waves, iii) dispersion in organic solvents, iv) modifying with dry-ice. Milling using glass bead with size 2.5 mm was effective to be size decrease of 36.4% in comparison with control group. Mixed treatment of glass bead (size 2.5 mm) and ultrasonic waves (225W, 10 min) showed relative size decrease of 76%, suggesting that the size decrease depends on the size of glass bead, intensity of ultrasonic waves and treatment time. Solvents of Ethyl acetate (EA) and Isoprophyl alcohol (IPA) were used in order to improve dispersion by modifying surface of graphene. IPA of them showed a favorable dispersion with more -CO functional groups in the FT-IR analysis. On the other hand, the oxygen content of graphene surface modified by dry-ice was highly increased from 0.8 to 4.9%. From the results, it was decided that the favorable dispersion state for a long time was obtained under the condition of -CO functional group increase in IPA solvent.

Graphene의 플라즈마 표면 개질과 박테리아 셀룰로오스와의 결합성 검토

임은채 ( Eun Chae Yim ),김성준 ( Seong Jun Kim ),오일권 ( Ii Kwon Oh ),기창두 ( Chang Doo Kee ) 한국화학공학회 2013 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.51 No.3

The study was focused to evaluate the possibility for combination membrane of bacterial cellulose (BC) and graphene with high electrical properties. BC with natural polymer matrix was known to have strong physical strength. For the combination of graphene with BC, the surface of graphene was modified with oxygen plasma by changing strength and time of radio waves in room temperature. Water contact angle of modified graphene grew smaller from 130o to 12o. XPS analysis showed that oxygen content after treatment increased from 2.99 to 10.98%. Damage degree of graphene was examined from ID/IG ratio of Raman analysis. ID/IG ratio of non-treated graphene (NTG) was 0.11, and 0.36 to 0.43 in plasma treated grapheme (PTG), increasing structural defects of PTG. XRD analysis of PTG membrane with BC was 2θ same to BC only, indicating chemically combined membrane. In FT-IR analysis, 1,000 to 1,300 cm-1 (C=O) peak indicating oxygen radicals in PTG membrane had formed was larger than NTG membrane. The results suggest that BC as an alternation of plastic material for graphene combination has a possibility in some degree on the part like transparent conductive films.

Bacterial cellulose를 기반으로 하는 투명전도성막의 제조 및 특성평가

임은채 ( Eun Chae Yim ),김성준 ( Seong Jun Kim ),기창두 ( Chang Doo Kee ) 한국화학공학회 2013 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.51 No.6

A transparent film was fabricated based on bacterial cellulose (BC), BC has excellent physical strength and stability at high temperature and it is an environmental friendly flexible material. In order to improve the conductivity, silver nanowire (AgNW) and/or graphene were introduced to the BC membrane. The aspect ratio of the AgNW synthesized in this study was 214, with a length of 15 μm and width of 70 nm. The higher aspect ratio improved the conductivity by reducing the contact resistance. The thermal and electrical properties of 7 types of films prepared were investigated. Each film was fabricated with rectangular shape (2 mm × 2 mm × 50 μm). The films were scored with a net shape by a knife, and filled with AgNW and graphene to bestow conductivity. The film filled with AgNW showed favorable electrical characteristics with a thickness of 350 μm, electron concentration of 1.53×1019, electron mobility of 6.63×105, and resistivity of 0.28. The film filled with graphene had a thickness of 360 μm, electron concentration of 7.74 ×1017, electron mobility of 0.17, and resistivity of 4.78. The transmittances at 550 nm were 98.1% and 80.9%, respectively. All the films were able to light LEDs bulbs although their brightness differed. A thermal stability test of the BC and PET films at 150±5 oC showed that the BC film was more stable, whereas the PET film was quickly banded. From these results, it was confirmed that there it is possible to fabricate new transparent conductivity films based on BC.

MMFAN : 감정인식을 위한 멀티모달 융합 어텐션 네트워크

임은채(Eun-Chae Lim),판트 수다르산(Sudarshan Pant),응웬 당 칸(Dang-Khanh Nguyen),권시온(Zion Kwon),양형정(Hyung-Jeong Yang),김수형(Soo-Hyung Kim),김애라(Aera Kim) 한국정보과학회 2023 한국정보과학회 학술발표논문집 Vol.2023 No.6