황화수소와 암모니아를 함유한 악취폐가스의 세미파일럿 규모 바이오필터 처리: 2. 분리 미생물들을 접종한 담체를 충전한 바이오필터 운전

임광희 ( Kwang Hee Lim ) 한국화학공학회 2014 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.52 No.2

황화수소와 암모니아를 포함한 악취폐가스를 처리하기 위하여 여러 semi-pilot 바이오필터 운전 조건 하에서 Bacilluscereus DAH-1056과 Arthrobacter sp. KDE-0311를 고정한 semi-pilot 바이오필터 시스템을 운전하였다. Semi-pilot 바이오필터 운전조건에서 Thiobacillus sp. IW와 반송슬러지를 고정한 바이오필터의 황화수소 removal efficiency는 약80%이었고 암모니아의 removal efficiency는 약 50% 정도이었던 반면에 Bacillus cereus DAH-1056과 Arthrobacter sp. KDE-0311를 고정한 본 연구에서 황화수소의 removal efficiency는 약 90%이었고 암모니아의 removal efficiency는 약60% 정도이었다. 따라서 본 연구에서 Thiobacillus sp. IW와 반송슬러지를 고정한 semi-pilot 바이오필터의 경우를 기준으로 황화수소 및 암모니아의 removal efficiency가 각각 약 13% 및 20% 정도 제고되었다. 또한 본 연구에서는 암모니아의 최대 elimination capacity가 약 35 g/m3/h로서 Thiobacillus sp. IW와 반송슬러지를 고정한 semi-pilot 바이오필터의 경우보다 3~5 g/m3/h 정도 제고되어 10~17% 더욱 높았다. 한편 본 연구의 황화수소의 최대 elimination capacity는 약 63 g/m3/h 정도로 약 15% 증가하였다. 본 연구에서는 같은 inlet load의 황화수소라 할지라도 높은 농도의 황화수소가 낮은 농도의 황화수소보다 바이오필터의 암모니아 처리를 더 어렵게 하거나, 같은 inlet load의 암모니아라 할지라도 낮은 농도의 암모니아의 경우가 높은 농도의 암모니아보다 더 큰 removal efficiency와 elimination capacity를갖는 것이 관찰되었다. 본 연구에서의 황화수소 최대처리용량은 황화수소와 암모니아를 동시처리 하였음에도 불구하고 황화수소만을 바이오필터로 처리한 선행연구에서의 황화수소 최대처리용량을 초과하거나 비슷하였다. 또한 본 연구에서는 바이오필터로 황화수소와 암모니아를 동시처리한 선행연구보다 더 높은 암모니아 제거용량을 보였다. A semi-pilot biofilter inoculated with the microbes consortium of Bacillus cereus DAH-1056 and Arthrobacter sp. KDE-0311 was operated under various operating conditions in order to treat malodorous waste air containing both hydrogen sulfide and ammonia. When both hydrogen sulfide and ammonia contained in malodorous waste air were treated simultaneously by semi-pilot biofilter inoculated with Thiobacillus sp. IW and return-sludge, the removal efficiencies of hydrogen sulfide and ammonia were ca. 80% and ca. 50%, respectively. On the other hand, in this study, there moval efficiencies of hydrogen sulfide and ammonia were ca. 90% and ca. 60%, respectively. Therefore, the removal efficiencies of hydrogen sulfide and ammonia were enhanced by ca. 13% and 20%, respectively, compared to the semipilot biofilter inoculated with Thiobacillus sp. IW and return-sludge. In addition, in this study, the maximum elimination capacities of hydrogen sulfide and ammonia were enhanced by ca. 15% (8 g/m3/h) and 10~17% (3~5 g/m3/h), respectively. In this study, it was observed either that in case of even a same inlet load of hydrogen sulfide, a higher concentration of hydrogen sulfide causes more difficulties in treating ammonia containing in waste air than a lower one, or that in case of even a same inlet load of ammonia, a lower concentration of ammonia results in higher removal efficienciy and elimination capacity than a higher one. Even though hydrogen sulfide and ammonia were treated simultaneously by a biofilter in this study, the maximum elimination capacity of hydrogen sulfide in this study exceeded or was similar to that in previous study of biofilter treating only hydrogen sulfide. In addition, this study showed the higher maximumelimination capacity of ammonia than other previous investigation of biofilter treating hydrogen sulfide and ammoniasimultaneously.

캐나다 온타리오주 코발트 지역의 휴로니안 퇴적암에 발달한 황화물 광화작용에 관한 연구

김원사 한국광물학회 2006 광물과 암석 (J.Miner.Soc.Korea) Vol.19 No.3

Base metal sulfides occur in the Huronian sedimentary rocks that cover the Archean volcanic rocks in the Cobalt area, Ontario, Canada. They are mostly concentrated in the basal conglomerate which was formed in the pre-Huronian basin structure. Sulfide occurrence can be grouped as massive sulfide clasts in the basal and Coleman conglomerate, disseminated sulfides throughout the sediments, and disseminated sulfides near Ag-Co-Ni-As carbonate veins. Detrital mechanism can explain features such as angularity of sulfide fragments and graded bedding of dissemnated sulfides. Sulfides concentrated near carbonate veins are probably of hydrothermal origin. Nearby strata-bound type massive sulfide ore deposits and mineralized interflow units are the most probable sources for syngenetic sulfides. This is supported by the angularity of sulfide fragments, presence of massive sulfide boulders which are identical in mineralogy and texture to the strata-bound type sulfide deposits in the Archean basement, and a similar composition of sphalerite in the Archean volcanic rocks and Huronian sedimentary rocks. Some sulfide grains, especially in sandstones and argillites, were undergone recrystallization during the intrusion of the Nipissing diabase.

Acidithiobacillus thiooxidans AZ11의 황화계 악취가스 제거 특성

류희욱,이은영,조경숙 한국냄새환경학회 2003 실내환경 및 냄새 학회지 Vol.2 No.1

A deodorizing bacterium strain AZ11, which could degrade sulfur-containing malodorous gases, was isolated from the enrichment culture of soil suspension by the continuous supplying of hydrogen sulfide. It was identified to be Acidithiobacillus thiooxidans according to the results of the main fatty acids, quinone, and it's morphological, physiological, and nutritional characteristics. In order to investigate the applicability of the isolate to a deodorizing bacterium that could effectively treat high concentration of hydrogen sulfide for a long period, the growth and sulfur oxidizing characteristics of A. thiooxidans AZ11 were studied. When elemental sulfur was supplemented to the mineral salt medium as a sole energy source, the maximum specific sulfur oxidation rate of A. thiooxidans AZ11 was 22 g-S․g-DCW-1․d-1. Moreover, it was a sulfate-tolerant bacterium that could display sulfur oxidizing-activity when 80 g/L sulfate was accumulated in the medium. The removal of sulfur-containing odors by the biofilter inoculated with A. thiooxidans AZ11 was investigated. The maximum removal rates of hydrogen sulfide, methanethiol, and dimethyl sulfide were 424.8, 3.9 and 1.9×10-2 g-S․m-3․h-1, respectively. The maximum removal rate of hydrogen sulfide was 2.5~28 times higher than those of previously published biofilters, indicating that A. thiooxidans AZ11 was a very effective bacterium for biofiltration. 토양현탁액에 H2S 가스를 지속적으로 공급하여 순치시킨 집식배양액으로부터 분리한 AZ11 균주의 형태적․생리적․생화학적 특징 및 quinone과 세포벽의 주요 지방산 분석 결과, Acidithiobacillus thiooxidans로 동정되었다. 분리 균주 A. thiooxidans AZ11을 고농도의 황화계 악취를 장기간에 걸쳐 효과적으로 제거하는 탈취균주로 이용하기 위하여 황산염의 농도 증가에 따른 황산화특성을 알아보았다. 유일 에너지원으로 elemental sulfur를 첨가한 경우 22 g-S․g-DCW-1․d-1의 최대황산화속도를 보였으며, 황산염이 80 g/L로 축적되어도 황산화반응을 발휘할 수 있는 황산염 내성 균주이었다. A. thiooxidans AZ11을 접종한 세라믹 biofilter의 황화계 악취물질의 제거 특성을 조사한 결과, hydrogen sulfide, methanethiol 및 dimethyl sulfide 에 대한 최대제거속도는 각각 424.8, 3.9, 1.9×10-2 g-S․m-3․h-1이었다. A. thiooxidans AZ11를 이용하여 얻은 hydrogen sulfide 최대제거속도는 기존의 바이오필터 성능의 약 2.5~28 배에 해당되며, 이는 분리 균주가 biofiltration에 적용할 수 있는 매우 우수한 탈취 균주임을 의미한다.

Discriminative sensing of sulfide and azide ions in solution by a nitrobenzoxadiazole-dansyl dyad by simply tuning the water content

Jeong, Y.A.,Chang, I.J.,Chang, S.K. Elsevier Sequoia 2016 Sensors and actuators. B, Chemical Vol.224 No.-

A new chromogenic and fluorogenic probe for the discriminative signaling of sulfide and azide ions using a nitrobenzoxadiazole (NBD)-dansyl dyad 3 has been investigated. Probe 3 showed prominent colorimetric and fluorescence signaling behavior toward sulfide and azide ions in aqueous tetrahydrofuran (THF). Anion selectivity was controlled by the water content in THF. In a water rich system (H<SUB>2</SUB>O/THF=99:1, v/v), probe 3 reacted mainly with sulfide ions, owing to the sulfide-selective cleavage of the NBD-OSO<SUB>2</SUB>Ar bond, to yield the pink-colored NBD-SH and fluorescent dansyl acid. However, in water deficient conditions (H<SUB>2</SUB>O/THF=10:90, v/v), probe 3 exhibited both azide- and sulfide-selective reactions, due to the cleavage of the NBD-OSO<SUB>2</SUB>Ar bond, to yield either NBD-N<SUB>3</SUB> (for azide ions) or NBD-SH (for sulfide ions), and dansyl acid. Azide ions can be discriminatively signaled by selective excitation at the NBD-N<SUB>3</SUB> without interference from the sulfide signaling products. This selective signaling behavior is not affected by other anions that might be present in the environmental samples. To test the practical use of this probe, we created a test strip that could be used to detect sulfide and azide ions.

응집제 및 산화제를 이용한 하·폐수 용존성 황화물의 제거

김지슬,이은영,조경숙 한국냄새환경학회 2019 실내환경 및 냄새 학회지 Vol.18 No.4

Sulfide dissolved in wastewater is a potential source of hydrogen sulfide. Hydrogen sulfide is an odorous substance that causes civil complaints and is a dangerous substance that threatens the corrosion of structures and the safety and health of workers. The removal efficiencies of the chemical oxidant and the coagulants were compared to evaluate the removal of dissolved sulfide. Since the effectiveness may vary depending on the characteristics of the wastewater, water was used as a control, and 5 mg/L of dissolved sulfide was dissolved in water and sewage wastewater. When oxidant was used, the results showed a high sulfide removal rate in sewage wastewater than water, and the removal efficiency was enhanced with increasing oxidant concentration. Sulfide removal efficiencies after one hour after injecting oxidants H2O2, NaOCl, NaClO2 to sewage wastewater were 70%, 90%, and 100%, respectively. After the oxidants were administered four times, the removal was 90%, 100%, and 100%, respectively. In the case of sulfide removal with the oxidizing agent, the removal efficiency was NaClO2, NaOCl, H2O2 (highest -lowest). NaClO2 showed 100% removal efficiency within 10 minutes under all conditions (A condition, B condition), making it the most sewage effective agent in this study. In the case of the coagulants, 100% of the sulfides dissolved in water were removed in the first 10 minutes under all conditions. In sewage wastewater, FeCl2 and FeSO4 also showed 100% removal efficiency under all conditions after one hour, and FeCl3 showed 90% and 99% removal rates under A and B conditions, respectively. That is, the monovalent iron coagulants (FeCl2, FeSO4) were found to be somewhat more effective in the removal of sulfides in sewage wastewater than the divalent iron (FeCl3) coagulants. When the sulfides were removed with coagulants, FeCl2 had the highest removal efficiency followed by FeSO4 and FeCl3. Moreover, it was found that NaClO2 has the best reaction efficiency at the minimum reaction time and the reaction concentration.

Effect of sulfidation and dissolved organic matters on toxicity of silver nanoparticles in sediment dwelling organism, Chironomus riparius

Lee, S.W.,Park, S.Y.,Kim, Y.,Im, H.,Choi, J. Elsevier Pub.Co 2016 Science of the Total Environment Vol.553 No.-

The properties, fate, and toxicity of silver nanoparticles (AgNPs) are readily modified in the environment. Thus, in order to predict the environmental impact of AgNPs, the toxicity test should be conducted to assess the interactions of AgNPs with environmental matrices. Dissolved organic matter (DOM) is known to mitigate AgNPs toxicity in natural systems, and it is also known that silver binds strongly to sulfur. Little is known, however, about the effect of sulfidation and to what extent it could compete with DOM in the sediment. We therefore investigated the effect of sulfide on a sediment dwelling organism, Chironomus riparius using ecotoxicity endpoints. We then investigated how sulfide and a combination of sulfide and DOM affect the toxicity of AgNPs in C. riparius. We also monitored the concentrations of silver in the water and sediment compartments, as well as in C. riparius tissue, in the presence and absence of sulfide. Finally, in order to investigate how sulfide and DOM affect the release of ions from AgNPs, we also monitored released Ag<SUP>+</SUP> in each treatment. In the presence of sulfide, AgNPs were found to be less toxic to C. riparius in acute and chronic endpoints than AgNPs alone, whereas DOM treatment did not modulate the toxicity of AgNPs. Sulfide treatment reduced the release of Ag<SUP>+</SUP> from AgNPs. Water-spiked AgNPs with sulfide were found to be more slowly incorporated into both sediment and larvae as compared to the AgNP alone. Overall, the results suggest that the presence of sulfide in sediment mitigates the ecotoxicity of AgNPs in C. riparius.

CIGS 태양전지 버퍼층으로의 활용을 위한 인듐설파이드의 전기화학적 합성

김현진,김규원,Kim, Hyeon-Jin,Kim, Kyu-Won 한국전기화학회 2011 한국전기화학회지 Vol.14 No.4

Copper indium gallium selenide (CIGS) 기반 박막 태양전지는 저렴한 제작 단가 및 다른 박막 태양전지에 비해 높은 효율을 보여 실리콘 기반 태양전지의 차세대 태양전지로 각광을 받고 있다. 구성 요소 중 buffer 층은 window 층과 absorber 층 사이의 높은 밴드 갭(band gap)을 해소 해주는 역할을 한다. 기존의 cadmium sulfide(CdS)의 인체 유해성 때문에 이를 대신할 indium sulfide(In2S3)를 이용한 buffer 층의 연구가 활발히 진행되고 있다. 본 연구에서는 전기화학적인 방법을 통해 값싸고 간편하게 indium sulfide buffer 층을 전극 표면에 합성하는 연구를 진행하였다. Indium-Tin-Oxide(ITO) 전극표면을 sodium thiosulfate 및 indium sulfate의 혼합물 용액에 담그고 환원 전위를 인가하여 indium sulfide를 합성하였다. 크기가 다른 두 전압을 교대로 인가하여 확산 한계(diffusion limit)를 최소화 함으로써 표면에 균일한 조성을 가지는 buffer 층을 합성해 낼 수 있었다. 또한 합성 중 온도의 조절을 통해 buffer 층의 밴드 갭을 최적화 할 수 있었다. 이렇게 전기화학적으로 합성된 buffer 층은 X-선 광전자 분광법과 회절법의 분석을 통해 ${\beta}$-indium sulfide 결정구조를 가짐을 확인 하였다. CIGS solar cells are kind of thin film solar cells, which are studied several years. CdS buffer layer that makes heterojunction between window layer and absorbing layer was one of issue in the CIGS solar cell study. New types of buffer layer consisted of indium sulfide are being studied these days owing to high price and environmental harmful of CdS. In this study, we demonstrated electrochemical synthesis of indium sulfide film as a buffer layer, which is cheaper and faster than other methods. A uniform indium sulfide film was obtained by applying two different alternating potentials. The band gap of the film was optimized by controlling temperature during the electrochemical synthesis. Using x-ray photoelectron spectroscopy and diffraction method we confirmed that ${\beta}$-indium sulfide was formed on ITO electrode surface.

황화수소와 암모니아를 함유한 악취폐가스의 세미파일럿 규모 바이오필터 처리: 1. Thiobacillus sp. IW 및 반송슬러지를 고정한 담체를 충전한 바이오필터 운전

이은주 ( Eun Ju Lee ),박혜리 ( Hye Ri Park ),임광희 ( Kwang Hee Lim ) 한국화학공학회 2013 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.51 No.5

퇴비공장 또는 공공시설에서 발생되는 악취폐가스의 대표적인 제거대상 오염원인 황화수소와 암모니아를 포함한 악취폐가스를 처리하기 위하여 여러 운전 조건 하에서의 Thiobacillus sp. IW 및 반송슬러지를 고정한 담체를 충전한 semi-pilot 바이오필터 시스템을 운전하였다. Semi-pilot 바이오필터 운전 초반 및 중반에서는 황화수소 제거효율은 암모니아 부하와 무관하였으나, 암모니아 제거효율은 황화수소 부하가 커짐에 따라서 감소하였다. 그럼에도 불구하고 semi-pilot 바이오필터 운전 후반에서는 황화수소 부하가 커짐에도 불구하고 암모니아 제거효율이 영향을 받지 않았다. 이것은 semi-pilot 바이오필터 운전 후반의 buffer solution의 지속적 투입으로 인하여 semi-pilot 바이오필터담체의 산성화가 크지 않음에 기인한다고 간주된다. Semi-pilot 바이오필터시스템으로 황화수소와 암모니아의 동시제거를 할 때에 황화수소와 암모니아의 최대 elimination capacity 값은 각각 약 58 및 30 g/m3/h이었다. 이와 같이 semi-pilot 바이오필터 운전에 의하여 황화수소와 암모니아를 동시 제거한 경우에는 실험실규모 바이오필터의 유사한 운전조건 하에서 둘중의 하나만을 함유한 경우보다 제거용량이 각각 약 39와 46% 만큼 감소하여서, 황화수소와 암모니아를 동시 제거한 경우에 암모니아 최대제거용량이 황화수소 최대제거용량보다 7% 만큼 더 감소하였다. A semi-pilot biofilter packed with media with immobilized Thiobacillus sp. IW and return sludge, was operated under various operating conditions in order to treat malodorous waste air containing both hydrogen sulfide and ammonia which are major air pollutants emitted from composting factories and many publicly owned treatment works (POTW). At the incipient and middle stages of a semi-pilot biofilter operation, the hydrogen sulfide-removal efficiency behaves regardless of an inlet-load of ammonia. However, the ammonia-removal efficiency decreased as an inlet-load of hydrogen sulfide increased. Nevertheless, at the final stage of the semi-pilot biofilter operation, the ammonia-removal efficiency was not affected by the increase of hydrogen sulfide-inlet load. It is attributed to that a serious acidification of semi-pilot biofilter-media did not occur due to continuous injection of buffer solution at the final stage of the semi-pilot biofilter operation. When both hydrogen sulfide and ammonia contained in malodorous waste air were treated simultaneously by semi-pilot biofilter, the maximum elimination capacities of hydrogen sulfide and ammonia turned out to be ca. 58 and 30 g/m3/h, respectively. These maximum elimination capacities were estimated to be ca. 39 and 46% less than those for lab-scaled biofilter-separate elimination of hydrogen sulfide and ammonia, respectively. Thus, for the simultaneous biofilter-treatment of hydrogen sulfide and ammonia, the maximum elimination capacity of ammonia decreased by 7% more than that of hydrogen sulfide.

전자코와 GC/MS에 의한 가시파래 향기 성분 분석

백승연(Seung Yeon Baek),윤성유(Sung Yoo Youn),오재순(Jae Soon Oh),오성욱(Sung Wok Oh),김다희(Da Hee Kim),김수진(Su Jin Kim),김미리(Mee Ree Kim) 한국식품영양과학회 2020 한국식품영양과학회지 Vol.49 No.4

국내산 가시파래는 비타민, 무기질, 생리활성물질들이 풍부하여 다양한 식품에 첨가되어 연구가 되고 있지만 산업화 및 상품화에 어려움이 있어 향 성분을 분석하고자 하였다. 국내산 가시파래의 향 성분을 분석하기 위해 GC/MS와 전자코를 이용하였다. GC/MS에 의해 검출된 향 성분은 총 47가지로 함황 화합물 2가지, 알데하이드류 14가지, 알코올류4가지, 케톤류 9가지, 기타 18가지 화합물이 검출되었다. 그중 가장 넓은 peak 면적을 차지한 것은 methyl sulfide로 95.88%를 차지했으며 dimethyl sulfoxide도 검출되었고 두 화합물 모두 methionine에서 유래되었을 것으로 생각된다. 또한 heptanal, hexanal, hexenal, pentenal, octanal, heptadienal이 검출되었는데, 이는 가시파래에 함유된 다가불포화지방산이 lipoxygenase에 의해 반응하여 생성된 휘발성 화합물일 것으로 생각되며 lipoxygenase에 의해 생성되는 저급 알데하이드류는 풋내뿐만 아니라 비린내의 원인이 되므로 가시파래의 lipoxygenase를 불활성화시킨다면 알데하이드류에 의한 비린내는 감소할 것으로 생각된다. 또한 1-penten-3-ol, 1-octen-3-ol, 2,6-dimethylcyclohexanol, 1,2-cyclohexanediol도 검출되었는데, 과산화물의 분해물인 알데하이드류의 환원반응에 의해서 생성된 것으로 생각된다. 지방의 산화에 의해 생성된 화합물들에 대해서는 전자코 분석에서도 hexenal, heptenal, heptadienal, pentenol, octanol 등이 검출되어 유사한 결과가 나타났다. 또한 가시파래의 향기 성분을 극대화하기 위한 방법으로 증류수를 처리하여 향 성분을 비교하였고 증류수를 처리 시에 대부분의 향 성분의 peak 면적이 유의적으로 증가하였다. 증류수 첨가 시에는 (E)-2-heptenal, (E)-2-octenal, 2-methylbutanal이 검출되었는데, 이는 증류수 처리에 의해 수분 함량 및 수분 활성도가 증가하여 lipoxygenase의 활성이 증가했기 때문으로 사료된다. 또한 증류수 처리 시에는 fenchol이 검출되었으며, 2-methylfuran, 2-ethylfuran, methional, pent-1-en-3-ol, pyridine의 면적이 증가하였는데 해당 성분들이 가시파래 고유의 풍미를 증진시킬 것으로 생각된다. 관능평가 결과 전자코 결과와 유사한 radar plot을 나타내었고 증류수 처리 시 가시파래 향과 비린향의 강도가 유의적으로 증가하였다. 또한 전반적인 수용도에서 가시파래 분말은 3.9, 증류수 처리 시에 5.0으로 유의적으로 높게 나타났다. GC/MS, 증류수를 처리한 가시파래의 전자코 분석과 관능평가 결과를 참고하여 가장 많이 나타난 향의 특성을 분류해 가시파래 향기 성분을 전자코로 분석했으며, dimethyl sulfide가 peak area의 75.0%를 차지하여 가장 많이 검출된 화합물로 나타나 GC/MS와 유사한 결과로 생각된다. 이상의 결과를 종합해 볼 때 가시파래의 향 성분은 주로 methionine에 의해 생성되는 dimethyl sulfide, methyl sulfide일 것으로 사료되며, 이외에 성분은 아미노산의 분해, 지방의 산화에 의해 영향을 받는 것으로 보인다. 또한 가시파래에 증류수를 처리했을 경우 향 성분이 더 많아지나 지방 산화에 의한 가시파래의 비린내를 제거 혹은 감소시키기 위한 처리 방법에 대해서는 추가적인 연구가 필요한 것으로 생각된다. Enteromorpha prolifera (EP) from Korea is rich in phytochemicals such as vitamins, minerals, phycocyanin, and chlorophyll, however, it has a fishy odor. The purpose of this study was to analyze the aromatic compounds of EP using gas-chromatography mass spectrometry (GC/MS) and electronic nose (E-nose). Forty-seven aromatic compounds were detected with GC/MS, and methyl sulfide, with the largest peak area, accounted for 95.88%. In addition, aldehydes and alcohols produced by lipoxygenase were detected in the GC/MS analysis. To further analyze aromatic compounds of EP using E-nose, it was treated with distilled water. After the treatment, the peak areas of all the aromatic compounds were increased. Especially, 2-methylfuran, 2-ethylfuran, methional, pent-1-en-3-ol, and pyridine were increased and (E)-2-heptenal, (E)-2-octenal, 2-methylbutanal, and fenchol were detected only with the distilled water treatment. The results of the sensory property tests showed that all the aromatic characteristics were intense, and the score of overall acceptability was 5.0 for distilled water treated EP, which was higher than that of EP powder. Based on the above results, of aromatic compounds and characteristics, aromatic compounds of EP were classified using E-nose. In the E-nose analysis, dimethyl sulfide accounted for 75.0% of the peak areas, and was the largest peak. Therefore, the main aromatic compound of EP is considered to be methionine-derived dimethyl sulfide and methyl sulfide, and it is thought to be affected by degradation of amino acid or oxidation of fats.

Evolution of copper isotopes in arc systems: Insights from lavas and molten sulfur in Niuatahi volcano, Tonga rear arc

Wang, Zaicong,Park, Jung-Woo,Wang, Xia,Zou, Zongqi,Kim, Jonguk,Zhang, Pingyang,Li, Ming Pergamon Press 2019 Geochimica et cosmochimica acta Vol.250 No.-

<P><B>Abstract</B></P> <P>Metal transfer from mantle wedge to primitive arc magmas and subsequent enrichment by magmatic fractionation and volatile exsolution are critical processes for mineralization in arc systems. Copper is one of the most important ore-forming elements whose behavior is sensitive to oxygen fugacity. Copper isotope composition (δ<SUP>65</SUP>Cu) may provide valuable insights into Cu transfer and enrichment in hydrous oxidized arc magmas. However, the extent of Cu isotopic variation in arc systems and its link to Cu transfer and enrichment for ore mineralization have been poorly explored. Here we report the Cu isotopes in basalts, dacites and molten sulfur in Niuatahi volcano, Tonga rear arc to address the issue. These samples, as well as associated black smoker chimneys, represent products of magmatic fractionation and degassing of hydrous oxidized arc magmas with ore mineralization.</P> <P>Sulfide-undersaturated differentiation of basalts in the Niuatahi and their high water content and oxygen fugacity suggest complete exhaustion of sulfides in the mantle source during fluxed melting and transfer of nearly all Cu, Ag and other chalcophile metals to the primary magmas. The δ<SUP>65</SUP>Cu of Niuatahi basalts thus reflect that of the mantle source. The basalts display δ<SUP>65</SUP>Cu of 0.01‰ to 0.17‰ (n = 3; external uncertainty of 0.05‰, 2sd), similar to mid-ocean ridge basalts (MORBs), komatiites and the depleted mantle (0.06 ± 0.20‰, 2sd). These results, together with their Cu contents indistinguishable from MORBs, suggest that oxidized slab components are very likely to have limited influence on the Cu budget and mean δ<SUP>65</SUP>Cu of the mantle wedge.</P> <P>The Niuatahi magma became sulfide saturated after magnetite crystallization during magma differentiation from basalt to dacite. Constant Cu/Ag in the basalts and dacites suggests segregation of immiscible sulfide melts instead of crystalline sulfides. The sulfide segregation significantly decreased contents of Cu and other chalcophile metals but hardly changed δ<SUP>65</SUP>Cu in dacites (−0.01‰ to 0.35‰, n = 11 with a mean of 0.21 ± 0.24‰, 2sd), implying restricted fractionation of δ<SUP>65</SUP>Cu during magnetite fractionation and sulfide melt segregation. Molten sulfurs, which are formed by intensive magmatic degassing of arc lavas and characterized by substantial enrichment of Cu and other metals, show δ<SUP>65</SUP>Cu of 0.30‰ to 0.37‰. These values are indistinguishable from those of comagmatic dacites (0.34‰). Although the published δ<SUP>65</SUP>Cu of sulfide chimneys in the Niuatahi appears slightly lighter (0.00‰ to 0.29‰ ± 0.18‰, 2sd), the overall limited range of δ<SUP>65</SUP>Cu in molten sulfur and sulfide chimneys indicates that discharging magmatic volatiles and hydrothermal venting with significant removal of Cu hardly fractionates δ<SUP>65</SUP>Cu. The δ<SUP>65</SUP>Cu data from arc lavas, molten sulfur and sulfide chimneys thus reveal limited variations in δ<SUP>65</SUP>Cu (within 0.35‰) during fluxed melting, magmatic fractionation, magma degassing and mineralization in arc systems. If these results represent general processes, they imply that the heavier or lighter δ<SUP>65</SUP>Cu in other sulfide chimneys and associated deposits should result from the complex hydrothermal processes and/or low-temperature secondary reworking.</P>