Shota Tajima, Tatsuya Kato, S. Fuchida, T. Kitagawa, C. Tokoro
Silica scale formation is one of the significant problems for the practical operation of geothermal plants because geothermal fluids used for the electricity generation often contain a high amount of silicic acid. Acidification of geothermal fluid (pH<6) is a general process to avoid silica scale formation; however, this could cause corrosion of metal pipes. In this study, we investigated the effect of pH and temperature (298–353 K) on the polymerization rate of silica and examined optimal pH and temperature conditions on the treatment process of waste geothermal fluids. When silica solution (500 mg/dm 3 ) reacted at different pH 3, 6, and 9 for 336 h, initial decrease patterns of dissolved silica concentrations (<0.1um) were different in pH condition at 298 K; it reduced to 200 and 400 mg/dm 3 at pH 6 and 9 within 48 h, respectively, whereas did not change at pH 3. This initial decrease of dissolved silica concentration is related to the nucleus growth in the early stage of silica polymerization, followed by the aggregation as the latter stage of the polymerization. At pH 6, since nucleus growth was most promoted at 298 K, the pseudo-equilibrium concentration of dissolved silica concentration gradually increased with increasing temperature and was 400 mg/dm 3 at 333 K. However, its rates were almost same at the pH. Furthermore, the induction periods until start to nucleus growth were prolonged with increasing temperature and its reaction did not start at 353 K. The pseudo-equilibrium concentration was represented the Van't Hoff equation. On the other hand, at pH 9, the pseudo-equilibrium concentration reduced from 400 mg/dm 3 at 298 K to 300 mg/dm 3 at 313 K, while no polymerization was found over 333 K. The
{"title":"Kinetic Modeling of pH and Temperature Effects on Silica Polymerization","authors":"Shota Tajima, Tatsuya Kato, S. Fuchida, T. Kitagawa, C. Tokoro","doi":"10.46427/gold2020.2529","DOIUrl":"https://doi.org/10.46427/gold2020.2529","url":null,"abstract":"Silica scale formation is one of the significant problems for the practical operation of geothermal plants because geothermal fluids used for the electricity generation often contain a high amount of silicic acid. Acidification of geothermal fluid (pH<6) is a general process to avoid silica scale formation; however, this could cause corrosion of metal pipes. In this study, we investigated the effect of pH and temperature (298–353 K) on the polymerization rate of silica and examined optimal pH and temperature conditions on the treatment process of waste geothermal fluids. When silica solution (500 mg/dm 3 ) reacted at different pH 3, 6, and 9 for 336 h, initial decrease patterns of dissolved silica concentrations (<0.1um) were different in pH condition at 298 K; it reduced to 200 and 400 mg/dm 3 at pH 6 and 9 within 48 h, respectively, whereas did not change at pH 3. This initial decrease of dissolved silica concentration is related to the nucleus growth in the early stage of silica polymerization, followed by the aggregation as the latter stage of the polymerization. At pH 6, since nucleus growth was most promoted at 298 K, the pseudo-equilibrium concentration of dissolved silica concentration gradually increased with increasing temperature and was 400 mg/dm 3 at 333 K. However, its rates were almost same at the pH. Furthermore, the induction periods until start to nucleus growth were prolonged with increasing temperature and its reaction did not start at 353 K. The pseudo-equilibrium concentration was represented the Van't Hoff equation. On the other hand, at pH 9, the pseudo-equilibrium concentration reduced from 400 mg/dm 3 at 298 K to 300 mg/dm 3 at 313 K, while no polymerization was found over 333 K. The","PeriodicalId":12817,"journal":{"name":"Goldschmidt Abstracts","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75620654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Petrogenesis and Element Mobility of Neoarchean Alkaline Granitic Gneisses in the Southeastern Margin of the North China Craton","authors":"Haiyan Su, Yican Liu, Yang Yang","doi":"10.46427/gold2020.2477","DOIUrl":"https://doi.org/10.46427/gold2020.2477","url":null,"abstract":"","PeriodicalId":12817,"journal":{"name":"Goldschmidt Abstracts","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75659932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Associated with an intense geological event from - 820 to 520 My, East Africa was the place of major metamorphism. It yielded several mineral resources including high-quality gemstones. Those treasures are markers of the geological conditions during their formation. A relatively common mineral -axinite- is found in Merelani (Tanzania) with a rare undocumented pink colour of mysterious origin with an uncommon orange luminescence. We have characterized two extremely rare “pink” axinites from the famous Merelani deposit with classical gemological methods, energy-dispersive analysis on a scanning electron microscope, UV-Visible, Raman and luminescence spectroscopies. We compared the two pink samples to three other crystals from Merelani and one axinite-(Fe) from Oisans (France). Chemical analysis revealed the two pink axinites corresponded to axinite-(Mg). The pink to purple colour is due to a large broad band centred around 550 - 560 nm. Its position and shape are typical for Mn 3+ . Manganese is present in both pink samples as Mn 2+ , and we surmise that radiation from nearby minerals or rocks converted some Mn 2+ into Mn 3+ . The orange luminescence -weaker under shortwave ultraviolet-of the six axinites is related to a broad emission band at 631 nm caused by Mn 2+ and the more unusual red luminescence is associated with two sharp peaks at 688 and 694 nm attributed to Cr 3+ . This unique mineralization expands our knowledge of the impact of local lithology on gemstone colour.
{"title":"Pink Axinite from Merelani, Tanzania:\u0000 a Natural Luminescent Mineral Irradiated in the Neoproterozoic Mozambique Metamorphic Belt","authors":"M. Vigier, E. Fritsch","doi":"10.46427/gold2020.2681","DOIUrl":"https://doi.org/10.46427/gold2020.2681","url":null,"abstract":"Associated with an intense geological event from - 820 to 520 My, East Africa was the place of major metamorphism. It yielded several mineral resources including high-quality gemstones. Those treasures are markers of the geological conditions during their formation. A relatively common mineral -axinite- is found in Merelani (Tanzania) with a rare undocumented pink colour of mysterious origin with an uncommon orange luminescence. We have characterized two extremely rare “pink” axinites from the famous Merelani deposit with classical gemological methods, energy-dispersive analysis on a scanning electron microscope, UV-Visible, Raman and luminescence spectroscopies. We compared the two pink samples to three other crystals from Merelani and one axinite-(Fe) from Oisans (France). Chemical analysis revealed the two pink axinites corresponded to axinite-(Mg). The pink to purple colour is due to a large broad band centred around 550 - 560 nm. Its position and shape are typical for Mn 3+ . Manganese is present in both pink samples as Mn 2+ , and we surmise that radiation from nearby minerals or rocks converted some Mn 2+ into Mn 3+ . The orange luminescence -weaker under shortwave ultraviolet-of the six axinites is related to a broad emission band at 631 nm caused by Mn 2+ and the more unusual red luminescence is associated with two sharp peaks at 688 and 694 nm attributed to Cr 3+ . This unique mineralization expands our knowledge of the impact of local lithology on gemstone colour.","PeriodicalId":12817,"journal":{"name":"Goldschmidt Abstracts","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75848621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Cesar, J. Wood, P. Humez, M. Nightingale, V. Becker, O. Ardakani, B. Mayer
{"title":"Stable Carbon Isotope Proxies for the Development of Unconventional Petroleum Reservoirs and the Protection of Groundwater Resources","authors":"J. Cesar, J. Wood, P. Humez, M. Nightingale, V. Becker, O. Ardakani, B. Mayer","doi":"10.46427/gold2020.347","DOIUrl":"https://doi.org/10.46427/gold2020.347","url":null,"abstract":"","PeriodicalId":12817,"journal":{"name":"Goldschmidt Abstracts","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74422992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chelsea W. Neil, M. Mehana, R. Hjelm, M. Hawley, Yimin Mao, H. Viswanathan, Q. Kang, Hongwu Xu
{"title":"Small-Angle Neutron Scattering Reveals Pressure-Dependent Methane Trapping in Shale","authors":"Chelsea W. Neil, M. Mehana, R. Hjelm, M. Hawley, Yimin Mao, H. Viswanathan, Q. Kang, Hongwu Xu","doi":"10.46427/gold2020.1905","DOIUrl":"https://doi.org/10.46427/gold2020.1905","url":null,"abstract":"","PeriodicalId":12817,"journal":{"name":"Goldschmidt Abstracts","volume":"64 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74533864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Deciphering Evolution of Polymetamorphic Terranes: The Western Carpathians Case Study","authors":"D. Plašienka, Š. Méres, Tomáš Potočný","doi":"10.46427/gold2020.2092","DOIUrl":"https://doi.org/10.46427/gold2020.2092","url":null,"abstract":"","PeriodicalId":12817,"journal":{"name":"Goldschmidt Abstracts","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74632622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Klöcking, K. Czarnota, P. Ball, D. Champion, D. Davies
{"title":"Spatio-Temporal Evolution of the Australian Lithosphere-Asthenosphere Boundary from Mafic Volcanism","authors":"M. Klöcking, K. Czarnota, P. Ball, D. Champion, D. Davies","doi":"10.46427/gold2020.1335","DOIUrl":"https://doi.org/10.46427/gold2020.1335","url":null,"abstract":"","PeriodicalId":12817,"journal":{"name":"Goldschmidt Abstracts","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74661788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Sial, Jiubin Chen, L. D. de Lacerda, C. Korte, Jorge Spnagenberg, J. C. Silva-Tamayo, C. Gaucher, V. Ferreira, J. Barbosa, N. Pereira, P. Riedel
Mercury (Hg/TOC) spikes from eight classical PTB sections display similar patterns across the extinction interval. At Meishan, these spikes are in the LPME and ETME while at Hovea-3, Ursula Creek, Idrijca and Rizvanu š a they are at the LPME and PTB. The Rizvanu š a section displays one peak at the ETME; Zal and Abadeh sections, at the LPME and ETME, while Misci shows enrichment at the LPME. Three Hg/TOC spikes are seen in the Stevns Klint, Gubbio, Um Sohringkew and Poty K/Pg sections: spike I within the CF2 biozone, spike II at the K/Pg boundary layer, and spike III within the P1a subzone. In a δ 202 Hg (MDF) vs ∆ 201 Hg (MIF) plot, most samples from the PT extinction interval lie within the volcanic-emission box. Hg-isotope signatures resulted from mixing of volcanic and normal marine sediment Hg, generating four trends whose ∆ 201 Hg show negligible variation. Rizvanu š a, Idrijca and Misci sections, closer to the STLIP,
{"title":"Globally Enhanced Hg Deposition and Hg Isotopes in the K/Pg and PT Boundaries: Link to Volcanism","authors":"A. Sial, Jiubin Chen, L. D. de Lacerda, C. Korte, Jorge Spnagenberg, J. C. Silva-Tamayo, C. Gaucher, V. Ferreira, J. Barbosa, N. Pereira, P. Riedel","doi":"10.46427/gold2020.2378","DOIUrl":"https://doi.org/10.46427/gold2020.2378","url":null,"abstract":"Mercury (Hg/TOC) spikes from eight classical PTB sections display similar patterns across the extinction interval. At Meishan, these spikes are in the LPME and ETME while at Hovea-3, Ursula Creek, Idrijca and Rizvanu š a they are at the LPME and PTB. The Rizvanu š a section displays one peak at the ETME; Zal and Abadeh sections, at the LPME and ETME, while Misci shows enrichment at the LPME. Three Hg/TOC spikes are seen in the Stevns Klint, Gubbio, Um Sohringkew and Poty K/Pg sections: spike I within the CF2 biozone, spike II at the K/Pg boundary layer, and spike III within the P1a subzone. In a δ 202 Hg (MDF) vs ∆ 201 Hg (MIF) plot, most samples from the PT extinction interval lie within the volcanic-emission box. Hg-isotope signatures resulted from mixing of volcanic and normal marine sediment Hg, generating four trends whose ∆ 201 Hg show negligible variation. Rizvanu š a, Idrijca and Misci sections, closer to the STLIP,","PeriodicalId":12817,"journal":{"name":"Goldschmidt Abstracts","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74758691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Terrestrial Plants δ13Corg and Environmental Changes: Two Case Studies from the Permian of Northern Italy","authors":"Giuseppa Forte, E. Kustatscher, N. Preto","doi":"10.46427/gold2020.730","DOIUrl":"https://doi.org/10.46427/gold2020.730","url":null,"abstract":"","PeriodicalId":12817,"journal":{"name":"Goldschmidt Abstracts","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72989871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marine Environmental Information (MEIS) System The Noksan Dam, built in 1934, blocks the flow of the West Nakdong River, and the Nakdong River Estuary (NRE) Dam (i.e. bank, dike, embankment, etc.) was completed between 1983 and 1987 to regulate the flow of the East Nakdong River [1]. Beginning in May 2015, the MEIS has been run in real time (1-s intervals) and has made periodic marine observations (one to four times a year). The real-time data consist of two items and the periodic marine observation data consist of five items [2].
{"title":"Characteristics of the Brackish Water Zone Using a MEIS System in the Nakdong River Estuary (NRE), Busan City, South Korea","authors":"Jun-Ho Lee, H. Woo, H. Jung","doi":"10.46427/gold2020.1436","DOIUrl":"https://doi.org/10.46427/gold2020.1436","url":null,"abstract":"Marine Environmental Information (MEIS) System The Noksan Dam, built in 1934, blocks the flow of the West Nakdong River, and the Nakdong River Estuary (NRE) Dam (i.e. bank, dike, embankment, etc.) was completed between 1983 and 1987 to regulate the flow of the East Nakdong River [1]. Beginning in May 2015, the MEIS has been run in real time (1-s intervals) and has made periodic marine observations (one to four times a year). The real-time data consist of two items and the periodic marine observation data consist of five items [2].","PeriodicalId":12817,"journal":{"name":"Goldschmidt Abstracts","volume":"86 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73057227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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