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A unique subseafloor microbiosphere in the Mariana Trench driven by episodic sedimentation

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Marine Life Science & Technology 2024年第1期6卷 168-181页

作者： Jiwen Liu Da-Wei Li Xinxin He Ronghua Liu Haojin Cheng Chenglong Su Mengna Chen Yonghong Wang Zhongsheng Zhao Hanyue Xu Zhangyu Cheng Zicheng Wang Nikolai Pedentchouk David J.Lea-Smith Jonathan D.Todd Xiaoshou Liu Meixun Zhao Xiao-Hua Zhang Frontiers Science Center for Deep Ocean Multispheres and Earth System and College of Marine Life SciencesOcean University of ChinaQingdao 266003China Laboratory for Marine Ecology and Environmental Science Laoshan LaboratoryQingdao 266237China Institute of Evolution and Marine Biodiversity Ocean University of ChinaQingdao 266003China Key Laboratory of Marine Chemistry Theory and Technology Ministry of EducationOcean University of ChinaQingdao 266100China Key Lab of Submarine Geosciences and Prospecting Techniques Ministry of Education/College of Marine GeosciencesOcean University of ChinaQingdao 266100China Key Laboratory of Physical Oceanography Ministry of Education/Research Vessel CentreOcean University of ChinaQingdao 266100China School of Environmental Sciences University of East AngliaNorwich NR47TJUK School of Biological Sciences University of East AngliaNorwich NR47TJUK

Hadal trenches are characterized by enhanced and infrequent high-rate episodic sedimentation events that likely introduce not only labile organic carbon and key nutrients but also new microbes that significantly alter the subseafloor microbiosphere.Currently,the role of high-rate episodic sedimentation in controlling the composition of the hadal subseafloor microbiosphere is unknown.Here,analyses of carbon isotope composition in a~750 cm long sediment core from the Challenger Deep revealed noncontinuous deposition,with anomalous ^(14)C ages likely caused by seismically driven mass transport and the funneling effect of trench geomorphology.Microbial community composition and diverse enzyme activities in the upper~27 cm differed from those at lower depths,probably due to sudden sediment deposition and differences in redox condition and organic matter availability.At lower depths,microbial population numbers,and composition remained relatively constant,except at some discrete depths with altered enzyme activity and microbial phyla abundance,possibly due to additional sudden sedimentation events of different magnitude.Evidence is provided of a unique role for high-rate episodic sedimentation events in controlling the subsurface microbiosphere in Earth’s deepest ocean floor and highlight the need to perform thorough analysis over a large depth range to characterize hadal benthic populations.Such depositional processes are likely crucial in shaping deep-water geochemical environments and thereby the deep subseafloor biosphere.

关键词： Hadal subseafloor Deep water sediment Mariana Trench Radiocarbon Microbial community redox potential

Tetrathiafulvalene esters with high redox potentials and improved solubilities for non-aqueous redox flow battery applications

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Green Energy & Environment 2024年第5期9卷 899-908页

作者： Weikang Hu Jiaqi Xu Nanjie Chen Zongcai Deng Yuekun Lai Dongyang Chen College of Materials Science and Engineering Fuzhou UniversityFuzhou350116China College of Chemical Engineering Fuzhou UniversityFuzhou350116China

The exploitation of high performance redox-active substances is critically important for the development of non-aqueous redoxﬂow batteries.Herein,three tetrathiofulvalene(TTF)derivatives with different substitution groups,namely TTF diethyl ester(TTFDE),TTF tetramethyl ester(TTFTM),and TTF tetraethyl ester(TTFTE),are prepared and their energy storage properties are evaluated.It has been found that the redox potential and solubility of these TTF derivatives in conventional carbonate electrolytes increases with the number of ester groups.The battery with a catholyte of 0.2 mol L^(-1) of TTFTE delivers a speciﬁc capacity of more than 10 Ah L^(-1) at the current density of 0.5 C with two discharge voltage platforms locating at as high as 3.85 and 3.60 V vs.Li/Liþ.Its capacity retention can be improved from 2.34 Ah L^(-1) to 3.60 Ah L^(-1) after 100 cycles by the use of an anion exchange membrane to block the crossover of TTF species.The excellent cycling stability of the TIF esters is supported by their well-delocalized electrons,as revealed by the density function theory calculations.Therefore,the introduction of more and larger electron-withdrawing groups is a promising strategy to simultaneously increase the redox-potential and solubility of redox-active ma-terials for non-aqueous redoxﬂow batteries.

关键词： Non-aqueous redox flow batteries Tetrathiofulvarene redox potential Solubility Substituent effect

Control of redox potential by oxygen limitation in selective bioleaching of chalcocite and pyrite

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Rare Metals 2014年第5期33卷 622-627页

作者： Biao Wu Jian-Kang Wen Bo-Wei Chen Guo-Cheng Yao Dian-Zuo Wang National Engineering Laboratory of Biohydrometallurgy General Research Institute for Nonferrous Metals

Based on the bioleaching mechanism and electrochemical studies of metal sulfides, the dissolution rates of chalcocite and pyrite are controlled by redox potentials. Experiment on the bioleaching of chalcocite and pyrite under constant redox potential by sparging with nitrogen gas was demonstrated. By leaching at low and constant redox potential（〈760 mV, vs SHE）, copper recoveries of 90 %–98 % are achieved, which are 10 times more than iron recoveries. The iron-oxidizing bacterial populations are observed to continue to reduce under oxygen limitation conditions, but the Acidithiobacillus that have only sulfur-oxidizing capabilities are an attractive alternative for redox-controlled bioleaching of chalcocite.Thus, the described redox control technique might be one of the effective approaches to balance acid and iron in Zijinshan copper bio-heap leaching practice.

关键词： Pyrite Chalcocite Bioleaching redox potential Oxygen limitation

Dual-parameter Correlation Analysis of the redox potential Data of 1-Methyl-2-formyl-5-substituted Pyrroles and their Hydrazones

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Chinese Chemical Letters 2001年第12期12卷 1097-1100页

作者： Hai Ying HE Chen Lin Cheng Xue ZHAO Xi Kui JIANG Department of Chemistry Shanghai Jiaotong UniversityShanghai 200240 Shanghai Institute of Organic Chemistry Shanghai 200032

By using 1-methyl-2-formyl-5-substituted pyrroles (1-Y), 1-methyl-2-formyl-5-substituted pyrrole phenylhydrazones (2-Y) and 1-methyl-2-formyl-5-substituted pyrrole (4-nitrophenyl)-hydrazones (3-Y) as model structures for nitrogen-containing heterocyclic aromatic compounds, correlation analysis of their redox potential data show that the transition states (TS) of the polarographic process are mainly affected by the polar effects, but spin-delocalizatin effects also exist.

关键词： correlation analysis polar effect spin-delocalization effect redox potential

redox potential E_H [Se(VI)/Se(IV)] of aqueous extractof soils from Yongshou Kaschin-Beck diseaseregion and the influence by humic acid

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Journal of Environmental Sciences 1989年第2期1卷 29-36页

作者： Peng An and Xu Langqiu Research Center for Eco-Environmental Sciences,Academia Sinica,Beijing 100083,China

The relation between EH [Se(VI)/Se(IV)] and pH of soil aqueous extract in Kaschin-Beck disease region and the effects of natural redox agents, namely humic substances, MnO2 and Fe2+, on the redox property of the system were studied. The results indicated that both humic acid and Fe2+ could enhance the reducibility of Se(VI) and MnO2, a limited oxidizability for Se(IV). Fe2+ showed a weak reducibility only at low pH value. The reducibilities of three sulfur-containing compounds for Se(VI) were in following order:thioglycollic acid > L-cysteine > sulfide

关键词： selenium redox potential Kaschin-Beck disease humic acid.

Mammalian Cytosolic Thioredoxin Reductase:redox potential and redox Status

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Mammalian Cytosolic Thioredoxin Reductase:Redox Potential an...

TiO2 nanoparticles in aquatic environments:impact on heavy metals distribution in sediments and overlying water

第九届全国酶学学术讨论会暨邹承鲁诞辰85周年纪念会

作者： Guanglei Zhai Liangwei Zhong College of Life Sciences,Graduate University of Chinese Academy of Sciences,YuQuan Road 19(A),Beijing 100049

There are three isoenzymes of mammalian thioredoxin reductase (TrxR) i.e. cytosolic,mitochondrial and testis specific TrxR,all of which are homodimers associated in a head-to-tail fashion.In contrast to E.coli TrxR,ma... 详细信息

关键词： thioredoxin reductase trx system redox potential

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Acta Geochimica 2022年第6期41卷 968-981页

作者： Ali Marefat Abdolreza Karbassi Behzad Aghabarari School of Environment College of EngineeringUniversity of TehranTehranIran Research Department of Nano-technology and Advanced Materials TehranIran

The extensive application of TiO_(2)nanoparticles(NPs)highlights the importance of investigating their influence on aquatic systems.In this work,the effect of TiO_(2)NPs on heavy metals speciation was studied on a lab scale.For this goal,a series of aquaria containing water,sediment,and TiO_(2)NPs with various concentrations were set up.The study results revealed that TiO_(2)NPs caused(copper)Cu,(mercury)Hg,(titanium)Ti,and(zinc)Zn to be adsorbed by sediments in the forms of exchangeable and Fe-Mn species.According to measurements,30μg/L of TiO_(2)NPs made Cu,Hg,Ti and Zn concentration in the water column decreased from 33,1.14,20,and 32 to 4,0.58,3,and 22.3μg/L,respectively.Manganese(Mn)was also adsorbed by sediment,and in all experiments,its concentration in the water column reduced from 44 to about 20μg/L.Due to the photocatalytic capacity of TiO_(2)NPs,arsenic(As)concentration in the water column increased from 0 to 8.7μg/L with the introduction of30μg/L of TiO_(2)NPs.The sequential extraction results showed that in all experiments,concentrations of lead(Pb),nickel(Ni),and cobalt(Co)remained constant in different chemical species of sediment,which meant conservative behavior of them in presence of TiO_(2)NPs.In addition,a remarkable change was observed in water quality parameters such as ORP,TDS,TOC,BOD,NO3’and PO_(4)after the introduction of TiO_(2)NPs to aquaria.The reason behind these changes could be related to the decomposition of sediment organic content by TiO_(2)NPs.

关键词： TiO2 nanoparticles Heavy metal speciation redox potential Chemical extraction Cluster analysis

The profile of sound speed and dissolved oxygen in the polymetallic nodules depositional area in the Western Pacific

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Journal of Oceanology and Limnology 2023年第6期41卷 2090-2100页

作者： Bowen LI Yonggang JIA Zhihan FAN Kai LI College of Oceanography and Space Information China University of PetroleumQingdao 266580China Laboratory for Marine Geology Qingdao National Laboratory for Marine Science and TechnologyQingdao 266100China Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering Ocean University of ChinaQingdao 266100China

With the consumption of terrestrial metal resources,the exploitation of deep-sea polymetallic nodule minerals has been widely concerned around the world.Therefore,the environmental impact of deep-sea polymetallic nodule mining cannot be ignored.However,duo to the lacks in stable and safe deep-sea(the depth>1000 m)vertical profile observation systems and consequently in long-term in-situ observation data,the sound speed and dissolved oxygen and the other water environment factors in the deposition areas of polymetallic nodules remains poorly understood.In this study,a deep-sea in-situ observation system was designed and deployed,and the water environment data of the polymetallic nodule deposition area were collected and analyzed.Result shows that the dissolved oxygen in the depth of 0–600 m was mainly affected by biological factors,while that in the area deeper than 600 m was affected by physical factors.The sound speed in the water body was mainly affected by temperature and pressure.At depths below 840 m,the sound speed is mainly controlled by temperature,and at depths between 840 m and 5700 m,the sound speed is mainly controlled by pressure.The correlations of sound speed vs.pressure and vs.temperature were regressed into equation.The resuspension of sediments rich in various metals may result in the reduction of dissolved oxygen and the improvement of redox potential.This environmental impact caused by a single sediment resuspension could last for 24 h or more.These findings enrich the understanding of the background value of the water environment in the polymetallic nodule deposition area.

关键词： deep sea dissolved oxygen redox potential sound speed conductivity

Phosphorus release: A biogeochemical insight from a restored lakeside wetland in the Yangtze-Huaihe region, China

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Journal of Environmental Sciences 2010年第3期22卷 347-354页

作者： Xiaoling Zhou, Baoqing Shan, Hong Zhang State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

The heavy intensification of agriculture in East China since the 1980s caused the decrease of lake area and water storage capacity with impediment of regulation, lake eutrophication and frequent floods. Many restoration projects have been conducted. However, the knowledge of biogeochemical factors that drive nutrient cycles during the early stage of restoration is still limited. We studied the effect of the remediation of a patch of near-shore shallow wetland on the northern bank of Chaohu Lake in the Yangtze-Huaihe region, China, which was used as rice paddy for many years, on the behavior of phosphorus. redox potential （ORP）, temperature and dissolved oxygen were monitored in situ from May 2006 to November 2007. Samples of soil pore water were collected during this time for the determination of different forms of iron and phosphorus. ORP showed a clear transition of the wetland soil from an oxidized state in winter to a reduced state in summer. The decrease of ORP correlated with the release of large amounts of Fe and P. The maxima of total dissolved Fe and total dissolved P in the summer of the second year were （13.8 ± 6.8） mg/L and （0.88 ± 0.27） mg/L, respectively. It is worth noticing that P concentration far exceeded the critical value of lake eutrophication （0.02 mg/L）. The pressure of P release to the adjacent lake during the first two years of wetland restoration from rice fields should be taken into account by environmental policy makers.

关键词： wetland restoration phosphorus eutrophication redox potential iron