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Simultaneous removal of selected oxidized contaminants in groundwater using a continuously stirred hydrogen-based membrane biofilm reactor

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Journal of Environmental Sciences 2013年第1期25卷 96-104页

作者： Siqing Xia Jun Liang xiaoyin xu Shuang Shen State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and EngineeringTongji University

A laboratory trial was conducted for evaluating the capability of a continuously stirred hydrogen-based membrane biofllm reactor to simultaneously reduce nitrate （NO3--N）, sulfate （SO42-）, bromate （BrO3-）, hexavalent chromium （Cr（VI）） and para- chloronitrobenzene （p-CNB）. The reactor contained two bundles of hollow fiber membranes functioning as an autotrophic biofiim carder and hydrogen pipe as well. On the condition that hydrogen was supplied as electron donor and diffused into water through membrane pores, autohydrogenotrophic bacteria were capable of reducing contaminants to forms with lower toxicity. Reduction occurred within 1 day and removal fluxes for NO3--N, SO42-, BrO3-, Cr（VI）, and p-CNB reached 0.641, 2.396, 0.008, 0.016 and 0.031 g/（day.m2）, respectively after 112 days of continuous operation. Except for the fact that sulfate was 37% removed under high surface loading, the other four contaminants were reduced by over 95 %. The removal flux comparison between phases varying in surface loading and 1-12 pressure showed that decreasing surface loading or increasing 1-12 pressure would promote removal flux. Competition for electrons occurred among the five contaminants. Electron-equivalent flux analysis showed that the amount of utilized hydrogen was mainly controlled by NO3--N and SO42- reduction, which accounted for over 99% of the electron flux altogether. It also indicated the electron acceptor order, showing that nitrate was the most prior electron acceptor while sulfate was the second of the five contaminants.

关键词： oxidized contaminant groundwater simultaneous removal hydrogen-based membrane biofilm reactor

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Arsenic removal from groundwater by acclimated sludge under autohydrogenotrophic conditions

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Journal of Environmental Sciences 2014年第2期26卷 248-255页

作者： Siqing Xia Shuang Shen xiaoyin xu Jun Liang Lijie Zhou State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and Engineering Tongji University

Arsenic in the environment is attracting increasing attention due to its chronic health effects. Although arsenite （As（III）） is generally more mobile and more toxic than arsenate （As（V））, reducing As（V） to As（III） may still be a means for decontamination, because As（III） can be removed from solution by precipitation with sulfide or by adsorption or complexation with other metal sulfides. The performance of As（V） bio-reduction under autohydrogenotrophic conditions was investigated with batch experiments. The results showed that As（V） reduction was a biochemical process while both acclimated sludge and hydrogen were essential. Most of the reduced arsenic remained in a soluble form, although 20% was removed with no addition of sulfate, while 82% was removed when sulfate was reduced to sulfide. The results demonstrated that the reduced arsenic was re-sequestered in the precipitates, probably as arsenic sulfides. Kinetic analysis showed that pseudo first-order kinetics described the bio-reduction process better than pseudo second-order. In particular, the influences of pH and temperature on As（V） reduction by acclimated sludge under autohydrogenotrophic conditions and total soluble As removal were examined. The reduction process was highly sensitive to both pH and temperature, with the optimum ranges of pH 6.5-7.0 and 30-40℃ respectively. Furthermore, Arrhenius modeling results for the temperature effect indicated that the As（V） reduction trend was systematic. Total soluble As removal was consistent with the trend of As（V） reduction.

关键词： arsenic autohydrogenotrophic bio-reduction hydrogen groundwater

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基于长短时记忆的农作物生长环境数据预测

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深圳大学学报（理工版） 2024年第5期41卷 563-573页

作者：吴超周紫静黄锦铧许啸寅邱洪彭业萍深圳大学机电与控制工程学院广东深圳518060 深圳大学广东省电磁控制与智能机器人重点实验室广东深圳518060

针对传统温室农作物生长监控系统控制灵活性差且精确度低等问题,设计了一个面向智慧农业的农作物生长闭环监控系统.引入单变量长短时记忆(long short-term memory,LSTM)网络模型,对土壤含水率、土壤温度和土壤电导率3个农作物生长环境... 详细信息

针对传统温室农作物生长监控系统控制灵活性差且精确度低等问题,设计了一个面向智慧农业的农作物生长闭环监控系统.引入单变量长短时记忆(long short-term memory,LSTM)网络模型,对土壤含水率、土壤温度和土壤电导率3个农作物生长环境数据进行预测研究.在优化时间步长参数的基础上,分析不同预测步长对单变量LSTM模型预测准确性的影响,采用不同时间段的测试集数据对模型的预测性能和稳定性进行验证.分别采用单变量LSTM模型、最小绝对值收敛和选择算法、随机森林回归、双向LSTM模型和编解码LSTM模型进行预测对比,结果表明,单变量LSTM模型预测的平均绝对误差值和均方根误差值均为最小,模型具有更好的准确性和稳定性.本研究设计的农作物生长闭环监控系统能有效预测农作物的生长环境数据,为农作物监控系统的智能控制提供有效数据支撑.

关键词：人工智能监控系统预测模型环境数据长短时记忆网络时间序列智慧农业

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Study on removing selenate from groundwater by autohydrogenotrophic microorganisms

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Frontiers of Environmental Science & Engineering 2013年第4期7卷 552-558页

作者： Siqing XIA Shuang SHEN Jun LIANG xiaoyin xu State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and Engineering Tongji University Shanghai 200092 China

Performance of autohydrogenotrophic bac- teria for bio-reduction of selenate （Se（VI）） under anaerobic conditions was investigated with batch experiments. Results showed Se（VI） was bio-reduced to selenite （Se（IV）） as an intermediate product, and then to elemental selenium （Se）. Reduction kinetics could be described by the pseudo-first-order model. In particular, the influences of pH value and temperature on Se（VI） reduction by autohydrogentrophic organisms were examined. The high degradation rate was achieved at pH 7.0 to 8.0; and the best reduction temperature was between 25℃ and 35℃. This study is of help for treating groundwater with selenium contamination by autohydrogenotrophic bacteria as well as its reactor development.

关键词： autohydrogenotrophic selenate hydrogen,groundwater

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Bioreduction of vanadium(V) in groundwater by autohydrogentrophic bacteria:Mechanisms and microorganisms

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Journal of Environmental Sciences 2015年第4期27卷 122-128页

作者： xiaoyin xu Siqing Xia Lijie Zhou Zhiqiang Zhang Bruce E.Rittmann State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and Engineering Tongji University Swette Center for Environmental Biotechnology Biodesign Institute at Arizona State University Key Laboratory of Yangtze River Water Environment Ministry of Education College of Environmental Science and EngineeringTongji University

As one of the transition metals, vanadium（V）（V（V）） in trace amounts represents an essential element for normal cell growth, but becomes toxic when its concentration is above 1 mg/L. V（V） can alter cellular differentiation, gene expression, and other biochemical and metabolic phenomena. A feasible method to detoxify V（V） is to reduce it to V（IV）, which precipitates and can be readily removed from the water. The bioreduction of V（V） in a contaminated groundwater was investigated using autohydrogentrophic bacteria and hydrogen gas as the electron donor. Compared with the previous organic donors,H2 shows the advantages as an ideal electron donor, including nontoxicity and less production of excess biomass. V（V） was 95.5% removed by biochemical reduction when autohydrogentrophic bacteria and hydrogen were both present, and the reduced V（IV）precipitated, leading to total-V removal. Reduction kinetics could be described by a first-order model and were sensitive to p H and temperature, with the optimum ranges of p H 7.5–8.0 and 35–40°C, respectively. Phylogenetic analysis by clone library showed that the dominant species in the experiments with V（V） bioreduction belonged to theβ-Proteobacteria. Previously known V（V）-reducing species were absent, suggesting that V（V）reduction was carried out by novel species. Their selective enrichment during V（V）bioreduction suggests that Rhodocyclus, a denitrifying bacterium, and Clostridium, a fermenter known to carry out metal reduction, were responsible for V（V） bioreduction.

关键词： Vanadium Bioreduction Hydrogen Rhodocyclus Clostridium

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咪达唑仑复合瑞芬太尼用于女性乳腺手术患者无肌松气管插管的效果观察

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中国基层医药 2024年第4期31卷 570-573页

作者：付莉珺刘祖莹樊家鸣谢艳乐徐笑茵樊肖冲郑州大学第一附属医院疼痛科郑州450052 郑州大学第一附属医院围手术期医学麻醉科郑州450052

目的评价咪达唑仑复合瑞芬太尼用于女性乳腺手术患者无肌松气管插管的效果。方法研究对象为郑州大学第一附属医院2023年1—6月拟行气管插管全身麻醉的女性乳腺病患者40例。采用回顾性研究方法,根据插管时有无应用肌松药分为对照组(n=20... 详细信息

目的评价咪达唑仑复合瑞芬太尼用于女性乳腺手术患者无肌松气管插管的效果。方法研究对象为郑州大学第一附属医院2023年1—6月拟行气管插管全身麻醉的女性乳腺病患者40例。采用回顾性研究方法,根据插管时有无应用肌松药分为对照组(n=20)和观察组(n=20)。对照组静脉注射罗库溴铵,观察组不用肌松药。两组均静脉注射咪达唑仑0.1 mg/kg和瑞芬太尼4μg/kg后气管插管。按照置入喉镜难易、是否有咳嗽体动等方面对插管条件进行评价。结果两组患者年龄、身高和体质量差异均无统计学意义(均P>0.05)。观察组优秀率[45%(9/20)]低于对照组[85%(17/20)](χ^(2)=7.03,P=0.008);良好率[40%(8/20)]高于对照组[5%(1/20)](χ^(2)=7.03,P0.05)。观察组的术中知晓评分为(2.59±0.44)分,较对照组的(2.61±0.31)分差异无统计学意义(P>0.05)。两组术中未出现心律失常,术后未出现肌僵、恶心呕吐、皮肤瘙痒等不良反应。结论在无肌松药下,咪达唑仑0.1 mg/kg复合瑞芬太尼4μg/kg诱导女性乳腺手术患者气管插管可提供良好的气管插管条件,防止患者术中知晓发生。

关键词：麻醉,全身乳腺疾病咪达唑仑芬太尼插管法,气管内术中知晓肌松弛药,中枢性

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Critical review of strategies for CO_2 delivery to large-scale microalgae cultures

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Chinese Journal of Chemical Engineering 2018年第11期26卷 2219-2228页

作者： Qi Zheng xiaoyin xu Gregory J.O.Martin Sandra E.Kentish Peter Cook Centre for CCS Research Department of Chemical EngineeringThe University of Melbourne Algal Processing Group Department of Chemical EngineeringThe University of Melbourne

Microalgae have great, yet relatively untapped potential as a highly productive crop for the production of animal and aquaculture feed, biofuels, and nutraceutical products. Compared to conventional terrestrial crops they have a very fast growth rate and can be produced on non-arable land. During microalgae cultivation, carbon dioxide(CO_2) is supplied as the carbon source for photosynthesising microalgae. There are a number of potential CO_2 supplies including air, flue gas and purified CO_2. In addition, several strategies have been applied to the delivery of CO_2 to microalgae production systems, including directly bubbling CO_2-rich gas, microbubbles, porous membrane spargers and non-porous membrane contactors. This article provides a comparative analysis of the different CO_2 supply and delivery strategies and how they relate to each other.

关键词： Bubble Carbon dioxide Flue gas Bioreactors

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Low-Noise Intensity Amplification of a Bright Entangled Beam

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Chinese Physics Letters 2021年第9期38卷 6-10页

作者： Yanbo Lou xiaoyin xu Shengshuai Liu Jietai Jing State Key Laboratory of Precision Spectroscopy Joint Institute of Advanced Science and TechnologySchool of Physics and Electronic ScienceEast China Normal UniversityShanghai 200062China CAS Center for Excellence in Ultra-intense Laser Science Shanghai 201800China Department of Physics Zhejiang UniversityHangzhou 310027China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

We experimentally demonstrate a low-noise phase-sensitive amplifier(PSA)scheme that is able to amplify bright entangled beams at a high level intensity gain of up to ***,we demonstrate that the PSA scheme introduces much less uncorrelated extra noise to the entangled state than the phase-insensitive amplifier scheme with the same intensity *** PSA scheme has potential applications for quantum communication in continuous variable regimes.

关键词： scheme quantum phase

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Enhanced struvite recovery from wastewater using a novel cone-inserted fluidized bed reactor

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Journal of Environmental Sciences 2014年第4期26卷 765-774页

作者： Awoke Guadie Siqing Xia Wei Jiang Lijie Zhou Zhiqiang Zhang Slawomir W.Hermanowicz xiaoyin xu Shuang Shen UNEP-Tongji Institute of Environment for Sustainable Development College of Environmental Science and Engineering Tongji University State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and Engineering Tongji University Key Laboratory of Yangtze River Water Environment Ministry of Education College of Environmental Science and Engineering Tongji University Department of Civil and Environmental Engineering University of California

The feasibility of struvite recovery at low （12.5 mg/L） and high （120 mg[L） phosphorus concentrations was studied by constructing a novel fluidized bed reactor with cones （FBRwc） and without cones （FBRwoc）. The crystallization process was continuously operated for 133 days under different hydraulic retention times （HRT = 1-10 hr）, pH （7.5-10）, and molar ratios of Mg/P （0.75-1.75）, N/P （1-10） and Ca/Mg （0-2）. The optimum operating conditions of HRT, pH, Mg/P and N/P molar ratios were found to be 2 hr, 9, 1.25, and 7.5, respectively. Under these optimum conditions, the phosphorus precipitation efficiencies of FBRwc were 93% for low and 98% for high phosphorus influent; however, the efficiencies were 78% and 81% for FBRwoc, respectively. Due to crystal losses at each junction （17%-31%）, the crystal recovery efficiency of FBRwoc was relatively low （47%-65%） for both influent concentrations. However, the losses were minimal in FBRwc, which showed 75% and 92% crystal recovery for low and high phosphorus concentrations, respectively. At low calcium concentration, crystal chemical analysis showed the product to be pure struvite （〉 99%）. The scanning electron microscope and X-ray diffraction results further confirmed that the crystal recovered from FBRwc contained pure struvite, which could be considered a high quality fertilizer. Except HRT, all parameters （pH, Mg/P, N/P and Ca/Mg） were found to be influencing factors for FBRwc performance. Overall, inserting cones in each part of the reactor played a significant role in enhancing struvite recovery from a wide range of phosphorus-containing wastewater.

关键词： ftuidized bed reactor phosphorus recovery struvite wastewater

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High photoelectric conversion efficiency and fast relaxation time of FA_(0.4)MA_(0.6)PbI_(3) applied in ultrafast modulation of terahertz waves

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Journal of Energy Chemistry 2024年第4期91卷 299-305页

作者： Zhibo xu Ying Zeng Xinran Zhao xiaoyin Chen Aoyu Fan Furi Ling Jiang Li Jianquan Yao School of Optics and Electronic Information Huazhong University of Science and TechnologyWuhan 430074HubeiChina College of Precision Instrument and Optoelectronics Engineering Tianjin UniversityTianjin 300072China Institute of Fluid Physics China Academy of Engineering PhysicsMianyang 621900SichuanChina School of Information Engineering Wuhan University of TechnologyWuhan 430070HubeiChina National Engineering Research Center of Fiber Optic Sensing Technology and Networks Wuhan University of TechnologyWuhan 430070HubeiChina Hubei Key Laboratory of Broadband Wireless Communication and Sensor Networks Wuhan 430070HubeiChina

Active control of terahertz(THz)waves is attracting tremendous attentions in terahertz communications and active photonic ***,due to its excellent photoelectric conversion performance and simple manufacturing process,has emerged as a promising candidate for optoelectronic ***,the exploration of perovskites in optically controlled THz modulators is still *** this work,the photoelectric properties and carrier dynamics of FA_(0.4)MA_(0.6)PbI_(3)perovskite films were investigated by optical pumped terahertz probe(OPTP)*** ultrafast carrier dynamics reveal that FA_(0.4)MA_(0.6)PbI_(3)thin film exhibits rapid switching and relaxation time within picosecond level,suggesting that FA_(0.4)MA_(0.6)PbI_(3)is an ideal candidate for active THz devices with ultrafast ***,as a proof of concept,a FA_(0.4)MA_(0.6)PbI_(3)-based metadevice with integrating plasma-induced transparency(PIT)effect was fabricated to achieve ultrafast modulation of THz *** experimental results demonstrated that the switching time of FA_(0.4)MA_(0.6)PbI_(3)-based THz modulator is near to 3.5 ps,and the threshold of optical pump is as low as 12.7μJ cm^(-2).The simulation results attribute the mechanism of ultrafast THz modulation to photo-induced free carriers in the FA_(0.4)MA_(0.6)PbI_(3)layer,which progressively shorten the capacitive gap of PIT *** study not only illuminates the potential of FA_(0.4)MA_(0.6)PbI_(3)in THz modulation,but also contributes to the field of ultrafast photonic devices.

关键词： Terahertz modulation Perovskites Metamaterials Plasmon-induced transparency

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