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Enhanced photo-catalytic activity of gold ion and gold modified

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Journal of Environmental sciences 2001年第2期13卷 201-204页

作者： LI Fang-bai GU Guo-bang HUANG Guo-feng LI Xin-jun WAN Hong-fu guangdong institute of Eco-Environment and soil science Guangzhou 510650China College of Chemical Engineering South China University of TechnologyGuangdong 510642China

The gold ion modified TiO2 was prepared by means of sol-gel whereas gold deposited TiO2 was prepared by means of photoreduction. The physical properties were influenced significantly by the presence of gold ion or gold. The enhanced photo-activity of gold modified TiO2 vas quantified in terms of methylene blue degradation. The presence of gold ion in TiO2 lattices or gold on TiO2 surface enhanced their-photo-activity. The optimum molar content of gold ion doping and gold deposition all was 0.5%. The first-order rates constants of gold modified TiO2 was more than that of pure TiO2, and decreased by increasing the content of gold ion and gold when their contents were more than 0.5%. Gold ion doped in TiO2 lattices was more effective to enhance the photo-activity than gold on TiO2 surface. Moreover, the relationship between physical properties, chemical properties and photo-activity has been discussed.

关键词： gold modification titanium dioxide photo-catalysis methylene blue

Root-associated(rhizosphere and endosphere) microbiomes of the Miscanthus sinensis and their response to the heavy metal contamination

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Journal of Environmental sciences 2021年第6期33卷 387-398页

作者： Xiaoxu Sun Benru Song Rui Xu Miaomiao Zhang Pin Gao Hanzhi Lin Weimin Sun National-Regional Joint Engineering Research Center for soil Pollution Control and Remediation in South China Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and ManagementInstitute of Eco-environmental and Soil SciencesGuangdong Academy of SciencesGuangzhou 510650China

The plant root-associated microbiomes, including both the rhizosphere and the root endosphere microbial community, are considered as a critical extension of the plant genome. Comparing to the well-studied rhizosphere microbiome, the understanding of the root endophytic microbiome is still in its infancy. Miscanthus sinensis is a pioneering plant that could thrive on metal contaminated lands and holds the potential for phytoremediation applications. Characterizing its root-associated microbiome, especially the root endophytic microbiome, could provide pivotal knowledge for phytoremediation of mine tailings. In the current study, M. sinensis residing in two Pb/Zn tailings and one uncontaminated site were collected. The results demonstrated that the metal contaminant fractions exposed strong impacts on the microbial community structures. Their influences on the microbial community, however, gradually decreases from the bulk soil through the rhizosphere soil and finally to the endosphere, which resulting in distinct root endophytic microbial community structures compared to both the bulk and rhizosphere soil. Diverse members affiliated with the order Rhizobiales was identified as the core microbiome residing in the root of M. sinensis. In addition, enrichment of plant-growth promoting functions within the root endosphere were predicted, suggesting the root endophytes may provide critical services to the host plant. The current study provides new insights into taxonomy and potential functions of the root-associated microbiomes of the pioneer plant, M. sinensis, which may facilitate future phytoremediation practices.

关键词： Tailing Miscanthus sinensis Root endosphere Metal(loid)s contamination

Influence of Exogenous Lanthanum on Fertility Parameters of Red soil and Paddy soil

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Journal of Rare Earths 2001年第3期19卷 229-232页

作者：谢祖彬朱建国褚海燕曾青张雅丽曹志洪 Chinese Acad sci Inst Soil Sci Lab Mat Cycling Pedosphere Nanjing 210008 Peoples R China

The effects of exogenous La on the fertility parameters such as cation exchange capacity ( CEC), exchangeable basic cations, and exchangeable acidity in red soil and paddy soil were studied with soil column simulation. The results show that with increasing amount of the added La, the proportion of exchangeable La in soils increases and there is more exchangeable La in red soil than in paddy soil. When the concentration of La is more than 600 mg(.)kg(-1) the proportion of exchangeable La almost remains constant. When the concentration of La is less than 1200 mg(.)kg(-1) there is no significant effect on CEC in red soil. But when the concentration of La is more than 1200 mg(.)kg(-1,) it has significant effect on CEC in paddy soil. The application of La resulted in increasing exchangeable aluminum, Ca and Mg in soil solution, and decreasing exchangeable Ca and Mg retained in soils. But when the concentration of La is less than 150 mg(.)kg(-1), it has no significant influence on CEC, exchangeable Ca and Mg, and exchangeable acidity in red soil and paddy soil.

关键词： rare earths lanthanum fertility red soil paddy soil

Effects of Lanthanum on Microbial Biomass Carbon and Nitrogen in Red soil

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Journal of Rare Earths 2001年第1期19卷 63-66页

作者：褚海燕朱建国谢祖彬曹志洪李振高曾青 Chinese Acad sci Inst Soil Sci Lab Mat Cycling Pedosphere Nanjing 210008 Peoples R China

The result of soil. culture experiment shows that lanthanum has inhibitory effect on the microbial biomass C and N in red soil, and the inhibition is strengthened with increasing concentration of La. The result of rice pot culture experiment shows that low concentration of La has slight stimulative effect on the microbial biomass C and N in red soil, but its high concentration has inhibitory effect and the inhibition is strengthened with increasing concentration of La. soil microbial biomass is an important indicator for evaluating rare earths-polluted soil. It is assumed that the critical La concentration is 100 ***(-1) at which red soil tends to be polluted.

关键词： rare earths lanthanum red soil microbial biomass C microbial biomass N

Simulation study on dynamic mechanism of land use and soil erosion in loess hilly regions of Shanxi and Shaanxi provinces

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Chinese science Bulletin 1997年第21期42卷 1833-1839页

作者： Zhang, HX Shao, MG Chinese Acad sci Inst Soil & Water Conservat Yangling 712100 Peoples R China

soil erosion in the hilly region of Shanxi and Shaanxi provinces is very severe, and unreason-able land use is the main reason. There have been many research reports on the prediction ofsoil erosion, and most of them use regression methods. The resulting co-relative equations areused to predict small-scale erosion of fields or farms and to select agricultural measures.

关键词： land use soil erosion dynamic mechanism simulation S.D. model devdopment mode.

Experimental determination of sediment transport capacity of rill flow over sandified loess slope

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International soil and Water Conservation Research 2023年第2期11卷 301-310页

作者： Ren Feng Jiacun Chen Zhenyue Xie Dingqiang Li Zaijian Yuan National-Regional Joint Engineering Research Center for soil Pollution Control and Remediation in South China Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and ManagementInstitute of Eco-environmental and Soil SciencesGuangdong Academy of SciencesGuangzhou510650China Meizhou International institute of soil and Water Conservation Meizhou514000China

Rill erosion is affected by the sand particle content in soil,especially in the wind and water erosion transition region of the Loess *** sediment transport capacity(STC)is a key parameter in rill erosion research,assessing the impact of aeolian sand intrusion on the STC of rill flow is of importance for a better understanding of rill *** study aimed to assess the effect of aeolian sand intrusion on the STC on sandified loess slopes,with typical slopes and flow discharges,using a flume system which consisting of a sediment-feeding and a sediment-supply/settlement *** sediment feeding flume was jointed by 10°higher than that of the sediment measurement flume *** flow discharges(2,4,and 8 L min^(-1))and four slope gradients(5°,10°,15°,and 25°)were used to represent the natural hydrological conditions under three intrusion rates(SIR)of aeolian sands(10%,20%,and 50%).The results show that STC increased with slope gradient and flow discharge,and the relationship between the STC and the SIR was significantly affected by the slope gradient;the STCs decreased with the SIR on a slope of 5°but increased with the SIR on steep slopes of 15°-25°,implying a significant impact of slope gradient on the relationship between SIR and *** SIR of 50%resulted in the highest sediment concentration nearly 1200 kg m^(-3)on slopes of 25°.On sandified loess slopes of 10%,20%,and 50%SIR,the STC were about 30%,46%,and 57%higher than on loess slopes,indicating an increased erosion rate by sand particle intrusion into loess *** results highlight the impact of sand intrusion on STC of rill flow and provide deeper insights into the soil loss process on the sandified loess slope.

关键词： Sand intrusion Loess soil Rill flow Transport capacity

Sorption phenomena of PCBs in environment

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Chinese science Bulletin 2001年第2期46卷 89-97页

作者： Qingyu Meng Shaogang Chu Xiaobai Xu Chinese Acad sci Ecoenvironm Sci Res Ctr Beijing 100085 Peoples R China

The relationship between the properties of PCBs and the behavior of soil and sediment is reviewed. The sorp-tion phenomena of PCBs in the environment are described with different models. The research progress on the s... 详细信息

关键词： PCBs sorption environmental transport.

Geochemical Implication of Rare Earth Elements in Process of soil Development

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Journal of Rare Earths 2001年第1期19卷 57-62页

作者：黄成敏龚子同 Sichuan Univ Coll Environm Sci & Engn Chengdu 610065 Peoples R China Chinese Acad sci Inst Soil Sci Nanjing 210008 Peoples R China

The geochemical characteristics and behavior of rare earth elements (REE) in soils developed on the basalts in the northern part of Hainan Island erupted in different time were studied as well as the REE partition in the soil-formation process and its implication on soil development degree. The results show that the total REE content in soils is correlative with soil age significantly and can be selected as the index to show soil evolution. With the soil developing intensively, light rare earth elements (LREE) gain and heavy rare earth elements (HREE) lose. The trends of positive Ce-anomaly and negative Eu-anomaly are remarkable with soil development.

关键词： rare earths soil geochemistry basalt partition

Electrochemical and spectroscopic characteristics of dissolved organic matter in a forest soil profile

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Journal of Environmental sciences 2013年第10期25卷 2093-2101页

作者： Ran Bi Qin Lu Tian Yuan Shungui Zhou Yong Yuan Yanfei Cai Guangzhou institute of Geochemistry Chinese Academy of Sciences guangdong institute of Eco-Environmental and soil sciences College of Resources and Environment SouthChina Agricultural University

Dissolved organic matter （DOM） represents one of the most mobile and reactive organic compounds in ecosystem and plays an important role in the fate and transport of soil organic pollutants, nutrient cycling and more importantly global climate change. Electrochemical methods were first employed to evaluate DOM redox properties, and spectroscopic approaches were utilized to obtain information concerning its composition and structure. DOM was extracted from a forest soil profile with five horizons. Differential pulse voltammetry indicated that there were more redox-active moieties in the DOM from upper horizons than in that from lower horizons. Cyclic voltammetry further showed that these moieties were reversible in electron transfer. Chronoamperometry was employed to quantify the electron transfer capacity of DOM, including electron acceptor capacity and electron donor capacity, both of which decreased sharply with increasing depth. FT-IR, UV-Vis and fluorescence spectra results suggested that DOM from the upper horizons was enriched with aromatic and humic structures while that from the lower horizons was rich in aliphatic carbon, which supported the findings obtained by electrochemical approaches. Electrochemical approaches combined with spectroscopic methods were applied to evaluate the characteristics of DOM extracted along a forest soil profile. The electrochemical properties of DOM, which can be rapidly and simply obtained, provide insight into the migration and transformation of DOM along a soil profile and will aid in better understanding of the biogeochemical role of DOM in natural environments.

关键词： dissolved organic matter electrochemical characteristics soil profile spectroscopic characteristics