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Effect of Selected Organic Acids on Cadmium Sorption by Variable- and Permanent-Charge Soils

Pedosphere 2007年第1期17卷 117-123页

作者： HU Hong-Qing LIU Hua-Liang HE Ji-Zheng huang qiao-yun Key Laboratory of Subtropical Agriculture Resource and Environment Ministry of Agriculture Huazhong Agricultural University Wuhan 430070 （China） Research Center for Boo-Environment Chinese Academy of Sciences Beijing 100085 （China）

Batch equilibrium experiments were conducted to investigate cadmium （Cd） sorption by two permanent-charge soils, a yellow-cinnamon soil and a yellow-brown soil, and two variable-charge soils, a red soil and a latosol, with addition of selected organic acids （acetate, tartrate, and citrate）. Results showed that with an increase in acetate concentrations from 0 to 3.0 mmol L^-1, Cd sorption percentage by the yellow-cinnamon soil, the yellow-brown soil, and the latosol decreased. The sorption percentage of Cd by the yellow-clnnamon soil and generally the yellow-brown soil （permanent-charge soils） decreased with an increase in tartrate concentration, but increased at low tartrate concentrations for the red soil and the latosol. Curves of percentage of Cd sorption for citrate were similar to those for tartrate. For the variable-charge soils with tartrate and citrate, there were obvious peaks in Cd sorption percentage. These peaks, where organic acids had maximum influence, changed with soil type, and were at a higher organic acid concentration for the variable-charge soils than for the permanent charge soils. Addition of cadmium after tartrate adsorption resulted in higher sorption increase for the varlable-charge soils than permanent-charge soils. When tartrate and Cd solution were added together, sorption of Cd decreased with tartrate concentration for the yellow-brown soil, but increased at low tartrate concentrations and then decreased with tartrate concentration for the red soil and the latosol.

关键词： cadmium sorption organic acids variable- and permanent-charge soils

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Elemental Composition and Geochemical Characteristics of Iron-Manganese Nodules in Main Soils of China

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Pedosphere 2006年第1期16卷 72-81页

作者： TAN Wen-Feng LIU Fan LI Yong-Hua HU Hong-Qing huang qiao-yun College of Resources and Environment Huazhong Agricultural University Wuhan 430070 （China）. Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101（China）

Elemental composition and geochemical characteristics of iron-manganese nodules from nine main soils in China were studied by chemical and multivariate statistical analyses to better understand the reactions and functions of iron-manganese nodules in soils and sediment. Compared to the corresponding soils, Mn, Ba, Cd, Co and Pb had strong accumulation, Ni had moderate accumulation, while Ca, Cu, Fe, Na, P, Sr and Zn accumulated to a minor degree in the iron-manganese nodules. In contrast, Si, Al, K, Mg and Ti were reduced in the iron-manganese nodules. The contents of Ba, Cd, Co, Cu, Ni, Pb and Zn were positively and significantly correlated with that of MnO2 in the iron-manganese nodules, while the contents of Cr, Cu, Ni, Pb and Zn were positively and significantly correlated with that of Fe2O3 in soils. Based on a principle component analysis, the elements of iron-manganese nodules were divided into four groups: 1) Mn, Ba, Cd, Co, Cu, Li, Ni, Pb and Zn that were associated with Mn oxides, 2) Fe, Cr and P that were associated with Fe oxides, 3) Si, K, and Mg that were included in the elemental composition of phyllosilicate, and 4) Ca, Na, Al and Ti that existed in todorokite, birnessite, lithiophorite and phyllosilicate. It was suggested that accumulation, mineralization and specific adsorption were involved in the formation processes of soil iron-manganese nodules.

关键词： elemental composition geochemical characteristics iron-manganese nodule soil

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Amplification of plasmid DNA bound on soil colloidal particles and clay minerals by the polymerase chain reaction

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Journal of Environmental Sciences 2007年第11期19卷 1326-1329页

作者： CAI Peng huang qiao-yun LU Yan-du CHEN Wen-li JIANG Dai-hua LIANG Wei State Key Laboratory of Agricultural Microbiology Huazhong Agricultural University Wuhan 430070 China Key Laboratory of Subtropical Agricultural Resources a~ld Environment Huazhong Agricultural University Wuhan 430070 China

Polymerase chain reaction （PCR） was used to amplify a 600-base pair （bp） sequence of plasmid pGEX-2T DNA bound on soil colloidal particles from Brown soil （Alfisol） and Red soil （Ultisol）, and three different minerals （goethite, kaolinite, montmorillonite）. DNA bound on soil colloids, kaolinite, and montmorillonite was not amplified when the complexes were used directly but amplification occurred when the soil colloid or kaolinite-DNA complex was diluted, 10- and 20-fold. The montmorillonite-DNA complex required at least 100-fold dilution before amplification could be detected. DNA bound on goethite was amplified irrespective of whether the complex was used directly, or diluted 10- and 20-fold. The amplification of mineral-bound plasmid DNA by PCR is, therefore, markedly influenced by the type and concentration of minerals used. This information is of fundamental importance to soil molecular microbial ecology with particular reference to monitoring the fate of genetically engineered microorganisms and their recombinant DNA in soil environments.

关键词： adsorption amplification mineral PCR plasmid DNA soil colloid

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Isothermal Microcalorimetry:A Review of Applications in Soil and Environmental Sciences

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Pedosphere 2007年第2期17卷 137-145页

作者： RONG Xing-Min huang qiao-yun JIANG Dai-Hua CAI Peng LIANG Wei Key Laboratory of Subtropical Agricultural Resources and Environment Ministry of Agriculture Huazhong Agricultural University Wuhan 430070 （China）

Isothermal microcalorimetry provides thermodynamic and kinetic information on various reactions and processes and is thereby a powerful tool to elucidate their mechanisms. Certain improvement in isothermal microcalorimetry with regard to the studies on soil and environmental sciences is briefly described. This review mainly focuses on the use of microcalorimetry in the determination of soil microbial activity, monitoring the toxicity and biodegradation of soil organic pollutants, the risk evaluation of metals and metalloids, the heat effect of ion exchange and adsorption in soil, and environmental researches. Promising prospects for the applications of the technique in the field are also discussed.

关键词： environment isothermal microbial activity microcalorimetry soil

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Adsorption and Insecticidal Activity of Toxin from Bacillus thuringiensis on Rectorite

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Pedosphere 2007年第4期17卷 513-521页

作者： ZHOU Xue-Yong huang qiao-yun CAI Peng YU Zi-Niu Hubei Province Key Laboratory of Refractories and Ceramics Wuhan University of Science and Technology Wuhan 430081 （China）. College of Biotechnology and Chemical Engineering Tianjin University of Technology Tianjin 300191 （China） State Key Laboratory of Agricultural Microbiology College of Resources and Environment Huazhong Agricultural Uni- versity Wuhan 430070 （China）

The adsorption and desorption of the toxin from Bacillus thuringiensis strain WG-001 on rectorite were studied at different toxin and/or rectorite concentrations, pH values and temperatures. The insecticidal activity of the adsorbed toxin was evaluated by determining the lethal concentration to kill 50% of the larvae of Heliothis armigera （LC50）. The adsorption of the toxin on rectorite in sodium carbonate buffer （pH 9） reached equilibrium within 0.5-1.0 h and the adsorption isotherm of the toxin followed the Langmuir equation （R^2 〉 0.99）. In the pH range from 9 to 11 （carbonate buffer）, the adsorbed toxin decreased with increasing pH. The adsorption amounts decreased with increasing rectorite：toxin ratio. The adsorption was not significantly affected by the temperature between 10 and 50 ℃. The X- ray diffraction analysis indicated occurrence of the intercalation of the rectorite by the toxin. The infrared absorption spectrum showed that the binding of the toxin did not alter its structure. The LC50 wlues of the adsorbed toxin were smaller than those of the free toxin. The rectorite protected the toxin from ultraviolet irradiation damage. The desorption of the adsorbed toxin in water ranged from 37.5% to 56.4% and from 27.4% to 41.8% in a carbonate buffer. The desorption percentage also decreased with increasing rectorite：toxin ratio.

关键词： Bacillus thuringiensis insecticidul uctivity rectorite toxin udsorption und desorption

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Poultry Manure Compost Alleviates the Phytotoxicity of Soil Cadmium: Influence on Growth of Pakchoi (Brassica chinensis L.)

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Pedosphere 2010年第1期20卷 63-70页

作者： CHEN Han-Song huang qiao-yun LIU Li-Na CAI Peng LIANG Wei LI Ming Key Laboratory of Subtropical Agriculture and Environment of Ministry of Agriculture Huazhong Agricultural University Wuhan 430070 (China) State Key Laboratory of Agricultural Microbiology Huazhong Agricultural University Wuhan 430070 (China)

The growth performance of pakchoi （Brassica chinensis L.） in relation to soil cadmium （Cd） fractionations was investigated to evaluate the remediating effect of poultry manure compost on Cd-contaminated soil. A yellow-brown soil （Alfisol） treated with various levels of Cd （0 50 mg Cd kg^-1 soil） was amended with increasing amounts of compost from 0 to 120 g kg^-1. Compost application transformed 47.8%-69.8% of soluble/exchangeable Cd to the organic-bound fraction, and consequently decreased Cd uptake of pakchoi by 56.2%-62.5% as compared with unamended soil. Alleviation of Cd bioavailability by compost was attributed primarily to the increase of soil pH and complexation of Cd by organic matter including dissolved organic matter. In general, the improvement of pakchoi performance was more pronounced in higher Cd-contaminated soil. Addition of large amount of compost also favored the anti-oxidative capability of pakchoi against Cd toxicity. This low cost remediation method seems to be very effective in the restoration of Cd-eontaminated soils.

关键词： contamination heavy metal plant remediation

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Binding and Transformation of Extracellular DNA in Soil

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Pedosphere 2005年第1期15卷 16-23页

作者： CAIPeng huangqiao-yun ZHANGXue-Wen CHENHao StateKeyLaboratoryofAgriculturalMicrobiology CollegeofResourcesandEnvironmentHuazhongAgricultureUniversityWuhan430070China StateKeyLaboratoryofAgriculturalMicrobiology CollegeofResourcesandEnvironmentHuazhongAgricultureUniversityWuhan430070China／／CollegeofScienceHuazhongAgricultureUniversityWuhan430070China CollegeofScience HuazhongAgricultureUniversityWuhan430070China

DNA is the genetic material of various organisms. Extracellular DNA adsorbed or bound on surface-active particles in soils has been shown to persist for long periods against nucleases degradation and still retain the ability to transform competent cells. This paper reviews some recent advances on the binding and transformation of extracellular DNA in soils, which is fundamental to understanding the nature of the soil, regulating biodiversity, and assessing the risk of releasing genetically engineered microo…

关键词： adsorption binding extracellular DNA soil transformation

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PBL抗剪连接件疲劳后的剩余力学性能研究

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湖南大学学报（自然科学版） 2017年第7期44卷 128-135页

作者：汪炳黄侨邹韵李文贤东南大学交通学院江苏南京210096

为研究钢-混凝土组合结构中PBL(Perfobond Leiste)抗剪连接件在疲劳荷载作用后的力学性能退化规律,设计并制作了9个PBL连接件的推出试件分别进行静力和疲劳试验.其中3个试件为静力破坏试验,重点关注了试件的破坏模式、极限承载力及荷载... 详细信息

为研究钢-混凝土组合结构中PBL(Perfobond Leiste)抗剪连接件在疲劳荷载作用后的力学性能退化规律,设计并制作了9个PBL连接件的推出试件分别进行静力和疲劳试验.其中3个试件为静力破坏试验,重点关注了试件的破坏模式、极限承载力及荷载-滑移曲线.其余6个试件为在经历一定疲劳荷载循环次数后进行静力破坏试验,以疲劳循环次数,疲劳荷载比为参数变量,得到在不同疲劳参数作用后,PBL连接件的极限承载力、残余滑移量、抗剪刚度等力学性能的变化情况.研究结果表明,PBL连接件具有较好的延性,其静载和疲劳后静载的破坏模式均为一侧贯穿钢筋剪断、另一侧贯穿钢筋屈服.疲劳荷载比对PBL连接件剩余承载力影响较大,在同样经历了300万次的循环加载后,荷载比为0.5的极限承载力基本没有下降,而荷载比为0.7的承载力仅为初始静载试验的76.1%;在相同荷载比(0.6)情况下,PBL连接件的承载力随疲劳加载次数呈先慢后快的非线性退化趋势.相对于荷载比而言,残余滑移量对疲劳循环次数更为敏感.抗剪刚度在整个疲劳加载过程中基本保持不变.

关键词： PBL连接件钢-混凝土组合结构疲劳剩余力学性能

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耐重金属细菌对土壤胶体及矿物体系吸附镉的影响

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湖北农业科学 2010年第4期49卷 855-858页

作者：谢朝阳黄巧云黄敏武汉生物工程学院环境工程系武汉430415 华中农业大学资源与环境学院武汉430070 武汉理工大学资源与环境工程学院武汉430063

以从大冶铜矿区土壤筛选的耐重金属细菌NTG-01为试验菌株,研究在不同pH值及不同菌量条件下该细菌对土壤胶体和粘土矿物体系吸附Cd2+的影响。结果表明,土壤胶体、矿物与细菌的共存体系对Cd2+的吸附仍符合Langmuir方程,相关系数为0.99以... 详细信息

以从大冶铜矿区土壤筛选的耐重金属细菌NTG-01为试验菌株,研究在不同pH值及不同菌量条件下该细菌对土壤胶体和粘土矿物体系吸附Cd2+的影响。结果表明,土壤胶体、矿物与细菌的共存体系对Cd2+的吸附仍符合Langmuir方程,相关系数为0.99以上。在细菌NTG-01的存在下,土壤胶体、矿物对Cd2+的吸附量较无菌时增加,且在一定菌量范围内,随着体系中细菌量的增加,体系对镉的吸附量增加。红壤胶体、褐土胶体和针铁矿体系对Cd2+的pH—吸附率曲线与无菌时相比整体左移。

关键词：细菌土壤胶体矿物镉吸附

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一种监督型的连续属性离散化算法的研究

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三明学院学报 2015年第4期32卷 60-64,82页

作者：黄巧云福州大学至诚学院计算机工程系福建福州350002

提出一种监督型的连续属性离散化算法,利用云模型实现对属性区域的划分,以此引入边界的模糊性;再利用属性对类别的决定作用,判断是否对云模型进行归并操作,从而选择出合适的云模型集合,以实现离散化的目的。实验结果表明,该算法具有较... 详细信息

提出一种监督型的连续属性离散化算法,利用云模型实现对属性区域的划分,以此引入边界的模糊性;再利用属性对类别的决定作用,判断是否对云模型进行归并操作,从而选择出合适的云模型集合,以实现离散化的目的。实验结果表明,该算法具有较少的离散化区间数以及较高的分类精度。

关键词：云模型信息熵离散化

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