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Utilization of recycled solid waste as ecological reclamation materials based on plant growth experiments and soil quality analysis

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Journal of Mountain Science 2024年第3期21卷 820-834页

作者： QIN Xiaochun NI Anchen YANG Dongxiao XING Wenhu LIU Shiliang College of Civil Engineering Beijing Jiaotong UniversityBeijing 100044China Shanxi Road&Bridge Construction group Co. LtdShanxi 030006China School of Environment Beijing Normal UniversityBeijing 111875China

During the highway construction,a large number of spoil areas will be generated while a large amount of waste slag and soil could not be rationally ***,the vegetation recovery is slow in the spoil areas due to the soil *** at recycling the solid waste,the sieved engineering waste slag with local red clay and corn straw biochar was supplied to solve the problem of insufficient nutrients in engineering waste slag and *** addition,planting experiments of alfalfa(Medicago sativa L.)and Amorpha fruticosa *** with physical and chemical experiments were carried out to prove the feasibility of the novel improved substrate for the reclamation of spoil *** results show that the substrate's improvement effect is mainly affected by the soil to slag ratio and the biochar *** improvement effect of soil matrix in highway spoil area decreases with the increase of the waste slag content,especially when the soil-slag ratio is less than 3,and the promotion of plants is *** the contrary,the improvement effect is proportional to the biochar content(3%-8%).But it is noted that the Cu and Pb in the soil will exceed the clean limit corresponding to the Nemero soil pollution index level when the biochar content is 8%.Therefore,it is recommended that the soil-slag ratio should be≥3,and the biochar content should reach 3%-5%.This research provides experimental basis and technical support for utilizing solid waste resources in the reclamation of highway spoil areas.

关键词： Highway Spoil area Waste slag Modified soil Ecological reclamation

Experimental Interactions Between clay Minerals and Bacteria: A Review

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Pedosphere 2015年第6期25卷 799-810页

作者： Barbara MUELLER clay mineralogy group Institute for Geotechnical EngineeringETH Zurich Plant Pathology Institute of Integrative BiologyETH Zurich

Interactions between microbes and minerals have the potential to contribute significantly to global cycles of various processes and serve as a link between the geosphere and life. clays and clay minerals occur commonly in agriculturally utilized soils, are naturally grown underground(soil and rock) and are used in construction material. clay minerals serve as natural, geological and technical barriers in geotechnics and environmental geotechnics. Bacteria in turn are ubiquitous in natural soils, subsoils and rocks and are in permanent contact with clay minerals. There are numerous ways in which bacteria can interact with clay minerals and alter them:dissolution, refinement and transformation, reduction of trace elements incorporated in the clay minerals and uptake of trace elements from these minerals, e.g., by the production of siderophores and chelators and enhancement or reduction of adsorbance of trace elements on clay minerals. In addition, bacteria can influence layer charge, cation exchange capacity(CEC), exchangeable cations,Brunauer-Emmett-Teller surface, swelling and the rheological properties of clay minerals. The field of clay mineral-microorganism interaction is still wide open because of the large potential that the interactions of bacteria with clay minerals in soils and sediments may result in changes in clay mineral properties and behaviors. Further detailed studies on all these tentative changes and underlying mechanisms as well as broad surveys of quantifications of extents and rates of clay mineral-microorganism interactions, especially in mimicking natural systems, are highly required. This review summarizes the influences of various bacteria on the properties of different clay minerals as determined experimentally using viable bacteria.

关键词：粘土矿物相互作用实验确定细菌环境岩土工程微量元素阳离子交换量交换性阳离子

Soil disturbance evaluation of soft clay based on stress-normalized smallstrain stiffness

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 990-999页

作者： Yanguo Zhou Yu Tian Junneng Ye Xuecheng Bian Yunmin Chen MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering Institute of Geotechnical EngineeringCenter for Hypergravity Experiment and Interdisciplinary ResearchZhejiang UniversityHangzhou310058China Ningbo Rail Transit group Co. Ltd.Ningbo315010China

Soil disturbance includes the change of stress state and the damage of soil *** field testing indices reflect the combined effect of both changes and it is difficult to identify the soil structure disturbance directly from these *** the present study,the small-strain shear modulus is used to characterize soil structure disturbance by normalizing the effective stress and void ratio based on Hardin *** procedure for evaluating soil sampling disturbance in the field and the further disturbance during the subsequent consolidation process in laboratory test is proposed,and then validated by a case study of soft clay *** seismic testing in the field,portable piezoelectric bender elements for the drilled sample and bender elements in triaxial apparatus for the consolidated sample were used to monitor the shear wave velocity of the soil from intact to disturbed and even remolded *** is found that soil sampling disturbance degree by conventional thin-wall sampler is about 30%according to the proposed procedure,which is slightly higher than that from the modified volume compression method proposed by Hong and Onitsuka(1998).And the additional soil disturbance induced by consolidation in laboratory could reach about 50%when the consolidation pressure is far beyond the structural yield stress,and it follows the plastic volumetric strain quite well.

关键词： Natural clay Soil sample disturbance Shear wave velocity Small-strain shear modulus Hardin equation

Occurrence and vertical distribution of aluminum and rare earths in weathered crust elution-deposited rare earth ore:Effect of soil solution pH and clay minerals

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Journal of Rare Earths 2024年第7期42卷 1394-1402,I0007页

作者： Jiaxin Pan Longsheng Zhao Zheng Li Xiaowei Huang Zongyu Feng Jun Chen National Engineering Research Center for Rare Earth China GRINM Group Co.Ltd.Beijing100088China School of Metallurgical and Ecological Engineering University of Science and Technology Beijing(USTB)Beijing100083China GRIREM Hi–Tech Co. Ltd.Langfang065201China GRIREM Advanced Materials Co. Ltd.Beijing100088China GRIMAT Engineering Institute Co. Ltd.Beijing101407China

Weathered crust elution-deposited rare earth ore is crucial source of medium and heavy rare earths,with in-situ leaching being the most common mining *** high contents of impurity of aluminum in the leach solution are a significant challenge for the subsequent enrichment process of rare earths.A comprehensive understanding of the occurrences and vertical distribution of aluminum and rare earths within typical vertical profiles can provide valuable insights into entire design of the in-situ *** paper improves a five-step sequential extraction method to analyze the occurrence and vertical distribution of rare earths and aluminum in vertical profiles from Chongzuo and *** results demonstrate that soil solution pH is the main factor affecting the vertical distribution of ionexchangeable rare *** samples have distinct areas of enrichment for ion-exchangeable rare earths or ***-exchangeable rare earths are primary concentrated in the middle and lower parts of the ore layer(4-13 m in Chongzuo,14-22 m in Longyan),while the ion-exchangeable aluminum is mainly enriched in the upper part of the ore layer(1-5 m in Chongzuo,and 2-14 m in Longyan).The vertical distribution of inorganic hydroxy aluminum is likely influenced by the micromorphology and particle size of the clay *** inorganic hydroxy aluminum concentration in Chongzuo samples decreases continuously from 415.65 to 120.95 mg/kg with increasing sampling depth,whereas the concentration in Longyan samples(110.55-171.27 mg/kg)is almost independence with sampling *** results provide direct guidance for the entire design of the injection well depth and the leaching parameters,thereby inhibiting the leaching of impurity of aluminum and lower the consumption of leaching agent.

关键词： Weathered crust elution-deposited rare earth ore Sequential extraction Occurrence Aluminum Rare earth elements

Microstructure and water-swelling mechanism of red-bed mudstone in the Xining region,Northeastern Tibetan Plateau

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2537-2551页

作者： Huan Guan Yong Ren Sixiang Ling Xiyong Wu Tao Yu Xian Li Sen Wang Chunwei Sun School of Civil Engineering Southwest Jiaotong UniversityChengdu610031China Faculty of Geosciences and Engineering Southwest Jiaotong UniversityChengdu611756China Moe Key Laboratory of High-speed Railway Engineering Southwest Jiaotong UniversityChengdu610031China Guangzhou Metro Design and Research Institute Co Ltd. Guangzhou510010China Chengdu City Construction Investment group Co Ltd. Chengdu610036China

This paper examines the effect of the microstructure and electrical conductivity(EC)on the swelling ratio and pressure in red-bed mudstone sampled from arid areas in the Xining region in the northeastern Tibetan Plateau.A series of laboratory tests,including swelling experiments,X-ray diffraction(XRD),and scanning electron microscope(SEM),was carried out for mechanical and microstructural *** coupled influence of the EC and microstructural parameters on the expansion ratio and pressure was investigated,and the weight coefficients were discussed by the entropy weight *** results revealed an increasing exponential trend in EC,and the maximum swelling speed occurred at an EC of approximately 10 mS/*** addition,a method for predicting the expansion potential is proposed based on the microstructure,and its reliability is verified by comparing with swelling experimental *** addition,according to the image analysis results,the ranges of the change in the clay minerals content(CMC),the fractal dimension(FD),the average diameter(AD)of pores,and the plane porosity(PP)are 23.75%e53%,1.08e1.17,7.53e22.45 mm,and 0.62%e1.25%,***,mudstone swelling is negatively correlated with the plane porosity,fractal dimension and average diameter and is linearly correlated with the clay mineral ***,the weight values prove that the microstructural characteristics,including FD,AD,and PP,are the main factors influencing the expansion properties of red-bed mudstones in the Xining *** on the combination of macro and micro-analyses,a quantitative analysis of the swelling process of mudstones can provide a better reference for understanding the mechanism of expansion behavior.

关键词： Mudstones Microstructure Swelling characteristics Electrical conductivity(EC) Scanning electron microscope Water-swelling

水-瓦斯耦合作用下煤岩抗压特性劣化试验研究

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Journal of Central South University 2024年第2期31卷 477-495页

作者：吕科江宁尹大伟孟书宇高志友吕涛 College of Energy and Mining Engineering Shandong University of Science and TechnologyQingdao 266590China General Institute of Exploration and Research of China National Administration of Coal Geology Beijing 100039China Shandong Geology and Mineral Resources Engineering group Co. Ltd.Jinan 250013China

闭坑高瓦斯矿井中煤岩体在水和瓦斯的劣化作用下力学特性劣化,这将直接影响其稳定性和安全性。为研究水-瓦斯耦合作用下煤岩抗压特性,基于水-岩-气耦合试验系统,开展了浸泡环境下的全水浸(EW)、半水浸半气浸(WG)及全气浸(EG)煤样和干燥(... 详细信息

闭坑高瓦斯矿井中煤岩体在水和瓦斯的劣化作用下力学特性劣化,这将直接影响其稳定性和安全性。为研究水-瓦斯耦合作用下煤岩抗压特性,基于水-岩-气耦合试验系统,开展了浸泡环境下的全水浸(EW)、半水浸半气浸(WG)及全气浸(EG)煤样和干燥(CZ)煤样的单轴压缩试验,分析了煤样抗压强度及变形破坏特征,并从煤样浸泡前后的组分、宏观结构及破裂断口细观特征的角度,揭示了水-瓦斯耦合作用下煤岩的宏观、细观劣化机制。结果表明,在三种浸泡条件下,煤样抗压强度较干燥煤样均降低,EG组、WG组和EW组煤样抗压强度分别降低了18.92%、38.31%和53.45%,三种浸泡条件下煤样破坏模式由干燥煤样的剪切破坏转变为剪切-拉伸混合式破坏,破坏程度也随之增大,煤样由脆性破坏转变为塑性破坏,导致浸泡后煤样局部化带范围和错动程度增大;煤样在三种浸泡环境中劣化效果主要表现为:1)水和瓦斯的侵入导致煤样内部黏土矿物分解和析出,与CZ组相比,EG组、WG组和EW组煤样平均黏土矿物含量分别降低了3.8%、28.85%和45.94%,煤样孔隙结构发生改变;2)各组煤样浸泡后表面出现劣化效应,EG组表面孔隙发育程度劣于EW组,且EW组煤样表面出现剥落现象,WG组煤样水浸部分孔隙发育程度要胜于气浸部分;3)水和瓦斯的劣化作用使煤样内部孔隙结构发生改变,EW组、WG组和EG组煤样破裂断口平均孔隙率较CZ组分别增加了706.84%、362.95%、147.47%。在三种浸泡环境下煤样初始承载结构被破坏,降低了煤样破坏前储存能量的能力,破坏后煤样内部的剩余弹性能降低,耗散能增加,声发射累计振铃计数降低。上述研究对于认识闭坑高瓦斯矿井中煤岩体的稳定性具有一定的参考意义。

关键词：水-瓦斯耦合废弃矿井抗压特性劣化特性

Characterization and Geotechnical Classification of Soils and Lateritic Gravelly Materials along the Songololo-Lufu Road Axis (Kongo Central Province, DR Congo)

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Journal of Geoscience and Environment Protection 2024年第5期12卷 355-372页

作者： Jean-Luc Albini Tshupa Blaise Mutombo Kabulu Ivon Ndala Tshiwisa Clément N’zau Umba-Di-Mbudi Geo-Hydro-Energy Research group Geosciences Department Faculty of Sciences and Technologies University of Kinshasa Kinshasa Democratic Republic of Congo Geosciences Department Faculty of Sciences and Technologies University of Kinshasa Kinshasa Democratic Republic of Congo Geological and Mining Research Center (CRGM) Kinshasa Democratic Republic of Congo Polytechnic Faculty President Joseph Kasa-Vubu University Boma Democratic Republic of Congo

This study aims to characterize from a geotechnical point of view, the soils as well as the lateritic gravels along the Songololo-Lufu road route in the Kongo Central Province in the Democratic Republic of Congo (DRC). Ten soil samples and eight lateritic gravel samples were analysed and tested in the laboratory. For each sample, identification parameters were determined such as particle size analysis, natural water content, Atterberg limits (plasticity index and consistency index), but also compaction and lift parameters such as optimal water content, maximum dry density and CBR lift index. All materials and soils have been classified according to the Congolese Road Standard (NRC) and according to the American HRB classification. The test results show us that clay soils almost always contain between 70% and 90% fine fraction;the grained fraction represents less than 30% in clay samples. For lateritic gravels soils, the percentage of fine elements varies between 35% and 15%;in sand around 20%;the gravelly fraction represents a little more than 50% of the soil. The majority of soil facies encountered define a plasticity index lower than 15. As for the consistency index, we obtained values greater than 1, both for clayey soils and for gravelly soils. The classification according to NRC defined for these soils the types Ae1 and Ae2 for the clayey facies and the types GL1 and GL2 for the gravelly soils, while that of the HRB identified the classes and subclasses A-6 and A-7-6 for clayey soils, and subclass A-2-6 for gravelly soils. The optimal water content values obtained range between 10.2% and 23.10%;the maximum dry densities are between 1.66 and 2.07 t/m3 and the CBR index is between 6 and 26. As for the lateritic gravels materials of the Songololo region, the percentage of fine elements generally remains between 12% and 31%;the plasticity index is between 8 and 18;the optimal dry density is around 2 t/m3;the optimal water content is between 9.

关键词： Songololo-Lufu Lateritic Gravels Classification Geotechnical NRC

Glucosamine supplementation during late gestation alters placental development and increases litter size

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Journal of Animal Science and Biotechnology 2018年第1期9卷 135-144页

作者： Jeffrey L.Vallet Jeremy R.Miles Bradley A.Freking Shane Meyer USDA ARS U.S. Meat Animal Research Center (USMARQ P.O. Box 166 Clay Center NE Nebraska 68933 USA Plymouth Ag group Diller NE Nebraska 68342 USA

Background： During late gestation the placental epithelial interface becomes highly folded, which involves changes in stromal hyaluronan. Hyaluronan is composed of glucoronate and N-acetyl-glucosamine. We hypothesized that supplementing gestating dams with glucosamine during this time would support placental folded-epithelial-bilayer development and increase litter size. In Exp. 1, gilts were unilaterally hysterectomizedovariectomized（UHO）. UHO gilts were mated and then supplemented daily with 10 g glucosamine（n = 16） or glucose（control, n = 17） from d 85 of gestation until slaughter（d 105）. At slaughter, the number of live fetuses was recorded and each live fetus and its placenta was weighed. Uterine wall samples adjacent to the largest and smallest fetuses within each litter were processed for histology. In Exp. 2, pregnant sows in a commercial sow farm were supplemented with either 10 g glucosamine or glucose daily from d 85 of gestation to farrowing. Total piglets born and born alive were recorded for each litter. In Exp. 3, the same commercial farm and same protocol were used except that the dose of glucosamine and glucose was doubled to 20 g/***： In Exp. 1, the number of live fetuses tended to be greater in glucosamine-treated UHO gilts（P = 0.098）.Placental morphometry indicated that the width of the folded bilayer was greater（P = 0.05） in glucosamine-treated gilts. In Exp. 2, litter size did not differ between glucosamine-and glucose-treated sows. However in Exp. 3, the increased dose of glucosamine resulted in a significant treatment by parity interaction（P ≤ 0.01）, in which total piglets born and born alive were greater in glucosamine treated sows of later parity（5 and 6）.Conclusions： These results indicated that glucosamine supplementation increased the width of the folds of the placental bilayer and increased litter size in later parity, intact pregnant commercial sows.

关键词： Fructose Glucosamine Hyaluronan Swine Uterine capacity

Phase modification and dielectric properties of a cullet–paper ash–kaolin clay-based ceramic

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International Journal of Minerals,Metallurgy and Materials 2018年第3期25卷 350-356页

作者： K.A.Samah M.R.Sahar M.Yusop M.F.Omar Advance Optical Material Research group Department of Physics Faculty of Science Universiti Teknologi Malaysia

Novel ceramics from waste material made of(x) paper ash–(80-x) cullet–20 kaolin clay(10 wt% ≤ x ≤ 30 wt%) were successfully synthesized using a conventional solid-state reaction technique. Energy-dispersive X-ray analysis confirmed the presence of Si, Ca, Al, and Fe in the waste material for preparing these ceramics. The influence of the cullet content on the phase structures and the dielectric properties of these ceramics were systematically investigated. The impedance spectra were verified in the range from 1 Hz to 10 MHz at room temperature. The phase of the ceramics was found to primarily consist of wollastonite(CaSiO_3), along with minor phases of γ-dicalcium silicate(Ca_2SiO_4) and quartz(SiO_2). The sample with a cullet content of 55 wt% possessed the optimum wollastonite structure and exhibited good dielectric properties. An increase of the cullet content beyond 55 wt% resulted in a structural change from wollastonite to dicalcium silicate, a decrease in dielectric constant, and an increase in dielectric loss. All experimental results suggested that these novel ceramics from waste are applicable for electronic devices.

关键词： ceramics cullet glass paper ash wollastonite structural properties dielectric properties