含重金属的尾矿渣场复垦还田种植农作物的安全技术     

刘瑞平  徐友宁  张江华  乔冈  柯海玲  陈华清  何芳 《西北地质》2019,(2):236-246

含有毒重金属的尾矿渣场复垦还田的安全经济技术方法是目前国内外的难点。为了探索尾矿渣场复垦还田后,种植农作物的安全性和经济性,笔者开展了小秦岭金矿区尾矿渣场不同覆土厚度农作物种植试验研究。结果表明:尾矿渣为土壤、农作物重金属提供了丰富的物源,尾矿渣、土壤和农作物中重金属排序为Pb>Cd>Hg;成熟中后期的农作物内重金属超过国家标准的风险高于成熟早期,叶菜类、果实类蔬菜及粮食类作物的风险主要来自Hg、Pb、Cd;块根类蔬菜是比较安全经济的种植作物,其中萝卜、土豆、青菜的经济安全种植厚度应大于40cm、50cm、70cm,在最大覆土厚度90cm上种植其他农作物也是不安全的;种植农作物后,土壤中Pb、Cd减少量与尾矿渣上覆土厚度有一定相关性,而Hg元素还与自身的挥发性有关;农作物对重金属的选择与重金属在黄土中的迁移能力是影响农作物吸收重金属的重要影响因素。试验结果可为研究金矿尾矿渣复垦还田的安全技术方法提供借鉴作用。  相似文献   

Wind tunnel investigation of the influence of surface moisture content on the entrainment and erosion of beach sand by wind using sands from tropical humid coastal southern China   总被引：2，自引：0，他引：2  

Qingjie Han  Jianjun Qu  Kecun Zhang  Ruiping Zu  Qinghe Niu  Kongtai Liao 《Geomorphology》2009,104(3-4):230-237

Wind erosion has major impacts on dune growth, desertification, and architecture on sea coasts. The deflation threshold shear velocity is a crucial parameter in predicting erosion, and surface moisture greatly affects this threshold and thus sand stability. Wind tunnel studies have shown that reduced moisture contents decrease entrainment thresholds and increase wind erosion, but field and wind tunnel test data is lacking for tropical humid coastal areas. In this study, we investigated the influence of surface moisture contents (at 1 mm depth) on sand entrainment and erosion using tropical humid coastal sands from southern China. Shear velocities were deduced from velocity profiles above the sand. The threshold shear velocity increased linearly with increasing ln100M (M, gravimetric moisture content). The increase was steepest below a moisture content of 0.0124 (i.e., at M_1.5, the moisture content in the sand at a matric potential of − 1.5 MPa). We compared several popular models that predict threshold shear velocity of moisture sediment, and found substantial differences between their predicted results. At a surface moisture content of 0.0124, the predicted increase in the wet threshold shear velocity compared with the dry threshold shear velocity ranged from 34% to 195%. The empirical model of Chepil and Selah simulated the data well for M < 0.0062 (i.e., 0.5M_1.5), whereas Belly's empirical model simulated the data best for M > 0.0062. Wind erosion modulus increased with increasing effective wind velocity following a power function with a positive exponent at all moisture contents, but decreased with increasing surface moisture content following a power function with a negative exponent. When wind speed and moisture content varied simultaneously, wind erosion modulus was proportional to the 0.73 power of effective wind velocity, but inversely proportional to the 1.48 power of M. The increase in resistance to erosion at low moisture contents probably results from cohesive forces in the water films surrounding the sand particles. At a moisture content near M_1.5, wind erosion ceases nearly for all wind velocities that we tested.  相似文献   

用天然碳酸钙除去硫酸钾肥料中游离酸     

梅祖明 《岩矿测试》2000,19(2):149-151

研究了天然碳酸钙的粒度对除去K2 SO4肥料中游离酸的影响 ,实验表明 ,粒径小于0 1 49mm的天然CaCO3能有效除去游离酸 ,按m(CaCO3)∶m(K2 SO4) =4∶1 0 0的比例控制天然CaCO3的加入量 ,可使K2 SO4中的游离酸酸度小于 0 50 %。  相似文献   

山东东营凹陷南坡地区沙四段纯下亚段湖相碳酸盐岩滩坝发育的控制因素探讨^*   总被引：2，自引：0，他引：2       下载免费PDF全文

宋国奇  王延章  路达  闫瑞萍  杨静 《古地理学报》2012,14(5):565-570

碳酸盐岩滩坝是断陷湖盆中一种重要的沉积类型。文章通过对古气候、古地貌、古物源、古水深和古盐度等因素对碳酸盐岩滩坝形成与分布控制作用进行研究,总结出了“古气候是基础,古地貌和古物源是条件,古水深是关键,古盐度是保障”是东营凹陷南坡地区沙河街组四段纯下亚段碳酸盐岩滩坝的“五古”控制模式。较干旱的温热适中的古气候条件下蒸发作用较强,有利于湖相碳酸盐岩的形成;水下隆起及其斜坡是碳酸盐岩滩坝沉积的有利场所,较低的碎屑岩物源供给指数为碳酸盐岩的发育提供了良好的环境;3～32m左右的古水深是碳酸盐岩发育的主要深度;古盐度为碳酸盐岩的沉积提供了物质保障,在一定程度上控制了白云岩和石灰岩的分布。采用主因素分析法对碳酸盐岩的控制因素进行了排序,古地貌对碳酸盐岩发育的控制作用最大,其次为古物源和古水深,古盐度的控制作用最小。  相似文献   

Temporal variations of sandstorms in Minqin oasis during 1954–2000     

Kecun Zhang  Jianjun Qu  Ruiping Zu  Haiyan Fang 《Environmental Geology》2005,49(2):332-338

The purpose of this present study is to investigate in detail the frequency and variation of sandstorms in the Minqin oasis. Using daily observational data from sandstorms and other meteorologic data from 1954 to 2000, the relationship between a sandstorm and meteorological parameters and human activities, which can be used for daily weather forecasting, have been illuminated. The results of the analysis show that sandstorms have a clear daily and monthly variation. Monthly mean and annual mean duration of sandstorms in the Minqin oasis coincide well with the frequencies of sandstorm occurrence.  相似文献   

塔克拉玛干沙漠地面风场特征及周边地区沙丘排列关系分析   总被引：9，自引：0，他引：9       下载免费PDF全文

俎瑞平张克存  屈建军凌裕泉 《应用气象学报》2005,16(4):468-475

通过对1996~2000年17个气象站风资料的分析和计算, 结合高空环流形势分析, 对塔克拉玛干沙漠近地面风场特征进行了研究, 并对风场特征与周边地区沙丘排列方向之间的关系进行了分析。研究表明:①塔克拉玛干沙漠近地面风场特征是在高空西风带的背景下, 经过青藏高原、天山山脉的动力分支和抬升等作用下形成的。冬季, 尼雅河以东盛行偏东风, 以西盛行偏西风; 夏季, 克里雅河以西地区盛行偏西北风和西风, 以东盛行东北风。②从东到西, 东北风系影响逐渐减弱而西北风系影响逐渐加强; 南北方向变化较为复杂。③除若羌地区外, 塔克拉玛干沙漠输沙势都小于200 VU, 属于低能风环境, 且以单峰或锐双峰为主。在区域分布上, 沙漠东部及中部强度较大, 西部及南部较小。④沙丘排列方向主要由主、次输沙方向的夹角及二者的输沙比率决定, 其走向与最大输沙总量垂直。  相似文献   

Grain size in sediments from Lake Sugan: a possible linkage to dust storm events at the northern margin of the Qinghai–Tibetan Plateau     

Mingrui Qiang  Fahu Chen  Jiawu Zhang  Ruiping Zu  Ming Jin  Aifeng Zhou  Shun Xiao 《Environmental Geology》2007,51(7):1229-1238

Samples of surface deposits in the Lake Sugan catchment, as well as surface lake sediments, eolian materials occulted in the lake ice cover, and airborne dust were collected for grain-size analysis. The results show that the coarse fraction of the lake sediments could be transported by ambient winds and to a lesser extent by river flow in the study area. Sediment cores were retrieved from Lake Sugan in December 2000, and ²¹⁰Pb and ¹³⁷Cs dating and grain-size analyses were performed on these samples. ²¹⁰Pb ages and the volume percentage of the fraction of lake sediments >63 μm were used to reconstruct the dust storm history from 1957 to 2000. Observational data for dust storm events collected at a local meteorological station largely agrees with the reconstructed trend for the past 44 years, suggesting that lake sediments can be employed to trace the dust storm history of the northern Qinghai–Tibetan Plateau.  相似文献   

The origin,historical variations,and distribution of heavy metals in the Qiongzhou Strait and nearby marine areas   总被引：1，自引：0，他引：1  

Zhiqiang Zhang  Liang Chen  Weiping Wang  Tuanjie Li  Tingting Zu 《中国海洋大学学报(英文版)》2017,16(2):262-268

We analyzed heavy metal concentrations in a number of surface sediments and cores from the Qiongzhou Strait and surrounding marine areas.The areas of high concentrations are primarily outside the eastern mouth of the Qiongzhou Strait and on the west side of the Leizhou Peninsula,whereas the areas of low concentrations are located primarily in the eastern Qiongzhou Strait.The maximum Cd,Pb and Zn concentrations in the samples collected in our study do not exceed the official standards for marine sediments,whereas the concentrations of Cr and Cu slightly exceed the standards.Correlations exist between the concentrations of Cu,Pb,Zn,Cr and Cd,and the concentrations of these metals are positively correlated with the mean particle size(φ value),indicating that the finer sediments have adsorbed greater amounts of heavy metal elements than the coarser sediments.An evaluation of the potential environmental risks demonstrates that certain indices of heavy metal pollution and environmental risks are relatively low and may be assigned low risk levels,thereby indicating that,in terms of heavy metals,the marine sedimentary environment in this region is only mildly impacted.Our analysis of the contaminant origins shows that the heavy metals in this region primarily originate in the Pearl River Estuary and that a small amount of them is derived from local runoff.The elevated heavy metal concentrations from the upper sections of the cores started 130 years ago,which indicats that heavy metals in the surface sediments are primarily due to human activities associated with industrialization.  相似文献   

地脉动在系舟山北麓断裂次级断裂探测中的应用          下载免费PDF全文

闫小兵  梁瑞平  王伟君  郝雪景 《地震工程学报》2023,(2):421-430

系舟山北麓断裂为1038年定襄■级地震的发震构造，在盆地内部可能存在一条或多条次级断裂，并有可能非常邻近忻州城区，使用地脉动方法对系舟山北麓断裂是否存在次级隐伏断裂进行探测。通过共振频率的横向变化以及基岩深度和频率的关系获得了约17个比较显著的断点位置，指示出系舟山山前存在三条比较显著的次级断裂，以及它们的断点位置、相对错距和相应的走向分布，为忻州市区防震减灾提供基础资料。  相似文献