湖北恩施地区土壤-植物系统中Se元素的地球化学特征

在对恩施地区典型农业活动区——芭蕉、长平和鱼塘坝三地土壤中Se元素含量进行调查的基础上,通过与富Se土壤质量标准进行对比,发现除长平地区外,其余两地分别属于富Se和高Se地区,并通过土壤理化性质、形态分析和土壤中所生长的植物进行比较,初步研究了Se在土壤-植物体系中迁移转化的规律。结果表明：整体来看,鱼塘坝地区属于超富Se地区,植物中Se的含量也最高,长平地区属于非富Se地区,芭蕉地区则属于中等富Se地区;植物对Se的吸收受一定的土壤理化性质的影响,不同类型的植物对Se的吸收富集相差较大;形态分析研究表明,鱼塘坝地区土壤中生物可利用的Se含量较高,而芭蕉地区土壤中残渣态Se的比例较高,表现为Se的生物可利用性低于鱼塘坝地区。     

湖北恩施地区土壤-植物系统中Se元素的 地球化学特征

在对恩施地区典型农业活动区——芭蕉、长平和鱼塘坝三地土壤中Se元素含量进行调查的基础上,通过与富Se土壤质量标准进行对比,发现除长平地区外,其余两地分别属于富Se和高Se地区,并通过土壤理化性质、形态分析和土壤中所生长的植物进行比较,初步研究了Se在土壤-植物体系中迁移转化的规律。结果表明：整体来看,鱼塘坝地区属于超富Se地区,植物中Se的含量也最高,长平地区属于非富Se地区,芭蕉地区则属于中等富Se地区;植物对Se的吸收受一定的土壤理化性质的影响,不同类型的植物对Se的吸收富集相差较大;形态分析研究表明,鱼塘坝地区土壤中生物可利用的Se含量较高,而芭蕉地区土壤中残渣态Se的比例较高,表现为Se的生物可利用性低于鱼塘坝地区。     

恩施州富硒区儿童发镉的调查

恩施州富硒区儿童发镉的调查邵器行（中国地质大学,武汉４３００７４）毛大钧苏宏灿（恩施州卫生防疫站,湖北恩施４４５０００）（恩施州妇幼保健院,湖北恩施４４５０００）关键词镉元素的组合效应儿童富硒区湖北恩施Ｃｄ是对人体有害的微量元素。在铅锌多金属硫化物矿...     

渔塘坝微地域硒分布的景观地球化学研究

选取迄今世界上唯一发生过人群硒中毒爆发性流行的地区－－湖北恩市双河乡渔塘坝为研究区。研究表明,在表生中－－强风化环境中,硒是个相当活泼的元素。在渔塘坝０．０１ｋｍ＾２的微地域内,土壤硒、玉米硒的分布存在着显著的不均一性。微地形、淋失条件是影响二者硒贪主其分布的主要因素。土壤硒含是基本决定了玉米硒含量。渔塘坝中硒在玉米中的基本分布规律是雄花、雌蕊〉叶〉籽〉根〉茎,上部叶片〉下部叶片、上部茎节〉下部茎     

Characterization of Secondary Native Selenium in the Yutangba Se Deposit,Western Hubei,China

Secondary native Se minerals that are appreciably coarser grained and vary morphologically than primary native Se minerals were observed in the abandoned dumps of the No. 3 and No. 4 orebodies of the Yutangba Se deposit, western Hubei Province, China. The secondary native Se minerals exhibit three crystal forms, namely prismatic, tabular, and granular. Based on geochemical and mineralogical data, the secondary native Se minerals are interpreted to have resulted from natural oxidation of selenide minerals in the primary Se ores, or from vaporization of Se caused by burning of “stone coal” (a highly carbonaceous mudstone) during the production of lime. The occurrence of secondary native Se minerals in the deposit would be helpful not only to further study on mineralogy, ore geochemistry and environmental geochemistry of Se, but also to improve the technology of reclaiming Se from the black rock series.     

湖北恩施地区土壤一植物系统中Se元素的地球化学特征

在对恩施地区典型农业活动区——芭蕉、长平和鱼塘坝三地土壤中se元素含量进行调查的基础上,通过与富Se土壤质量标准进行对比,发现除长平地区外,其余两地分别属于富Se和高Se地区,并通过土壤理化性质、形态分析和土壤中所生长的植物进行比较,初步研究了se在土壤一植物体系中迁移转化的规律。结果表明：整体来看,鱼塘坝地区属于超富se地区．植物中se的含量也最高,长平地区属于非富se地区,芭蕉地区则属于中等富se地区;植物对se的吸收受一定的土壤理化性质的影响,不同类型的植物对se的吸收富集相差较大;形态分析研究表明,鱼塘坝地区土壤中生物可利用的se含量较高．而芭蕉地区土壤中残渣态se的比例较高．表现为Se的生物可利用性低于鱼塘坝地区．．     

恩施富硒茶叶中Se含量与对应土壤中Se及重金属元 As、Cd、U的关系

采用氢化物—原子荧光分光光度法(AFS)对恩施芭蕉地区玉露茶园不同坡度的茶叶、土壤样品中的Se及重金属元素Cd、U的质量分数分别进行了测试.研究了恩施富硒茶叶中的Se与As质量分数的关系以及其Se质量分数与其种植土壤中的Se质量分数和重金属元素Cd、U质量分数的关系,旨在为恩施富硒茶叶的种植提供依据.研究表明:在w(S...     

Geochemistry of the Yutangba Se Deposit in Western Hubei, China

1IntroductionThecontentsofSeinthecrustareextremelylow ,onlyabout0 .0 5mg/kg .Innatureitishardtoformindependentminerals,insteaditisdispersedinothermineralsandmedia.Althoughitscon tentsarefarhigherthanthoseofTeinthecrust,seleniumisusuallydispersedinsulfidesinitsas cendingandformingprocesses (D’yachkovaandKhodakovskiy ,1 968) .Thisisthereasonwhyse leniummineralsarefarlessthantelluriummineralsandsulfidesinnature (Simonetal.,1 997) .Forthisreason ,thegeochemicalstudyofseleniumdidnotattractanyat…     

湖北渔塘坝硒矿床中次生自然硒的特征与意义

在湖北渔塘坝硒矿床氧化矿石及地表松散堆积物中存在大量罕见的次生自然硒。自然硒呈柱状、板状和它形粒状。它的形成一方面与硒矿石的风化作用有关,另一方面系当地居民用石煤烧石灰过程中导致硒的蒸发而发生次生富集的结果。矿床中大量次生自然硒的发现,不仅对硒的矿物学、矿床地球化学、环境地球化学研究具有重要价值,而且对解决或改进含碳硒矿石或岩石中硒的冶炼回收工艺流程具有一定的启迪意义。     

类芽孢杆菌对铜陵新桥矿区土壤中Cu化学形态的影响

采用Tessier五步连续提取法和红外光谱技术,研究类芽孢杆菌对铜陵新桥矿区重金属污染土壤中Cu化学形态的影响,初步探讨了Cu形态变化的机理。结果表明,不同投入量的类芽孢杆菌接种到土壤培养一周后,土壤溶液pH值降低,土壤中可交换态、有机结合态Cu含量增加,碳酸盐结合态、铁锰氧化物结合态和残渣态Cu的含量降低。土壤中可交换态、铁锰氧化物结合态和残渣态Cu含量的变化主要受土壤溶液的pH值控制;有机结合态升高主要与类芽孢杆菌菌数及其代谢产生的低分子量有机酸有关。类芽孢杆菌可以改变矿区土壤中Cu的化学形态,影响Cu的生物有效性。     

Accumulation and speciation of selenium in evaporation basins in California,USA

The accumulation of selenium in evaporation basins (or ponds) in the San Joaquin Valley, California is of a great concern due to its potential hazards to environments. In this study, the accumulation, speciation and concentrations of Se were examined in waters as well as sediments in a system of the evaporation ponds. A significant decrease in the total dissolved Se concentration in Cell 1 in which drainage water with higher Se concentration was pumped from Inlet Channels indicated that the immobilization of Se was active in the Cell 1 and resulted in the higher Se concentration in sediments compared to the terminal cell such as Cell 9. The percentage of reduced Se species such as selenite [Se(IV)] and org-Se of total Se in drainage waters was also found increased in Cell 1 compared to Inlet Channels. The total dissolved Se concentrations in water along flow paths from Cell 1 were relatively constant except for terminal cells such as Cells 9 and 10, which showed higher total dissolved Se concentrations due to evapoconcentration. The percentage of reduced Se forms of total Se was inversely proportional to the percentage of Se(VI) depending on the redox condition of evaporation ponds along the flow paths. Sequential extractions of Se species in sediments indicated that organic associated Se and elemental Se were prevalent forms in sediments in the ponds system. The higher concentrations of elemental Se and organic associated Se in sediments in Cell 1 indicated that the immobilization of Se was active in the sediments compared to Cell 9, while the percentage of both fractions of total Se in sediments in Cells 1 and 9 was relatively constant. The organic materials from algae might provide carbon sources for Se reduction and Se sink in sediments in its elemental and organic associated forms.     

Halomonas Xiaochaidanensis sp. nov.,a Halotolerant Bacterium Isolated from Xiaochaidan Lake of Qadam Basin,China

正A short-rod-shaped halotolerant bacterium,designated CUG00002T,was isolated from the sediment of Xiaochaidan Lake of Qadam Basin,China,using R2A medium.The cells are Gram-negative,aerobic and forming creamy and circular colonies with diameter of 1-     

新疆东天山小热泉子铜锌(硒)矿床硒的赋存状态及硫硒比值研究

小热泉子矿床是中-大型富铜、锌(硒)多金属矿床。文章通过电子探针较系统地分析了该矿床不同矿体中的不同容矿岩石的各种硫化物(241件)的微量元素。测定结果表明,该矿床的硫化物明显富硒,硫化物中w(Se)平均为0.045%,S/Se比值平均为829。经初步计算,该矿床硒资源量为813吨,已达大型规模。首次发现硫化物中方铅矿含硒最高,w(Se)最高可达11%,为硒方铅矿;其他硫化物黄铜矿、闪锌矿、铜蓝、黄铁矿中平均w(Se)分别为0.048%、0.041%、0.034%、0.054%;S/Se平均值分别为717、803、955、976。毒砂含硒最低,w(Se)均小于0.001%。不同矿体、不同容矿岩中硫化物的含硒量也有明显差别。Ⅰ号矿床硫化物的硒含量明显高于Ⅲ号矿床,二者硒平均含量分别为0.076%与0.013%,S/Se平均值分别是495和2802。不同容矿岩中凝灰质碎屑岩、绿泥石岩、石英脉中的硫化物w(Se)平均分别是0.056%、0.047%、0.018%;S/Se平均值分别为635、495、2102。这些数据表明该矿床的硫化物形成于较高温度,具岩浆热液作用的特征;Ⅰ、Ⅲ号矿床具不同的成矿环境及成矿多期性的特点,它对该矿床的成因及硒的赋存状态研究具有重要意义。     

Distribution and speciation of mercury in surface water in Wanshan Hg-mined areas, Guizhou Province, China

Mercury as a toxic element poses environmental concerns, especially in historically Hg-mined districts. The Wanshan Hg mine located in the eastern part of Guizhou Province, southwestern China, ranks the largest Hg-producing district in China. Mining at Wanshan was initiated in 221 B.C., but ceased in 2001. Approximately 22000 tons of Hg, 6000 tons of cinnabar and large quantities of mine-wastes had been produced at Wanshan. Significant quantities of calcines, which were piled irregularly near the old mine processing sites and retorts, continue to impact the local environments in the Wanshan area. In this study, a regional contamination of mercury in surface waters collected from the Meizixi, Dashuixi, Huandao and Gaolouping rivers, whose upstreams or branches originate from the hilly karstic area and receive drainage arising from the calcines, was investigated by determining all Hg species in a base-flow and a flood-flow season. Reactive, dissolved, particulate, and total Hg concentrations in surface water varied from 0.60 to 400 ng/L, 11 to 430 ng/L, 1.4 to 9210 ng/L, and 15 to 9260 ng/L, respectively. Total methylmercury in water samples ranges from 0.31 to 25 ng/L. The concentrations of total Hg and particulate Hg in water samples collected during the flood season are higher than those in the base-flow season, whereas, the concentrations of dissolved and reactive Hg are lower with the peak values observed in water samples collected in the base-flow season. A strong positive correlation between total Hg and particulate Hg is noticed in the water samples collected from Hg-mined areas with the proportion higher than 80%.     

Distribution and speciation of mercury in the Hongfeng Reservoir,Guizhou Province,China

The water, pore water, sediment, and fish samples were collected from the Hongfeng Reservoir in November 2003 and February 2004 in accordance with trace metal protocols. The average concentrations of total mercury （THg）, dissolved mercury （DHg）, reactive mercury, dissolved gaseous mercury, total methylmercury, and dissolved methylmercury in the water columns were 8.00, 5.70, 0.63, 0.05, 0.16, and 0.07 ng/L, respectively. THg and DHg in the water columns, THg in pore water and THg in lake sediments of the Hongfeng Reservoir showed the level of mercury in the Hongfeng Reservoir was higher than in other natural waters in the world due to the loading of a lot of waste water with relatively high concentrations of mercury, whereas methylmercury concentrations in fish （wet weight） varied from 1.73-51.00 ng/g, much lower than in most remote lakes and reservoirs reported in northern Europe and North America. Methylmercury distributions in pore water and sediments showed methylation occurred mainly in the upper several centimeters of sediment cores in the Hongfeng Reservoir. The concentrations of dissolved organic carbon, total suspended particles, total Hg, and methylmercury were higher at Houwu than those at Daba in November 2003. It is suggested that other pollutants such as N and P from fishing farm and other waste water at Houwu, which resulted in deterioration of water quality, affected the concentrations and distributions of mercury species in the reservoir.     

Isolation and characterization of phenanthrene-degrading strain Sphingomonas sp. GY2B

Polycyclic aromatic hydrocarbons （PAHs） are of great concern since most of them have been shown to be toxic, mutagenic, and carcinogenic. Bioremediation, based on certain species of microorganisms, is regarded as an alternative method to detoxify or remove PAHs from the contaminated sites. Phenanthrene has been often used as a model substance for microbial metabolism of ＂bay-region＂ and ＂K-region＂ containing carcinogenic PAH. The focus of the present study is to isolate and identify microorganisms which could use phenanthrene as the sole carbon and energy source. Such microorganisms are expected to be of interest as a source organism for the bioremediation of PAHs polluted soils. The bacterial consortia were enriched from PAH contaminated soils with water-silicon oil biphasic systems. An aerobic bacterial strain efficiently utilizing phenanthrene as the sole carbon and energy source was isolated from bacterial consortia GY2 and identified as Sphingomonas sp. strain GY2B. Strain GY2B was susceptible to some common used antibiotics such as cefuroxime, chloramphenicol, erythromycin and tetracycline and intermediate susceptible to amoxycillin. Moreover, no plasmids could be isolated from strain GY2B using the standard alkaline-SDS method. At pH 7.4 and 30℃ strain GY2B had an optimal growth condition and in this condition above 99.8% phenanthrene was degraded under initial concentration of 100 mg/L. The addition of low concentration of glucose （10-200 mg/L） in MSM containing 100 mg/L phenanthrene could enhance the growth of strain GY2B, while the high concentration of glucose （〉500 mg/L） could exert an inhibitive effect on cell growth. Besides phenanthrene, strain GY2B could also use naphthalene, phenol, 1-hydroxy-2-naphthoic acid, 2-naphthol, salicylic acid and catechol as the sole carbon and energy source. The growth of strain GY2B on salicylic acid and catechol showed that the degradation of phenanthrene might follow salicylate pathway.     

西秦岭降扎地区寒武系层控金矿床中 Au-Se共同富集成矿机制

西秦岭降扎地区寒武系中的层控金矿床,产于由碳质硅岩和碳质板岩组成的硅岩建造中,研究表明,无论是围岩还是金矿,匀普遍含有国高的硒,达到工业综合利用的要求,在局部地段甚至可以圈出独立的硒矿体,在金矿石中,矿主要呈独立矿物和以类质同象形式存在于硫化物中,且硒与金呈密切的正相关关系,尤为重要的是,在金矿石中常常见到自然金与一些硒矿物紧密共生,说明Au,Se可能以Au-S-Se或Au-Se络合物形式进行迁移,由于沸腾的成矿流体与下渗的富氧冷水混合而发生氧化还原作用,导致了Au和Se的共同富集成矿。     

Evaluation of aluminum speciation in surface waters in China and its environmental risk assessment

As the ongoing global research on acid precipitation is developing in depth, more and more attention has been paid to the ecological effects of aluminum (Al) due to its toxicity to plants and animals, which is caused by acid precipitation. As a very serious problem of terrestrial and aquatic environmental acidification occurs in China, especially in southwestern China, a systematic investigation of Al speciation in these regions is very important. In this paper, the Al speciation results of surface waters in China are reported and its ecological impacts is evaluated. More than 100 water samples were collected from about twenty provinces of China. Driscoll's Al speciation scheme combined with the modified MINQEL computer model is used for speciation of Al. This study shows that the ecological impacts of acidification are quite different between China and Western countries, because of different geographical environments and geological settings. In Western countries, acidification is mainly caused by NO₂^-. Due to low concentrations of K⁺, Na⁺, Ca²⁺, Mg²⁺, the buffer capacities of soil and water are weak. Therefore, natural waters can be acidified to pH<5 very easily, resulting in a considerable mobilization of Al and worsening of the ecological environment. In China, acid precipitation is mainly in the form of sulfuric acid. In northwestern China, concentrations of K⁺, Na⁺, Ca²⁺, Mg²⁺ are high in soil and surface waters. This leads to much higher capacity and a high resistance ability to acidification. The pH values of waters in this region are high (around 7) and no serious Al toxicity is found at present. However, in northeastern and southeastern China, the soil is rich in Al (unsaturated aluminosilicates in northeastern China, saturated aluminosilicates in north and central China, aluminum-rich soil in southeastern and southwestern China). The concentrations of K⁺, Na⁺, Ca²⁺, Mg²⁺ in soil and waters are lower than those of northwestern China. Therefore the buffer capacity is limited. Numerous surface waters have already been acidified and pH values declined to 5. The impacts of Al toxicity on ecological systems in these regions are very serious, especially in Jiangxi, Hubei Provinces and Chongqing Municipality.     

南疆焉耆盆地土壤-小麦系统硒耦合关系及生物有效性

为研究土壤-小麦系统硒的关联性,采集南疆焉耆盆地小麦主要种植区小麦及对应根系土样品,通过相关分析、多元逐步线性回归方法,探讨土壤、小麦中Se含量及形态,查明影响小麦中硒的主要控制因素。结果表明,强有机质结合态硒（SOM-Se）和残渣态硒（Re-Se）是土壤硒的主要赋存形态,占土壤总Se含量的65.15%;土壤中硒受土壤风化程度、土壤质地和有机质含量影响明显;小麦籽粒中硒主要以有机硒形式存在,无机硒仅占全Se含量的6.39%,小麦硒的可给性高;土壤总Se含量可以很好地指示小麦Se含量水平,水溶态硒（Sol-Se）、离子交换态硒（Ex-Se）为有效硒的重要指标。基于土壤总Se、B、SOM构建的小麦硒吸收模型,可解释小麦吸收硒67%的方差。结合实际生产,给出了研究区高效富硒（含硒）小麦判别标准。据此编制富硒土壤高效利用区划图,有效地支撑了焉耆盆地富硒小麦标准化管理和面粉加工,提高了富硒土壤划定的科学性和实用性。     

湖北恩施双河硒矿床地球化学特征及成因探讨

湖北恩施双河硒矿床赋硒岩石的化学成分中SiO2含量不仅相对较低,而且变化范围较大;Al2O3,K2O,TiO2,MgO含量相对较高。主要氯化物比值与火山或热水成因硅质岩接近。在氧化物协变图解中样品主要投影在火山成因区内。Al/（Al＋Fe＋Mn）的半均值约为0．72,最大值为0．93,大于生物成因型硅质岩沉积物,说明有富Al的陆源物质加入。来自深源的向量元素Se,Te,Mo表现出超异常的富集;而V,Ag,Sb,Cr等元素也有较高程度的富集,这些特征与世界上火山成因硅质岩相似。更为重要的是在赋硒岩石夹层中首次发现了泥化的火山碎屑角砾,由此表明该矿床物质来源与火山碎屑沉积物之间有着密切的成因联系。同时研究区样品中的Co/Ni〈1,U/Th〉1;在P2O5-Y的相关图解中亦呈现出某些热水成因的特点。稀土元素8Ce呈负异常,平均值为0．61;REE总量和同期、邻区的峨眉山玄武岩相近;HREE有富集趋势,北美页岩标准化稀土配分曲线以不同程度略向左倾斜,这些特征又表明该矿床在其成岩成矿过科中一定程度上受热水作用影响。