骨炭、过磷酸钙对稀土矿区停耕稻田土壤细菌群落的影响

磷是农作物生长和高产必不可少的元素，细菌是揭示土壤生态环境演变的重要指示剂。运用盆栽实验探讨骨炭、过磷酸钙对稀土矿区土壤细菌群落的影响。研究表明，含磷材料对稀土矿区停耕土壤细菌群落的影响与P含量、pH、稀土元素离子浓度，时间、温度等因素相关。过磷酸钙添加40 d后、骨炭添加80 d后，稀土矿区停耕稻田土壤细菌群落Chao、Ace指数均有升高，土壤细菌群落多样性增大；pH是影响细菌群落结构和功能的关键因子，酸杆菌门(Acidobacteria)与pH显著负相关，疣微菌门(Verrucomicrobia)与pH显著正相关；骨炭、过磷酸钙中的P促进变形菌门(Proteobacteria)的生长，无论是40 d,还是80 d时，骨炭处理与过磷酸钙处理的土壤变形菌门(Proteobacteria)所占比例均大于对照处理；骨炭、过磷酸钙中的磷酸根离子与土壤中的稀土元素反应形成磷酸稀土沉淀，减少了溶液中的稀土元素浓度，导致骨炭、过磷酸钙处理的土壤柯氏假丝酵母菌(Candidatus＿koribacter)丰度低于对照处理；土壤细菌群落结构受时间、温度等因素的影响，骨炭、过磷酸钙、对照处理40～80 d时，随着时间、温度的变化，疣微菌门(Verrucomicrobia)丰度发生了显著变化。研究表明，骨炭、过磷酸钙对稀土矿区停耕稻田均有一定的修复效果。     

红壤中稀土元素的有效性及其环境意义

研究了不同母质来源的红壤剖面层中稀土元素结构形态的变化以及可溶稀土元素含量的变化，结果表明，红壤中稀土元素的有效性较其他类型土壤为高，稀土 的有效性主要与土壤中粘土矿物及有 机质等组分对稀土的吸附有关。     

赣南富稀土矿区农田土壤中稀土元素的环境化学特征

选择江西赣县大田稀土矿区，研究了矿区耕作农田土壤中稀土元素的含量、分布及赋存形态特征。结果表明，该区土壤中稀土元素含量明显高于对照区和全国土壤平均含量，且相对富含重稀土元素。土壤中稀土元素的分布模式受成土母岩及元素性质控制，呈现Eu和Ce负异常。稀土元素主要以可交换态和有机结合态（特别是松结有机态）形式存在，具有较高的活性和生物有效性，可能影响生态环境安全。     

模拟酸雨对酸性土壤铝溶出及其形态转化的影响

研究了我国南方酸沉降区主要土壤类型在模拟酸雨影响下，土壤中铝离子释放及铝形态转化的特点。结果表明，酸雨淋洗造成土壤中铝离子释放，酸雨pH值越低，铝离子释放量越大；酸雨淋洗还造成土壤中铝形态发生变化，酸雨pH越低，土壤中羟基态铝和腐殖质铝含量愈低，交换态铝含量越高，土壤中铝对植物和生态系统的危害性也越大。     

沉水植物对沉积物及土壤垂向各形态无机磷的影响

该研究利用相同区域湖泊沉积物及土壤在室内模拟条件下培养黑藻,运用化学连续浸提法分离不同层次底质中各形态无机磷,并通过对水体中磷质量浓度和Eh值的测定,分析不同层次底质中各形态无机磷质量分数和间隙水中磷质量浓度的变化,揭示在沉水植物作用下淹水土壤和沉积物中不同层次各形态无机磷的迁移转化规律.结果表明,本试验条件下,黑藻主要影响上层和下层(根系所在层)底质中各形态无机磷的迁移转化;黑藻主要吸收利用弱吸附态磷和可还原态磷,并通过改变底质氧化还原环境影响可还原态磷和铁铝氧化态磷的迁移转化;黑藻的生长促进钙结合态磷的释放,但是黑藻的腐烂促进钙结合态磷的沉积;土壤中各形态无机磷比营养水平相当的沉积物中的磷容易迁移转化,黑藻对沉积物中各形态无机磷迁移转化的影响大于土壤.     

土壤中腐殖酸对外源农用稀土生物可利用性的影响

采用盆栽实验方法，研究了腐殖酸对稀土元素在土壤-植物体系中的迁移、富集和生物可利用性的影响，结果表明，在试验土壤红壤中，稀土元素主要富集在小麦根部，加入低浓度的腐殖酸后，促进了小麦对稀土元素的吸收：而高浓度的腐殖酸则抑制小麦对稀土元素的吸收，腐殖酸浓度过高时，对小麦生长产生毒害作用，同时发现，小麦中叶绿素含量与小麦中稀土含量存在相关关系。     

模拟酸雨对土柱中稀土元素迁移的影响

模拟研究酸雨对土柱中稀土元素迁移的影响.结果表明,在雨水、酸雨淋溶下,对照组红壤土柱中所含稀土元素有向下迁移的趋势,并且随淋溶液pH值的降低,稀土元素向下迁移的能力增加.外源稀土迁移量的大小顺序为;Ce>La>Nd>Pr,其顺序与各稀土元素在稀土微肥中含量大小的顺序相同.表明外源稀土的迁移性与外源稀土的总量密切相关.外源稀土在土柱中的含量随着红壤深度的增加而减少,稀土元素主要在土柱中第一、二层持留;随着淋溶液酸度的下降,稀土元素向下迁移的能力增加.     

红壤中稀土元素的有效性及其环境意义

研究了不同母质来源的红壤剖面层中稀土元素结合形态的变化以及可溶态稀土元素含量的变化，结果表明，红壤中稀土元素的有效性较其他类型土壤为高，可溶态稀土元素在土壤稀土总量中所占的比例可达６％～７％左右，稀土的有效性主要与土壤中粘土矿物及有机质等组分对稀土的吸附有关。     

赣南典型稀土矿区周边土壤和动植物产品中稀土元素组成特征及其健康风险评价

通过野外取样调查和室内ICP-MS测定,研究了赣南典型稀土矿区周边土壤、动植物产品中稀土元素的组成特征,并评价了稀土元素对人体的健康风险.结果表明,赣南稀土矿区周边土壤稀土平均含量为402.74±200.03 mg·kg~(-1),分别是全国土壤稀土含量均值及世界土壤稀土中值的2.28倍和2.08倍;植物产品稀土平均含量为343.48μg·kg~(-1);动物产品稀土平均含量为460.00μg·kg~(-1);土壤、植物产品和动物产品中Ce含量最高,占总稀土比重分别为34.22%、35.31%和62.95%;其中轻稀土元素所占比重分别为75.29%、75.17%和75.82%.当地居民每日通过动植物产品摄入稀土元素日量为3.95—30.49μg·kg~(-1)·d~(-1),均值为10.36μg·kg~(-1)·d~(-1),均远低于稀土元素对人体亚临床损害剂量的临界值(110μg·kg~(-1)·d~(-1)),表明赣南矿区周边动植物产品中稀土元素不会对消费者产生健康风险.     

湘江(长沙段)沿岸土壤中铬的形态分布及其在水草中的积累

铬在土壤中主要以Cr(Ⅲ)和Cr(Ⅵ)两种形态存在,而Cr(Ⅵ)主要以CrO2-4,Cr2O2-7,Cr(Ⅲ)主要以Cr3 和CrO-2等形式存在.上述存在形式在土壤中的迁移转化主要受土壤pH值和氧化还原电位(Eh)的制约.另外,也受土壤有机质含量、无机胶体组成、土壤质地及其化合物种类的影响.不同形态的铬在一定条件下可以相互转化.但是单从价态来区分并不能完全反映土壤中铬的真实存在形态,当前较为公认的是Tesseler的形态划分法. 本文研究了湘江(长沙段)沿岸土壤中铬的形态分布、转化及其在水草中的吸收.     

稀土元素在土壤中迁移、转化模型的建立及验证

建立了稀土在褐土土壤中迁移、转化模型，定量评价稀土在土壤中的迁移、转化过程。模型包括土壤中稀土化学热力学平衡体系、土壤水分物理形状和土壤剖面的稀土通量。在中国农业大学内进行了田间实验，对模型进行了验证，模拟值与实测值能很好的拟合。     

Major and trace elements in paddy soil contaminated by Pb–Zn mining: a case study of Kočani Field,Macedonia

The objective of this study was to assess the bulk chemical composition as well as the extent and severity of heavy metal contamination in the paddy soil of Kočani Field (eastern Macedonia). The results revealed that the paddy soil of the western part of Kočani Field is severely contaminated with Pb, Zn, As and Cd in the vicinity of the Zletovska River due to irrigation with riverine water that is severely affected by acid mine and tailing effluents from the Pb–Zn mine in Zletovo. The detected total concentrations of these metals are far above the threshold values considered to be phytotoxically excessive for surface soil. The paddy soil in the vicinity of the Zletovska River was also found to exhibit elevated levels of Ba, Th, U, V, W, Mo, Cu, Sb, Bi, Ag, Au, Hg and Tl, with concentrations above their generally accepted median concentration values obtained during this study. A correlation matrix revealed that the Mn and Fe oxides/hydroxides are the most important carrier phase for several trace elements, with the exception of rare earth elements (REEs). These also represent a major sink for the observed heavy metal pollution of the soil. REEs are mostly associated with two phases: light (L)REEs are bound to K-Al, while heavy (H)REEs are bound to Mg-bearing minerals. Although there is no direct evidence of a health risk, the paddy soil in the vicinity of Zletovska River needs further investigation and an assessment should be made of its suitability for agricultural use, particularly in view of the highly elevated concentrations of Pb, Zn, As and Cd.     

稀土元素在水体食物链生物中迁移的摸拟研究

本文用动态和静态摸拟系统分别研究了稀土元素在小球藻-大型溞-鲤鱼食物链生物上的迁移。结果表明:水生生物对稀土的生物积累作用有从水体直接摄取和从食物间接摄取两种方式,但稀土元素在该食物链上无生物放大作用,生物体中积累的稀土量和水环境中残余的稀土浓度从轻稀土向重稀土递减,稀土元素在水环境中迁移的最重要形式可能是物理-化学迁移。     

Species and distribution of rare earth elements in the Baotou section of the Yellow River in China

This paper analyses the contents and species distributions of rare earth elements (REEs) in the water-suspended particulate-sediment system of the Baotou section of the Yellow River, China, with known anthropogenic REE input from industrial discharges. The major forms of REEs were suspended and dissolved in the mainstream and the tributaries of the Baotou section, respectively. The concentrations of the dissolved and suspended REEs had the same trends in the overlying water along the mainstream, which increased from the Seqi section (site A) to the mouth of the Sidaosha River (site D), reaching a maximum value at site D, and tending to decrease thereafter. The contents of REEs in sediment cores showed enrichment with light rare earth elements (LREEs). The bound to carbonates and to Fe–Mn oxides are the major forms of REE in the secondary phase and the REE exhibited LREE enrichment pattern and moderate Eu depletion in suspended particulates and surface sediments. The contents and species distributions of REEs in the water-suspended particulate-sediment system of the Baotou section suggest that the anthropogenic source of REEs from Baotou city have enhanced REE accumulation to the Baotou section. This information is important for predicting possible pollution resulting from anthropogenic REE input into rivers.     

稀土对植物抗逆作用的自由基机制

通过研究及收集的资料，提出在植物生长期中，稀土元素能增加植物的抗逆性，当植物受到酸雨、重金属及盐胁迫时，稀土表现出抗氧化性质，而且稀土对植物的抗逆作用是由于其具有清除含氧自由基的作用。     

土壤中稀土元素的生态毒性研究进展

为了解稀土元素对农田生态系统的影响,综述了近几十年来国内外有关土壤稀土元素生态毒性的研究进展,包括土壤稀土元素的主要来源途径,稀土元素对农田生态系统中植物、动物和微生物生长、发育、繁殖的影响。高浓度的稀土元素会破坏植物细胞膜的性质和结构,影响植物的抗氧化系统,扰乱植物对矿质营养元素的正常吸收和利用,诱使植物细胞发育不良、染色体畸变等现象发生。稀土元素可影响动物的消化、呼吸、生殖、神经、血液和免疫系统等。稀土元素对土壤微生物数量、种类、群落结构与功能多样性等均有影响。探讨了土壤稀土元素的生态毒性诊断方法,目前常见的植物毒性诊断法、蚯蚓毒性诊断法、土壤微生物诊断法、生物标记物诊断法和遗传毒性诊断法等可用来诊断土壤中稀土元素的生态毒性。提出了以后开展土壤稀土元素生态毒性研究应加强的方面:在群落、个体和细胞水平上研究稀土元素对土壤动物和微生物的影响,加强稀土元素生态毒性诊断新方法和新技术的探讨,进行稀土元素生物有效性与土壤因素关系的研究等。     

The chemistry and parent material of urban soils in Bristol (UK): implications for contaminated land assessment

An earlier survey of topsoil from parks and allotment in the city of Bristol (UK) revealed the presence of relatively high levels of “pseudo-total” Cd, As, Cu, Pb and Zn, with Cd and As exceeding present UK soil guidelines. This follow-up work aimed at (1) estimating geochemical thresholds for these elements based on “near-total” soil, bedrock and sediment heavy metals and (2) determining the genetic relationship between soil and bedrock using rare earth elements (REEs or lanthanides) as tracers. “Near-total” concentration of 34 elements (Al, Ca, Fe, K, Mg, Na, As, Ba, Cd, Cr, Cu, Li, Mn, Ni, P, Pb, Sc, Ti, V, Zn, Y and the rare earth elements Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Sm, Tb, Yb) were obtained by ICP-MS and ICP-OES. The results show that the soil composition is largely controlled by the soil parent material, though extreme outliers are indicative of contamination at a few sites of parkland and allotments. Cumulative frequency plots show the presence of different data sets for which separate “background” values should be determined. The REE data provide evidence that weathering of the underlying sandstone was a determinant factor leading to the relatively high heavy metal enrichment found in soil samples and sediments. Reference to UK soil guidelines to decide on possible remediation measures could be very misleading due to the natural high background levels of some elements in the underlying bedrock. Before defining land as “contaminated”, a thorough geochemical investigation is required at local scale in order to produce a more realistic and correct environmental assessment.