Cesium-137 Concentrations in Sediments and Aquatic Plants from the Pinios River, Thessalia (Central Greece)

The levels of radioactive contamination by artificial radiocesium (¹³⁷Cs) were evaluated in sediments and the commonest species of water plants. Specimens were collected from a range of biotopes along the Pinios River and its tributaries, during the years 1998 and 2010. The ¹³⁷Cs concentrations within the above period clearly indicate that this radionuclide still decrease in the River Pinios. A marked decrease is also observed in comparison to our previous results in 1993. ¹³⁷Cs concentration activities in the sediment are higher than in the plant material. In general, roots showed greater ¹³⁷Cs concentration than leaves, while stems showed the lowest concentration. Significant differences in ¹³⁷Cs concentrations were found among different species growing under similar environmental conditions. ¹³⁷Cs content in collected aquatic plants was in the descending order: Ceratophyllum demersum L. > Myriophyllum spicatum L. > Paspalum pasalodes Scribner > Cladophora glomerata L. > Cyperus longus L. > Potamogeton nodosus Poiret. A comparison of the studied stations indicated that the southwest side of Thessalia plain, where the first two initial sampling stations of the Pinios River and the tributaries Enipeas and Kalentzis are situated, was highly contaminated. Low ¹³⁷Cs concentrations were observed in the Titarisios tributary, originated from the northeast part of Thessalia plain, behind Mt. Olympus and the last sampling stations of the Pinios River.     

东北黑土中137Cs背景值研究

通过测定东北黑土背景点样品中137Cs活度,探讨了土壤剖面中137Cs的分布特征,对因风蚀造成背景点土壤表层137Cs的沉积进行了校正,得出了黑土的137Cs背景值,为水蚀风蚀两相侵蚀地区土壤137Cs背景值的确定提供了新思路。结果表明:黑土背景点土壤剖面中137Cs比活度的分布呈指数型,其拟合方程为Cs=76.744e-0.2566h,相关系数达到0.994。剖面中75.7%的137Cs分布在0～5cm的表层中,92.5%的137Cs分布在0～10cm的土壤上层;黑土的137Cs背景值为2463.64Bq/m2,与平坦黑土耕地中137Cs的沉降总量接近,可以利用该背景值进行黑土侵蚀速率的估算。     

阳洼流域土壤137Cs的空间分布及侵蚀研究

利用137Cs示踪技术,研究了宁南黄土高原阳洼流域土壤137Cs的空间分布和侵蚀特征.研究结果表明,流域137Cs背景值为1 966.99 Bq/m2,流域内不同土地利用方式下土壤137Cs比活度不同,且有比较明显的137Cs比活度分异.流域内林草地土壤剖面137Cs呈现指数分布模式,坡耕地剖面的137Cs则呈均匀分布模式.不同土地利用方式下土壤137Cs的面积活度表现为沟台＞林草地＞农耕坡地,其中农耕坡地、沟台地土壤侵蚀、沉积表现出较大的变异,变异系数达65%以上.阳洼流域土壤侵蚀模数与137Cs比活度呈现出相反的分布趋势,但都明显具有斑块状和条带状分布的特点.流域土壤以中、强度侵蚀为主,中、强度侵蚀面积占流域总面积的46%,在流域土壤侵蚀防治中坡耕地仍是治理的关键.     

日本福岛核事故引起的土壤中铯-137的积累和污染调查

2011年3月发生在日本大地震之后的福岛第一核电站(NPP)爆炸事故引起的铯-137(137Cs)的积累与污染,137Cs的半衰期为30.1年,对农业和畜牧业的危害巨大,能够影响人类生活数十年。因此,铯污染备受人们关注。     

Migration of Cesium-137 in typical soils of North Germany ten years after the Chernobyl accident

Ten years after the Chernobyl disaster the Cs-137 migration of typical soils of North Germany (Folic Histosol, Haplic Podzol, Dystric Gleysol, Eutric Fluvisol) has been investigated and compared to their Cs distribution in 1986. In 1986 nearly 90% of the Cs-137 occurred in the upper 1–5 cm soil sections, whereas it was 50–70% in 1996. The more regular distribution ten years after the accident shows that migration processes have taken place. The Podzol presented a high migration with marked Cs-137 losses in the top soil. The Gleysol showed the lowest migration down to 10 cm depth. A nearly similar pattern at the top was found within the Histosol, however, a ratio of 10% Cs-137 in the 10–15 cm section indicated a deeper migration. Despite the large clay content, the Fluvisol showed a regular Cs distribution within its profile, probably resulting from cattle steps and/or peloturbation.     

宁南黄土高原土壤137Cs分布与相关影响因子研究

利用137Cs示踪方法,对宁南黄土高原阳洼流域纵断面土壤137Cs分布及相关影响因子进行了初步研究。结果表明:流域纵断面137Cs面积活度随坡面海拔和水平距离的变化,表现为一种不规则的波动振荡趋势。随海拔降低,纵断面上、中部137Cs面积活度逐步下降,有明显的土壤侵蚀发生;坡面下部137Cs面积活度最高,泥沙沉积的再分布现象明显。流域内林草地剖面土壤137Cs呈指数型分布,坡耕地、梯田137Cs在耕层内呈均一分布,其分布模式与各土地类型土壤有机质的分布状态完全一致。相关分析表明,两者在P<0.01水平达到极显著相关(r2=0.336,n=417)。土壤137Cs的损失和土壤有机质的移动具有相同的物理路径和运移机制;农耕坡地土壤137Cs面积活度随坡度增加有逐步降低的趋势;土地利用方式、坡度、耕作活动是影响纵断面土壤137Cs空间异质性的主要因素。137Cs示踪方法是研究土壤侵蚀空间分布的一种有效工具。     

宁南黄土高原土壤^137Cs分布与相关影响因子研究

利用^137Cs示踪方法,对宁南黄土高原阳洼流域纵断面土壤^137Cs分布及相关影响因子进行了初步研究。结果表明：流域纵断面^137Cs面积活度随坡面海拔和水平距离的变化,表现为一种不规则的波动振荡趋势。随海拔降低,纵断面上、中部^137Cs面积活度逐步下降,有明显的土壤侵蚀发生;坡面下部^137Cs面积活度最高,泥沙沉积的再分布现象明显。流域内林草地剖面土壤^137Cs呈指数型分布,坡耕地、梯田^137Cs在耕层内呈均一分布,其分布模式与各土地类型土壤有机质的分布状态完全一致。相关分析表明,两者在P〈0．01水平达到极显著相关（r^2=0．336,n=417）。土壤^137Css的损失和土壤有机质的移动具有相同的物理路径和运移机制;农耕坡地土壤^137Cs面积活度随坡度增加有逐步降低的趋势;土地利用方式、坡度、耕作活动是影响纵断面土壤^137Cs空间异质性的主要因素。^137Cs示踪方法是研究土壤侵蚀空间分布的一种有效工具。     

阿勒泰地区参考作物蒸散量时空变化特征

基于阿勒泰地区7个气象站1961—2012年逐日气象资料,采用Penman-Monteith模型计算了逐日参考作物蒸散量,运用Mann-Kendall非参数检验法、小波分析法,并结合ArcGIS软件对作物参考蒸散量的时空变化特征进行了研究。结果表明:阿勒泰年和春季作物参考蒸散量呈增加趋势,而夏季、秋季和冬季作物参考蒸散量呈减少趋势。年和夏季的作物参考蒸散量分别在1994年、1992年发生突变,而春季、秋季和冬季的作物参考蒸散量则没有发生突变。年和四季的作物参考蒸散量都存在27 a的周期。空间分布上,年、春季、夏季和秋季的平均作物参考蒸散量呈自阿勒泰市南部和福海县西北部向东部、南部和西部逐渐递减的变化趋势。而冬季作物潜在蒸散量大致呈现自西向东逐渐递减。变化趋势上,春季潜在蒸散量在空间上都呈增加趋势,而年、夏季、秋季和冬季的潜在蒸散量在阿勒泰的东部呈增加趋势,在西部则呈减少趋势。     

宁南黄土高原阳洼流域137Cs分布及侵蚀特征研究

利用137Cs示踪方法,对宁南黄土高原阳洼流域土壤137Cs分布及土壤侵蚀进行了初步研究。结果表明:流域137Cs基准值为(1 966.99±112.06)Bq/m2。流域内林草地土壤剖面137Cs呈指数型分布,坡耕地137Cs在耕层内呈均一分布。受坡位影响,坡耕地上坡137Cs质量活度为中、下坡的25.14%~27%。流域内坡耕地土壤侵蚀最高,平均为3 889.95 t/km2,自然荒坡最小,仅为坡耕地的17.83%,坡耕地是流域泥沙的主要侵蚀溯源区。阳洼流域土壤侵蚀存在明显的空间格局,不同土地类型下土壤137Cs面积活度、土壤侵蚀模数呈斑块状镶嵌分布,以靠近流域西南边界、中部及东南部区域土壤侵蚀模数最大,平均侵蚀速率在3 405.59~7 080.73 t/(km2.a),沉积与侵蚀明显区域间有过渡区域。坡度是影响该流域土壤侵蚀空间变化的主导因子,但土壤侵蚀速率并不简单随坡度增加而增大,它还受土地利用方式、坡位、降雨等因素影响。     

^137Cs技术对长江三角洲丘陵区小流域土壤侵蚀初步估算

采集了长江三角洲丘陵区某一小流域的 8个土壤剖面共 2 6个样品 ,通过分析发现该小流域的土壤 1 37　Cs含量与采样深度之间具有比较良好的线性关系 (0 .98>R2 >0 .6 9) ;以坡顶作为参考点 ,提出该地区土壤中的 1 37Cs背景值约为 2 40 0 Bq/m2 ;建立了基于 1 37Cs技术的土壤侵蚀定量模型 ,并对该流域土壤侵蚀量进行了初步估算 ,结果表明侵蚀最严重的丘坡中部马尾松林地占总侵蚀量 38.2 3% ,坡麓的菜园土壤亦达 32 .89%。因而 ,对坡中和坡麓地貌部位采取相应的保护措施 ,可有效地防治水土流失带来的各种危害。     

红壤侵蚀沉积点^137Cs垂直剖面分布特征

研究了红壤农田和荒地侵蚀沉积点中 1 3 7Cs的剖面分布特征 ,结果表明 ,沉积点在 1 7cm处有明显的峰谷 ,农田沉积点 1 3 7Cs含量要高于荒地 ;经估算 ,两沉积点的沉积速率相近 ,1 96 3年以来为 1 .0 3 cm/ a,近 2 0年约为 0 .74cm/ a;沉积点的 1 3 7Cs分布显示该区域侵蚀有减小的趋势 ;1 3 7Cs活度与有机质存在较好的相关性 ;1 3 7Cs在侵蚀研究中具有重要意义     

Regional Contamination in Lakes from the Noril'sk Region in Siberia,Russia

Sediment and water chemistry data were collected from ten lakes within a 110 km radius of Noril'sk in Siberia, the largest smelting complex in the world. Metals showing the most pronounced increase in enrichment near the smelters were Cu, Ni, Co, Ba and Zn. Cu and Ni appear to be as or more enriched in lake sediments around Noril'sk compared with levels previously reported for other locations. Although SO4 concentrations were highly elevated in the areas closest to the smelting complex, lake water pH remained elevated due to high concentrations of base cations in the waters. Sediment mercury enrichment was high in sediments near the smelting complex, but not more so than in other parts of the Arctic, suggesting that Hg either is not a major smelting product at Noril'sk, or that Hg is transported greater distances than other metals due to its longer atmospheric residence time.     

镇江地区不同地类土壤侵蚀~(137)Cs法初步研究

选择江苏镇江地区作为研究区,采集仑山水库附近的12个土壤剖面共116个土壤样品,运用137Cs示踪方法,探讨了撂荒地、油菜地、茶园、林草地、林地、水稻田6种地类的137Cs含量及其侵蚀模数。研究表明:该区土壤中的137Cs背景值为1760.48Bq/m2。在0—50cm深度范围内,137Cs含量平均值为844.03Bq/m2,土壤侵蚀模数平均值为2642.89t/(km2.a)。不同地类按137Cs含量的大小排序,非耕作土为林草地>撂荒地>林地,耕作土为水稻田>油菜地>茶园;按土壤侵蚀模数的大小排序,非耕作土为林地>撂荒地>林草地,耕作土为茶园>油菜地>水稻田。非耕作土为轻度侵蚀,耕作土多为中度到强烈侵蚀。     

新疆阿勒泰地区汛期降水集中度和集中期的时空变化特征

利用新疆阿勒泰地区7个台站1961-2007年5-9月（第25-54候）逐侯降水资料,分别讨论全区和各站汛期降水集中度和集中期在时间和空间上的分布特征和变化规律。结果表明：降水集中度（PCD）和集中期（PCP）能够定量表征降水量在时空场上的非均一性。阿勒泰全区汛期降水平均集中度为0.205,平均集中期为第38.12侯。平均集中度空间分布不均匀,东部比西部大;平均集中期基本一致,阿勒泰、福海站比其它站略偏晚。利用Morlet小波变换求出阿勒泰全区及各站PCD和PCP的变化周期,周期在空间分布上表现出较大的地域差异。通过降水距平与集中度和集中期的相关合成分析表明,大部分站的集中度和集中期与汛期降水距平呈负相关;多水年的集中度比少水年小,多水年的集中期比少水年早,但空间分布存在相同和不同之处。     

宁镇地区黄棕壤土壤颗粒组成与~(137)Cs含量关系研究

土壤粒组组成对137Cs含量及其再分配过程具有决定作用,因此,137Cs吸附的粒度效应研究是运用其示踪土壤侵蚀的重要环节。宁镇地区代表性样点的土样测试与数据分析结果表明,黄棕壤耕作土不同粒级的土壤颗粒对137Cs有着不同的吸附效应:(1)2μm和2～5μm粒级土壤颗粒对137Cs有着较强的吸附能力;(2)5～10μm和10～50μm粒级的土壤颗粒含量与137Cs质量活度之间存在着明显的负相关;(3)50μm粒级的土壤颗粒含量与137Cs质量活度之间的关系较为复杂;(4)数据分析结果中出现的一些偏差可能与侵蚀作用所造成的颗粒分选以及沉积区物源复杂有关。     

植物对~(137)Cs污染土壤的修复

选用了南瓜、油菜、虎尾草、红梗叶甜菜、东升叶甜菜和红甜菜等几种植物,通过盆栽模拟,研究不同活度137Cs污染的广东大亚湾水稻土、浙江秦山水稻土和北京褐土的生物修复作用。结果表明,供试植物在3种土壤上均对137Cs有较强的吸收能力,并随137Cs施入量的增加而增加,两者呈显著正相关r2=0.9989。在污染水平相同的情况下,试验发现,虎尾草、油菜和南瓜所吸收137Cs的比活度随土壤的pH值降低而增加。6种植物的生物修复能力差异较大,综合评价结果为,对137Cs污染土壤修复能力的顺序是:虎尾草>油菜>红梗叶甜菜>南瓜>红甜菜>东升叶甜菜。     

Evidence of plaggen soils in European North Russia (Arkhangelsk region)

To clarify whether a particular group of soils of Archangelsk region (European N Russia) with humus‐rich topsoils exceeding the plowing zone supports an anthropogenic formation, four exemplary profiles were investigated. The investigation sites are characterized by distinct elevated surfaces, and the soils show thick toplayers of up to 60 cm with enrichment of soil organic matter and artifacts like brick, charcoal, and peat fragments, all indicating an anthropogenic origin. Increased phytolith amounts and high P contents of up to 800 mg kg^–1 citric acid–soluble P and up to 1,400 mg kg^–1 total P in the top horizons support an anthropogenic influence. These properties are very similar to the Plagganthrepts of NW Europe. The same is true regarding the main management aims: increasing soil fertility and overcoming the need of bedding materials. Having the required depths of the anthropogenic topsoil, the properties of the soils of the Archangelsk region allow a classification as Agrozems (Russian classification), Plaggenesche (German classification), and Plagganthrepts (US taxonomy). Since the high base saturation of the topsoil excludes a designation as plaggic horizon, the topsoil has to be considered as terric horizon, which leads to a classification as Terric Anthrosol according to WRB.     

辽东湾沿岸土壤中~(137)Cs背景值及分布特征研究

在辽东湾沿岸区域采集了20个土壤表层样和7个非耕作土壤剖面样(其中一个为标准剖面),通过对采集的土壤样品中的137 Cs进行测量与分析,确定该区域土壤中137 Cs的背景值,并探讨了土壤中137 Cs的分布特征。结果表明,研究区137 Cs的背景值为(1 704±40)Bq/m2;表层土壤中137 Cs的比活度范围为0.84～19.90Bq/kg,不同土地利用类型表层土壤中的137 Cs比活度有明显差异,比活度高低依次为:草地>盐碱地>耕地;非耕作土壤剖面中137 Cs的总量范围为65～1 535Bq/m2,大部分土壤剖面中137 Cs呈指数递减分布,且剖面中的137 Cs发生不同程度的流失,而受到沉积扰动作用的剖面中137 Cs分布无规律。通过探讨辽东湾沿岸区域土壤中137 Cs的背景值及137 Cs的分布特征,为利用137 Cs示踪技术定量研究该区域物质输移和辽东湾沉积物来源提供依据。     

Microbiological activity in the anthills of fallow lands (Ryazan Region)

A bacterial complex associated with several species of ants, the inhabiting soil, and their anthills was studied. The biodiversity of bacteria in ants was higher than that in the anthills and control soil. The latter was dominated by Bacillus (more than 80%); the anthill of Formica was dominated by the Flavobacterium-Bacteroides-Cytophaga group. In addition, actinomycetes were widespread in the anthills of Formica and Lisius. Numerous staphylococci (20%) were found in the L. flavus ants, but the main dominants of the bacterial community were Streptomyces bacteria (68.5%). Tetramorium had no pronounced dominants and many Bacteroides bacteria (28%). Actinomycetes of Streptomyces were detected in the bacterial complexes of all studied ants, except for F. cunicularia.     

Cr(III) oxidation coupled with Mn(II) bacterial oxidation in the environment

Purpose  

Cr(III) oxidation to Cr(VI) significantly increases Cr mobility and toxicity and thus its environmental risks. Manganese (Mn) oxides may serve as the potential oxidants of Cr(III) in environment. Natural Mn oxides in the environment are believed to be derived from bacterial oxidation. The objective of this study was to examine the Cr(III) oxidation capacity of biogenic Mn oxide and the role of Mn-oxidizing bacteria in Cr(III) oxidation.