Effects of forms and rates of potassium fertilizers on cadmium uptake by two cultivars of spring wheat (Triticum aestivum, L.)

A greenhouse pot experiment was conducted to study the influence of potassium fertilizers in different forms and rates on cadmium (Cd) uptake by two cultivars of spring wheat (Triticum aestivum, L.): Brookton and Krichauff. Potassium fertilizers were added to soil at four levels: 0, 55, 110 and 166 mg K kg(-1) soil as KNO(3) (N), KCl (C) or K(2)SO(4) (S). CdCl(2) was added to all the treatments at a uniform rate equivalent to 15 mg Cd kg(-1) soil. Plant shoot and root dry weights (DW) of both cultivars were reduced significantly by the addition of K-fertilizer in C and S treatments but there were only marginal changes in the N treatments. The Cd concentrations in shoots and whole plants increased significantly (P<.001) with increasing K addition, from 37.5 to 81.4 mg kg(-1) and from 42.9 to 86.8 mg kg(-1) for Brookton and Krichauff, respectively. However, no obvious effect was observed in the N treatments, except for the highest K level (K3) where there was a sharp increase in Cd concentration compared to the lower additions. Forms of K-fertilizers significantly influenced the Cd concentrations in plant shoots and roots (P<.001), but there was no significant difference between C and S treatments. This experiment showed that anions Cl(-) and SO(4)(2-) increase Cd uptake by plants, which can be interpreted as Cl(-) and SO(4)(2-) complexing readily with Cd(2+) and thereby increasing the bioavailability of Cd(2+) in soils. The effect of potassium itself on plant uptake of Cd was also observed. We suggest that when applying potassium fertilizer to Cd-contaminated soils, the forms and rates should be considered.     

湖北农村降水中SO_4~(2-)浓度变化研究

在湖北农村 10个地点 ,利用澳大利亚集雨器自 1996年 1月至 1998年 6月 ,按季度采集大气降水样品测定SO2 - 4浓度 ,并对数据进行统计分析。研究结果表明 ,各地 1997年降水中SO2 - 4浓度年均值比 1996年显著升高 ;大多数地点 1996、1997、1998年 1季度和 2季度降水中SO2 - 4浓度呈逐年升高趋势 ;大多数地点每年 1、4季度降水中SO2 - 4浓度高 ,2、3季度降水中SO2 - 4浓度低 ,说明湖北农村降水中的硫对秋冬作物影响比对春夏作物影响大 ;湖北农村降水中SO2 - 4浓度近两年不仅有时间变化规律 ,而且同一季度内的地区差异也很明显 ,在 1996年和 1997年 8个季度 10个点的降水SO2 - 4浓度最大值中 ,有 4个最大值出现在襄樊 ,它是目前湖北继宜昌市区、恩施市区之后又一个酸雨发展较快的地区     

Measurements of major ion concentration in settled coarse particles and aerosols at a semiarid rural site in India

Deposition rates and deposition velocities of water-soluble ions (F, Cl, NO3, SO4, NH4, Ca, Mg, Na and K) were measured at a rural site (Gopalpura, Agra). Dry deposition samples were collected throughout the year from December 1995 to August 1997, while the aerosol samples were collected only during the winter season of 1996. Surrogate technique was used to collect the dry deposition samples, while aerosol samples were collected on PTFE membrane filter. Deposition velocities (Vd) of SO4 and NO3 are < or = 0.01 m s(-1) while Ca, Mg, Na, K, NH4, F and Cl exhibit greater than 0.01 m s(-1) Equivalent concentration ratios of K/Na, Ca/Na and Mg/Na conform with the corresponding ratios of local soil, indicating the dominant contribution of local sources. Deposition rates are maximum in winter, followed by summer and monsoon. No significant differences are found in dry deposition rates of all ions or in atmospheric concentrations of soil-derived elements with respect to wind direction. However, in aerosols, concentrations of F, Cl, NO3 and SO4 are higher with winds from southwesterly and westerly directions corresponding to pollution sources located in these directions. Deposition data have been used to calculate the critical load of S and N for soil with respect to Triticum vulgaris. The critical load of actual acidity was found to be 622.4 eq ha(-1) year(-1) within the range of 500-1,000 eq ha(-1) year(-1) as assessed by the RAINS-Asia model for this region. The present load of S and N (77.4 and 86.4 eq ha(-1) year(-1)) was much lower than the critical load of S and N (622.4 and 2,000 eq ha(-1) year(-1)), indicating that at present there is no harmful effect on ecosystem structure and function.     

Perfluorosulfonates and perfluorocarboxylates in snow and rain in Dalian,China

Samples of precipitation events (snow and rain) in Dalian, a typical coastal town in China, were analyzed for perfluorosulfonates (PFSAs) and perfluorocarboxylates (PFCAs) to investigate atmospheric contamination by these compounds. In the snow event on December 16, 2006, samples were collected from 21 different sites and in another 6 precipitation events, samples were collected from a single location. Four PFSAs (C4, C6, C8, C10) and seven PFCAs (C6–12) were analyzed. Among the homologues, perfluorooctane sulfonate (PFOS) concentrations were the highest with a geometric mean (GM) of 145 ng/L (n = 21) during the snow event on December 16, 2006, followed by perfluorooctanoate (PFOA) with a GM of 24.7 ng/L (n = 21). Concentrations of perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS) and perfluoroheptanoate (PFHpA) were more than two orders of magnitude lower than that of PFOS. Other PFSAs and PFCAs were found to be below the limit of detection in all the samples. In other 6 precipitation events, PFSAs and PFCAs were detected approximately in the same order of magnitude in both snow and rain. The results indicate that wet deposition may be a potential transport mechanism of perfluorinated chemicals in the environment.     

The relationship of climatic and hydrological parameters to surface water quality in the lower Mekong River

The relationship between climatic, hydrological and water quality parameters of the lower Mekong River flowing through four different countries (Thailand, Cambodia, Lao PDR and Vietnam) was studied. The Mekong River Commission (MRC) secondary data of climatic and hydrological parameters included precipitation, evaporation, average air temperatures, mean water level and discharge flow. Water quality parameters consisted of TSS, NO(3)(-), PO(4)(3-), DO, pH, conductivity, Ca, Mg, Na, K, alkalinity, Cl, SO(4)(2-), Fe, TP, Si and COD. Pearson's correlation was used to determine their relationship. The results reveal that the correlations of climatic, hydrological and water quality parameters in those four countries located along the lower Mekong River had the same trend. Precipitation had fair positive correlations with mean water level (ranging 0.375-0.661), discharge flow (ranging 0.526-0.659) and mean air temperature (ranging 0.515-0.621), however had weak negative correlation with evaporation (ranging 0.169-0.468). Concerning relationship with water quality, the results show that TSS, NO(3)(-), PO(4)(3-), TP and COD had weak to fair positive correlations with precipitation, mean water level, discharge flow. However, DO, pH, conductivity, Ca, Mg, Na, K, alkalinity, Cl, SO(4)(2-) and Si had fair to strong negative correlations with all hydrological parameters. Finally, TSS, alkalinity and conductivity were proposed as sensitive water quality parameters for monitoring impacts of changing climate in the lower Mekong River.     

南方冰冻雨雪灾害年的环流及气象要素异常的统计分析

利用NCEP/NCAR的2.5°×2.5°格点的逐日再分析资料,通过分析我国南方19个冰冻雨雪灾害年的36个冰冻雨雪天气个例的环流形势,总结了发生冰冻雨雪天气的4种天气类型:北脊南槽型、乌山脊型、横槽南支型和高纬低涡型,后两种天气类型持续时间长、影响范围广,极易造成南方严重的持续冰冻雨雪灾害;进一步分析南方持续冰雪天气的物理量场和要素场特征,结果表明,对流层低层850~700 hPa辐合中心较垂直上升速度中心提前1~2 d出现,预示低温雨雪增强;冻雨严重年份在700 hPa维持大于0℃的融化层,南支槽前的西南急流为雨雪天气提供了水汽和热量输送,这种配置利于冻雨天气的发展和维持。天气类型的建立及气象要素的统计有利于为南方冰雪灾害天气预测预警服务。     

上海地区酸雨类型格局转变研究

采用STARS（Sequential 〖WTBX〗t〖WTBZ〗 test analysis of regime shifts）,以降水中SO2-4、NO-3以及SO2-4/NO-3为指标,研究了上海地区酸雨类型在1991～2006年的格局转变规律。上海地区降水中SO2-4含量在1991～2006年具有两种格局,2004年发生转变;转变前的SO2-4含量平均12670 mg/L,转变后SO2-4含量大幅度降低,平均6525 mg/L;降水中NO-3含量存在3种格局,两次转变;1996年转变前的NO-3浓度相对较低,平均1842 mg/L;此次转变后升高,平均2622 mg/L;2005年再次发生转变,使得NO-3含量下降,平均1998 mg/L;与NO-3含量的格局类似,SO2-4/NO-3也存在着3种格局,两次转变;1995年转变前,SO2-4/NO-3平均7316;此次格局转变后,SO2-4/NO-3降为5666;2000年的格局转变中SO2-4/NO-3降为3635。表明NO-3对酸雨的贡献逐渐增加,SO2-4对酸雨的贡献逐渐减弱,酸雨类型逐渐由硫酸型酸雨过渡成硫酸和硝酸混合型酸雨,并逐渐接近硝酸型酸雨。上海地区酸雨类型格局在1991～2006年发生5次格局转变,其格局转变指数（RSI）在1995、1996,2000,2004和2005年分别为0826、0260、0959,1378和0066。〖     

Sorption of metals onto natural organic matter as a function of complexation and adsorbent-adsorbate contact mode

The effect of complexing anion and adsorbate-adsorbent contact mode (static equilibrium or dynamic non-equilibrium) on binding and partition of Cu(2+), Cd(2+) and Zn(2+) onto organic matter (exemplified in a low-moor peat) was studied. The study comprised comparative batch and column flow-through sorption experiments on monometallic solutions of Me-Cl and Me-SO(4) salts, at pH 4.0, and sequential fractionation of sorbed metals with respect to binding strength. Both the presence of an anion having complexing properties (Cl(-)) as well as a contact mode was found to quantitatively and qualitatively affect the sorption capacity and binding strength of organic matter (peat) for metal ions. Complexing effect of Cl(-) on metal ions resulted mostly in reduction of metal ability to form strongly bound metal-organic compounds, in accordance with the order of stability constant of complex ions log K: Cd>Zn>Cu. Flow-through (dynamic) contact mode, which is the most appropriate to simulate environmental conditions, appeared to strongly attenuate the complexing effect of chloride ions on Cd and Zn sorption, and significantly enhance sorption capacity also in the absence of complexing ions. For Cd, it was mainly due to the enrichment in the strongly bound "insoluble organic" fraction, while for Zn the quantitative increase of sorption capacity did not alter significantly its partitioning. Neither a quantitative nor qualitative effect of contact mode on Cu binding was observed. Complex and diverse effects of different environmental parameters on metal sorption capacity and binding strength onto organic matter, which strongly influence metal mobility, leads to the conclusion that the correct simulation of these parameters for ecotoxicological testing is crucial for the reliable predicting of metal bioavailability under actual terrestrial environmental conditions.     

上海地区酸雨类型格局转变研究

采用STARS(Sequentialt-test analysis of regime shifts),以降水中SO24-、NO3-以及SO42-/NO3-为指标,研究了上海地区酸雨类型在1991～2006年的格局转变规律。上海地区降水中SO42-含量在1991～2006年具有两种格局,2004年发生转变;转变前的SO42-含量平均12.670mg/L,转变后SO42-含量大幅度降低,平均6.525mg/L;降水中NO3-含量存在3种格局,两次转变;1996年转变前的NO3-浓度相对较低,平均1.842mg/L;此次转变后升高,平均2.622mg/L;2005年再次发生转变,使得NO3-含量下降,平均1.998mg/L;与NO3-含量的格局类似,SO24-/NO3-也存在着3种格局,两次转变;1995年转变前,SO42-/NO3-平均7.316;此次格局转变后,SO42-/NO3-降为5.666;2000年的格局转变中SO24-/NO3-降为3.635。表明NO3-对酸雨的贡献逐渐增加,SO42-对酸雨的贡献逐渐减弱,酸雨类型逐渐由硫酸型酸雨过渡成硫酸和硝酸混合型酸雨,并逐渐接近硝酸型酸雨。上海地区酸雨类型格...     

湖北省旅游景区大气负氧离子浓度分布特征以及气象条件的影响

通过利用湖北省气象服务中心在全省27个旅游景区内建设的30个大气负氧离子自动监测站数据,对湖北省旅游景区大气负氧离子浓度分布特征及气象条件对负氧离子浓度的影响进行了分析。研究表明：湖北省旅游景区的大气负氧离子资源十分丰富,西部山区高于东部平原地区,整体呈现从东向西、从北向南逐渐增加的趋势,鄂西南地区为全省大气负氧离子最为丰富的地区,负氧离子浓度夏季最高,冬季最低,秋季略大于春季。从3月开始,负氧离子浓度逐月增加,至8月达到最大值,后又逐渐减小。凌晨和上午的负氧离子浓度要大于下午和晚上,夜间呈逐渐上升的趋势。大气负氧离子浓度晴天最大,阴天小于晴天,而雾霾天和小雨天负氧离子浓度均较小;中雨以上降水、闪电活动与负氧离子浓度呈正相关。     

湖北省旅游景区大气负氧离子浓度分布特征以及气象条件的影响

通过利用湖北省气象服务中心在全省27个旅游景区内建设的30个大气负氧离子自动监测站数据,对湖北省旅游景区大气负氧离子浓度分布特征及气象条件对负氧离子浓度的影响进行了分析。研究表明:湖北省旅游景区的大气负氧离子资源十分丰富,西部山区高于东部平原地区,整体呈现从东向西、从北向南逐渐增加的趋势,鄂西南地区为全省大气负氧离子最为丰富的地区,负氧离子浓度夏季最高,冬季最低,秋季略大于春季。从3月开始,负氧离子浓度逐月增加,至8月达到最大值,后又逐渐减小。凌晨和上午的负氧离子浓度要大于下午和晚上,夜间呈逐渐上升的趋势。大气负氧离子浓度晴天最大,阴天小于晴天,而雾霾天和小雨天负氧离子浓度均较小;中雨以上降水、闪电活动与负氧离子浓度呈正相关。     

大坝拦截对河流水溶解组分化学组成的影响分析——以夏季乌江渡水库为例

以乌江渡水库为主要研究对象，揭示了大坝拦截条件下的夏季水化学特征：阴离子以HCO-3,SO2-4为主，阳离子以Ca2+,Mg2+为主，其余离子含量低于10%，说明了碳酸盐岩的风化对水体化学组成起到了主要控制作用，蒸发盐岩石的风化对水体化学组成影响较小。水库水体存在温度分层现象，形成了不同层位的水体有着不同的水化学组成，即水化学分层。水化学的分层形成了溶解组分在水库垂直深度上的规律分布，比如受藻类的影响，Si和叶绿素随深度成相反的变化特征；HCO-3受光合作用和有机质降解的影响，30 m 以上随着水深的增加而递增，30 m 以下呈现相反趋势；水库泄水方式明显改变了水化学各种参数和离子在水体中的分配。乌江水库两主要支流（息烽河和偏岩河）分别对乌江渡坝前水体中的Ca2+,SO2-4,HCO-3,Mg2+和K+,Na+,Cl-有贡献。网箱养鱼、生活污水、农业施肥、酸性矿山废水以及酸雨沉降都会对水体造成不同程度的污染。     

On monitoring anthropogenic airborne uranium concentrations and (235)U/(238)U isotopic ratio by Lichen - bio-indicator technique

Lichens are widely used to assess the atmospheric pollution by heavy metals and radionuclides. However, few studies are available in publications on using lichens to qualitatively assess the atmospheric pollution levels. The paper presents research results applying epiphytic lichens as bio-monitors of quantitative atmospheric contamination with uranium. The observations were conducted during 2.5 years in the natural environment. Two experimental sites were used: one in the vicinity of a uranium contamination source, the other one - at a sufficient distance away to represent the background conditions. Air and lichens were sampled at both sites monthly. Epiphytic lichens Hypogimnia physodes were used as bio-indicators. Lichen samples were taken from various trees at about 1.5m from the ground. Air was sampled with filters at sampling stations. The uranium content in lichen and air samples as well as isotopic mass ratios (235)U/(238)U were measured by mass-spectrometer technique after uranium pre-extraction. Measured content of uranium were 1.45 mgkg(-1) in lichen at 2.09 E-04 microgm(-3) in air and 0.106 mgkg(-1) in lichen at 1.13 E-05 microgm(-3) in air. The relationship of the uranium content in atmosphere and that in lichens was determined, C(AIR)=exp(1.1 x C(LICHEN)-12). The possibility of separate identification of natural and man-made uranium in lichens was demonstrated in principle.     

Application of SO(4)(2-)/TiO2 solid superacid in decontaminating radioactive pollutants

Polyaniline doped with SO(4)(2-)/TiO(2) superacid shows good conductive ability. When used in a strippable coating film for decontaminating radioactive pollutants, the SO(4)(2-)/TiO(2) solid superacid replacing HCl exhibits higher electrical conductivity (7.01 s/cm) and a decontamination ratio higher than 97%. Coating and electrolyzing the film in solution or in dry medium were effective methods, the latter was more promising for decontaminating radioactive pollutants which were attached to the surface or within the body of equipments used in nuclear industry.     

湖北省2008年初低温雨雪冰冻过程气候特征分析

2008年初，湖北省出现了严重的低温雨雪冰冻灾害，直接经济损失高达110亿元以上，有必要对灾害期间的气候特征进行系统、科学的分析和总结。对湖北省76个气象站2008年1月12日～2月3日气温、降水（雪）、日照以及低温持续日数等要素进行时空间差异分析及历史与同期比较，并选取10个代表站历史上所有低温雨雪天气过程，对其过程持续低温日数、最长连续雨雪日数、过程极端低温进行比较分析。结果表明：（1）此次过程的平均气温异常偏低，该省大部为-1～-2℃，比常年同期偏低4～6℃，为各站历史同期最低，其中主要是最高气温异常偏低所致，但极端低温并不低；（2）降雪过程频繁，雨雪量异常偏多；（3）低温冰冻持续时间长，该省大部在16～22 d，位于历史第一；（4）日照异常偏少。持续而稳定的大气环流异常形势是湖北省大范围低温雨雪天气的直接原因。     

Formation of radioactivity enriched soils in mountain areas

A field study was carried out in the Mercantour Mountains at 2200 m altitude to investigate the processes of soil enrichment in atmospheric Chernobyl (137)Cs. Soils with high (137)Cs activities have been collected in the pasture areas with frequently measured (137)Cs activity values of the order of 7000 Bq m(-2). At some single spots (about 6% of the studied area), activity in soils reached 300000 Bq m(-2), which represents 44% of the (137)Cs of the total area. Data further showed that spatial distribution of Cs depends widely on its origin: Chernobyl Cs is mainly concentrated in "enriched" soils, whereas older Cs and (241)Am fallout from nuclear weapons tests (NWTs) and natural atmospheric (210)Pb in soils is less heterogeneously distributed.In order to elucidate the processes which have led to the enrichment in Chernobyl (137)Cs in the Alps in May of 1986, we have studied the repartition of atmospheric (7)Be isotope (half-life=53.3 d) in the pasture compartments (soil, litter, grass, and snow). Snow (7)Be data give evidence that fallout enrichment is related to snow accumulation (snow drift). The transfer of beryllium occurs rapidly to the grass and litter, where the strongest pollutant accumulations were measured. However, (7)Be transport to the soil required more than 8 months.     

Radionuclides deposition over Antarctica

A detailed and comprehensive map of the distribution patterns for both natural and artificial radionuclides over Antarctica has been established. This work integrates the results of several decades of international programs focusing on the analysis of natural and artificial radionuclides in snow and ice cores from this polar region. The mean value (37+/-20 Bq m(-2)) of (241)Pu total deposition over 28 stations is determined from the gamma emissions of its daughter (241)Am, presenting a long half-life (432.7 yrs). Detailed profiles and distributions of (241)Pu in ice cores make it possible to clearly distinguish between the atmospheric thermonuclear tests of the fifties and sixties. Strong relationships are also found between radionuclide data ((137)Cs with respect to (241)Pu and (210)Pb with respect to (137)Cs), make it possible to estimate the total deposition or natural fluxes of these radionuclides. Total deposition of (137)Cs over Antarctica is estimated at 760 TBq, based on results from the 90-180 degrees East sector. Given the irregular distribution of sampling sites, more ice cores and snow samples must be analyzed in other sectors of Antarctica to check the validity of this figure.     

Kinetics of radiocesium released from contaminated soil by fertilizer solutions

(137)Cs is one of the major artificial radionuclides found in environments; but the mechanisms behind fertilizer-induced (137)Cs desorption from soil remain unknown. This study aimed to investigate the kinetics and mechanisms underlying the various cations and anions that cause Cs release from soil under acidic conditions. NH(4)H(2)PO(4) (1M), 0.5M (NH(4))(2)SO(4), 1M NH(4)Cl, 1M KCl or 1M NaCl solutions were added to (137)Cs-contaminated soil. The power function model well described the short term (137)Cs desorption with the solutions. The rate coefficients for (137)Cs release from soil in NH(4)H(2)PO(4), (NH(4))(2)SO(4), NH(4)Cl, and KCl solutions were 7.7, 7.3, 6.8, and 6.1 times higher than the rate observed in a NaCl solution, respectively. The NH(4)H(2)PO(4) and (NH(4))(2)SO(4) solutions induced significantly greater (137)Cs release from the contaminated soil than the NH(4)Cl, KCl and NaCl solutions. After four times repeated extractions with the fertilizer solutions, the total amount of (137)Cs extracted by (NH(4))(2)SO(4) and NH(4)Cl solutions reached equilibrium, while that extracted using an NH(4)H(2)PO(4) solution continued to increase. The combined effect of phosphate and protons was the major mechanism behind (137)Cs release from contaminated soils, when an NH(4)H(2)PO(4) solution was used.     

近38年安徽省夏季降水日数和强度的分布与变化特征

选用1971～2008年安徽省78个地面气象站的观测资料,分析夏季降水和暴雨的气候变化规律。从结果来看安徽省夏季降水主要受到地理位置、地形地貌和风、温、湿等气象因素的影响。根据主要影响因子的不同,按照降水特性以及行政边界将安徽省划分成了10个区,不同区域内降水特征和分布结构各有差异。在时间变化上,雨日出现概率有下降的趋势,但暴雨日比重和降水量均有升高的变化特征。综合而言,安徽省的降水朝着具有局地性、突发性的强降水过程方面发展,从而导致部分区域内突发性暴雨过程频发     

长江南通站含沙量及水化学变化与流域的风化过程

1960—2001年间长江河水含沙量递减趋势方程为：S=-4．7273a 582．94。近些年来泥沙含量递减趋势可能会对流域生态环境产生重要影响，应引起社会的关注。长江河水化学组分在1997-2001年的5年间受到季节和年际变化的影响较为有限。河水中HCO3^-与Ca^3 占主导地位，占总离子当量浓度的55％以上。主要受到碳酸盐类溶解的控制。硅酸盐类的风化过程较弱，可能主要是钙镁硅酸盐类的溶解，对流域离子的总体贡献不大。岩盐、石膏和芒硝的水解对河水中的Na^ 、SO4^2-和Cl^-的贡献最大。由此长江流域发生的主要风化过程有：白云石和方解石的溶解、钙镁长石的分解和岩盐、石膏、芒硝等的水解过程等，这与长江流域的岩石特征是基本一致的。粗略的估计．大气CO2对河流中HCO3^-的贡献量占河水中离子总当量浓度的20％左右，其余80％河水溶解质为风化岩石提供。