Sorption of pyrene on two paddy soils and their particle-size fractions

In the present study, the sorption of pyrene on two kinds of bulk paddy soils, Gleyic Stagnic Anthrosols, and Ferric accumulic Stagnic Anthrosols as well as their particle-size fractions was investigated. The sorption isotherms fitted well with Freundlich equation. For both soils, the clay fraction（ 〈 2μm） and coarse sand fraction（2000-250μm） had higher sorption capacity than fine sand fraction（250-20 μm） and silt fraction（20-2 μm）. The IogKoc values obtained of each soil and its particle-size fractions were similar, proving that SOM content was a key factor affecting pyrene sorption. The Kd values showed a significant correlation with contents of dithionite-extractable Fe in both paddy soils and a good relationship with CEC in Gleyic Stagnic Anthrosols, indicating possible effects of surface properties of particle-size fractions on the sorption of pyrene.     

阳极溶出伏安法连续测定底泥中的总镉和总铅

底泥样品经盐酸-硝酸-氢氟酸-高氯酸消解后,用1 1盐政溶解残渣,以高氯酸做支持电解质,采用阳极溶出伏安法的标准加入法,连续测定样品中的总镉和总铅.该方法测定土壤标准样品中镉和铅的相对标准偏差分别为5.6%和4.6%,相对误差分别为2.4%和～1.7%;测定自采底泥样品中镉和铅的相对偏差分别为7.7%和8.1%,方法的重复性好;测定土壤标准样品中镉加标回收率为94.0%～106.8%,铅加标回收率为95%～103.8%;自采样品中镉加标回收率为93.0%～105.6%,铅加标回收率为90.0%～105.0%,方法的准确度较高.实验中,镉和铅的半波电位稳定,峰形对称.     

西北地区高速公路建设中的水土保持

就西北地区高速公路建设的水土流失特点进行了分析，并提出了工程防范措施。     

Relation between some variations of soil and surface vegetatio and desertization in agriculture-pasture interlacing zone an example from Kangbao County,North Hebei,China

The studied agriculture-pasture interlacing zone has its specific natural conditions,at which the natural systems are unstable ,their self-regulation capability is low and the equilibrium is easily broken, and hence the habitat is fairly vulnerable.During last 20 years the increasing population and livestock ,over-reclamation,over-pasturing,over-deforesting, and other intensified negative human activities in the zone resulted in coarsening of surface soil,decrease of organic mater content in soil, reduction of vegetation coverage ,variation and degradation of flora structure, and hence in desertization of the land, although average of gales and sandstorms some decreased and the climate tended to be better in the region.However, the frequent sandstorms occurring in the springs of last and present years has attracted much attention.Investigations confirmed that the main cause for the phenomena is the unreasonable human activites rater than the natural factors.     

云南土壤钴元素背景值及其特征研究

对云南省土壤钴元素背景值进行了采样分析,结果显示:云南土壤钴元素含量呈对数正态分布,中位值16.0mg/kg,几何均值14.88mg/kg,95%置信区间0.92~41.17mg/kg,背景值高于全国,接近南方部分地区。并对其特征进行了研究。     

CrⅥ adsorption on four typical soil colloids: equilibrium and kinetics

It is observed that the adsorption of chromium are greater on kaolinite minerals, red soil (R) and laterite (L) colloids than that on montmorillonite, indicotic black (IB) and yellow brown (YB) soil colloids. The adsorption process of CrⅥ on these media can be further described by Langmuir or Freundlich equation quite well. The adsorption reaction of CrⅥ is fast, and the adsorption equilibrium can be reached within the first two hours in moderate temperature. The adsorption quantity of CrⅥ to kaolinite mineral increased with the increasing pH in the range of 2.0 to 7.0, then decreased at higher pH. But it showed some consistence among the four soil colloids. The lower the pH, the stronger the adsorption. The possible mechanisms are further discussed here. Meanwhile the influence of temperature on CrⅥ adsorption on different soil colloid and clay minerals are also investigated.     

滕南煤田煤矸石对土壤的影响分析

通过对山东滕南煤田地区的土壤、煤矸石及部分农作物的灰份进行化学分析，从理论上探讨了其促进植物增产的机理；并认为该煤田3煤层的矸石含有与该地区土壤类似的化学组成，但其所含植物生长需要的主要元素普遍高于土壤中的含量，即煤矸石中含有较丰富的植物生长所需的矿物肥料。     

复杂粘性土层深基坑挡土桩受力分析

针对目前桩锚式支护计算方法的局限性，对复杂土层中下端固定的锚定式挡土桩作了受力分析，并编写了计算机程序，适用于处理深基坑支护中的分层土(砂土、粘性土)、有超载、存在地下水等各种复杂土层。     

新农药环境化学行为研究(V)-—三氟羧草醚(Acifluorfen)在土壤和水环境中的滞留、转化

从如下几方面研究了三氟羧草醚在土壤－水环境中的化学行为：一是土壤对该药的吸附，结果表明，吸附强度与土壤理化特性密切相关，Ｆｒｅｕｎｄｌｉｃｈ常数ｋｆ＝０．９４Ｗｏｍ＋０．６５Ｗｃｌａｙ－９．５９ｐＨ（ｒ＾２＝０．９４）；二是吸附机理研究，发现三氟羧草醚能与碱金属以外的许多金属离子形成配合物，并证实了与ＣＵ＾２＋形成的双核桥联合物的可能性；三是实验指出它在水中避光有一定的稳定性，不易水解；四是它在〈     

大庆油田落地原油对土壤污染的研究

大庆油田是中国最重要的原油生产基地,开发建设50多年来,已累计生产原油18.2亿吨.不可避免地在油田生产过程中产生大量的落地原油,对土壤造成了严重的污染.落地原油在土壤中的迁移主要有横向迁移和纵向迁移:横向迁移对土壤的污染成辐射状分布,污染强度随污染源的距离增加而迅速降低,污染源周围污染最重的区域在0 m～40 m范围内,占总量90%以上,横向迁移范围确定在150 m以内;落地原油纵向迁移绝大部分集中在距土壤表面0 cm～10 cm范围内,竖向迁移一般不超过70 cm.落地原油污染土壤中主要污染物包括总烃、芳烃、酚、苯并[a]芘和硫化物,通过落地原油污染土壤的模拟实验可知总烃、芳烃、苯并[a]芘和硫化物含量,随原油浓度增加而明显增加,呈明显正相关性;其一元线性回归方程分别为Y=0.470X-17.88、Y=0.119X-6.13、Y=0.0076X-0.30、Y=0.000055X 0.089.