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.     

Fulvic acid removal by nanoparticle TiO2 using a submerged membrane photocatalysis reactor

The degradation of fulvic acid（FA） by nanoparticle TiO2 in a submerged membrane photocatalysis（SMPC） reactor was studied. In this reactor, photocatalytic oxidation and membrane separation co-occured. The continuous air supplier provided O2 for the photocatalytical reaction and mixed the solution through an airflow controller. The particle TiO2 could automatically settle due to gravity without particle agglomeration so it could be easily separated by microfiltration（MF） membrane. It was efficient to maintain high flux of membranes. The effects of operational parameters on the photocatalytic oxidation rate of FA were investigated. Results indicated that photocatalyst at 0.5 g/L and airflow at 0.06 m^3/h were the optimum condition for the removal of fulvic acid, the removal efficiency was higher in acid media than that in alkaline media. The effects of different filtration duration on permeate flux rate of MF with P25 powder and with nanoparticle TiO2 were compared. Experimental results indicated that the permeate flux rate of MF was improved and the membrane fouling phenomenon was reduced with the addition of nanoparticle TiO2 catalyst compared with conventional P25 powder. Therefore, this submerged membrane photocatalysis reactor can faciliate potential application of photocatalytic oxidation process in drinking water treatment.     

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。     

Au/ZnO催化剂的表征及常温常湿 条件下CO氧化性能研究

常温下考察了焙烧温度、金含量及水分对Au/ZnO催化剂上CO氧化性能的影响 ,并在常湿条件下考察了ZnO上CO氧化活性同温度的关系。结果表明 ,金的存在极大地提高了催化剂CO的氧化活性。另外焙烧温度和金含量对Au/ZnO催化剂的活性和稳定性均有较大影响 ,在常温常湿条件下 ,2 4 0℃焙烧的 2 %Au/ZnO催化剂 ,可连续反应 1 750h保持CO完全转化。XRD结果表明 ,锌的化学状态对催化剂的稳定性有较大的影响 ,氧化锌较碳酸锌表现出较高的稳定性。     

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。     

Transboundary air pollution balance in the new integrated European environment

Ten out of the 12 new EU members, used to belong to the so-called “former eastern block”, with a post WWII environmental policy radically different from the tendencies followed in Western Europe. The lack of conservation regulations has resulted in a rather harmful industrialization, regarding natural resources and environmental quality. While air pollution transfer is a phenomenon of transboundary level, there is a particular interest in examining the contribution of the new EU member states to the environmental pressure faced by the older member states and vice versa. The current study utilises the official data for almost 20 years published by the European Monitoring and Evaluation Program concerning the transboundary transfer of NO_x and SO₂ in order to analyse the situation and discuss the present and future environmental policy regarding air pollution.     

影响土壤重金属生物毒性的若干因子

本文应用发光细菌法探讨了土壤类型、粘土矿物、无定形金属氧化物、吸附剂对重金属纯溶液以及重金属污染土壤的降毒效应.红壤、砖红壤对Cu、Cd、Pb呈现负的降毒效应,而对As具有明显的降毒作用.黑土、黄棕壤对供试阳离子金属具有明显的降毒效应,对As降毒却不明显.试验证明粘土矿物及其组成是影响土壤重金属毒性的最基本因素.无定形氧化锰对供试阳离子金属的降毒能力大于无定形氧化铁,对As的效应二者则相反.不同吸附剂对Cu、Cd、Pb呈现基本相同的降毒顺序,即炉烟灰>活性炭>泥炭>干活性污泥,不同配比吸附剂对红壤添加性阳离子和东乡铜矿污染土壤均具有明显的降毒作用.添加吸附剂的东乡铜矿污染土壤随着土壤溶液毒性的消除,随之也消除或减轻了其对水稻种芽的急性毒害.     

复合氧化物汽车尾气净化催化剂抗SO2中毒机理研究

复合氧化物催化剂(ASC)具有较高的活性和良好的抗SO_2中毒性能.用IR、XPS、TPD等技术研究了该催化剂抗SO_2中毒机理,结果表明,与易失活催化剂相比,ASC经500h反应(反应气含SO_2约20ppm),其活性组分价态无显著变化,仅表面发生SO_2的化学吸附,经与约500ppm的SO_2作用20h后,发现仅有少量SO_4~(2-)形成.这是由于在ASC催化剂中添加了特殊助剂,而使催化剂活性组分得到保护的缘故.