排序方式： 共有8条查询结果，搜索用时 109 毫秒
1
1.
Screening Effect of the Diffusive Boundary Layer in Sediments of Lake Aha in the Suburbs of Guiyang City,Guizhou Province 总被引：6，自引：0，他引：6
The redox cycle of iron and manganese is a major geochemica process at the boundary layers of lake sediments.Lake Aha,which lies in the suburbs of Guiyang City,Guizhou Province,China,is a medium-sized artificial reservoir with seasonally anoxic hypolimnion,Long-term sedimentary accumulation of iron and manganese resulted in their enrichment in the upper sediments,In the anoxic season,Fe^2 and Mn^2 ,formed by diological oxidation,would diffuse up to overlying waters from sediments.However,the concentration of oxidation,would diffuse up to overlying waters from sediments,However,the concentration of Fe^2 increased later and decreased earlier than that of Mn^2 .Generally,sulfate reduction occurred at 6 cm below the sediment-water interface.Whereas,in the anoxic season.the reduction reached upper sediments,inhibiting the release of Fe^2 ,The Fe concentration of anoxic water is quickly decreased from high to low as a result of reduction of the suplhur system. 相似文献
2.
Microbiological denitrification and denitrifying activity ofParacoccus Denitrificans 总被引：2，自引：0，他引：2
With rapidly industrial and agricultural development,more and more fertilizers,chemicals and heavy ions will be discharged into lakes and rivers,which would cause lake eutrophication and quality deterioration in drinking water sources.Therefore,denitrification is essential for controlling the amounts of nitrogen,During the transformation process from nitrate to the end products-nitrogen and several intermediated[e.g.nitrite(NO2^-),nitrous oxide(N2O) and nitric oxide(NO)]may be accumulated,which have more toxic influences on the environment.in This study,the denitrification effect of Paracoccus Denitrificans was examined on the changes between oxic and anoxic conditions at varying pH.At pH=7.5,denitrification proceeded well after 3 switches from oxic to anoxic conditions and vice versa,Production of N2 was constant and the amounts of NO2-,N2O and NO were extremely low.How ever,at pH=6.8,denitrification activity was inhitied and there large amounts of the intermaediates.The denitrifying bacteria decreased violently in dry weight and were washed out. 相似文献
3.
I.INTRODUCTIONLakeAhaisamedium--sizedartificialreservoirwithseasonallyanoxichypolirnnion,andawaterresourceofGuizhouProvince,China,builtin1958,workedin1960andexpandedin1982.Ithasadrainagebasinof190kmZwithaverageannualtemperatureof15.3tandprecipitationof1109rum.Openplantcover,containiflgshrubandgrass,surroundsthelake,andsialliticandstfeteyellowsoilisdevelopedonPe~ianlimestoneandcoallayer,meanwhile,OThisprojectwassupportedbytheNationalNaturalaudienceFOundationofChinaandtheaudienceFOund… 相似文献
4.
论阿哈湖水铁锰季节性污染机制万国江，黄荣贵，陈振楼，普勇，万曦，周兢业（中国科学院地球化学研究所，贵阳５５０００２）关键词环境地球化学，铁锰季节性变化，污染机制，阿哈湖海洋、湖泊沉积物不仅是水环境物质输送后的储存场所，而且其蓄积的一些化学组分可能通过... 相似文献
5.
6.
万曦 《矿物岩石地球化学通报》1994,(3)
阿哈湖沉积物─水界面Ｆｅ－Ｍｎ循环的微生物影响分析万曦（中国科学院地球化学研究所，贵阳５５０００２）关键词阿哈湖，沉积物，Ｆｅ－Ｍｎ循环，微生物微生物参与的湖泊沉积地球化学作用在沉积物－水界面物质循环中具有重要意义。本文通过贵阳阿哈湖沉积物－水界面Ｆ... 相似文献
7.
万曦 《矿物岩石地球化学通报》1992,(3)
微生物地球化学是研究微生物在生物地球化学循环中作用机理的一门新兴边缘科学。它作为独立学科被人们承认,不过是近一二十年的事。然而,它未来的发展前景却是不可低估的。自然界中,生物通过自身的生命活动,一方面将其所需的各种无机化学元素合成为有机物,另一方面又能将这些有机物分解成无机组分并输送圆自然界。由此,化学元素不断地从非生命物质转变成生命物质,再从生命物质变成非生命物质。构成了地球上的生物地球化学循环。微生物在此循环中起着极为重要的纽带作用。如果没有微生物的参与,自然界的物质循环将无法进行,生命将得不到更替繁衍。因而,地球化学过程与微生物作用休戚相关;二者间的联系越来越被人们关注。 相似文献
8.
~７Ｂｅ示踪红枫湖汇水区表土季节性侵蚀白占国，万国江，王长生，万曦，黄荣贵（中国科学院地球化学研究所．贵阳５５０００２）关键词~７Ｂｅ示踪，表土季节性侵蚀，红枫湖汇水区~７Ｂｅ是宇宙线作用所产生的短寿命放射性核素，在一定地域的散落通量相近。由于７Ｂｅ仅?.. 相似文献
1