Studies On The Accumulation Of Heavy Metals And Microbial Characteristics In Urban Soils Of Changchun

Comparing production function of the natural soil with the urban soil, theenvironmental and ecological function should be paid attention to. The urban andoutskirts soil not only closely involves the health and security of numerous livesin city, but also influence the food security through the food chain, or watersystem through exchange function, atmosphere in addition. Changchun is locatedin the Songliao plain, the area Northeast Asian in the center of economic zone asthe capital of Jilin Province. It is the centre of polity, economy and culture of thewhole province. With the development of commerce and tourist industry,increase of population (include floating population ) in recent years and areaenlargement , the increase of industrial waste gas, waste water ,waste solidmaterial , tail gas , domestic rubbish and sanitary sewage has greatly influencedsoil physical and chemical characteristics of the urban area and suburbs ofChangchun, and cause the cumulation of the heavy metallic element in the soilsuch as lead , cadmium , copper , zinc ,etc.. To understand soil heavy metalpollution distribution state and original cause of formation is very important todeal with urban problem of environmental pollution and soil contaminating. Andit also has realistic meanings to prevent and control pollution in Changchun city.It is late that the urban soil is studied and started at domestic and abroadfield, and it is still at the starting stage overall. This text has explained physicaland chemical nature, microbial nature and nutrient state of the urban soil at first.Then we have described the heavy metal pollution resources and distributioncharacteristic in the urban soil. Studies discovered that the environmentalpollution mainly pointed to mercury , cadmium , lead , chromium and arsenicwith remarkable biological toxicity, additional including toxic heavy metal: zinc ,copper , cobalt , nickel , tin , vanadium ,etc.. Their sources come from differentsoil, industrial production, automobile tail gas discharge and automobile tirewearing.The above-mentioned results of study indicate the heavy metal pollution ofurban soil is very serious. It is particularly useful to find a method to signifyurban soil pollution and appraise the environmental quality. The soil enzymeactivation is affected by restrain of the heavy metal, so is the soil microbialactivation. It is sensitive that indexes of soil microbe are used in appraisingheavy metal pollution in soil ecosystem.We have soil samples come from both sides of main traffic, urban main parksand suburb agriculture fields. We gather road sides'soil 17 of samples altogether,park soil 8 of samples, and agriculture soil 5. Through lab experiment of soilfundamental properties , content of heavy metallic element , microorganism'samount C, intensity of microorganism breath, the intensity of cellulosicdecomposition and soil enzyme activities: catalase activity, peroxidase activity,polyphenol xidase activity, amylase activity and urease activity. Then therelativity of soil physical and chemical natures, content of heavy metals and soilmicrobial characteristics has been analyzed in three different function districts inurban area.The experimental results are the following conclusion:Because of Influence of the human activity, heavy metal content in soil ofChangchun have already been accumulated remarkably, amount of Pb and Cd insoil is as much 40 times and 7 times as ones of background respectively. It hasreflected that the heavy metals are accumulated and had a remarkable impact on...