The Components, Properties And Heavy Metals Contents Of Organic Matter In Urban Soils In Kaifeng City

Human activity in the environment has impact on soil ecology. However recent knowledge on properties of anthropogenic soils is still scarce. For this reason the purpose of this paper is to deliver data on the soil organic matter (SOM) composition and properties of urban soils with an example from the city of Kaifeng and to discuss the concentration of heavy metals in humic acids (HA) and fulvic acids (FA).There are five main parts of this dissertation:Part I In this part, the current situation and development tendency of the research about the composition and properties of the soil organic matter(SOM) were generally introduced. Then the author summarized the present situation of the study abroad on the SOM in urban soil.Part II Informations of study area such as the history,the natural general situation and the economy were introduced.Part III Mainly introduces the principles, methods, sample processing and preparation of soil and wheat, and also the steps of experimental methods.Part IV Based on the experimental data , The law of content and distribution of SOM and WSOM in the soil was analyzed. The composition and properties of the humus of soil were analyzed. And the relationship between heavy metal content and FA and HA was analysed. The the factors that impact the significant different between urban soil and nature soil were also studied.Part V In this part, the main conclusions were drawn.(1) In comparison with natural soils, urban soils were characterized by a very high level of the SOM. In general it was rich in the east and south of Kaifeng. And so was in the old city. We find that the content of SOM in different functional zones may show different intensity of human activities. The order of the content of SOM in different functional zones is traffic zone> industry zone> civil zone>scenery zone> resident zone. The destribution of SOM of urban soils in vertical section was decline along with the depth. It was assembled significantly on the surface. However, some sections distributed in reverse order. This probably is due to the human activity. (2) The WSOM of urban soils in Kaifeng were distributed in spot-shape. The WSOM of urban soils is significantly richer and fluctuated than natural soils. The order of the content of SOM in different functional zones is traffic zone> civil zone> cenery zone> industry zone> resident zone. The distribution of WSOM of urban soils in vertical section was decline along with the depth.(3) The distribution law of WSOM and SOM is similar in evidence in Kaifeng. The WSOC/SOC is terribly low that the ratio is less than 1% in more than 90% soil samples .It probly because that the WSOC seeped and migrated down in the rain. The WSOC declined more slowly than SOM for their decompose coefficient.(4) The HA/FA of urban soil was higher than natural soil. This suggests that the properties of urban soil is not good at SOM decomposing and the extent of polymerization. In consequence, the level of FA is much more higher than HA. The order of the content of HA in different functional zones is: cenery zone>traffic zone> industry zone> civil zone>resident zone. And the FA order is: traffic zone> cenery zone>industry zone> civil zone>resident zone. The order of the the densitometric curve of HA of the first layer of the soils in different functional zones is: traffic zone>suburb zone >resident zone > cenery zone> civil zone> industry zone. This suggest that the molecular HA fraction and aromatic C content become higher,the hydroxide and aromatic extent turn stronger from traffic zone to industry zone.(5) Between the heavy metals in HA and FA, there are diffrence. The heavy metals in FA is remarkable higher than it in HA. The order of the heavy metal enrichment capacity in HA is Cu>Pb>Zn>Cd. The order of the heavy metal enrichment capacity in FA is Cu>Cd >Pb>Zn. Between the heavy metals in HA and FA, there are positive correlation in Zn, moderate correlation in Cu, low correlation in Pb, zero correlation in Cd. The properties of heavy metals should be taken into account for it.