【作者】 张春梅；

【导师】 卢升高；

【作者基本信息】 浙江大学 ， 土壤学， 2006， 硕士

【摘要】 城市土壤是城市生态系统的重要组成部分。人类活动促使城市土壤理化性质的强烈改变,加剧了土壤污染的程度,由此产生了一系列生态和环境效应。本文以杭州市和洛阳市的土壤为例,研究城市土壤的重金属污染状况,土壤重金属的主要载体和生态风险评价。取得的主要结果如下: 1.洛阳城市工业区和道路污染表土样品的重金属含量变化很大。Pb的变化范围为48.4～2273.6mg/kg,平均值为257.0mg/kg;Mn的变化范围为330.3～1197.2mg/kg,平均值为538.6mg/kg;Cr的变化范围为51.1～460.1mg/kg,平均值为104.2mg/kg;Cd的变化范围为0.9～2.0mg/kg,平均值为1.3mg/kg;Zn的变化范围为162.3～569.9mg/kg,平均值为364.2mg/kg;Cu的变化范围为47.1～278.9mg/kg,平均值为111.3mg/kg。其中变幅最大的是Pb和Cr,变异系数分别为189%和89%;其次为Cu和Zn,变异系数分别为48%和35%;最小的是Mn和Cd,变异系数分别为34%和24%。 杭州城市工业区和道路污染表土样品中,Pb的变化范围为31.9～344.5mg/kg,平均值为134.1mg/kg;Mn的变化范围为398.6～1042.0mg/kg,平均值为572.2mg/kg;Cr的变化范围为29.3～119.6mg/kg,平均值为63.3mg/kg;Cd的变化范围为2.1～5.0mg/kg,平均值为3.4mg/kg;Zn的变化范围为106.7～873.1mg/kg,平均值为282.9mg/kg;Cu的变化范围为35.1～177.3mg/kg,平均值为93.0mg/kg。其中变幅最大的是Pb和Zn,变异系数分别为55%和55%;其次为Cu和Cr,变异系数分别为44%和35%;最小的是Mn和Cd,变异系数分别为25%和22%。 2.采用超声分散和磁分离方法提取城市土壤中的磁性物质,结果表明:磁性物质的含量与土壤磁化率在0.01水平上呈极显著相关,相关方程为:洛阳（y=0.0035x-0.2551,r=0.920）、杭州（y=0.004x-0.0563,r=0.973）。磁性物质的矿物组成主要为石英（SiO₂）、赤铁矿（α-Fe₂O₃）、磁铁矿（Fe₃O₄）和高岭土（Al₂Si₂O₅（OH）₄）。更多还原

【Abstract】 Urban soil is an important component of urban ecosystems. Human activities shtrongly changed physics and chemistry of the urban nature soil and exacerbated the soil’s contamination, resulting in a series of ecological and environmental effects. Due to the rapid growth of population and industrial activity, the urban soils have been seriously polluted with heavy meatal, which resulted in a series of environmental problems. The objectives of this study were to the conditions of the heavy metal contamination in urban soil, the main carrier of heavy metal in soil and ecological risk assessment1. Results showed that selected urban topsoils were heavily polluted by heavy metal. The content of Pb ranged from 48.4 to 2273.6mg/kg with a mean content of 257.0 mg/kg. The content of Cr ranged from 51.1 to 460.1 mg/kg with a mean content of 104.2mg/kg. The content of Mn ranged from 330.3 to 1197.2mg/kg, with a mean content of 538.6mg/kg. The content of Zn ranged from 162.3 to 569.9mg/kg with a mean conten of 364.2mg/kg. The content of Cu ranged from 47.1 to 278.9mg/kg with a mean content of 111.3mg/kg.In Hangzhou city, the heavy metal content strongly varied greatly. The content of Pb ranged from 31.9 to 344.5mg/kg with a mean content ofl 34.1 mg/kg. The content of Cr ranged from 29.3 to 119.6mg/kg with a mean content of 63.3mg/kg. The content of Mn ranged from398.6 to 1042.0mg/kg with a mean content of 572.2mg/kg. The content of Zn ranged from106.7 to 873.1mg/kg with a mean content of 282.9mg/kg. The content of Cu ranged from 35.1 to 177.3mg/kg with a mean content of 93.0mg/kg. Pb and Zn varied greatly in range, CV are 55% and 55%, secondly Cu and Cr, CV are 44% and 35%, and the last Mn and Cd, CV are 25% and 22%2. The magnetic material in urban topsoils was extracted by magnet in combination with the ultrasonic dispersion. The relationship between magnetic fraction content with the soil magnetic susceptibilities was analysed. The results showed: magnetic material content had a highly significantly correlation with soil magnetic susceptibilities. The mineral component are made up of Quartz（SiO₂）、 Hematite （α-Fe₂O₃ ）、 Magnetite （ Fe₃O₄ ） and Kaoline（Al2Si205（0H）4）c3. The concentration analysis of heavy metals showed that heavy metal enriched on agnetic material. The enrichment factor in Luoyang city ranged from 3.3 to 15.8, and the enriching order follows in Fe>Cr>Cu>Mn>Pb>Zn, the factor of Fe is the largest and the factor of Zn is the smallest. In Hangzhou city, the enrichment factor ranged from 2.9 to 20.1, and the enriching order follows in Fe>Cr>Mn=Cu>Zn>Pb, the factor of Fe is the largest and the factor of Pb is the smallest. At the same time, the heavy metal content between magnetic and non-magnetic part of the soil is significantly positively correlated and the correlation factor of Mn, Zn, Pb, Cr and Cu are 0.778, 0.839, 0.937, 0.858 and 0.880 respectively in Luoyang city. The correlation factor of Mn, Zn, Pb, Cr and Cu are 0.802, 0.816, 0.913, 0.963 and 0.789 respectively in Hangzhou city.4. Using TCLP procedure, ecological risk of heavy metal in urban topsoils was evaluated. Results indicted that the heavy metals contents extracted by two reagents are significantly related to the total contents. The extracted content increases with an increaseing of total content. The content extracted by the EDTA reagents is generally higher than the content of the TCLP extracting. Compared with the TCLP international standards, we found that the heavy metals extracted by TCLP in urban topsoils of Hangzhou city and Luoyang city are higher than the limit Cd and Pb pollution are the most severest, followed by Zn. All of the Cu content of the soil are less than the limit. In Luoyang city , for Cd, 80% of tolal samples had higher than the international standard（0.5mg/kg）, for Zn, 30% of the samples had higher than the international standard（25mg/kg） and for Pb, all of the samples had higher than the international standard（5mg/kg） , in the same way, In Hangzhou city , for Cd, 75% of total samples had higher than the limit （0.5mg/kg）, for Zn, 40% higher the international standard（25mg/kg） and all of the Pb higher the international standard（5mg/kg）. Compared with soil environmental quality standard, the TCLP procedure will be more effective on the environmental risks of soil heavy metal pollution and the impact on people’s health, which is concerned about the hazards of heavy metals effective ingredients.更多还原