喀什市土壤重金属的分布特征及其来源解释

Distribution characteristics of soil heavy metal content in Kashi City and its source explanation

运用石墨炉(TAS-990)原子吸收光谱法对喀什市不同剖面土壤重金属含量进行测定,并利用统计软件Pearson系数法、主成分分析法进行重金属含量特征和来源分析。结果表明:各功能区的重金属含量随着剖面深度的增加呈逐渐减小的趋势;Pb-Ni、Cd-Ni、Cr-Zn、Cr-Ni、Pb-Cu、Cr-Cd之间显著相关,相关系数分别为0.90、0.81、0.79、0.74、0.69、0.68、0.67,并且通过了0.01水平的检验,这进一步说明了土壤中重金属的污染来源是相同的或是复合的。通过主成分分析求得1个主成分;PC1的贡献率70.9%,第一主成分元素为Ni、Pb、Cr,载荷系数分别为0.93、0.90、0.88,揭示了土壤中的重金属元素的同源性,这深入证实了土壤母质是土壤中重金属的重要来源。

In this work,TAS- 990 atomic absorption spectrophotometer was used to determine the heavy metal content in soil of different profile from the urban areas of kashi City. Using Pearson correlation analysis the source of these particulate heavy metals was revealed. The result was as follows： Comparative analysis showed that the soil heavy metal contents of the various functional areas decrease with the increasing of soil depth; generally,total heavy metal content at various soil depths of 0- 10 cm,10- 20 cm,20- 40 cm and 40- 60 cm in functional areas of different city are with an order of traffic congested site,industrial site,residential area and public park. Pearson correlation analysis demonstrated that the heavy metal contents（ Cr,Cd,Pb,Zn,Cu,Ni） in soil have correlation with each other,Pb- Ni,Cd- Ni,Cr- Zn,Cr- Ni,Pb- Cu and Cr- Cd are positively correlated at 0. 01 significant level,correlation coefficients are 0. 90,0. 81,0. 79,0. 74,0. 69,0. 68 and 0. 67 respectively. It showed that the sources of heavy metal in soil of different functional areas are same or mixed. Principle content analysis illustrated that there is one principle content,contributive rate of PC1 is 70. 9%; it included Ni,Pb and Cr,loading matrix is 0. 93,0. 90 and 0. 88,it revealed that the heavy metals have same resource,that the soil is the main source of heavy metals.