中文摘要：

选择典型的广西乐业大石围巨型岩溶漏斗（天坑）为研究对象,采集大石围漏斗不同部位的表层土壤,采用气象仪器观测大石围漏斗的环境因子,利用气相色谱-质谱仪（GC-MS）测定16种多环芳烃（PAHs）优先控制污染物.结果表明,大石围天坑群地表（正地形）土壤中ΣPAHs浓度范围为75.20～373.79 ng·g^-1,平均值120.70 ng·g^-1;地下（负地形）土壤,绝壁中ΣPAHs浓度范围为19.88～330.79 ng·g^-1,平均值131.86 ng·g^-1;底部中ΣPAHs浓度范围为127.48～661.62 ng·g^-1,平均值395.22 ng·g^-1;地下河（洞穴）中ΣPAHs浓度范围为1 132.11～1 749.95 ng·g^-1,平均值为1 412.39 ng·g^-1;土壤中PAHs以4～6环为主.比值法推断大石围漏斗土壤PAHs的来源主要为化石燃料燃烧源,主要污染途径为大气传输沉降.总体上,大石围漏斗土壤中PAHs浓度的空间分布随温差和相对湿度的升高呈现地面-绝壁-底部-地下河（洞穴）逐渐增加,PAHs显示＂冷陷阱效应＂的垂向富集与分异作用.影响PAHs分布的主要环境因素是温度,其次是湿度、风向和风速,在漏斗局部显示多环境因子共同作用.环境因子夏季影响大于冬季.监测发现,2007年比2006年大石围漏斗底部土壤中PAHs的浓度增加了3.5倍.因此,本研究提出巨型岩溶漏斗PAHs的富集和分异作用与环境因素密切相关.

英文摘要：

With typical Dashiwei karst great doline（Tiankeng） located in Leye county,Guangxi in China as study area,the soil samples of different karst topography were collected and analyzed utilizing GC-MS for the 16 PAHs.Environmental factors were observed by weather instrument.The results showed that the total PAHs concentration in soils of the ground（the positive landform） of Dashiwei great doline ranged from 75.20 ng·g^-1 to 373.79 ng·g^-1,with an average of 120.70 ng·g^-1.In Dashwei great doline（the negative landform）,the total PAHs concentration in soils of cliff ranged from 19.88 ng·g^-1 to 330.79 ng·g^-1,with an average of 131.86 ng·g^-1;the concentration of the bottom section ranged from 127.48 ng·g^-1 to 661.62 ng·g^-1,with an average of 395.22 ng·g^-1;and the concentration of the underground river ranged from 1 132.11 ng·g^-1 to 1 749.95 ng·g^-1,with an average of 1 412.39 ng·g^-1.The PAHs compounds were mainly 4-6 rings PAH.The primary sources of PAHs were pyrogenic sources.The pollution approaches were mainly atmospheric transportation and deposition.As a whole,the spatial distribution of PAHs in soils in Dashiwei doline gradually increased from the surface-the cliff-the bottom-the underground river with the increase of temperature and relative humidity.Accumulation and differentiation of PAHs in a vertical way were showed by＂coal trap effect＂.Environmental factors influencing the distribution of PAHs in soils were majorly temperature,followed by humidity,wind direction and wind speed,and in some parts multi environmental factors worked together.The effect of the environmental factors was bigger in summer than in winter.Monitoring of PAHs discovered that the total PAHs concentration in soils of the bottom was 3.5 times higher in 2007 than in 2006.As a consequence,this study suggested that the accumulation and differentiation of karst doline was related with these important environmental factors.