轮作条件下水稻-土壤系统多环芳烃的动态过程  

Dynamics of Polycyclic Aromatic Hydrocarbons (PAHs) in the Paddy-Soil System During the Crop Rotation Process

作　　者：焦杏春[1] 叶传永[2] 陈素华[2] 杨永亮[1] 武振艳[1] 

机构地区：[1]国家地质实验测试中心生态地球化学地科院重点实验室,北京100037 [2]南昌航空大学环境与化学工程学院,南昌330063

出　　处：《环境科学》2010年第7期1625-1630,共6页Environmental Science

基　　金：国家自然科学基金项目(40703029);国家地质实验测试中心基本科研业务项目(200607CSJ16)

摘　　要：探讨了在水稻收割-土地闲置-次年再种植水稻的轮作期间,水稻根系-土壤系统中多环芳烃的动态变化情况,尝试分析了轮作状态下水稻根系对水稻土多环芳烃的清除作用及影响因素.结果表明,在轮作期间,水稻根系中的ΣPAHs动态与空气、颗粒物等环境介质ΣPAHs相关性不明显(r<0.7,p>0.1),与根际土ΣPAHs呈负相关关系(r=0.7,p<0.1),与根系表面积呈明显的正相关关系(r=0.8,p<0.05).说明水稻根系中的ΣPAHs动态并未依赖于其它环境介质中ΣPAHs的改变,而是根据其生长状况直接吸附和吸收来自土壤的ΣPAHs.从水稻籽粒中ΣPAHs含量看,水稻对土壤多环芳烃的吸收并不影响人类的安全食用.水稻土中的ΣPAHs和活性有机碳含量在水稻进入收割期时都显著降低,经过轮作进入来年的再种植期后,又因为施用有机肥、外源输送等途径使土壤TOC和ΣPAHs增加.The concentrations of polycyclic aromatic hydrocarbons （PAHs） in the paddy root-soil system were determined to study the dynamic and the influencing factors during crop rotation period.It showed that the dynamic of PAHs in paddy roots was most correlative with the factor of root surface area,but less correlated with PAHs in air and particles,which indicates that the physiological characters rather than the environment media are the main factors influencing the PAHs accumulation in paddy roots.According to the EPA risk standard about BaP and Σ PAHs,the PAHs accumulation in the paddy seeds won＇t decrease the food security to human being.The PAHs concentrations in paddy soil showed a declined trend during the period of paddy growth,which was affected not only by the processes of water elution and microbe degradation,but also depended on the absorption rate of paddy roots.When the crop rotation begins and paddy planting rolls into the next growing period,the PAHs in the paddy soil will again increase into a higher level which is correlated with the TOC content in the soil.

关 键 词：多环芳烃 轮作 水稻根 水稻土 动态 

分 类 号：X173[环境科学与工程—环境科学]