多氯联苯在模拟水生态系统中的分布、积累与迁移动态研究

利用微宇宙模拟水生态系统对多氯联苯在水体环境中的行为 ,包括多氯联苯在水体、沉积物、生物体 (皇冠草、河蚬、鲢 )不同分配相及生物体不同组织、器官中含量、分布以及迁移、富集等时间变化动态过程进行了研究。结果表明 ,水草对PCB有一定程度的吸收 ;河蚬对PCBs有明显的吸收积累 ,并且吸收达到平衡的时间较长。鱼体对PCB的吸收积累在不同组织中有明显的差别 ,在内脏和肌肉组织中积累较高 ,鳃组织中积累较低。

DISTRIBUTION,ACCUMULATION AND TRANSFER DYNAMICS OF PCB1254 IN A SIMULATED MICRO-COSMOS SYSTEM

The distribution,accumulation and transfer dynamics of PCB 1254 in water,sediments and biota in a simulated micro-cosmos system were studied. The results showed that PCB 1254 released into water body were mainly absorbed upon the surface of suspending particles or precipitated into the sediments due to its high octanol-water partition coefficients(Kow),the concentration of PCBs dissolved in water was very low. The increase of organic material content in water would lead to transfer of PCB 1254 from sediments to water column,The distribution and equilibrium of PCB 1254 between the water column and sediments phase were related to the organic materials contents such as excrement of fish and shellfish,remnants of life. The extent to which PCBs enter biota is highly dependent on the physical and chemical properties of the compounds and the metabolism capacity of organisms.There were differences in the distribution,accumulation and transfer dynamics of PCB 1254 for different organisms:Echinodorus amazonicus adsorbed the PCB 1254 mainly by its leaf instead of its roots with a way of physical absorption to some extents and very quickly reached to the equilibrium;Corbicula fluminea had obviously the accumulation of PCB 1254,especially in visceral tissue,increasing continually during the 45-day experiment. For Hypophthalmichthys molitrix,the significant differences of PCB 1254 accumulation existed between gill,visceral and muscle tissues. It is higher in visceral and muscle than in gill,indicating that the accumulation of PCB 1254 was closely related to the content of lipids in different tissues. It is the highest in BCFs(Bioconcentration Factors)of PCB 1254 in the visceral tissues of Corbicula fluminea. In which BCFs was about 89418 times,followed by Hypophthalmichthys molitrix,lowest for Echinodorus amazonicus with BCFs(7648.9 times)