生物扰动作用对河口沉积物中荧蒽去除的影响

通过室内微宇宙实验系统研究了天津厚蟹(Helice tientsinensis)和双齿围沙蚕(Perinereis aibuhitensis)生物扰动作用下河口沉积物中荧蒽的去除情况。实验结果显示,天津厚蟹扰动组中荧蒽的去除率显著高于沙蚕扰动组(P=0.05)和对照组(P=0.003),其中对表层(0~2 cm)和中层(3~5 cm)的促进效果最为显著;虽然各实验组表层沉积物中荧蒽的去除率均超过50%,但扰动组的去除更快,在36 d时就达最高去除率68%;双齿围沙蚕扰动组底层沉积物中荧蒽的去除率高于厚蟹扰动组和对照组,但差异不显著。研究表明表层沉积物中的荧蒽易去除,厚蟹生物扰动对荧蒽去除有显著促进作用;在距离表层5cm以下的沉积物中荧蒽的持久性增强,但生物扰动作用可促进其去除。

Impact of Bioturbation on the Removal of Fluoranthene in Muddy Estuarine Sediment

The degradation of sediment-associated fluoranthene was investigated in microcosms with bioturbation of crab Helice tientsinensis and polychaete Perinereis aibuhitensis. The results indicated that the removal rate of fluoranthene in crab bioturbation microcosms was higher than that in polychaete bioturbation microcosms (P = 0.05) and control microcosms (P = 0.003), and the enhancement was more significant for surface (0-2 cm) and middle (3-5 cm) layer sediment. Though the removal rates were all more than 50% for surface sediment in all treatment microcosms, the fluoranthene was removed rapidly in crab bioturbation microcosms than controls with the most removal rate of 68% at 36 d. The fluoranthene in bottom layer sediment was removed more in polychaete bioturbation microcosms than that in crab bioturbation and control microcosms, but not significantly. It was manifested that the fluoranthene in surface sediment was labile and crab bioturbation could enhance the removal efficiently. Bioturbation could still enhance the removal of fluoranthene in sediment deep than 5 cm where the fluoranthene be more persistent.