底泥不同预处理对潜在活性磷形成及释放的抑制作用

以校园河流底泥为材料,研究了不同预处理(底泥曝气、水曝气)对底泥中潜在活性磷的形成及释放的抑制作用.结果表明,底泥曝气对上覆水中的磷向底泥迁移的促进作用明显优于水曝气.底泥经不同预处理后,磷的释放量明显降低.与未处理底泥相比,经底泥曝气和水曝气预处理底泥,溶解性磷酸盐释放量分别下降了193.6 mg·kg^-1和44.7 mg·kg^-1,总磷释放量分别下降了334.0 mg·kg^-1和163.8 mg·kg^-1;而对于潜在活性磷而言,前者降低了58.6 mg·kg^-1,后者则增加了167.4 mg·kg^-1.其原因可能是,上覆水中的磷向底泥迁移时,首先形成潜在活性磷,而通过不同的预处理,潜在活性磷向难释放态磷的转化得到了强化.底泥曝气的这种强化作用比水曝气更为明显.

Inhibition on Formation and Release of Potentially Mobile Phosphorus in Sediments by Various Pretreatments

Inhibition on formation and release of potentially mobile phosphorus in sediments by various pretreatments (aerating to sediments, aerating to water) were studied, using sediments from the campus canal as materials. The results show that the improvement on phosphorus migration from overlying water to sediments by aerating to sediments was better than that by aerating to water. With different pretreatments, release of phosphorus was decreased obviously. After aerating to sediments and aerating to water, release of soluble reactive phosphate was reduced by 193.6 mg·kg^-1, 44.7 mg·kg^-1 and release of total phosphorus was reduced by 334.0 mg·kg^-1,163.8 mg·kg^-1 respectively compared with that of the sediments without pretreatments. As for potentially mobile phosphorus in sediments, the former was reduced by 58.6 mg·kg^-1, while the later was increased by 167.4 mg·kg^-1.The possible reason of it could be that phosphorus was transformed into potentially mobile phosphorus at the first step in migration from overlying water to sediments, while the pretreatments would enhance the transformation from potentially mobile phosphorus to refractory forms in sediments. The enhancement to this transformation by aerating to sediments was more evident than that by aerating to water.