不同水力扰动强度对老化PSMPs在泥水两相间迁移的影响

Influence of Different Hydraulic Disturbance Intensities on the Migration of Aged PSMPs Between Sediment and Water

以太湖为研究对象,针对老化聚苯乙烯微塑料(PSMPs),探讨了水力扰动强度对PSMPs在泥水两相间的迁移过程,并通过FTIR和SEM-EDS等微观表征手段对PSMPs的形貌和元素等进行表征.结果发现,扰动条件下(55 r·min^(-1)和120 r·min^(-1)),上覆水中悬浮物(SS)和PSMPs均高于对照实验.这是缘于无扰动条件下,PSMPs受浮力影响,团聚在水面.在低强度(55 r·min^(-1))扰动下,上覆水中SS和PSMPs分别为(264.67±16.01)mg·L^(-1)和(239.67±6.51)n·mL^(-1),而高强度(120 r·min^(-1))扰动下,上覆水中SS和PSMPs分别为(264.67±16.01)mg·L^(-1)和(239.67±6.51)n·mL^(-1).在底泥中,PSMPs分别为(491.00±23.46)mg·L^(-1)和2.00 n·mL^(-1).且根据SEM-EDS分析,PSMPs表面具有底泥元素(Si等),这表明高强度下更易于促使PSMPs被悬浮物吸附.底泥中PSMPs的丰度也证实,扰动强度越大,越容易促进PSMPs向底泥迁移.

Taking Taihu Lake as the research object,for the aged polystyrene microplastics(PSMPs),the influence of hydraulic disturbance intensity on the migration process of PSMPs between mud and water phases was discussed,and the morphology and elements of PSMPs were analyzed using microscopic characterization methods including FTIR and SEM-EDS,as was done for characterization.The results showed that under disturbance conditions(55 r·min^(-1)and 120 r·min^(-1)),the suspended solids(SS)and PSMPs in the overlying water were higher than those in the control experiment.This was due to the fact that the PSMPs were affected by buoyancy and reunited on the water surface under undisturbed conditions.Under low-intensity(55 r·min^(-1))disturbances,SS and PSMPs in the overlying water were(264.67±16.01)mg·L^(-1)and(239.67±6.51)n·mL^(-1),respectively,and(120 r·min^(-1))under high intensity.Under disturbance,the SS and PSMPs in the overlying water were(264.67±16.01)mg·L^(-1)and(239.67±6.51)n·mL^(-1),respectively.In the bottom mud,PSMPs were(491.00±23.46)mg·L^(-1)and 2.00 n·mL^(-1),respectively.Additionally,according to the SEM-EDS analysis,the surface of PSMPs had sediment elements(Si,etc.),which showed that it was easier to promote the adsorption of PSMPs by suspended solids under high strength.The abundance of PSMPs in the sediments also confirmed that the greater the intensity of the disturbance,the easier it was to promote the migration of PSMPs to the sediments.