悬浮泥沙环境下微塑料颗粒的絮凝特征研究

Study on flocculation characteristics of microplastic particles with biofilm in suspended sediment environment

微塑料颗粒与悬浮泥沙的絮凝特征研究,尤其在天然水体环境中生物膜附着的情况下,对于微塑料颗粒在紊动水体中与悬浮泥沙的沉积动力学过程具有科学意义。选用高岭土作为悬浮泥沙的代表,与聚乙烯微塑料颗粒在紊动剪切率可控的搅拌槽中进行絮凝试验,并采用非侵入式絮凝体观测系统进行观测,分析絮团在不同悬浮泥沙浓度及不同紊动剪切率条件下的絮凝特征。试验结果表明,随着紊动剪切率和悬浮泥沙浓度的增加,絮团的特征粒径总体呈现出先增大后减小的规律。利用Winterwerp模型对试验数据进行拟合,数值模拟结果较好地印证了试验的结果。

Study on the flocculation characteristics of microplastic particle and suspended sediment,especially in the case of biofilm attachment in the natural.water environment,is of scientific significance for the sedimentation kinetic processes of microplastic particle and suspended sediment in turbulent water body.Kaolin was selected as the representative of suspended sediment for flocculation experiments with polyethylene microplastic particles colonized by biofilm in a mixing tank with controlled turbulent shear rate,and a non-invasive floc observation system was used to directly observe the variation of flocs.The flocculation characteristics of flocs under different suspended sediment concentrations and different turbulent shear rates were analyzed and checked by the Winterwerp model after fitting the experiment data.The result shows that the characteristic particle size of flocs generally increases first and then decreases with the increasing of turbulent shear rate and suspended sediment concentration,and which is confirmed by the numerical simulation results.