Abstract：
Microplastics (MPs) vary in shape and surface characteristics in the environment. The attachment of MPs to surfaces can be studied using the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. However, this theory does not account for the shape MPs. Therefore, we investigated the attachment of spherical, pear-shaped, and peanut-shaped polystyrene MPs to quartz sand in NaCl and CaCl2 solutions using batch tests. The attachment of MPs to quartz sand was quantified using the attachment efficiency (alpha). Subsequently, alpha behaviors were interpreted using energy barriers (EBs) and interaction minima obtained from extended DLVO calculations, which were performed using an equivalent sphere model (ESM) and a newly developed equivalent Cassini model (ECM) to account for the shape of the MPs. The ESM failed to interpret the alpha behavior of the three MP shapes because it predicted high EBs and shallow minima. The alpha values for spherical MPs (0.62-1.00 in NaCl and 0.48-0.96 in CaCl2) were higher than those for pear- and peanut-shaped MPs (0.01-0.63 in NaCl and 0.02-0.46 in CaCl2, and 0.01-0.59 in NaCl and 0.02-0.40 in CaCl2, respectively). Conversely, the ECM could interpret the alpha behavior of pear- and peanut-shaped MPs either by changes in EBs or interaction minima as a function of orientation angles and electrolyte ionic strength. Therefore, the particle shape must be considered to improve the attachment analyses.
摘要：
微塑料（MPs）在环境中的形状和表面特性各不相同。可以使用Derjaguin-Landau-Verwey-Overbeek（DLVO）理论研究MP与表面的附着。然而,这个理论没有解释国会议员的形状。因此,我们研究了球形的附着，梨形,和花生形聚苯乙烯MPs在NaCl和CaCl2溶液中的石英砂使用批量测试。使用附着效率(α)定量MP对石英砂的附着。随后，使用从扩展的DLVO计算获得的能量势垒(EB)和相互作用最小值来解释α行为，使用等效球体模型（ESM）和新开发的等效卡西尼模型（ECM）来解释MP的形状。ESM未能解释三种MP形状的alpha行为，因为它预测了高EB和浅最小值。球形MPs的α值（在NaCl中为0.62-1.00，在CaCl2中为0.48-0.96）高于珍珠形和花生形MPs的α值（在NaCl中为0.01-0.63，在CaCl2中为0.02-0.46，在NaCl中为0.01-0.59，在CaCl2中为0.02-0.40）。相反，ECM可以通过EB的变化或相互作用最小值作为取向角和电解质离子强度的函数来解释珍珠形和花生形MP的α行为。因此,必须考虑颗粒形状以改善附件分析。
