Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China.
Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China.
Environ Pollut. 2022 Jul 15;305:119307. doi: 10.1016/j.envpol.2022.119307. Epub 2022 Apr 19.
Biochar particles are extensively used in soil remediation and interact with microplastics (MPs), especially metal oxide-modified biochar may have stronger interactions with MPs. The mechanism of interactions between humic acid (HA) and different valence cations is different and the co-effect on the transport of MPs is not clear. In this study, the co-effects of HA and cations (Na, Ca) on the transport and retention of MPs in saturated porous media with peanut shell biochar (PSB) and MgO-modified PSB (MgO-PSB) were systematically investigated. Breakthrough curves (BTCs) of MPs were fitted by the two-site kinetic retention model for analysis. In the absence of HA, the addition of PSB and MgO-PSB significantly hindered the transport of MPs in saturated porous media, and the retention of MPs increased from 34.2% to 59.1% and 75.5%, respectively. In Na solutions, the HA concentration played a dominant role in controlling MPs transport, compared to the minor role of Na. The transport capacity of MPs always increased gradually with the increase of HA concentration. Whereas, in Ca solutions, Ca concentrations had a stronger effect than HA. The transport ability of MPs was instead greater than that in Na solutions as the HA concentration increased at low ionic strength (1 mM). However, the transport capacity of MPs was significantly reduced with increasing HA concentrations at higher ionic strength (10, 100 mM). The two-site kinetic retention model indicated that chemical attachment and physical straining are the main mechanisms of MPs retention in the saturated porous media.
生物炭颗粒广泛应用于土壤修复，并与微塑料（MPs）相互作用，特别是金属氧化物改性生物炭可能与 MPs 具有更强的相互作用。腐殖酸（HA）与不同价态阳离子相互作用的机制不同，对 MPs 迁移的协同作用尚不清楚。在这项研究中，系统研究了腐殖酸和阳离子（Na、Ca）对花生壳生物炭（PSB）和 MgO 改性 PSB（MgO-PSB）饱和多孔介质中 MPs 迁移和滞留的协同作用。通过双位点动力学保留模型对 MPs 的穿透曲线（BTC）进行拟合分析。在没有 HA 的情况下，PSB 和 MgO-PSB 的添加显著阻碍了 MPs 在饱和多孔介质中的迁移，MPs 的保留率分别从 34.2%增加到 59.1%和 75.5%。在 Na 溶液中，HA 浓度在控制 MPs 迁移方面起主导作用，而 Na 的作用较小。随着 HA 浓度的增加，MPs 的迁移能力逐渐增加。然而，在 Ca 溶液中，Ca 浓度的影响比 HA 强。当离子强度较低（1 mM）时，随着 HA 浓度的增加，MPs 的迁移能力反而大于 Na 溶液中的迁移能力。然而，当离子强度较高（10、100 mM）时，随着 HA 浓度的增加，MPs 的迁移能力显著降低。双位点动力学保留模型表明，化学附着和物理堵塞是 MPs 在饱和多孔介质中滞留的主要机制。
