Sorption kinetics, isotherms and mechanisms of PFOS on soils with different physicochemical properties
Sorption kinetics, isotherms and mechanisms of PFOS on soils with different physicochemical properties
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PFOS在不同理化性质土壤上的吸附动力学、等温线及机理
DOI：
10.1016/j.ecoenv.2017.03.040
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发表时间：
2017
影响因子：
6.8
通讯作者：
Hu Zhihao
中科院分区：
文献类型：
--
作者：
Wei Changlong;Song Xin;Wang Qing;Hu Zhihao
全氟辛烷磺酸 (PFOS) 是一种新兴污染物，具有环境持久性、生物累积性，对人类健康和生态系统有毒。它已在地下水、地表水、土壤和沉积物中广泛检测到。迄今为止，很少有研究报道全氟辛烷磺酸在土壤上的吸附行为，这是影响其在地下的命运和迁移的主要过程之一。在本研究中，研究了 PFOS 在六种不同理化性质的土壤上的吸附和解吸情况。通过批量实验对六种土壤上的 PFOS 吸附进行了动力学和平衡研究。 PFOS 在六种土壤上的吸附动力学表明，PFOS 吸附在 48 小时内达到平衡，并且与实验数据拟合良好的伪二级动力学模型表明化学吸附参与了 PFOS 在土壤上的吸附。颗粒内扩散模型结果表明，薄膜扩散和颗粒内扩散都是六个土壤样品中五个的限速步骤，而颗粒内扩散是第六个土壤上全氟辛烷磺酸吸附的唯一限制步骤。所有六种土壤的 PFOS 吸附等温线都可以通过 Freundlich 模型很好地描述（R2=0.979–0.999）。 PFOS的KF与土壤理化性质的相关性分析表明，KF与Al2O3、SOC和Fe2O3呈正相关。 FTIR 数据表明，疏水相互作用、离子交换、表面络合和氢键可能都在 PFOS 吸附到土壤样品上的过程中发挥作用。未来需要进一步探讨全氟辛烷磺酸对土壤矿物质，特别是氧化铁矿物质的吸附作用。
Perfluorooctane sulfonate (PFOS), an emerging contaminant, is environmentally persistent, bioaccumulative and toxic to human health and ecosystems. It has been widely detected in groundwater, surface water, soil and sediment. So far, very few research has reported on the PFOS sorption behaviors onto soils, one of the primary processes that influence its fate and transport in the subsurface. In this study, the sorption and desorption of PFOS onto six soils with different physicochemical properties were investigated. Kinetic and equilibrium studies of PFOS sorption onto six soils were carried out in batch experiment. The sorption kinetics of PFOS on the six soils demonstrated that PFOS sorption reached equilibrium within 48 h, and the well-fitted pseudo-second-order kinetic model to experimental data suggested that chemisorption was involved in PFOS sorption on soils. The intraparticle diffusion model results indicated that both film diffusion and intraparticle diffusion were the rate-limiting steps for five of the six soil samples, while the intraparticle diffusion was the only limiting step in the PFOS sorption on the sixth soil. PFOS sorption isotherms can be described by the Freundlich model well for all six soils (R2=0.979–0.999). The correlation analysis betweenKFof PFOS and the physicochemical properties of the soils showed that a positive correlation betweenKFand Al2O3, SOC and Fe2O3. The FTIR data demonstrated hydrophobic interaction, ion exchange, surface complexing and hydrogen bonding might all play a role in the PFOS sorption onto soil samples. PFOS sorption onto soil minerals, especially iron oxide minerals, needs to be further explored in future.