Performance comparison of hematite (α-Fe2O3)-polymer composite and core-shell nanofibers as point-of-use filtration platforms for metal sequestration
Performance comparison of hematite (α-Fe2O3)-polymer composite and core-shell nanofibers as point-of-use filtration platforms for metal sequestration
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DOI：
10.1016/j.watres.2018.10.048
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发表时间：
2019-01-01
期刊：
影响因子：
12.8
通讯作者：
Cwiertny, David M.
中科院分区：
文献类型：
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作者：
Greenstein, Katherine E.;Myung, Nosang V.;Cwiertny, David M.
使用点水处理技术可以帮助减轻饮用水污染的风险，特别是对于源自分配系统的金属（和准金属）（例如铬、铅、铜）或天然存在于私人地下水井中的金属（和准金属）（例如砷）。在这里，通过单锅静电纺丝合成了嵌入赤铁矿（α-Fe2O3）纳米粒子的聚丙烯腈（PAN）复合纳米纤维。通过随后在嵌入赤铁矿复合材料上水热生长 α-Fe2O3 纳米结构，还制备了核壳纳米纤维复合材料。使用静电纺丝合成变量（例如嵌入的 α-Fe2O3 纳米颗粒的尺寸和负载量）控制嵌入赤铁矿复合材料的性能，而核壳复合材料也通过水热处理条件（例如可溶性铁浓度和持续时间）进行定制。尽管 Cu(II)、Pb(II)、Cr(VI) 和 As(V) 的吸收在很大程度上与所探索的核-壳变量无关，但嵌入纳米纤维上的金属吸收随着 α-Fe2O3 负载量的增加而增加。两种材料均表现出最大表面积归一化吸附能力，可与 α-Fe2O3 纳米颗粒分散体相媲美，并超过商业氧化铁基吸附剂。此外，两种类型的复合材料在一系列与环境相关的 pH 值 (6.0-8.0) 范围内都表现出强大的性能。值得注意的是，核-壳结构的大部分表面可接近的α-Fe2O3，在动力学限制流过系统中的表现远好于嵌入复合材料，比在平衡批量系统中的相对性能所预期的要好。核壳纳米纤维过滤器还保留了嵌入纳米纤维所表现出的大部分耐用性和灵活性。对真实地下水样品的其他测试证明了核壳纳米纤维过滤器能够同时去除砷和悬浮固体，说明了它们作为纳米技术用于使用点水处理的前景。 (C) 2018 Elsevier Ltd. 保留所有权利。
Point-of-use water treatment technologies can help mitigate risks from drinking water contamination, particularly for metals (and metalloids) that originate in distribution systems (e.g., chromium, lead, copper) or are naturally occurring in private groundwater wells (e.g., arsenic). Here, composite nano fibers of polyacrylonitrile (PAN) with embedded hematite (alpha-Fe2O3) nanoparticles were synthesized via a single-pot electrospinning synthesis. A core-shell nanofiber composite was also prepared through the subsequent hydrothermal growth of alpha-Fe2O3 nanostructures on embedded hematite composites. Properties of embedded hematite composites were controlled using electrospinning synthesis variables (e.g., size and loading of embedded alpha-Fe2O3 nanoparticles), whereas core-shell composites were also tailored via hydrothermal treatment conditions (e.g., soluble iron concentration and duration). Although uptake of Cu(II), Pb(II), Cr(VI), and As(V) was largely independent of the core-shell variables explored, metal uptake on embedded nanofibers increased with alpha-Fe2O3 loading. Both materials exhibited maximum surface-area-normalized sorption capacities that were comparable to alpha-Fe2O3 nanoparticle dispersions and exceeded that of a commercial iron oxide based sorbent. Further, both types of composite exhibited strong performance across a range of environmentally relevant pH values (6.0-8.0). Notably, core-shell structures, with a majority of surface accessible alpha-Fe2O3,a performed far better than embedded composites in kinetically limited flow through systems than was anticipated from their relative performance in equilibrium batch systems. Core-shell nanofiber filters also retained much of the durability and flexibility exhibited by embedded nanofibers. Additional tests with authentic groundwater samples demonstrated the ability of the core-shell nanofiber filters to remove simultaneously both As and suspended solids, illustrating their promise as a nano-enabled technology for point-of-use water treatment. (C) 2018 Elsevier Ltd. All rights reserved.