Removal of As(III) from Water Using the Adsorptive and Photocatalytic Properties of Humic Acid-Coated Magnetite Nanoparticles
Removal of As(III) from Water Using the Adsorptive and Photocatalytic Properties of Humic Acid-Coated Magnetite Nanoparticles
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DOI：
10.3390/nano10081604
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发表时间：
2020-08-01
期刊：
影响因子：
5.3
通讯作者：
O'Shea, Kevin
中科院分区：
文献类型：
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作者：
Phuong Pham;Rashid, Mamun;O'Shea, Kevin
以腐植酸包裹的磁性纳米粒子(HA-MNP)为光敏剂，研究了高毒性亚砷酸盐(As(III))的氧化反应。对光诱导处理As(III)前后的HA-MNP进行了详细的表征。用350 nm光照射HA-MNP后，部分As(III)被氧化成砷酸盐(As(V))，并从水溶液中几乎定量地被去除。As(III)从水溶液中的分离主要是由于As(III)在HA-MNP上的强吸附作用。As(III)的去除可在60min内达到40%-90%，具体取决于HA-MNP的量。监测和定量了HA-MNP光解过程中活性氧物种(中心点OH和(1)O(2))的生成以及HA-MNP((3)HA-MNP*)的三重态激发态。结果表明：(3)根据反应条件的不同，HA-MNP*和/或单线态氧(O-1(2))负责将As(III)转化为毒性较低的As(V)。用电子转移探针2，4，6-三甲基苯酚(TMP)定量测定了(3)HA-MNP*的形成。(3)在TMP浓度为50亩M，HA-MNP浓度为1.0g L-1时，HA-MNP*的形成速率为8.0+/-0.6×10-9 M S(-1)。HA-MNP的简单制备、三重态激发态能力和单态产氧量以及磁分离能力表明，HA-MNP有可能成为修复砷(As)和其他易受高级氧化影响的污染物的光敏剂。
The oxidation of highly toxic arsenite (As(III)) was studied using humic acid-coated magnetite nanoparticles (HA-MNP) as a photosensitizer. Detailed characterization of the HA-MNP was carried out before and after the photoinduced treatment of As(III) species. Upon irradiation of HA-MNP with 350 nm light, a portion of the As(III) species was oxidized to arsenate (As(V)) and was nearly quantitatively removed from the aqueous solution. The separation of As(III) from the aqueous solution is primarily driven by the strong adsorption of As(III) onto the HA-MNP. As(III) removals of 40-90% were achieved within 60 min depending on the amount of HA-MNP. The generation of reactive oxygen species (center dot OH and(1)O(2)) and the triplet excited state of HA-MNP ((3)HA-MNP*) was monitored and quantified during HA-MNP photolysis. The results indicate(3)HA-MNP* and/or singlet oxygen (O-1(2)) depending on the reaction conditions are responsible for converting As(III) to less toxic As(V). The formation of(3)HA-MNP* was quantified using the electron transfer probe 2,4,6-trimethylphenol (TMP). The formation rate of(3)HA-MNP* was 8.0 +/- 0.6 x 10(-9)M s(-1)at the TMP concentration of 50 mu M and HA-MNP concentration of 1.0 g L-1. The easy preparation, capacity for triplet excited state and singlet oxygen production, and magnetic separation suggest HA-MNP has potential to be a photosensitizer for the remediation of arsenic (As) and other pollutants susceptible to advanced oxidation.