Enhanced degradation of isoproturon in soil through persulfate activation by Fe-based layered double hydroxide: different reactive species comparing with activation by homogenous Fe(II)
- 28 Downloads
Phenylurea herbicide residuals in soil may continuously contaminate surface water and groundwater due to unregulated and improper use. Herein, we reported a stable and active oxidation system including heterogeneous Fe-based layered double hydroxide materials as persulfate (PS) activators. Under mild conditions, 1% LDH in weight and 70 mM PS can completely degrade 500 mg/kg isoproturon in soil within 10 h, during which less than 0.1 ppm heavy metal leaching was detected. This remarkable performance was consistent in a broad pH range (3~11) and was resistant to various inorganic anions (Cl−, Br−, NO3−, HCO3−) and humic acid. Mechanism studies from scavenging tests, EPR, and fluorescence spectra collectively proved that besides •OH and •SO4−, singlet oxygen (1O2) and superoxide (•O2−) were also generated and were accounted for the oxidative degradation. This unique mechanism of generating diverse radicals was clearly distinguished from classic Fe(II)/PS system, significantly reduced the influence of varying parameters in water and soil matrix, and was suggestive to chemical oxidation system in soil remediation to avoid scavenging effects by background electrolytes or other components in water/soil matrix.
KeywordsPersulfate PS activation Herbicide Soil remediation Leaching Singlet oxygen
The authors thank the Analytical and Testing Center of Huazhong University of Science and Technology for help in XRD, FTIR, SEM, and XPS analyses.
This project was funded by the National Natural Science Foundation of China (No. 21671072), Chutian Scholar Foundation from Hubei province, and Shenzhen Science and Technology Development Funds (No. JCYJ20160429182628979).
- Guo Y, Liu X, Han Y, Bian X, Zhang Q (2017) Effective enrichment and simultaneous quantitative analysis of trace heavy metal ions mixture in aqueous samples by the combination of radial electric focusing solid phase extraction, UV-vis spectrophotometric determination and partial least squares regression. Water Air Soil Pollut 228(8):317CrossRefGoogle Scholar
- Liu Y, Zhou A, Gan Y, Li X (2016b) Variability in carbon isotope fractionation of trichloroethene during degradation by persulfate activated with zero-valent iron: effects of inorganic anions. Sci Total Environ 548:1–5Google Scholar
- Outsiou A, Frontistis Z, Ribeiro RS, Antonopoulou M, Konstantinou LK, Silva AMT, Faria JL, Gomes HT, Mantzavinos D (2017) Activation of sodium persulfate by magnetic carbon xerogels (CX/CoFe) for the oxidation of bisphenol A: process variables effects, matrix effects and reaction pathways. Water Res 124:97–107CrossRefGoogle Scholar