Degradation of imidacloprid by UV-activated persulfate and peroxymonosulfate processes: Kinetics, impact of key factors and degradation pathway

Qiongfang Wang; Pinhua Rao; Guanghui Li; Lei Dong; Xin Zhang; Yisheng Shao; Naiyun Gao; Wenhai Chu; Bin Xu; Na An; Jing Deng

doi:10.1016/j.ecoenv.2019.109779

Degradation of imidacloprid by UV-activated persulfate and peroxymonosulfate processes: Kinetics, impact of key factors and degradation pathway

Ecotoxicol Environ Saf. 2020 Jan 15:187:109779. doi: 10.1016/j.ecoenv.2019.109779. Epub 2019 Oct 19.

Authors

Qiongfang Wang¹, Pinhua Rao², Guanghui Li², Lei Dong³, Xin Zhang⁴, Yisheng Shao⁵, Naiyun Gao⁶, Wenhai Chu⁶, Bin Xu⁶, Na An⁶, Jing Deng⁷

Affiliations

¹ College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai, 201600, China. Electronic address: wqfang2010@126.com.
² College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai, 201600, China.
³ State Key Laboratory of Pollution Control Reuse, Tongji University, Shanghai, 200092, China; Shanghai Municipal Engineering Design Institute(Group)Co.,LTD, China.
⁴ Shanghai Municipal Engineering Design Institute(Group)Co.,LTD, China.
⁵ State Key Laboratory of Pollution Control Reuse, Tongji University, Shanghai, 200092, China; China Academy of Urban Planning & Design, Beijing, 100037, China.
⁶ State Key Laboratory of Pollution Control Reuse, Tongji University, Shanghai, 200092, China.
⁷ College of Civil Engineering and Architecture, Zhejiang University of Technology, Hangzhou, 310014, China.

PMID: 31639643
DOI: 10.1016/j.ecoenv.2019.109779

Abstract

UV-activated persulfate (UV/PS) and peroxymonosulfate (UV/PMS) processes as alternative methods for removal of imidacloprid (IMP) were conducted for the first time. The reaction rate constants between IMP and the sulfate or hydroxyl radical were calculated as 2.33×10⁹ or 2.42×10¹⁰ M^-1 s^-1, respectively. The degradation of IMP was greatly improved by UV/PS and UV/PMS compared with only UV or oxidant. At any given dosage, UV/PS achieved higher IMP removal rate than UV/PMS. The pH range affecting the degradation in the UV/PS and UV/PMS systems were different in the ranges of 6-8 and 9 to 10. SO₄^2-, F^- and NO₃^- had no obvious effect on the degradation in the UV/PS and UV/PMS systems. CO₃^2- and PO₄^3- inhibited the degradation of IMP in the UV/PS system, while they enhanced the degradation in the UV/PMS system. Algae organic matters (AOM) were used to consider the impact of the degradation of IMP for the first time. The removal of IMP were restrained by both AOM and natural organic matters. The higher removal rate of IMP demonstrated that both UV/PS and UV/PMS were suitable for treating the water containing IMP, while UV/PS was cost-effective than UV/PMS based on the total cost calculation. Finally, the degradation pathways of IMP were proposed.

Keywords: Degradation; Imidacloprid; Kinetics; Peroxymonosulfate; Persulfate; UV.

MeSH terms

Kinetics
Models, Theoretical
Neonicotinoids / analysis*
Nitro Compounds / analysis*
Oxidation-Reduction
Peroxides / chemistry*
Peroxides / radiation effects
Sodium Compounds / chemistry*
Sodium Compounds / radiation effects
Sulfates / chemistry*
Sulfates / radiation effects
Ultraviolet Rays*
Water Pollutants, Chemical / analysis*
Water Purification / methods*

Substances

Neonicotinoids
Nitro Compounds
Peroxides
Sodium Compounds
Sulfates
Water Pollutants, Chemical
peroxymonosulfate
imidacloprid
sodium persulfate