Contamination of neonicotinoid insecticides in source water and their fate during drinking water treatment in the Dongguan section of the Pearl River

Xiaoxin He; Shiming Song; Yingyan Huang; Xiongfei Huang; Haibao Huang; Tao Zhang; Hongwen Sun

doi:10.1016/j.scitotenv.2023.165935

Contamination of neonicotinoid insecticides in source water and their fate during drinking water treatment in the Dongguan section of the Pearl River

Sci Total Environ. 2023 Nov 25:901:165935. doi: 10.1016/j.scitotenv.2023.165935. Epub 2023 Jul 31.

Authors

Xiaoxin He¹, Shiming Song², Yingyan Huang³, Xiongfei Huang¹, Haibao Huang¹, Tao Zhang⁴, Hongwen Sun⁵

Affiliations

¹ School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China.
² School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China; School of Chemistry and Environment, Jiaying University, Mei Zhou 514015, China.
³ Guangzhou Hexin Instrument Co., Ltd., Guangzhou 510530, China.
⁴ School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China. Electronic address: zhangt47@mail.sysu.edu.cn.
⁵ MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.

PMID: 37532038
DOI: 10.1016/j.scitotenv.2023.165935

Abstract

Neonicotinoid insecticides (NEOs) as well as their metabolites are highly mobile on the subsurface and can potentially contaminate drinking water sources; however, their pollution status and fate in the drinking water system remains ambiguous. In this study, six parent NEOs and two characteristic metabolites were measured in drinking water source protection area (source water, n = 52) and two related drinking water treatment plants (DWTPs) (n = 88) located in the Dongguan section of the Pearl River. The ubiquitous of NEOs was observed in source water with the mean concentration of total NEOs (ΣNEOs) at 240 ng/L. Although advanced DWTP (A-DWTP; range: 26 % to 100 %) showed better removals of ΣNEOs and all individual NEOs rather than those in conventional DWTP (C-DWTP; range: -53 % to 28 %), the removals were still low for acetamiprid (ACE, 26 %), thiacloprid (THD, 59 %), thiamethoxam (THM, 56 %) and N-desmethyl-acetamiprid (N-dm-ACE, 45 %) in A-DWTP. Removal rates were positive in chlorination (48 %), final stage of sedimentation (F-Sed, 24 %), and granular activated carbon (GAC) filter effluent (19 %) in A-DWTP. It worthy to note that ΣNEOs has high negative removal rates at the start stage of sedimentation (S-Sed, -83 %), middle stage of sedimentation (M-Sed, -47 %), and sand filter effluent (-42 %) water in C-DWTP, which resulted in negative removals of ΣNEOs (-9.6 %), imidacloprid (IMI, -22 %), clothianidin (CLO, -37 %), flupyradifurone (FLU, -76 %), and N-dm-ACE (-29 %) in C-DWTP. Residual levels of NEOs were high in source water, and their low or negative removals in DWTPs should be highly concerning. Results would fill the existing knowledge gap of NEOs in aquatic environment and provide a scientific dataset for policy-making on pollution control and environmental protection.

Keywords: Drinking water system; Fate tracking; Neonicotinoids; Pearl River; Removal rates.