title: Spatial distribution of perchlorate, iodide and thiocyanate in the aquatic environment of Tianjin, China: environmental source analysis.
abstract: Although China is the largest producer of fireworks (perchlorate-containing products) in the world, the pathways through which perchlorate enters the environment have not been characterized completely in this country. In this study, perchlorate, iodide and thiocyanate were measured in 101 water samples, including waste water, surface water, sea water and paired samples of rain water and surface runoff collected in Tianjin, China. The concentrations of the target anions were generally on the order of rain>surface water≈waste water treatment plant (WWTP) influent>WWTP effluent. High concentrations of perchlorate, iodide and thiocyanate were detected in rain samples, ranging from 0.35 to 27.3 (median: 4.05), 0.51 to 8.33 (2.92), and 1.31 to 107 (5.62) ngmL(-)(1), respectively. Furthermore, the concentrations of the target anions in rain samples were significantly (r=0.596-0.750, p<0.01) positively correlated with the concentrations obtained in the paired surface runoff samples. The anions tested showed a clear spatial distribution, and higher concentrations were observed in the upper reaches of rivers, sea waters near the coast, and rain-surface runoff pairs sampled in urban areas. Our results revealed that precipitation may act as an important source of perchlorate, iodide and thiocyanate in surface water. Moreover, iodide concentrations in the Haihe River and Dagu Drainage Canal showed a good correlation with an ideal marker (acesulfame) of domestic waste water, indicating that input from domestic waste water was an important source of iodide in the surface waters of Tianjin.
authors.affiliation: College of Environmental Sciences and Engineering, Nankai University, Tianjin 300071, China; Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin 300071, China.
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Qin
authors.affiliation: School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510275, China. Electronic address: taozhang.swiss@gmail.com.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.affiliation: College of Environmental Sciences and Engineering, Nankai University, Tianjin 300071, China; Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin 300071, China.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Gan
authors.affiliation: College of Environmental Sciences and Engineering, Nankai University, Tianjin 300071, China; Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin 300071, China. Electronic address: sunhongwen@nankai.edu.cn.
authors.forename: Hongwen
authors.initials: H
authors.lastname: Sun
mesh_terms: D002681:China; D002851:Chromatography, High Pressure Liquid; D004784:Environmental Monitoring; D007454:Iodides / Q000032:analysis* / Q000302:isolation & purification; D010472:Perchlorates / Q000032:analysis* / Q000302:isolation & purification; D011891:Rain / Q000737:chemistry; D012623:Seawater / Q000032:analysis / Q000737:chemistry; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry; D013861:Thiocyanates / Q000032:analysis* / Q000302:isolation & purification; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D007454:Iodides; D010472:Perchlorates; D013861:Thiocyanates; D062065:Wastewater; D014874:Water Pollutants, Chemical; C031760:thiocyanate; C494474:perchlorate
keywords: Environmental source; Iodide; Perchlorate; Precipitation; Spatial distribution; Surface water