title: Hydrochemical characteristics of natural water and selenium-rich water resources in the Northern Daba Mountains, China.
abstract: The Northern Daba Mountains (NDM) of Shaanxi Province, China, are a well-known selenium (Se)-rich area, and the area is also known for endemic fluorine (F) and arsenic (As) poisoning. In order to study the hydrochemical characteristics and trace element contents of the natural waters of this region, 62 water samples were collected from Lan'gao area in the NDM. The hydrochemical composition was principally characterized by Ca·Mg-HCO3·SO4. F and As concentrations ranged from 0.01 to 0.67 mg/L and from 0.33 to 6.29 μg/L, respectively, lower than Chinese national standard and international guidelines for drinking water quality. One year of monitoring proved that F and As in natural water were not the sources of the local fluorosis and arseniasis in the NDM. The average Se concentration in fissure water was 5.20 μg/L. The average Se content of river water was 2.82 μg/L, 14 times that of the world's surface level (0.2 μg/L). The Se content in eight samples reached the Chinese national standards for mineral drinking water quality (>10 μg/L). Contrasting the water samples of May, July, and September in 2015 shows that the Se content is relatively stable and the increase of humidity might be beneficial to increase the content of selenium and strontium in water.
authors.affiliation: Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China E-mail: kunliluo@sohu.com.
authors.forename: Chao
authors.initials: C
authors.lastname: Zhao
authors.affiliation: Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China E-mail: kunliluo@sohu.com.
authors.forename: Kunli
authors.initials: K
authors.lastname: Luo
authors.affiliation: Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China E-mail: kunliluo@sohu.com; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Yajun
authors.initials: Y
authors.lastname: Du
authors.affiliation: Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China E-mail: kunliluo@sohu.com; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Tian
authors.affiliation: Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China E-mail: kunliluo@sohu.com; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Long
authors.affiliation: Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China E-mail: kunliluo@sohu.com; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Department of Chemistry, Tsinghua University, Beijing 100084, China.
authors.forename: Shixi
authors.initials: S
authors.lastname: Zhang
mesh_terms: D001151:Arsenic / Q000032:analysis*; D002681:China; D004784:Environmental Monitoring; D005461:Fluorine / Q000032:analysis*; D045483:Rivers / Q000737:chemistry; D012643:Selenium / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D060753:Water Quality; D062066:Water Resources
chemical_list: D014874:Water Pollutants, Chemical; D005461:Fluorine; D012643:Selenium; D001151:Arsenic