Selenium Contamination in Water. Группа авторов

Burden of Disease Attributable to Selected Major Risks.

      71 Yadav, S.K., Singh, I., Singh, D., and Han, S.D. (2005). Selenium status in soils of northern districts of India. Journal of Environmental Management 75 (2): 129–132.

      72 Yang, G.Q. and Xia, Y.M. (1995). Studies on human dietary requirements and safe range of dietary intakes of selenium in China and their application in the prevention of related endemic diseases. Biomedical and Environmental Sciences: BES 8 (3): 187–201.

      73 Yang, L., Shahrivari, Z., Liu, P.K.T. et al. (2005). Removal of trace levels of arsenic and selenium from aqueous solutions by calcined and uncalcined layered double hydroxides (LDH). Industrial & Engineering Chemistry Research 44 (17): 6804–6815.

      74 Zayed, A., Gowthaman, S., and Terry, N. (1998a). Phytoaccumulation of trace elements by wetland plants: I. Duckweed. Journal of Environmental Quality 27 (3): 715–721.

      75 Zayed, A., Lytle, C.M., and Terry, N. (1998b). Accumulation and volatilization of different chemical species of selenium by plants. Planta 206 (2): 284–292.

      76 Zhang, Y., Li, Y., Li, J. et al. (2011). Enhanced removal of nitrate by a novel composite: nanoscale zero valent iron supported on pillared clay. Chemical Engineering Journal 171 (2): 526–531.

      77 Zhang, M., Tang, S., Huang, X. et al. (2014). Selenium uptake, dynamic changes in selenium content and its influence on photosynthesis and chlorophyll fluorescence in rice (Oryza sativa L.). Environmental and Experimental Botany 107: 39–45.

      78 Zhang, X., Fan, W.Y., Yao, M.C. et al. (2020). Redox state of microbial extracellular polymeric substances regulates reduction of selenite to elemental selenium accompanying with enhancing microbial detoxification in aquatic environments. Water Research 172: 115538.

      79 Zhao, Q., Huang, J.C., He, S., and Zhou, W. (2020). Enhancement of a constructed wetland water treatment system for selenium removal. Science of the Total Environment 714: 136741.

      80 Zhu, Y.G., Pilon‐Smits, E.A., Zhao, F.J. et al. (2009). Selenium in higher plants: understanding mechanisms for biofortification and phytoremediation. Trends in Plant Science 14 (8): 436–442.

      81 Zhu, L., Zhang, L., Li, J. et al. (2017). Selenium sequestration in a cationic layered rare earth hydroxide: a combined batch experiments and EXAFS investigation. Environmental Science & Technology 51 (15): 8606–8615.

2 Selenium Distribution and Chemistry in Water and Soil

       Sulaxna Sharma1 and Awanish Kumar Sharma2

       1 THDC, IHET, Tehri, Uttarakhand, India

       2 Department of Physics, GEU, Dehradun, Uttarakhand, India

2.1 Introduction

Selenium is a rarer element on earth and ranked as 70th element among naturally occurring elements in order of its natural abundance. It was first discovered by Swedish chemist Jo¨ns Jacob Berzelius in 1818 when preparing sulfuric acid. He named it after the Greek word selene (meaning “moon”). Selenium after its discovery was almost unnoticed for decades (Hamilton 2004), until the identification of its nutritional essentiality in animals in 1957 (Schwarz and Foltz 1957). The interest of researchers in the trace element has grown substantially with the recognition of its nutritional role as antioxidant and toxicity among human beings (Rotruck et al. 1973). It is dispersed widely in low concentration in the Earth’s crust (Berrow and Ure 1989; Russell 2011) and its concentrations in the Earth’s crust and sea water are 0.004 and 0.09 μg/g, respectively. However, the average global concentration of Se in soil is 0.4 μg/g (i.e. ranging from 0.01–2 μg/g) (Dungan et al. 2002) and 3.1 μg/g in soil of Northwest India (Bajaj et al. 2011). However, only bioavailable Se is the key to determine Se in plant tissues ranging from 0.02–4000 μg/g, depending upon low to high seleniferous soil, which enters into food chain. Hamilton (2004) has reported that the trace to moderate amount, i.e. 40–400 μg/day, of Se is necessary for development and normal growth, and to maintain homeostatic functions, respectively. The deficiency of Se in diet (<3 μg/day, reported by Yang et al. (1983), in China) can weaken immune system and can cause Keshan disease and Kashin–Beck disease, (Coppinger and Diamond 2001). On the other hand, a higher concentration (>400 μg/day) of it may cause health hazard to living beings, including gastrointestinal, respiratory, and cardiovascular problems. It may also result in fragile nails, excessive tooth decay, hair loss, garlic‐smelling breath, discoloration and mental problems (Pedrero and Madrid 2009). The intake of Se recommended by World Health Organization (WHO) and different recommended Se intakes followed in different countries are summarized in Table 2.1.

Table 2.1 Recommended daily nutrient requirement of selenium (μg/d) as per WHO and NAS and followed by different countries and their daily Se intakes.

---

Скачать книгу

• В начало
• <
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• >
• В конец

Group	WHOa	NASb	Unique recommended Se intakes (μg/day) followed by countriesc,d
USA	Canada	UK	Europe	Australia	China	India
Men	40	55	55	55	75	55	85	e	e
Women	30	55	55	55	60	55	70	e	e
Daily Se intakes (μg/day)
Men			90a	98–224a	60c	38–48a	e	3–11,a,e	48a
Women			74a		60c		e	1338a,f;