สิ่งแวดล้อม มลภาวะ ของเสีย
เอกสารมาตรฐาน
สหรัฐอเมริกา
APHA
SMWW 3500-Se
Selenium
2023
8
Standard methods for the examination of water and wastewater (543.3 APHA 24th ed. Ref. Treatises&monographs FL2)
Selenium (Se) is the third element in Group VIA in the periodic table. It has an atomic number of 34, an atomic weight of 78.96, and valences of 2, 4, or 6. The average abundance of Se in the earth’s crust is 0.2 ppm; in soils it is 0.27 to 0.74 ppm; in streams it is 0.2 μg/L, and in groundwaters it is <0.1 mg/L. Selenium is used in electronics, ceramics, and shampoos...