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APHA
SMWW 4500-B
Boron
2023
3
Standard methods for the examination of water and wastewater (543.3 APHA 24th ed. Ref. Treatises&monographs FL2)
Boron (B) is the first element in Group IIIA of the periodic table. It has an atomic number of 5, an atomic weight of 10.81, and a valence of 3. The average abundance of B in the earth’s crust is 9 ppm. In soils it is 18 to 63 ppm, in streams it is 10 μg/L, and in groundwaters it is 0.01 to 10 mg/L. The most important mineral is borax, which is used in the preparation of heat-resistant glasses, detergents, porcelain enamels, fertilizers, and fiberglass...