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APHA
SMWW 3500-As
Arsenic
2023
4
Standard methods for the examination of water and wastewater (543.3 APHA 24th ed. Ref. Treatises&monographs FL2)
Arsenic (As) is the third element in Group VA of the periodic table. It has an atomic number of 33, an atomic weight of 74.92, and valences of 3 and 5. The average abundance of As in the earth’s crust is 1.8 ppm; in soils it is 5.5 to 13 ppm; in streams it is less than 2 μg/L, and in groundwater it is generally less than 100 μg/L. It occurs naturally in sulfide minerals such as pyrite. Arsenic is used in alloys with lead, in storage batteries, and in ammunition. Arsenic compounds are widely used in pesticides and in wood preservatives...