Chemistry of arsenic removal during coagulation and Fe-Mn oxidation

Journal Article · Thu Sep 01 04:00:00 EDT 1994 · Journal of the American Water Works Association; (United States)

OSTI ID:7011554

Edwards, M ^[1]

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1. Univ. of Colorado, Boulder, CO (United States). Dept. of Civil Engineering

Arsenic removal during coagulation or Fe-Mn oxidation is examined to aid utilities that desire to improve arsenic removal. Fundamental mechanisms of arsenic removal are discussed, optimization strategies are forwarded, and some new insights are provided to guide future research. Specifically, As(III) removals by coagulation are primarily controlled by coagulant dose and relatively unaffected by solution pH, whereas the converse is true for As(V). When compared on the basis of moles iron or aluminum hydroxide solid formed during coagulation, iron and aluminum coagulants are of demonstrably equal effectiveness in removing As(V) at pH < 7.5. However, iron-based coagulants are advantageous if soluble metal residuals are problematic, if pH is > 7.5, or if the raw water contains As(III). Arsenic removal during Fe-Mn oxidation is controlled by the quantity of iron removed [Fe(OH)[sub 3] formed] and is relatively independent of the quantity of manganese removed (MnOOH formed). 63 refs.

• OSTI ID: 7011554
• Journal Information: Journal of the American Water Works Association; (United States), Journal Name: Journal of the American Water Works Association; (United States) Vol. 86:9; ISSN 0003-150X; ISSN JAWWA5
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540220* -- Environment
Terrestrial-- Chemicals Monitoring &amp; Transport-- (1990-)
ARSENIC
CHEMICAL REACTIONS
CLEANING
DECONTAMINATION
DRINKING WATER
ELEMENTS
FLOCCULATION
HYDROGEN COMPOUNDS
OXIDATION
OXYGEN COMPOUNDS
POLLUTION
PRECIPITATION
REMOVAL
SEMIMETALS
SEPARATION PROCESSES
WATER
WATER POLLUTION