水的色度来源及处理
Source
Color in water is almost always due to organic material, which is usually
extracted from decaying vegetation. Color is common in surface water supplies,
while it is virtually non-existent in spring water and deep wells. Color in
water may also be the result of natural metallic ions (iron and manganese). A
yellow tint to the water indicates that humic acids are present, referred to as
“tann ins “. A reddish color would indicate the presence of precipitated iron.
Stains on bathroom fixtures and on laundry are often associated with color also.
Reddish-brown is ferric hydroxide (iron) will precipitate when the water is
exposed to air. Dark brown to black stains are created by manganese. Excess
copper can create blue stains.
Treatment
Color is removed by chemical feed, retention and filtration. Activated carbon
filtration will work most effectively to remove color in general. Anion
scavenger resin will remove tannins, but must be preceded by a softener or mixed
with fine mesh softener resin. See the headings Iron, Manganese, and Copper for
information their removal or reduction.
