Removal of Organic Dyes from Industrial Effluents: An Overview of Physical and Biotechnological Applications - Green Chemistry for Dyes Removal from Wastewater - page 7

Table 1.2 Classiication of dyes according to their usage and chemical types.

Class Principal substrates Method of application Chemical types

Acid nylon, wool, silk, paper,

inks, and leather

usually from neutral to acidic
dyebaths

azo (including premetallized),
anthraquinone,
triphenylmethane,
azine, xanthene, nitro and
nitroso

Azoic components
and compositions

cotton, rayon,
cellulose acetate and
polyester

iber impregnated with coupling
component and treated with a
solution of stabilized diazonium salt

Azo

Basic paper, polyacrylonitrile,

modiied nylon,
polyester and inks

applied from acidic dyebaths cyanine, hemicyanine,

diazahemicyanine,
diphenylmethane,
triarylmethane,
azo, azine, xanthene,
acridine, oxazine, and
anthraquinone

Direct cotton, rayon, paper,

leather and nylon

applied from neutral or slightly
alkaline baths containing additional
electrolyte

azo, phthalocyanine, stilbene,
and oxazine

( Continued )