The method optimized for dye removal of standard anionic dye
congo red was used for three commercial waste water samples taken from fabric dyers from the local market.
Capillary electrophoresis separations of prepared cationic and anionic dye
mixtures were reported in a previous publication (Egan et al.
Metanil Yellow was the only anionic dye
that had an easily interpretable laser desorption/ionization-mass spectrometry that could be assigned to the single-charged molecule at m/z 351.
Anionic polymeric flocculant hydrogels have been reported to be able to remove cationic dyes (15) but not for anionic dyes
such as Congo red (16).
The availability of positively charged groups at the adsorbent surface is necessary for the adsorption of anionic dye
are less soluble in SDS micelles than in aqueous solution .
It was also reported by Mall et al  that below pH 7, a significantly high electrostatic attraction exists between the positively charged surface of the adsorbent and anionic dye
So, chemically modified Eugenia jambolana seeds can be effectively employed for anionic dye
removal processes by biosorption.
The effect of humidity fabric surface geometry and dye type on the colour of cotton fabrics dyed with a select range of anionic dyes
The chitosan amino groups strongly adsorb anionic dyes
by electrostatic attraction.
Because oseltamivir phosphate (Figure 1) possesses amine groups, the protonated form may act as a cationic site for anionic dyes
such as Congo red and bromochlorophenol blue to produce colored ion-pairing complexes.
The rapid uptake of the ink immobilizes the anionic dyes
at the surface of the coating.
Our research work attempts to improve waterfastness by incorporating cationically modified boehmites into paper coating formulations that interact more strongly with anionic dyes
in the inks.
for the adsorption of acid blue 62 anionic dyes
onto sepiolite  and also by Mittal et al.
Evaluation of thermodynamics and effect of chemical treatments on sorption potential of Citrus waste biomass for removal of anionic dyes
from aqueous solutions.