306
Cationization as Tool for Functionalization of Cotton
3.6 Effect of Cationization on Environment
Many of the textile industries cause pollution by the untreated discharge of water and
a variety of chemicals. Effluents from textile wet processing industry is causing multiple problems to the environment. Compared with conventional dyeing, cationization
process reduces the consumption of water and chemicals like electrolyte, alkali, acid
or catalyst etc. Cationic solution can be reused for further processes which result
in the saving of water and chemicals. In the dyeing process, cationic dyed cotton
bath solution does not contain hydrolysed dye or other auxiliaries because the introduction of electrostatic attraction which increases the substantivity of dye/chemical
onto fibre (cotton) easily. The cationic cotton dyed materials also show good fixation
and excellent fastness properties. The absence of alkali and electrolyte in dyeing
treatment denotes negligible effluent load.
Many studies and researches have claimed that various cationizing agents, cationic
salts and cationic biopolymer are used for effluent treatments like removal of anionic
dyes of finishes and wastewater treatment [73, 74]. Blackburn and Burkinshaw, in
the year of 2003, reported that pre-treatment of cationizing agent on cotton reduces
the effluent load and level of water consumption in dyeing and finishing than the
normal wet processing methods [75].
Bioflocculants produced by microorganisms which are used for wastewater treatment in effluent plant in the presence of cationic salts like MnCl 2 , MgSO 4 and CaCl 2
showed effective removal of dye from textile effluent. The presence of such cationic
compounds were also used to determine the effect of salts on dye removal by the
bacterial bioflocculants at the optimum temperature and pH [76].
3.7 Advantages of Cationization
• Develops cationic sites on the surface by eliminating negative zeta potential.
• Cationic cotton attracts anionic chemicals and forms strong ionic bonds with
durable effect.
• Degree of fixation of anionic dyes and finishes increases giving improved fastness
properties.
• Electrolytes and alkali are eliminated from the dyeing process of anionic dyes still
giving maximum reactivity and minimum hydrolysis of dyes.
• Simple process with maximum water, chemicals and energy savings.
• Reduced effluent load.
• Ecological and environmental friendly processes [73].
Cationization as Tool for Functionalization of Cotton
3.6 Effect of Cationization on Environment
Many of the textile industries cause pollution by the untreated discharge of water and
a variety of chemicals. Effluents from textile wet processing industry is causing multiple problems to the environment. Compared with conventional dyeing, cationization
process reduces the consumption of water and chemicals like electrolyte, alkali, acid
or catalyst etc. Cationic solution can be reused for further processes which result
in the saving of water and chemicals. In the dyeing process, cationic dyed cotton
bath solution does not contain hydrolysed dye or other auxiliaries because the introduction of electrostatic attraction which increases the substantivity of dye/chemical
onto fibre (cotton) easily. The cationic cotton dyed materials also show good fixation
and excellent fastness properties. The absence of alkali and electrolyte in dyeing
treatment denotes negligible effluent load.
Many studies and researches have claimed that various cationizing agents, cationic
salts and cationic biopolymer are used for effluent treatments like removal of anionic
dyes of finishes and wastewater treatment [73, 74]. Blackburn and Burkinshaw, in
the year of 2003, reported that pre-treatment of cationizing agent on cotton reduces
the effluent load and level of water consumption in dyeing and finishing than the
normal wet processing methods [75].
Bioflocculants produced by microorganisms which are used for wastewater treatment in effluent plant in the presence of cationic salts like MnCl 2 , MgSO 4 and CaCl 2
showed effective removal of dye from textile effluent. The presence of such cationic
compounds were also used to determine the effect of salts on dye removal by the
bacterial bioflocculants at the optimum temperature and pH [76].
3.7 Advantages of Cationization
• Develops cationic sites on the surface by eliminating negative zeta potential.
• Cationic cotton attracts anionic chemicals and forms strong ionic bonds with
durable effect.
• Degree of fixation of anionic dyes and finishes increases giving improved fastness
properties.
• Electrolytes and alkali are eliminated from the dyeing process of anionic dyes still
giving maximum reactivity and minimum hydrolysis of dyes.
• Simple process with maximum water, chemicals and energy savings.
• Reduced effluent load.
• Ecological and environmental friendly processes [73].