Dyestuff Adsorbing Natural Composites for Wastewater Treatments
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caustic soda, chlorine like chemicals [5, 6], and the water characteristic is alkaline with 5% of BOD. For mercerized product, caustic soda can be seen with the
high amount, and its characteristics turn to strongly alkaline [7] with low BOD. In
wastewater of dyeing processes, dyestuff, reducing agents (hydrosulfide, sulfides,
soap, acetic acid), and mordants [8, 9] are seen, and it is strongly colored with
fairly high BOD which is 6% of the total BOD. Printing adds dyestuff or pigments,
gums, starch, mordants, china clay, oil, metallic salts, and acids into wastewater, and
its characteristic can be defined as highly colored and oily with fairly high BOD.
When the last process of finishing is applied to the product, chemicals like tallow,
Glauber salt, traces of starch, common salt, and special agents [10, 11] can be seen
in wastewater that is slightly alkaline with low BOD [3].
Dyestuffs cause the color and toxicity of the wastewater. Especially, cationic
dyestuffs that include benzidine or aromatic compounds can be carcinogenic or
mutagenic for water creatures and human beings. Anionic and reactive dyestuffs
have persistent behavior to be eliminated because of being water soluble and become
harmful to nature. Dyestuffs in water act like a photocatalytic material and do not let
sunlight to penetrate the water supply; thus, water living habitat gets harm with the
change of the oxygen balance; eutrophication which is uncontrolled reproduction of
algae in a small water supply is seen and some other species extinct due to suppression
of algae [3]. Dyestuff presence in water supplies decreases biodiversity.
Total dissolved solids (TDS) are one of the problems of wastewater, and the reason
for this is common salt and Glauber’s salt. Even it is at low level, TDS damages the
balance of the water habitat because the salt amount changes and osmotic balance
is damaged; thus, water creatures can get harm due to dehydration or excess water
penetration. Also, the water supply becomes useless for human activities [3].
Oil, grease, clay, silt, and gritty materials can be categorized under suspended
solids, and they form a barrier on the surface of the water; thus, oxygen and sunlight
inlet are prevented, and the temperature of water habitat decreases. As a result, water
creatures get serious harm from these impurities [3].
Toxic effects can be seen for all living things in case of drinking, eating, and respiration, in case of exposure to heavy metals as manganese, copper, arsenic, cadmium,
mercury, chromium, zinc, lead, etc., with amounts more than the limitations [3].
Furthermore, impurities can accumulate in pipes and results with clogging unless
the wastewater is refined with suitable methods. This can add an economic problem
to maintain it. Besides the economic problems, water scarcity and some illnesses
such as haemorrhage, dermatitis, an ulcer on the skin, vomiting gastritis, nausea,
skin irritation and risk of bladder cancer can be seen due to lack of clean and enough
water [12].
These contaminants must be eliminated at refining procedures before discharging
not to contaminate the nature and harm all living things. Refining is also needed
for reusing wastewater; thus, water consumption is also decreased with reuse policy.
This reuse policy provides water, chemical and energy saving, and decreasing waste
production.
105
caustic soda, chlorine like chemicals [5, 6], and the water characteristic is alkaline with 5% of BOD. For mercerized product, caustic soda can be seen with the
high amount, and its characteristics turn to strongly alkaline [7] with low BOD. In
wastewater of dyeing processes, dyestuff, reducing agents (hydrosulfide, sulfides,
soap, acetic acid), and mordants [8, 9] are seen, and it is strongly colored with
fairly high BOD which is 6% of the total BOD. Printing adds dyestuff or pigments,
gums, starch, mordants, china clay, oil, metallic salts, and acids into wastewater, and
its characteristic can be defined as highly colored and oily with fairly high BOD.
When the last process of finishing is applied to the product, chemicals like tallow,
Glauber salt, traces of starch, common salt, and special agents [10, 11] can be seen
in wastewater that is slightly alkaline with low BOD [3].
Dyestuffs cause the color and toxicity of the wastewater. Especially, cationic
dyestuffs that include benzidine or aromatic compounds can be carcinogenic or
mutagenic for water creatures and human beings. Anionic and reactive dyestuffs
have persistent behavior to be eliminated because of being water soluble and become
harmful to nature. Dyestuffs in water act like a photocatalytic material and do not let
sunlight to penetrate the water supply; thus, water living habitat gets harm with the
change of the oxygen balance; eutrophication which is uncontrolled reproduction of
algae in a small water supply is seen and some other species extinct due to suppression
of algae [3]. Dyestuff presence in water supplies decreases biodiversity.
Total dissolved solids (TDS) are one of the problems of wastewater, and the reason
for this is common salt and Glauber’s salt. Even it is at low level, TDS damages the
balance of the water habitat because the salt amount changes and osmotic balance
is damaged; thus, water creatures can get harm due to dehydration or excess water
penetration. Also, the water supply becomes useless for human activities [3].
Oil, grease, clay, silt, and gritty materials can be categorized under suspended
solids, and they form a barrier on the surface of the water; thus, oxygen and sunlight
inlet are prevented, and the temperature of water habitat decreases. As a result, water
creatures get serious harm from these impurities [3].
Toxic effects can be seen for all living things in case of drinking, eating, and respiration, in case of exposure to heavy metals as manganese, copper, arsenic, cadmium,
mercury, chromium, zinc, lead, etc., with amounts more than the limitations [3].
Furthermore, impurities can accumulate in pipes and results with clogging unless
the wastewater is refined with suitable methods. This can add an economic problem
to maintain it. Besides the economic problems, water scarcity and some illnesses
such as haemorrhage, dermatitis, an ulcer on the skin, vomiting gastritis, nausea,
skin irritation and risk of bladder cancer can be seen due to lack of clean and enough
water [12].
These contaminants must be eliminated at refining procedures before discharging
not to contaminate the nature and harm all living things. Refining is also needed
for reusing wastewater; thus, water consumption is also decreased with reuse policy.
This reuse policy provides water, chemical and energy saving, and decreasing waste
production.