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K. Amutha
mercerizing, dyeing, printing and finishing operations) with strong interconnection.
These processes are associated with wastewater, solid wastes, emissions to air and
noise pollution. Among these, the major environmental concern of the textile industry
is the effluent or the waste water [21].
The dyeing and finishing processes account for high levels of environmental
contamination as the process effluents contain large and diverse quantities of colour,
organic and inorganic contaminants and other hazardous chemicals including heavy
metals [24].
The textile industry is one of the leading polluters of surface water and consumes
about 200–270 tons of water to produce 1 ton of textile product [6]. The harmful
chemicals present in textile effluents react with many disinfectants especially chlorine
and form by products that are often carcinogens [18].
Huge amount of wastewater loaded with high amount of chemicals from textile
industries that are discharged into surface water is a major source of environmental
pollution. Suitable waste water treatment must be done to reduce the pollution load.
The textile wastewater effluent consists of chemicals including chlorinated solvents,
hydrocarbon solvents, oxygenated solvents, oils, waste fabrics drenched in grease
and oil, and dyestuffs and pigments [20].
The situation has become better due to stringent regulations by the government
and increase in awareness among the stakeholders of textile dyeing industry. Fashion
brands have become environmental conscious and started implementing sustainable
production across the textile supply chain. These oblige the wet processing industry
to follow zero liquid discharge (ZLD). The effluent treatment plant (ETP) is the only
possible way to recycle the waste water and achieve ZLD.
This chapter elucidates the nature of the textile waste water, classification of textile
waste water treatment methods and the use of low-cost and innovative materials for
waste water treatment that are different from conventional methods.
2 Nature of Textile Waste Water
Textile industry employs a wide array of chemicals for the wet processing of textiles
and the unfixed or residual chemicals are present in the waste water in varied
quantities. All these chemicals have to be removed from the waste water before
discharge.
The term wet processing of textiles includes all the processes such as sizing,
desizing, scouring, bleaching, mercerizing, dyeing, printing and finishing. Each of
these processes is specific and uses different chemicals and auxiliaries. Hence, the
effluent produced by these processes and its characteristics are also variable. Table
1 shows the various wet processes and the relevant effluent characteristics in detail.
The textile wastewater or effluent is highly complex in nature as it contains unfixed
dyes and other chemicals of different characteristics. The quantity of these chemical
compounds in the waste water also varies considerably from one process to the other.
The waste water from dyeing or printing process may be highly coloured while that
K. Amutha
mercerizing, dyeing, printing and finishing operations) with strong interconnection.
These processes are associated with wastewater, solid wastes, emissions to air and
noise pollution. Among these, the major environmental concern of the textile industry
is the effluent or the waste water [21].
The dyeing and finishing processes account for high levels of environmental
contamination as the process effluents contain large and diverse quantities of colour,
organic and inorganic contaminants and other hazardous chemicals including heavy
metals [24].
The textile industry is one of the leading polluters of surface water and consumes
about 200–270 tons of water to produce 1 ton of textile product [6]. The harmful
chemicals present in textile effluents react with many disinfectants especially chlorine
and form by products that are often carcinogens [18].
Huge amount of wastewater loaded with high amount of chemicals from textile
industries that are discharged into surface water is a major source of environmental
pollution. Suitable waste water treatment must be done to reduce the pollution load.
The textile wastewater effluent consists of chemicals including chlorinated solvents,
hydrocarbon solvents, oxygenated solvents, oils, waste fabrics drenched in grease
and oil, and dyestuffs and pigments [20].
The situation has become better due to stringent regulations by the government
and increase in awareness among the stakeholders of textile dyeing industry. Fashion
brands have become environmental conscious and started implementing sustainable
production across the textile supply chain. These oblige the wet processing industry
to follow zero liquid discharge (ZLD). The effluent treatment plant (ETP) is the only
possible way to recycle the waste water and achieve ZLD.
This chapter elucidates the nature of the textile waste water, classification of textile
waste water treatment methods and the use of low-cost and innovative materials for
waste water treatment that are different from conventional methods.
2 Nature of Textile Waste Water
Textile industry employs a wide array of chemicals for the wet processing of textiles
and the unfixed or residual chemicals are present in the waste water in varied
quantities. All these chemicals have to be removed from the waste water before
discharge.
The term wet processing of textiles includes all the processes such as sizing,
desizing, scouring, bleaching, mercerizing, dyeing, printing and finishing. Each of
these processes is specific and uses different chemicals and auxiliaries. Hence, the
effluent produced by these processes and its characteristics are also variable. Table
1 shows the various wet processes and the relevant effluent characteristics in detail.
The textile wastewater or effluent is highly complex in nature as it contains unfixed
dyes and other chemicals of different characteristics. The quantity of these chemical
compounds in the waste water also varies considerably from one process to the other.
The waste water from dyeing or printing process may be highly coloured while that