Snapshot

The textile industry is very water intensive. Water is used for cleaning the raw material and for many flushing steps during the whole production. Produced wastewater has to be cleaned from, fat, oil, colour and other chemicals, which are used during the several production steps. Textile wastewater includes a large variety of dyes and chemical additions that make the environmental challenge for the textile industry not only as liquid waste but also in its chemical composition.

  • The main pollution in textile wastewater come from dyeing and finishing processes
  • These processes require the input of a wide range of chemicals and dyestuffs, which generally are organic compounds of complex structure
  • Water is used as the principal medium to apply dyes and various chemicals for finishes.
  • Because all of them are not contained in the final product, became waste and caused disposal problems.
  • Major pollutants in textile wastewaters are high suspended solids, chemical oxygen demand, heat, colour, acidity, and other soluble substances
  • Substances which need to be removed from textile wastewater are mainly COD, BOD, nitrogen, heavy metals and dyestuffs

  • 425,000,000 gallons

    Daily consumption of water in Indian textile industry

There are many wastewater treatments for textile wastewater reuse, such as constructed wetland, activated carbon, ion exchange. However, the constructed wetland has poor removal effect on colour and the occupation area of it is very large. Activated carbon has a high removal rate on water-soluble dyes, but it cannot adsorb suspended solids (SS) and insoluble dyes

TREATMENT PROCESSES

There exist various techniques for the treatment of industrial effluents including textile waste water which are broadly categorized into physical, chemical and biological methods, or a combination of the methods such as the physicochemical and electrochemical methods.

PHYSICAL METHOD

  • Absorption
  • Ion Exchange
  • Membrane Filtration
  • Coagulation/Flocculation

CHEMICAL METHOD

Advanced Oxidative processes (AOP): UV (Photochemical), Ozonation based process

BIOLOGICAL METHOD

  • Aerobic
  •  Anaerobic
  • Biofilm-based
  • Fungal Metabolic activities

UV has shown positive results for disinfection and removal of pathogens and organic pollutants in water and wastewater. The effectiveness of UV reacting singly or in combination with other methods are found to be dependent on factors which include especially, pH and initial concentration.

The UV/H2O2-based processes have shown better performance with removal efficiencies higher than 80% for the investigated parameters obtained when it was integrated with the biological treatment, thereby meeting the discharge limits while no- biodegradability enhancement was shown when the process was used as an end treatment.

The formation of the hydroxyl radical in the UV/ H2O2 process is based on the photo dissociation of H2O2 by UV radiation in the range of 200-280nm and H2O2 is variously applied because it has no gaseous release or chemical residues as found with other chemical oxidants.

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