High Saline Textile Wastewater treatment methods by Activated Sludge microorganisms

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The Textile industry is considered to be one of the main sources of wastewater, as it uses high volumes of water in printing, dyeing and  various finishing processes. Textile wastewater is a mixture of various chemicals and different types of dyes. It also has a salty nature.

The most important resulting contaminant in this is dye, which is used in excess. The wastewater from textile and printing industries contain high quantity of colour and carcinogenic compounds.

 Cellulosic fibres are the most prevalent textile fibres. When they are in water, they are -ve charged because of the ionization of the OH- groups. For this, anionic dyes such as reactive dyes are required. An electrical repulsive force is caused between the two and this causes a reduction in fibre staining. To overcome this issue, NaCl is used in the dyeing bath thereby neutralizing the fibre surface charge and causing increased dye adsorption. This additional amount of dye with high quantities of salt in wastewater increases environmental contamination.


Wastewater resulting from the dying process causes the destruction of organisms, decrease in the supply of DO in the acceptor water environment and also increases BOD concentration.

 

Biological treatment methods have been selected to remove contamination from textile wastewater that contains salt, because they are sustainable, non-toxic, cost-effective and less polluting.

Out of many methods, the sequencing batch reactor is an useful activated sludge process used for treating saline wastewater. It involves a strong system, simple function, and high flexibility in procedures. Equalization, aeration, and clarification can all be achieved by this. The SBR is appropriate for wastewater treatment applications characterized by low or intermittent flow conditions. Different effluents such as domestic, municipal, tannery, brewery, hypersaline and dairy wastewaters can be treated using this biological system.



From different researches, high amounts of salt decreases the efficiency of biological treatment in wastewater treatment plant as it reduces the metabolic functions of activated sludge microorganisms but, gradually adapting the microorganisms to high saline conditions can help minimizing the effect caused by salt. A gradual increase in the salt concentration has less impact on the COD removal in the aerobic system with salt-adapted microorganisms rather than the one with non-adapted biomass.

 

Conclusion

Thus, SBR as a cost effective treatment system can be used for treatment and decolorization of textile wastewater even in saline conditions. So far, few studies have been done on treating wastewater containing dye under high saline conditions using the same treatment system and in future this method has a lot of scope if it is well-implemented.


References:

https://doi.org/10.1007/s10666-005-9025-3

R.L. Irvine and A.W. Busch, Sequencing biological reactor an overview, J. Water Pollut. Control Fed. 51(2) (1979) 235–243.Google Scholar 

https://doi.org/10.1016/j.watres.2010.05.023

https://doi.org/10.1016/j.jart.2017.01.012

Anjaneyulu, Y., Chary, N. S., & Raj, D. S. S. (2005). Decolourization of industrial effluents - Available methods and emerging technologies - A review. Reviews in Environmental Science and Bio/Technology, 4(4), 245-273. 

APHA. (2005). Standard methods for the examination of water and wastewater. New York: American Public Health Association.

 

 

 

 


Comments

  1. UnknownNovember 6, 2020 at 6:57 PM

    The effect of salt on treatment is an eye opener as it reduces metabolic functioning of microbes. Very Informative.

    ReplyDelete
  2. UnknownNovember 6, 2020 at 7:24 PM

    Highly informative contents
    Nice work bro.

    ReplyDelete

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