HAZARDS is the depletion of oxygen which is imperative


As there are numerous industries which
discharge effluents from dyeing and finishing salts and those can be hazardous.
It involves Sulphur, naphthol,
vat dyes, nitrates, acetic acid, soaps, chromium compounds and heavy metals like
copper, arsenic, lead, cadmium, mercury, nickel, and cobalt and certain
auxiliary chemicals and these together makes them more toxic.

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Dyeing effluent may consist of formaldehyde based dye fixing agents, hydro
carbon based softeners and non-bio degradable dyeing chemicals. This dyeing
effluent could be of very high temperature and PH, hence making it more

can be increased by the presence of colloidal particles with color and oily
scum in water which results in bad appearance and foul smell. 36

The most dreadful effect of waste
water is the depletion of oxygen which is imperative for marine life. It
actually obstructs the self-purification of water. Moreover, if this effluent
is allowed to pass in soil it damages the soil and hence soil productivity can
be lowered.

This waste water can also abrade
sewerage pipes if allowed to flow in the drains and it increases the
maintenance cost. It is strictly undesirable for human consumption which leads
to human illness. It also provides an estate of breading for bacteria and

This textile effluent is extremely damaging
not only for environmental degradation but also for human sicknesses. Waste
water consisting of organic matters can readily react with many disinfectants
especially chlorine so it’s of major consideration. These chemicals when
evaporated into air can be inhaled by us through our skin and causes allergic
reactions. This can also lead to serious abnormalities in children even before
their birth. 37


Textile effluent treatment can be categorized
into physical, chemical and biological methods. These three methods are
collectively important, if not done together then it would result in
insufficient color removal and other effluents as well. Some of the dyes are
difficult to biodegrade while hydrolyzed reactive and certain acidic dyes can’t
be absorbed by activated sludge so in a word the treatment is escaped. Hence
combination of various methods have to be done to remove unwanted matter from
waste water as much as 85%.

efficiency of the treatment can be determined by the analysis of effluents. It
measures the organic content and nutrients. These analyses should be highly
focused on the degradation of dyes as well the toxic matters if present. The
traditional methods measure and assess the removal of organic content such as
BOD, COD and Total Organic Carbon (TOC).

matters that may be present in waste water, the amount of oxygen needed to
oxidize them is termed as BOD. While COD is a measure of the amount of oxygen
needed to oxidize chemically the organic and inorganic compounds present in the
waste water. BOD is always time consuming than COD and their ratio is an
indication of the biodegradability of the contaminants present in the water.

measures all the organic carbon present in an effluent, including the part that
cannot be oxidized. These above analyses were for organic content but inorganic
matter should also be given special attention in order to measure them such as presence
of salts, in particular sodium chloride which are utilized in greater amount to
improve the binding of dyes resulting in plentiful in waste water. UV-visible
absorbance method is functional to assess the quality of dyeing waste water as
well as the performance of the treatment method. Dyes lose their ability to
absorb light when they are degraded.


Azo dyes
experience cleavage of azo bonds which results in formation of aromatic amines
through which color can be lost. Although these dyes are colorless but they are
very harmful i.e mutagenic so they must be degraded into organic compounds.
Most of the dyes and these aromatic amines which is produced as an outcome of
de-colorization can absorb light and all the credit goes to these aromatic
structures. So, in a nutshell the degradation of these resulting structures
could be used to measure the UV-absorbance.