The document discusses the treatment of textile effluent water. It notes that textile processing uses many chemicals that pollute the wastewater, making it high in biochemical oxygen demand (BOD) and chemical oxygen demand (COD). Primary treatment methods are outlined to remove solids and organic matter from the wastewater through physical processes like screening, sedimentation, and chemical coagulation. This reduces the total suspended solids (TSS), COD, and BOD by around 50-60% to produce effluent water that is safer to release back into the environment.

1. MADE BY:
SYEDA AELYA SHAH
ROLL# 36

2. REASONS OF TEXTILE EFFLUENT
 Wet processing of textiles involves, in addition to extensive
amounts of water and dyes, a number of inorganic and
organic chemicals aid in the dyeing process to impart the
desired properties to dyed textile products.
 Natural impurities such as waxes, proteins and pigment.
 Other impurities used in processing such as spinning oils,
sizing chemicals and oil stains present in cotton textiles,
are removed during desizing, scouring and bleaching
operations.
 This results in an effluent of poor quality, which is high in
BOD and COD load.

3. WHY WASTE WATER NEEDS TO BE
TREATED?
 Out of various activities in textile industry, chemical
processing contributes about 70% of pollution.
 Due to the nature of various chemical processing of
textiles, large volumes of waste water with numerous
pollutants are discharged.
 These streams of water affect the aquatic eco-system in
number of ways such as depleting the dissolved oxygen
content or settlement of suspended substances in
anaerobic condition, a special attention needs to be
paid.

4. DIFFERENT TYPE OF WASTE
GENERATED
 Appearance
 Ph
 Color
 Heavy Metal
 Suspended Solid
 Total Dissolved Solid
 Chemical Oxygen Demand (COD)
 Bio Chemical Oxygen Demand (BOD)
 Oil & Grease
 Surfactant

5. NATURE OF WASTE GENERATED AT
EACH STEP
High COD

6. LEVEL OF TREATMENT
Preliminary
PRIMARY
SECONDARY
TERTIARY

7. Preliminary Treatment
It involves removal of large solids such as
rags, sticks, grit and grease that may result in
damage to equipment or operational
problems (Physical treatment)

8. PRIMARY TREATMENT
It involves removal of floating and settable
materials, i.e. suspended solids and organic
matter (Physical and Chemical);

9. SECONDARY TREATMENT
It involves removal of biodegradable organic
matter and suspended solids (Biological and
Chemically)

10. TERTIARY TREATMENT
It involves removal of residual suspended
solids / dissolved solids (Physical, Chemical
and Biological)

13. SCREENING
 Coarse suspended matters such as
rags, pieces of fabric, fibres, yarns
and lint are removed.
 Bar screens and mechanically
cleaned fine screens remove most
of the fibres

14. EQUALIZATION
 Effluent streams are collected into
‘sump pit’.
 Sometimes mixed effluents are
stirred by rotating agitators or by
blowing compressed air from
below.
 The pit has a conical bottom for
enhancing the settling of solid
particles
EQUALIZATION TANK

15. SEDIMENTATION
 This process is particularly
useful for treatment of wastes
containing high percentage of
settable solids or when the waste
is subjected to combined
treatment with sewage.
 The sedimentation tanks are
designed to enable smaller and
lighter particles to settle under
gravity.
 The settled sludge is removed
from the sedimentation tanks by
mechanical scrapping into
hoppers and pumping it out
subsequently.
SEDIMENTATION TANK

16. NEUTRALIZATION
 Normally, pH values of cotton finishing effluents are
on the alkaline side. Hence, pH value of equalized
effluent should be adjusted.
 Use of dilute sulphuric acid and boiler flue gas rich in
carbon dioxide are not uncommon.
 Since most of the secondary biological treatments are
effective in the pH 5 to 9, neutralization step is an
important process to facilitate.

17. Chemical coagulation and
Mechanical flocculation
Finely divided suspended solids and colloidal
particles cannot be efficiently removed by simple
sedimentation by gravity. In such cases,
mechanical flocculation or chemical coagulation
is employed.

18. Chemical coagulation
 It is a controlled process, which
forms a floc (flocculent precipitate)
and results in obtaining a clear
effluent free from matter in
suspension or in the colloidal state.
 The degree of clarification obtained
also depends on the quantity of
chemicals used. In this method,
 80-90% of the TSS
 40-70% of BOD, 5days,
 30-60% of the COD and
 80-90% of the bacteria can be
removed.
 Most commonly used chemicals for
chemical coagulation are alum,
ferric chloride, ferric sulphate,
ferrous sulphate and lime.

19. Mechanical flocculation
 In mechanical flocculation, the
textile waste water is passed
through a tank under gentle
stirring; the finely divided
suspended solids coalesce into
larger particles and settle out.
 Specialized equipment such as
clari-flocculator is also available,
wherein flocculation chamber is
a part of a sedimentation tank.

20. Result After Primary Treatment
INLET EFFULENT
PARAMETER
AFTER PRIMARY
TREATMENT
PH
9.0-10.0
8.0-9.0
TSS
500-1500 mg/lit
250-750 mg/lit
(50%) decrease
COD
1500-3000 mg/lit
600-1200 mg/lit
(60%) decrease
BOD
200-400 mg/lit
50-100 mg/lit
(25%) decrease

21. THANK -YOU