textile effulent treatment, waste water treatment

21
TEXTILE EFFULENT GENERATION & WASTE WATER TREA MADE BY: SYEDA AELYA SHAH ROLL# 36

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Page 1: Textile effulent treatment, Waste water treatment

TEXTILE EFFULENT GENERATION &

WASTE WATER TREATMENT

MADE BY:SYEDA AELYA SHAHROLL# 36

Page 2: Textile effulent treatment, Waste water treatment

REASONS OF TEXTILE EFFLUENTWet 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.

Page 3: Textile effulent treatment, Waste water treatment

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.

Page 4: Textile effulent treatment, Waste water treatment

DIFFERENT TYPE OF WASTE GENERATEDAppearancePhColorHeavy MetalSuspended SolidTotal Dissolved SolidChemical Oxygen Demand (COD)Bio Chemical Oxygen Demand (BOD)Oil & GreaseSurfactant

Page 5: Textile effulent treatment, Waste water treatment

NATURE OF WASTE GENERATED AT EACH STEP

High COD

Page 6: Textile effulent treatment, Waste water treatment

LEVEL OF TREATMENT

Preliminary

PRIMARY

SECONDARY

TERTIARY

Page 7: Textile effulent treatment, Waste water treatment

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)

Page 8: Textile effulent treatment, Waste water treatment

PRIMARY TREATMENT

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

Page 9: Textile effulent treatment, Waste water treatment

SECONDARY TREATMENT

It involves removal of biodegradable organic matter and suspended solids (Biological and Chemically)

Page 10: Textile effulent treatment, Waste water treatment

TERTIARY TREATMENT

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

Page 11: Textile effulent treatment, Waste water treatment
Page 12: Textile effulent treatment, Waste water treatment

PRIMARY-TREATMENT

Page 13: Textile effulent treatment, Waste water treatment

SCREENINGCoarse 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

Page 14: Textile effulent treatment, Waste water treatment

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

Page 15: Textile effulent treatment, Waste water treatment

SEDIMENTATIONThis 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

Page 16: Textile effulent treatment, Waste water treatment

NEUTRALIZATIONNormally, 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.

Page 17: Textile effulent treatment, Waste water treatment

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.

Page 18: Textile effulent treatment, Waste water treatment

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.

Page 19: Textile effulent treatment, Waste water treatment

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.

Page 20: Textile effulent treatment, Waste water treatment

Result After Primary TreatmentINLET 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

Page 21: Textile effulent treatment, Waste water treatment

THANK -YOU