The document discusses waste water treatment and disposal of effluents from the textile industry. It describes the nature and sources of effluents, including dyes and auxiliaries washed off during manufacturing. Primary treatment involves screening, sedimentation, equalization and neutralization to remove solids and adjust pH. Secondary biological treatment uses aerobic processes like activated sludge or anaerobic digestion to reduce BOD. Tertiary treatments target non-biodegradable pollutants through various chemical, physical and membrane processes. The textile industry generates various categories of waste requiring different treatment approaches.
what is waste water? why waste water is treated? how waste water is treated? waste water treatment processes. what is reverse osmosis? how ro works? process of reverse osmosis. adventage & disadventage of reverse osmosis.
what is waste water? why waste water is treated? how waste water is treated? waste water treatment processes. what is reverse osmosis? how ro works? process of reverse osmosis. adventage & disadventage of reverse osmosis.
Environment impact assessment of textile industry Ekta161367
Environment impact assessment of textile industry
Introduction
History of Textiles Industry
Structure of textile Industry
Stages in Textile Manufacturing process Environment Impact Assessment .
The Impact of Textile and clothing Industry on Environment Conclusion References. .
Impact of Textile Effluent on Environment
Effluent is the stream of excess chemical liquor from an industry after using in original operation.
Textile industry employed various process such as sizing, desizing scouring, bleaching, dyeing, printing, finishing etc.
After using original operation large amount of excess liquor discharge to drain.
In a practical estimate, it has been found that 45% material in preparatory processing, 33% in dyeing and 22% are re-processed in finishing
The textile industry is one of the important industries which generates large amount of industrial effluents each year causing the main source of water pollution which is not only harmful for aquatic life but also mutagenic to human. It cause negative impact on environment as well as human beings.
introduction to the biological treatment of waste water. Part 2 will be uploaded soon. this set of slides will explain primary treatment and activated sludge system. this is for education usage only. not for any commercial use.
Dye effluents impose hazardous effects on human beings as well as on environment. The present powerpoint deals with some of the decolourization techniques that can be adopted for treating wastewater containing toxic dyes and chemicals
Textile dyeing industry: wastewater treatment and managementMd. Shamim Ahmed
small overview on wastewater treatment and management made by my brother(Roni Das) from another mother. I helped him to made this because he is greenhorn about power point presentation.
Advanced Oxidation Process for Industrial Water Treatment and Waste WaterUus Soedjak
Advanced Oxidation Process for Industrial Water Treatment and Waste Water is a liquid waste treatment technology which utilizes oxidation method using ozone gas. This technology is combined with ultraviolet light
Water is vital for the entire aspects of life and also an important feature that defines our planet. Deprived water quality due to poor wastewater management is a crisis faced by every country in the world. This crisis affects directly and indirectly on our biological diversity, disturbing the entire ecosystem that act as our life support system (Corcoran et al, 2010). There are many factors affecting the aforementioned crisis and textile industry effluent is one of major contributor among other industrial wastewater (Verma, Dash, & Bhunia, 2012). Recent literature acknowledged dyeing and finishing processes is the main aforementioned contributor (Khandegar & Saroha, 2013). This paper combines a discussion of 1) textile industry process and their effluent, 2) conventional method of effluent treatment including their advantages and limitation and 3) the updated technology in treating textile industry effluent such as electrocoagulation, Bioflotation and Fixed Bed Biofilm Reactor.
Textile Wastewater Treatment in BangladeshMahmudul Hasan
What is wastewater, textile wastewater treatment, Major Pollutants in textile wastewater, Steps of textile wastewater treatment, Brief overview of textile wastewater in Bangladesh.
Environment impact assessment of textile industry Ekta161367
Environment impact assessment of textile industry
Introduction
History of Textiles Industry
Structure of textile Industry
Stages in Textile Manufacturing process Environment Impact Assessment .
The Impact of Textile and clothing Industry on Environment Conclusion References. .
Impact of Textile Effluent on Environment
Effluent is the stream of excess chemical liquor from an industry after using in original operation.
Textile industry employed various process such as sizing, desizing scouring, bleaching, dyeing, printing, finishing etc.
After using original operation large amount of excess liquor discharge to drain.
In a practical estimate, it has been found that 45% material in preparatory processing, 33% in dyeing and 22% are re-processed in finishing
The textile industry is one of the important industries which generates large amount of industrial effluents each year causing the main source of water pollution which is not only harmful for aquatic life but also mutagenic to human. It cause negative impact on environment as well as human beings.
introduction to the biological treatment of waste water. Part 2 will be uploaded soon. this set of slides will explain primary treatment and activated sludge system. this is for education usage only. not for any commercial use.
Dye effluents impose hazardous effects on human beings as well as on environment. The present powerpoint deals with some of the decolourization techniques that can be adopted for treating wastewater containing toxic dyes and chemicals
Textile dyeing industry: wastewater treatment and managementMd. Shamim Ahmed
small overview on wastewater treatment and management made by my brother(Roni Das) from another mother. I helped him to made this because he is greenhorn about power point presentation.
Advanced Oxidation Process for Industrial Water Treatment and Waste WaterUus Soedjak
Advanced Oxidation Process for Industrial Water Treatment and Waste Water is a liquid waste treatment technology which utilizes oxidation method using ozone gas. This technology is combined with ultraviolet light
Water is vital for the entire aspects of life and also an important feature that defines our planet. Deprived water quality due to poor wastewater management is a crisis faced by every country in the world. This crisis affects directly and indirectly on our biological diversity, disturbing the entire ecosystem that act as our life support system (Corcoran et al, 2010). There are many factors affecting the aforementioned crisis and textile industry effluent is one of major contributor among other industrial wastewater (Verma, Dash, & Bhunia, 2012). Recent literature acknowledged dyeing and finishing processes is the main aforementioned contributor (Khandegar & Saroha, 2013). This paper combines a discussion of 1) textile industry process and their effluent, 2) conventional method of effluent treatment including their advantages and limitation and 3) the updated technology in treating textile industry effluent such as electrocoagulation, Bioflotation and Fixed Bed Biofilm Reactor.
Textile Wastewater Treatment in BangladeshMahmudul Hasan
What is wastewater, textile wastewater treatment, Major Pollutants in textile wastewater, Steps of textile wastewater treatment, Brief overview of textile wastewater in Bangladesh.
Effluent Treatment Plant
What is ETP
Need fo ETP
Design of ETP
Design of ETP
Sludge treatment process
Flowchart of ETP
Case study of ETP
ETP plant operation
Textile plant ETP
Equalization
Sedimentation
Settlers
Sludge treatment process
Flowchart of ETP
Case study of ETP
ETP plant operation
Textile plant ETP
Equalization
Sedimentation
Settlers
PH adjustment
Industrial Effluent Treatment by Modern Techniques.pptEr. Rahul Jarariya
Effluent Treatment Plant or ETP is one type of waste water treatment method which is particularly designed to purify industrial wastewater for its reuse and its aim is to release safe water to the environment from the harmful effect caused by the effluent. Helping achieve a greener society.
The dyestuff sector is one of the important segments of the chemicals industry in India, linked with a variety of sectors like textiles, leather, paper, plastics, printing inks and foodstuffs.
Unit operations and process involved in manufacturing of dyes and dye intermediates, wastewater characteristics of dyes and dye intermediates, effluent discharge standards, treatment technology for dye and dye intermediates, solid waste generation and Gaseous emissions.
Plan an ETP with detail process discussion following the instructionsMd Fahimuzzaman
Effluent is the stream of excess chemical liquor from an industry after using in original operation. For example, the excess dye liquor extracted from the textile industry after dyeing is an effluent of that dyeing industry. Effluent Treatment Plant or ETP is a waste water treatment method which is particularly designed to purify industrial waste water for its reuse and it’s aim is to release safe water to environment from the harmful effect caused by the effluent. Textile industry uses numerous hazardous chemicals during processing such as heavy metals, salts, surfactants, sulphite, and formaldehyde, which can cause major pollution in the effluents’ receiving waters. Since textile waste water contains a diversity of impurities and therefore specific treatment technology called ETP is required. The ETP Plant works at various levels and involves various physical, chemical, biological and membrane processes to treat waste water from different industrial sectors like chemicals, drugs, pharmaceutical, refineries, dairy, ready mix plants & textile etc.
With rising crude prices and depleting quality of crude, however, the level of wastewater pollutants in petroleum wastewater is at new high. Such conditions are forcing refineries to use a more advanced water treatment, water recovery methods, and robust processes that work well under a variety of conditions and can handle the changing refinery effluent flow rates. Finally a process that is economical in overall life time cost is needed to make all of this feasible. Aquatech has experience working with these refinery effluent pollutants in the refinery market and offers the advanced petroleum wastewater treatment and recovery technology necessary for the refinery’s needs.
ALL about textile .in this channel you can gain knowledge related textile and also if you want to study more about any topic so you can contact with me through my mail id or comment your topic in comment section https://youtu.be/1x_86UHv_P4
"Understanding the Carbon Cycle: Processes, Human Impacts, and Strategies for...MMariSelvam4
The carbon cycle is a critical component of Earth's environmental system, governing the movement and transformation of carbon through various reservoirs, including the atmosphere, oceans, soil, and living organisms. This complex cycle involves several key processes such as photosynthesis, respiration, decomposition, and carbon sequestration, each contributing to the regulation of carbon levels on the planet.
Human activities, particularly fossil fuel combustion and deforestation, have significantly altered the natural carbon cycle, leading to increased atmospheric carbon dioxide concentrations and driving climate change. Understanding the intricacies of the carbon cycle is essential for assessing the impacts of these changes and developing effective mitigation strategies.
By studying the carbon cycle, scientists can identify carbon sources and sinks, measure carbon fluxes, and predict future trends. This knowledge is crucial for crafting policies aimed at reducing carbon emissions, enhancing carbon storage, and promoting sustainable practices. The carbon cycle's interplay with climate systems, ecosystems, and human activities underscores its importance in maintaining a stable and healthy planet.
In-depth exploration of the carbon cycle reveals the delicate balance required to sustain life and the urgent need to address anthropogenic influences. Through research, education, and policy, we can work towards restoring equilibrium in the carbon cycle and ensuring a sustainable future for generations to come.
Characterization and the Kinetics of drying at the drying oven and with micro...Open Access Research Paper
The objective of this work is to contribute to valorization de Nephelium lappaceum by the characterization of kinetics of drying of seeds of Nephelium lappaceum. The seeds were dehydrated until a constant mass respectively in a drying oven and a microwawe oven. The temperatures and the powers of drying are respectively: 50, 60 and 70°C and 140, 280 and 420 W. The results show that the curves of drying of seeds of Nephelium lappaceum do not present a phase of constant kinetics. The coefficients of diffusion vary between 2.09.10-8 to 2.98. 10-8m-2/s in the interval of 50°C at 70°C and between 4.83×10-07 at 9.04×10-07 m-8/s for the powers going of 140 W with 420 W the relation between Arrhenius and a value of energy of activation of 16.49 kJ. mol-1 expressed the effect of the temperature on effective diffusivity.
Diabetes is a rapidly and serious health problem in Pakistan. This chronic condition is associated with serious long-term complications, including higher risk of heart disease and stroke. Aggressive treatment of hypertension and hyperlipideamia can result in a substantial reduction in cardiovascular events in patients with diabetes 1. Consequently pharmacist-led diabetes cardiovascular risk (DCVR) clinics have been established in both primary and secondary care sites in NHS Lothian during the past five years. An audit of the pharmaceutical care delivery at the clinics was conducted in order to evaluate practice and to standardize the pharmacists’ documentation of outcomes. Pharmaceutical care issues (PCI) and patient details were collected both prospectively and retrospectively from three DCVR clinics. The PCI`s were categorized according to a triangularised system consisting of multiple categories. These were ‘checks’, ‘changes’ (‘change in drug therapy process’ and ‘change in drug therapy’), ‘drug therapy problems’ and ‘quality assurance descriptors’ (‘timer perspective’ and ‘degree of change’). A verified medication assessment tool (MAT) for patients with chronic cardiovascular disease was applied to the patients from one of the clinics. The tool was used to quantify PCI`s and pharmacist actions that were centered on implementing or enforcing clinical guideline standards. A database was developed to be used as an assessment tool and to standardize the documentation of achievement of outcomes. Feedback on the audit of the pharmaceutical care delivery and the database was received from the DCVR clinic pharmacist at a focus group meeting.
Willie Nelson Net Worth: A Journey Through Music, Movies, and Business Venturesgreendigital
Willie Nelson is a name that resonates within the world of music and entertainment. Known for his unique voice, and masterful guitar skills. and an extraordinary career spanning several decades. Nelson has become a legend in the country music scene. But, his influence extends far beyond the realm of music. with ventures in acting, writing, activism, and business. This comprehensive article delves into Willie Nelson net worth. exploring the various facets of his career that have contributed to his large fortune.
Follow us on: Pinterest
Introduction
Willie Nelson net worth is a testament to his enduring influence and success in many fields. Born on April 29, 1933, in Abbott, Texas. Nelson's journey from a humble beginning to becoming one of the most iconic figures in American music is nothing short of inspirational. His net worth, which estimated to be around $25 million as of 2024. reflects a career that is as diverse as it is prolific.
Early Life and Musical Beginnings
Humble Origins
Willie Hugh Nelson was born during the Great Depression. a time of significant economic hardship in the United States. Raised by his grandparents. Nelson found solace and inspiration in music from an early age. His grandmother taught him to play the guitar. setting the stage for what would become an illustrious career.
First Steps in Music
Nelson's initial foray into the music industry was fraught with challenges. He moved to Nashville, Tennessee, to pursue his dreams, but success did not come . Working as a songwriter, Nelson penned hits for other artists. which helped him gain a foothold in the competitive music scene. His songwriting skills contributed to his early earnings. laying the foundation for his net worth.
Rise to Stardom
Breakthrough Albums
The 1970s marked a turning point in Willie Nelson's career. His albums "Shotgun Willie" (1973), "Red Headed Stranger" (1975). and "Stardust" (1978) received critical acclaim and commercial success. These albums not only solidified his position in the country music genre. but also introduced his music to a broader audience. The success of these albums played a crucial role in boosting Willie Nelson net worth.
Iconic Songs
Willie Nelson net worth is also attributed to his extensive catalog of hit songs. Tracks like "Blue Eyes Crying in the Rain," "On the Road Again," and "Always on My Mind" have become timeless classics. These songs have not only earned Nelson large royalties but have also ensured his continued relevance in the music industry.
Acting and Film Career
Hollywood Ventures
In addition to his music career, Willie Nelson has also made a mark in Hollywood. His distinctive personality and on-screen presence have landed him roles in several films and television shows. Notable appearances include roles in "The Electric Horseman" (1979), "Honeysuckle Rose" (1980), and "Barbarosa" (1982). These acting gigs have added a significant amount to Willie Nelson net worth.
Television Appearances
Nelson's char
UNDERSTANDING WHAT GREEN WASHING IS!.pdfJulietMogola
Many companies today use green washing to lure the public into thinking they are conserving the environment but in real sense they are doing more harm. There have been such several cases from very big companies here in Kenya and also globally. This ranges from various sectors from manufacturing and goes to consumer products. Educating people on greenwashing will enable people to make better choices based on their analysis and not on what they see on marketing sites.
2. Effluent:
• Effluent is liquid discharged from any source. Effluent can originate from
municipalities industries, farms ,ships, parking lots and camp ground.
There is a connotation that effluent contains contaminants but in the
strictest sense ,it could be pure water.
• The term effluent refers to the left over dyes and auxiliaries which get
washed during the manufacturing processes and create pollution.
Sludge:
• Sledges are the product of biological treatment of waste water. Sludge
comprise solids found in waste water plus organism used in the treatment
process.
3. 6/11/2020
Nature of the effluent
depends on
pH
Temperature
Total suspended
solids (TSS)
Total dissolved
solids(TDS)
Biological oxygen
demands(BOD)
Chemical oxygen
demands(COD)
4. POLLUTION PROBLEMS IN TEXTILE INDUSTRY
Color
• Presence of color in the waste water is one of the main problems in
textile industry.
• Colors are easily visible to human eyes even at very low concentration.
Hence, color from textile wastes carries significant aesthetic importance.
• Most of the dyes are stable and has no effect of light or oxidizing agents.
• They are also not easily degradable by the conventional treatment
methods.
• Removal of dyes from the effluent is major problem in most of textile
industries.
5. Dissolved Solids:
• Dissolved solids contained in the industry effluents are also a critical
parameter.
• Use of common salt and glauber salt etc. in processes directly increase
total dissolved solids (TDS) level in the effluent.
• TDS are difficult to be treated with conventional treatment systems.
• Disposal of high TDS bearing effluents can lead to increase in TDS of
ground water and surface water.
6. Toxic Metals
• Waste water of textiles is not free from metal contents. There are mainly
two sources of metals.
• The metals may come as impurity with the chemicals used during
processing such as caustic soda, sodium carbonate and salts.
• The source of metal could be dye stuffs like metalised mordent dyes. The
metal complex dyes are mostly based on chromium.
7. Others
• Textile effluents are often contaminated with non-biodegradable organics
termed as refractory materials.
• Detergents are typical example of such materials. The presence of these
chemicals results in high chemical oxygen demand (COD) value of the
effluent.
• Organic pollutants, which originate from organic compounds of dye stuffs,
acids, sizing materials, enzymes, tallow etc are also found in textile
effluent, Such impurities are reflected in the analysis of bio-chemical
oxygen demand (BOD) and COD.
9. Categorization of Waste Generated in
Textile Industry
6/11/2020
• Textile waste is broadly classified into four categories, each of
having characteristics that demand different pollution prevention
and treatment approaches. Such categories are discussed in the
following sections:
Categorization
of Waste textile
industry
Hard to Treat
Wastes
Hazardous or Toxic
Wastes
High Volume
Wastes
Dispersible Wastes
10. 1. Hard to Treat Wastes
This category of waste includes those that are persistent, resist
treatment, or interfere with the operation of waste treatment
facilities.
Non-biodegradable organic or inorganic materials are the chief sources
of wastes, which contain colour, metals, phenols, certain surfactants,
toxic organic compounds, pesticides and phosphates. The chief
sources are:
• Colour & metal and dyeing operation
• Phosphates - preparatory processes and dyeing
• Non-biodegradable organic materials ,surfactants
6/11/2020
11. Hazardous or Toxic Wastes
• These wastes are a subgroup of hard to treat wastes. But, owing
to their substantial impact on the environment, they are treated
as a separate class. In textiles, hazardous or toxic wastes include:
• metals,
• chlorinated solvents,
• non-biodegradable or volatile organic materials.
Some of these materials often are used for non-process applications
such as machine cleaning
12. High Volume Wastes
• Large volume of wastes is sometimes a problem for the textile
processing units.
Most common large volume wastes include:
• High volume of waste water
• Wash water from preparation and continuous dyeing processes
and alkaline wastes from preparatory processes
• Batch dye waste containing large amounts of salt, acid or alkali
These wastes sometimes can be reduced by recycle or reuse as well
as by process and equipment modification.6/11/2020
13. Dispersible Wastes
• The following operations in textile industry generate highly
dispersible waste:
• Waste stream from continuous operation (e.g. preparatory,
dyeing, printing and finishing)
• Print paste (printing screen, squeeze and drum cleaning)
• Lint (preparatory, dyeing and washing operations)
• Foam from coating operations
• Solvents from machine cleaning
• Still bottoms from solvent recovery (dry cleaning operation)
• Batch dumps of unused processing (finishing mixes)
16. Primary Treatment
• After the removal of gross solids, gritty materials and excessive
quantities of oil and grease, the next step is to remove the
remaining suspended solids as much as possible.
• This step is aimed at reducing the strength of the waste water
and also to facilitate secondary treatment.
6/11/2020
18. 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.
• The suspended fibres have to be removed prior to secondary
biological treatment; otherwise they may affect the secondary
treatment system.
• They are reported to clog trickling filters, seals or carbon beads.
19. Sedimentation:
• The suspended matter in textile effluent can be removed
efficiently and economically by 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 most common equipment used includes horizontal flow
sedimentation tanks and center-feed circular clarifiers.
• The settled sludge is removed from the sedimentation tanks by
mechanical scrapping into hoppers and pumping it out
subsequently.
20. 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.
Neutralisation:
• 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.
21. 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.
• Specialized equipment such as clariflocculator is also available,
wherein flocculation chamber is a part of a sedimentation tank.
• In order to alter the physical state of colloidal and suspended
particles and to facilitate their removal by sedimentation, chemical
coagulants are used.
• 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.6/11/2020
22. The degree of clarification obtained also depends on the quantity of
chemicals used. In this method:
• 80-90% of the total suspended matter,
• 40-70% of BOD,
• 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.
23. Secondary Treatment
• The main purpose of secondary treatment is to provide BOD
removal beyond what is achievable by simple sedimentation.
• It also removes appreciable amounts of oil and phenol.
• In secondary treatment, the dissolved and colloidal organic
compounds and colour present in waste water is removed or
reduced and to stabilize the organic matter.
This is achieved biologically using bacteria and other
microorganisms. Textile processing effluents are amenable for
biological treatments.
These processes may be:
• aerobic or
• anaerobic.6/11/2020
24. • In Aerobic Processes, bacteria and other microorganisms
consume organic matter as food.
• They bring about the following sequential changes:
• Coagulation and flocculation of colloidal matter Oxidation of
dissolved organic matter to carbon dioxide Degradation of
nitrogenous organic matter to ammonia, which is then converted
into nitrite and eventually to nitrate.
• Anaerobic Treatment is mainly employed for the digestion of
sludge.
• The efficiency of this process depends upon pH, temperature,
waste loading, absence of oxygen and toxic materials.
6/11/2020
26. Aerated lagoons:
• These are large holding tanks or ponds having a depth of 3-5 m
and are lined with cement, polythene or rubber.
• The effluents from primary treatment processes are collected in
these tanks and are aerated with mechanical devices, such as
floating aerators, for about 2 to 6 days.
• During this time, a healthy flocculent sludge is formed which
brings about oxidation of the dissolved organic matter.
• BOD removal to the extent of 99% could be achieved with
efficient operation.
• The major disadvantages are the large space requirements and
the bacterial contamination of the lagoon effluent, which
necessitates further biological purification.
27. Trickling filters:
• The trickling filters usually consists of circular or rectangular
beds, 1 m to 3 m deep, made of well-graded media (such as
broken stone, PVC, Coal, Synthetic resins, Gravel or Clinkers) of
size 40 mm to 150 mm.
• On prepared bed, wastewater is sprinkled uniformly on the entire
bed with the help of a slowly rotating distributor (such as rotary
sprinkler) equipped with orifices or nozzles.
• Thus, the waste water trickles through the media. The filter is
arranged in such a fashion that air can enter at the bottom;
counter current to the effluent flow and a natural draft is
produced.
28. Activated sludge process:
• This is the most versatile biological oxidation method employed for the
treatment of waste water containing dissolved solids, colloids and
coarse solid organic matter.
• In this process, the waste water is aerated in a reaction tank in which
some microbial flock is suspended.
• The aerobic bacterial flora bring about biological degradation of the
waste into carbon dioxide and water molecule, while consuming some
organic matter for synthesizing bacteria.
• The bacteria flora grows and remains suspended in the form of a floc,
which is called “Activated Sludge”. The effluent from the reaction tank
is separated from the sludge by settling and discharged.
• An efficient aeration for 5 to 24 hours is required for industrial wastes.
BOD removal to the extent of 90-95% can be achieved in this process.
29. Oxidation ditch:
• This can be considered as a modification of the conventional
Activated Sludge process.
• Waste water, after screening in allowed into the oxidation ditch.
• The mixed liquor containing the sludge solids is aerated in the
channel with the help of a mechanical rotor.
• The usual hydraulic retention time is 12 to 24 hrs and for solids, it
is 20-30 days.
• Most of the sludge formed is recycled for the subsequent
treatment cycle.
• The surplus sludge can be dried without odour on sand drying
beds.
30. Oxidation pond:
• An oxidation pond is a large shallow pond wherein stabilization of
organic matter in the waste is brought about mostly by bacteria
and to some extent by protozoa.
• The oxygen requirement for their metabolism is provided by
algae present in the pond. The algae, in turn, utilize the CO2
released by the bacteria for their photosynthesis.
• Oxidation ponds are also called waste stabilization ponds.
31. Tertiary Treatment Processes
• It is worthwhile to mention that the textile waste contains
significant quantities of non-biodegradable chemical polymers.
Since the conventional treatment methods are inadequate, there is
the need for efficient tertiary treatment process.
• Oxidation techniques: A variety of oxidizing agents can be used to
decolorize wastes. Sodium hypochlorite decolourizes dye bath
efficiently. Though it is a low cost technique, but it forms
absorbable toxic organic halides (AOX) .
• Ozone on decomposition generates oxygen and free radicals and
the later combines with colouring agents of effluent resulting in the
destruction of colours .
• The main disadvantage of these techniques is it requires an
effective sludge producing pretreatment.6/11/2020
33. Electrolytic precipitation & Foam fractionation
• The mechanism by which synthetic organic polymer removes
dissolved residual dyes from effluents is best described in terms of the
electrostatic attraction between the oppositely charged soluble dye
and polymer molecules.
• Many of the most problematic dye types, such as reactive dyes, carry a
residual negative charge in their hydrolysed dissolved form, and so
positively charged groups on the polymers provide the necessary
counter for the interaction and subsequent precipitation to occur.
• The immediate result of this co-precipitation is the almost
instantaneous production of very small coloured particles, having little
strength and breaking down at any significant disturbances.
• The agglomeration of the coloured precipitates by using appropriate
high polyelectrolyte flocculants produces stable flocs.
34. Electro chemical processes:
• It has lower temperature requirement than those of other
equivalent non-electrochemical treatment and there is no need
for additional chemical.
• It also can prevent the production of unwanted side products.
But, if suspended or colloidal solids were high concentration in
the waste water, they impede the electrochemical reaction.
• Therefore, those materials need to be sufficiently removed
before electrochemical oxidation
35. Ion exchange method:
• This is used for the removal of undesirable anions and cations
from waste water.
• It involves the passage of waste water through the beds of ion
exchange resins where some undesirable cations or anions of
waste water get exchanged for sodium or hydrogen ions of the
resin .
• Most ion exchange resins now in use are synthetic polymeric
materials containing ion groups such as sulphonyl, quarternary
ammonium group etc.
36. Photo catalytic degradation:
• An advanced method to decolourize a wide range of dyes depending
upon their molecular structure.
• In this process, photoactive catalyst illuminates with UV light, generates
highly reactive radical, which can decompose organic compounds.
Adsorption:
• It is the exchange of material at the interface between two immiscible
phases in contact with one another.
• Adsorption appears to have considerable potential for the removal of
colour from industrial effluents.
• Owen (1978) after surveying 13 textile industries has reported that
adsorption using granular activated carbon has emerged as a practical
and economical process for the removal of colour from textile effluents.
37. Thermal evaporation:
• The use of sodium per sulphate has better oxidizing potential
than NaOCl in the thermal evaporator.
• The process is ecofriendly since there is no sludge formation and
no emission of the toxic chlorine fumes during evaporation.
• Oxidative decolourisation of reactive dye by persulphate due to
the formation of free radicals has been reported in the literature .
38. Membrane filtration
• Membrane filtration offers potential applications:
• Processes using membranes provide very interesting possibilities
for : the separation of hydrolyzed dye-stuffs and dyeing auxiliaries
simultaneously reduce coloration and BOD/COD of the
wastewater used to treat reactive dye bath effluent,
• reduce waste volume and simultaneously recovering salt
• The advantages of membrane filtration are because it is a quick
method with low spatial requirement and the saturate can be
reused.
• The disadvantage with the membrane filtration method that it
has a limited life time before membrane fouling occurs and the
cost is also high.
39. 6/11/2020
• Reverse osmosis
membranes have a retention
rate of 90% or more for most types of
ionic compounds and produce a high
quality of permeate .
• Decoloration and elimination of
chemical auxiliaries in dye house
wastewater can be carried out in a
single step by reverse osmosis.
• Reverse osmosis permits the
removal of all mineral salts,
hydrolyzed reactive dyes, and
chemical auxiliaries.
• Greater the energy is required for
process of the separation of higher
concentration of dissolved salt.
Microfiltration
Ultrafiltration
Nano filtration
Reverse
Osmosis
Membrane
filtration
40. • Nanofiltration has been applied for the treatment of colored
effluents from the textile industry. A combination of adsorption
and nanofiltration can be adopted for the treatment of textile dye
effluents.
• Ultrafiltration enables elimination of macromolecules and
particles, but the elimination of polluting substances, such as
dyes, is never complete it is only between 31% and 76%.
• Microfiltration is suitable for treating dye baths containing
pigment dyes as well as for subsequent rinsing baths. The
chemicals used in dye bath, which are not filtered by
microfiltration, will remain in the bath. Microfiltration can also be
used as a pretreatment for nanofiltration or reverse osmosis
41. Advantages and disadvantages of different
effluent treatment processes
6/11/2020 Designed by PoweredTemplate.com 41