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.
First presentation of my whole life, That's i want to share with you people. I think this presentation (SECONDARY WASTEWATER TREATMENT) may fulfill your requirement.
Actually when my teacher told me about our assignment I was felling nervous because I've never done this type of thing. when she asked one of my classmate to upload his PPT in class common email-ID, then I felt very bad !!!! not on their success but because I COULDN'T. At that time i promised to myself and with the co-ordination of my group member MR. AYUSH GOVIL, MISS. VERSHA DABAS, MISS KRITI SINGHAL and myself RISHAW KUMAR (TIWARI). And finally i got not only me, we winzzzzz.
thanx to,
Dr. TANNU ALLEN (our prof.)
and special thanx to my group member and my classmate. and you guys also.
First presentation of my whole life, That's i want to share with you people. I think this presentation (SECONDARY WASTEWATER TREATMENT) may fulfill your requirement.
Actually when my teacher told me about our assignment I was felling nervous because I've never done this type of thing. when she asked one of my classmate to upload his PPT in class common email-ID, then I felt very bad !!!! not on their success but because I COULDN'T. At that time i promised to myself and with the co-ordination of my group member MR. AYUSH GOVIL, MISS. VERSHA DABAS, MISS KRITI SINGHAL and myself RISHAW KUMAR (TIWARI). And finally i got not only me, we winzzzzz.
thanx to,
Dr. TANNU ALLEN (our prof.)
and special thanx to my group member and my classmate. and you guys also.
Biological Nutrient Removal (BNR) is a process used for nitrogen and phosphorus removal from wastewater before it is discharged into surface or ground water.To control eutrophication in receiving water bodies, biological nutrient removal (BNR) of nitrogen and phosphorus has been widely used in wastewater treatment practice, both for the upgrade of existing wastewater treatment facilities and the design of new facilities.
•Introduction of bioremediation: Bioremediation refers to the process of using microorganisms to remove the environmental pollutants i.e. toxic wastes found in soil, water, air etc.
•In situ bioremediation:
It involves a direct approach for the microbial
degradation of xenobiotics at the sites of pollution
(soil, ground water).
•Types of in situ bioremediation:
Natural attenuation.
Engineered in situ bioremediation.
- Bioventing, biosparging, bioslurping,
phytoremediation.
•Ex situ bioremediation:
Waste or toxic pollutants can be collected from the polluted sites and bioremediation can be carried out at a designated place or site.
• Types of ex situ bioremediation
Land farming, windrow, biopiles, bioreactors.
•Microorganisms use in bioremediation:
A number of naturally occurring marine microbes
such as Pseudomonas sp. is capable of degrading oil and other hydrocarbons.
•Factors affecting bioremediation:
Nutrient availability, moisture content, pH, temperature, contaminant availability.
•References:
Satyanarayana U. Biotechnology. BOOKS AND ALLIED (P) Ltd.
Sharma P.D. Environmental Microbiology. RASTOGI PUBLICATIONS.
Gupta P.K. Biotechnology and Genomics. RASTOGI PUBLICATIONS.
Dubey R.C. A Textbook of Biotechnology. S Chand And Company Ltd.
Dubey R.C. A Textbook of Microbiology. S Chand And Company Ltd.
Willey/Sherwood/Woolverton. Prescott’s Microbiology. McGRAW-HILL INTERNATIONAL EDITION.
www.sciencedirect.com/bioremediation.
Deals with what is activated sludge, mechanisms and kinetics of treatment, design of activated sludge process, secondary clarifiers and their design and bulking sludge, raising sludge and foaming of ASP.
In his PPT you will come to know about the TREATMENT OF SOLID WASTE, ITS MANAGEMENT and MICROORGANISMS INVOLVED IN THE TREATMENT OF SOLID WASTE. do like, share and follow me to get more such PPT to be uploaded.
Wastewater Treatment for Sugar Industry Hülya Pala
I decided to share my another presentation about wastewater treatment which is especially about sugar industry to be beneficial for you.( The link for slide 5: https://www.youtube.com/watch?v=EP_fgp7zYKk)
Deals with the biological removal of nitrogen and phosphorus, Nitrification-denitrification removal of nitrogen, and Phosphate accumulating organisms and poly-hydroxibutirate in the phosphorus removal.
CH-3. Anaerobic treatment of wastewaterTadviDevarshi
Anaerobic treatment process, Effects of pH, temperature and other parameters on anaerobic treatment, Concept of anaerobic contact process, anaerobic filter, anaerobic fixed film reactor, fluidized bed and expanded bed reactors and up flow anaerobic sludge blanket (UASB) reactor.
This presentation is made for S.Y.Bsc. Students.
The presentation includes Wastewater microbiology. The presentation includes information about sources as well as methods of wastewater treatment.
Biological Nutrient Removal (BNR) is a process used for nitrogen and phosphorus removal from wastewater before it is discharged into surface or ground water.To control eutrophication in receiving water bodies, biological nutrient removal (BNR) of nitrogen and phosphorus has been widely used in wastewater treatment practice, both for the upgrade of existing wastewater treatment facilities and the design of new facilities.
•Introduction of bioremediation: Bioremediation refers to the process of using microorganisms to remove the environmental pollutants i.e. toxic wastes found in soil, water, air etc.
•In situ bioremediation:
It involves a direct approach for the microbial
degradation of xenobiotics at the sites of pollution
(soil, ground water).
•Types of in situ bioremediation:
Natural attenuation.
Engineered in situ bioremediation.
- Bioventing, biosparging, bioslurping,
phytoremediation.
•Ex situ bioremediation:
Waste or toxic pollutants can be collected from the polluted sites and bioremediation can be carried out at a designated place or site.
• Types of ex situ bioremediation
Land farming, windrow, biopiles, bioreactors.
•Microorganisms use in bioremediation:
A number of naturally occurring marine microbes
such as Pseudomonas sp. is capable of degrading oil and other hydrocarbons.
•Factors affecting bioremediation:
Nutrient availability, moisture content, pH, temperature, contaminant availability.
•References:
Satyanarayana U. Biotechnology. BOOKS AND ALLIED (P) Ltd.
Sharma P.D. Environmental Microbiology. RASTOGI PUBLICATIONS.
Gupta P.K. Biotechnology and Genomics. RASTOGI PUBLICATIONS.
Dubey R.C. A Textbook of Biotechnology. S Chand And Company Ltd.
Dubey R.C. A Textbook of Microbiology. S Chand And Company Ltd.
Willey/Sherwood/Woolverton. Prescott’s Microbiology. McGRAW-HILL INTERNATIONAL EDITION.
www.sciencedirect.com/bioremediation.
Deals with what is activated sludge, mechanisms and kinetics of treatment, design of activated sludge process, secondary clarifiers and their design and bulking sludge, raising sludge and foaming of ASP.
In his PPT you will come to know about the TREATMENT OF SOLID WASTE, ITS MANAGEMENT and MICROORGANISMS INVOLVED IN THE TREATMENT OF SOLID WASTE. do like, share and follow me to get more such PPT to be uploaded.
Wastewater Treatment for Sugar Industry Hülya Pala
I decided to share my another presentation about wastewater treatment which is especially about sugar industry to be beneficial for you.( The link for slide 5: https://www.youtube.com/watch?v=EP_fgp7zYKk)
Deals with the biological removal of nitrogen and phosphorus, Nitrification-denitrification removal of nitrogen, and Phosphate accumulating organisms and poly-hydroxibutirate in the phosphorus removal.
CH-3. Anaerobic treatment of wastewaterTadviDevarshi
Anaerobic treatment process, Effects of pH, temperature and other parameters on anaerobic treatment, Concept of anaerobic contact process, anaerobic filter, anaerobic fixed film reactor, fluidized bed and expanded bed reactors and up flow anaerobic sludge blanket (UASB) reactor.
This presentation is made for S.Y.Bsc. Students.
The presentation includes Wastewater microbiology. The presentation includes information about sources as well as methods of wastewater treatment.
Compared to terrestrial biomass, marine algae have a major potential to become a renewable resource of raw material for biofuels and bioproducts. Through their diverse chemical composition, marine algae can be the source of bioproducts for many industries. For the implementation in practice of the marine algae capitalization, it is necessary to obtain supplementary information from scientific research and solving some technological aspects for obtaining bioproducts under efficient economic conditions.
Find out about the problems your POND's been facing and how to go about itOrganica Biotech Pvt.Ltd
Ponds provide a holistic niche supporting fragile ecosystems.
This invaluable water resource confers an aesthetic appeal to the neighborhood.
Influx of pollutants due to various factors leads to it's misuse and affects the water quality. Thus, affecting the aquatic ecosystem.
Micro-organisms are well known for their ability to break down a huge range of organic compounds and absorb inorganic substances. Currently, microbes are used to clean up pollution treatment in processes known as ‘bioremediation’.
Lignocellulosic materials alone, in the form of agricultural wastes, are accumulated at a rate of 3480 Trillion grams per year. The bioconversions of agricultural wastes are mainly carried out by the microbial community which involves bacteria, fungi, actinomycetes etc. Many of these communities degrade a wide spectrum of agricultural compositions while some specific degradation activities are also observed. Hence the role of microorganisms and the mechanisms which they use for the degradation of agricultural waste biomass need to be discussed.
L11 -SECONDARY TREATMENT OF SEWAGE - TRICKLING FILTERS.pptxPRACHI DESSAI
Wastewater treatment is a process used to remove contaminants from wastewater and convert it into an effluent that can be returned to the water cycle. Once returned to the water cycle, the effluent creates an acceptable impact on the environment or is reused for various purposes (called water reclamation).
Role of Microorganisms in Sewage Treatment by Usama YounasUSAMAYOUNAS11
This presentation will help to understand the various microbes involved in the sewage treatment, also included the data regarding some sewage treatment plants present in Lahore, Punjab, Pakistan
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.
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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
WRI’s brand new “Food Service Playbook for Promoting Sustainable Food Choices” gives food service operators the very latest strategies for creating dining environments that empower consumers to choose sustainable, plant-rich dishes. This research builds off our first guide for food service, now with industry experience and insights from nearly 350 academic trials.
Natural farming @ Dr. Siddhartha S. Jena.pptxsidjena70
A brief about organic farming/ Natural farming/ Zero budget natural farming/ Subash Palekar Natural farming which keeps us and environment safe and healthy. Next gen Agricultural practices of chemical free farming.
Artificial Reefs by Kuddle Life Foundation - May 2024punit537210
Situated in Pondicherry, India, Kuddle Life Foundation is a charitable, non-profit and non-governmental organization (NGO) dedicated to improving the living standards of coastal communities and simultaneously placing a strong emphasis on the protection of marine ecosystems.
One of the key areas we work in is Artificial Reefs. This presentation captures our journey so far and our learnings. We hope you get as excited about marine conservation and artificial reefs as we are.
Please visit our website: https://kuddlelife.org
Our Instagram channel:
@kuddlelifefoundation
Our Linkedin Page:
https://www.linkedin.com/company/kuddlelifefoundation/
and write to us if you have any questions:
info@kuddlelife.org
"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.
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.
4. WASTES
• What is waste??
• Waste include all the items that people no longer have any use for, which they either
intend to get rid of or have already discarded.
• “Wastes are substances or objects, which are disposed of or are intended to be
disposed of or are required to be disposed of by the provisions of national law.” –
Basel convention-
• Interestingly, if biologically originated, any waste will decompose in nature under
natural low..
H.G.D.A.P.JAYASINGHE. BSc. (undergraduate) 10/20/2015
5. CLASSIFICATION OF WASTES
• Why classify wastes?
• It is essential for the management of wastes in a proper way for the protection of the
environment and also for human health
• Can be done according to;
• Physical state
• Place of origin
• Type of origin
• Mode of degradation
H.G.D.A.P.JAYASINGHE. BSc. (undergraduate) 10/20/2015
6. WASTE AND POLLUTANTS
• Pollutant is a waste material that pollutes air, water or soil.
• Severity of a pollutant depend on its;
• Chemical nature
• Concentration
• Persistence
• Damage done to environment can be long term or short term.
• Some are biodegradable. Hence, persistence is very low.
• But, some resultant chemicals of biodegradation of some wastes are themselves
polluting.
• Example: DDE and DDD arise from the biodegradation of DDT
H.G.D.A.P.JAYASINGHE. BSc. (undergraduate) 10/20/2015
7. WASTE WATER
• Any water that has been adversely affected in quality by anthropogenic influence.
• Origin can be a combination of;
• Domestic, industrial, commercial or agricultural activities or surface runoffs, sewer
inflow, storm runoffs etc.
• Municipal wastewater is normally called sewage. But recently, the term sewage is
also used to mean any type of wastewater.
• May contain various types of pollutants.
H.G.D.A.P.JAYASINGHE. BSc. (undergraduate) 10/20/2015
8. ADVERSE EFFECTS OF POLLUTED WATER
• When polluted water is discharged in to the environment;
• Drinking water may taste bad
• Eutrophication of water bodies
• Floating oil blankets
• Odor problems, aesthetic concerns
• Increase of aquatic life forms etc.
H.G.D.A.P.JAYASINGHE. BSc. (undergraduate) 10/20/2015
9. BIODEGRADATION
• Is a natural system in an equilibrium which ensures the circulation of matter
through the environment via recycling dead plant and animal matter.
• Done by environmental microorganisms.
• Hence, is a complex process of decomposition carried out by various microbial
biochemical reactions.
• Can occur aerobically and/or anaerobically.
• Generalized procedure;
Complex substances Simple substances gases + minerals
H.G.D.A.P.JAYASINGHE. BSc. (undergraduate) 10/20/2015
10. BIODEGRADATION CONT.
• Depends on microbial enzymatic activities.
• Microbial enzymes will degrade complex compounds in to simpler compounds.
• Hence, it’s a biological transformation of complex compounds in to simple
compounds.
• Simple compounds will be absorbed and broken down to gases and minerals and/or
converted in to biomass within cells.
H.G.D.A.P.JAYASINGHE. BSc. (undergraduate) 10/20/2015
11. BIODEGRADABILITY
• Ability of decomposition of a pollutant via biological activities such as microbial
metabolism in the environment.
• With respect to time it takes to be degraded, a pollutant can be;
• Very easily degradable
• Easily degradable
• Potentially degradable
• Very slowly degradable or;
• Non-biodegradable
H.G.D.A.P.JAYASINGHE. BSc. (undergraduate) 10/20/2015
13. AEROBIC BIODEGRADATION
• Biodegradation of waste materials by microorganisms in the presence of oxygen.
• A rapid process.
• Heat energy is released.
• Convert oxygen to water along with degradation of complex compounds in to simple
components.
• Both Gram positive and Gram negative microbes get involved.
H.G.D.A.P.JAYASINGHE. BSc. (undergraduate) 10/20/2015
14. MICROBES INVOLVED IN
AEROBIC BIODEGRADATION
Here, both Gram positives and Gram negatives
play their part
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
15. ANAEROBIC BIODEGRADATION
• Decomposition of waste materials by microorganisms in the absence of oxygen.
• Occurs when anaerobes are dominant over aerobes.
• No heat energy is released.
• Provides both volume and mass reduction. Hence, important in sludge and
biodegradable waste treatment.
• Anaerobic digestion involves four biological and chemical stages;
• Hydrolysis
• Acidogenesis
• Acetogenesis
• Methanogenesis
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
16. MICROBES INVOLVED IN
ANAEROBIC BIODEGRADATION
• Acidogenesis -
Clostridium
Eubacterium
Ruminococcus
• Acetogenesis -
Syntrophobacter wolanii
Syntrophomonas wolfii
• Methanogenesis -
Methanothrix
Methanosacenia
Here, different microbes are
involved in different stages of
degradation
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
17. AEROBIC VS. ANAEROBIC
WHO’S THE BEST?
Aerobic biodegradation
• Most rapid and fast
• No pungent gas production
• Expensive
• Large amounts of disposable wastes
generated
Anaerobic biodegradation
• Time consuming and slow
• Pungent gas produced
• Less expensive
• Less waste generated
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
18. NON-BIODEGRADABLE COMPOUNDS
• Compounds that cannot be digested via biological means.
• Some scientists believe that “nothing is non-biodegradable”
• Even if so, some compounds take too long to be degraded in the environment and by
the time, damage done to environment may be severe.
• Xenobiotic compounds are also falls under non-biodegradable compounds.
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
19. XENOBIOTIC COMPOUNDS
• A foreign chemical found within an organism, but is not normally naturally
produced by or expected to be present within that particular organism.
• Example: Antibiotics within human body
• Chemical compounds which are present in much higher concentrations than usual
within an organism also falls under this class.
• Term often used in context of pollutants.
• Dioxins and polychlorinated biphenyls. (xenobiotic to whole biota, not existed before
human synthesis)
• Alkyl Benzene Sulfonates
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
20. ALKYL BENZENE SULFONATES
• A major component in some anionic detergents.
• Two classes;
• Branched alkyl benzene sulfonates
• Linear alkyl benzene sulfonates
• Widely used in the formulation of house hold detergent and industrial cleaning products.
• Has a very slow rate of biodegradation.
• Discharge to the environment can cause un-restorable damages;
• Poisoning water life
• Pollution of ground water
• Foam formation in revers
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
21. BIO-MAGNIFICATION
• Increase in concentration of a substance within an organism exceeding the background
concentration of that substance in its diet.
• Is a combine result of three individual reasons;
• Persistence of the compound
• Food chain energetics
• Low or non-existent rate of internal degradation or excretion of the substance
• Many xenobiotic chemicals such as pesticides are biomagnified. Many are chlorobenzene
compounds
• Examples:
• DDT - Persistence over 15 years
• Malathion
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
22. RECALCITRANT COMPOUNDS
• Xenobiotic compounds that are completely resistant to biodegradation.
• Simple structural changes can lead these to be biodegradable.
• A xenobiotic may become recalcitrant due to followings;
• They may not be recognized by the existing bio-degradative enzymes
• They may be highly stable, i.e., chemically and biologically inert due to the presence of substitution groups
like halogens, nitro-, sulfonate, amino-, methoxy- and carbamyl groups
• Insolubility in water or absorbance in to external matrices like soil
• highly toxic or give rise to toxic products due to microbial activity
• large molecular size prevents entry into microbial cells
• Inability of the compounds to induce the synthesis of degrading enzymes
• Lack of the permease needed for their transport into the microbial cells.
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
24. WHAT IS WASTEWATER TREATMENT?
• Conversion of wastewater (water that is no longer needed nor suitable for its most
recent use), in an effluent that can either be returned to the water cycle with
minimum environmental issues or be reused.
• The physical infrastructure used is called;
• Waste Water Treatment Plant - WWTP
• Sewage Treatment Plant - STP
• Effluent Treatment Plant - ETP
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
25. SELF-PURIFICATION OF WATER BODIES
• Is complex process in natural water systems that often involves simultaneous working of;
• Physical processes
• Chemical processes
• Biological processes
• Returns DO back to the level required by the aquatic life
• Only better when rate of waste production is lower than the rate of biodegradation.
• Self purification will be affected by;
• Dilution
• Water current
• Temperature
• Sunlight
• Rate of oxidation
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
27. WASTEWATER TREATMENT PLANT
• Man made physical infrastructures to purify wastewater.
• Involves basic principles of self-purification of natural water bodies. And uses its three steps of water
purification with slight modifications.
• Physical purification
• Chemical purification
• Biological purification
• Objectives;
• To remove all toxic chemicals
• To remove all pathogens
• To remove all dissolved nutrients
• It is expected that the final end product (clean water/clear water) of a wastewater treatment plant should
be able to be used as portable water.
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
28. THE PROCEDURE
• Have designed to achieve improvement in water quality.
• It is closely related to the standards set for the effluent quality and ensures reaching
to them.
• Removes or should remove;
• Suspended solids
• Biodegradable organics
• Pathogenic microorganisms
• Dissolved nutrients
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
29. THE PROCEDURE CONT.
• In a general sewage treatment plant, there are three basic steps of water treatment.
• Primary treatment - Physical or mechanical purification
• Secondary treatment - Biological purification
• Tertiary treatment - Chemical purification
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
30. PRIMARY TREATMENT
• Designed to remove gross, suspended and floating solids from raw sewage.
• Involves mechanical purification techniques such as screening and sedimentation.
• Can reduce BOD from 20-30% and total suspended solids from 50-60%.
• There several operational units in primary treatment. Including;
• Screening
• Flow equalizing
• Neutralization
• Gravity separation
• Chemical aids
• Floatation
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
31. SCREENING
• First operational unit in primary treatment.
• Involves the operation of a screen filter.
• A screen is a device with openings, generally of uniform size that is used to retain
the coarse solids found in wastewater.
• Two classes; according to the size of openings.
• Coarse screens - openings ¼ inch or more
• Fine screens - openings less than ¼ inch.
• Can be mechanically cleaned or manually/hand cleaned.
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
32. FLOW EQUALIZING
• Also known as flow balancing.
• Waste water is collected in to a tank, mixed and discharged to downstream processes in a constant
rate.
• Can also be used as an emergency tank in case of any process failure.
• One of the important operational units to maintain a consistent flow rate.
• Inconsistent flow rates?
• Can cause sludge settling problems in activated sludge process etc.
• Flow balancing system must provide;
• Sufficient mixing - To create a homogenous mixture and to prevent solid deposition.
• Sufficient aeration - To prevent odor problems due to anaerobic decomposition
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
33. NEUTRALIZATION
• Wastewater entering biological treatment must have a pH around 6.5-9 for optimum
microbial growth.
• Industrial wastes mostly contain acidic or alkaline components and hence, require
neutralization.
• Acidic wastes are commonly neutralized with waste alkaline streams, lime,
dolomite, ammonia, caustic soda, or soda ash
• Alkaline wastes usually require treatment with a waste acidic stream, sulfuric acid
or hydrochloric acid.
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
34. GRAVITY SEPARATION
• Separation of suspended particles that are heavier than water via gravity settling.
• In WWTP, sedimentation may be used in several steps.
• During primary treatment, it is mainly used to remove grit and particulate matter.
• Done in a primary settling basin.
• After settling, primary sludge is collected from the bottom and sent in to anaerobic
digestion.
• Clarifier liquid is sent to further treatments downstream.
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
35. CHEMICAL AIDS
• Addition of chemicals (coagulants) to alter the physical state of dissolved and suspended
solids and facilitate their removal via sedimentation.
• Takes place in rapid mixed or flash mixed basins.
• Mixing is essential to disperse the coagulant so that it contacts all of the wastewater.
• Few most common coagulants;
• Alum - Al2(SO4)3.18H2O
• Ferrous Sulfate - FeSO4.7H2O
• Lime - Ca(OH)2
• Ferric Chloride - FeCl3
• Ferric Sulfate - Fe2(SO4)3
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
36. CHEMICAL AIDS CONT.
• Coagulation will remove;
• Total suspended solids - 80-90%
• BOD5 - 50-80%
• Bacteria - 80-90%
• In contrast, plain sedimentation will only remove;
• Total suspended solids - 50-70%
• BOD5 - 25-40%
• Bacteria - 25-75%
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
37. FLOATATION
• Separation is brought by introducing fine gas (usually air bubbles) into the liquid
phase.
• The bubbles attach to the particulate matter, and the buoyant force of the combined
particle and gas bubble is great enough to cause the particle to rise to the surface to form
a scum blanket, which is removed by a skimming mechanism.
• Grit and other heavy solids that settle to the bottom are raked to a central sludge for
removal.
• Very small or light particles that settle slowly can be removed more completely and
in a shorter time.
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
38. FLOATATION CONT.
AIR FLOATATION
• In this system, air bubbles are formed by introducing the gas phase directly into the
liquid phase through a revolving impeller through diffusers.
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
40. SECONDARY TREATMENT
• Primary treatment removes most of the rubbish and solid wastes.
• Secondary treatment removes dissolved nutrients and remaining solids via bacterial
decomposition.
• Uses naturally occurring biological processes.
• Steps followed in secondary treatment can be classified depending on different
parameters.
• According to oxygen requirement
• According to rate of biodegradation
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
41. ACCORDING TO OXYGEN REQUIREMENT
1. Aerobic methods - require oxygen for commencement
• Activated sludge system - suspended growth system
• Tickling filters - attached growth system
• Aerobic lagoons and ponds- suspended growth system
Activated sludge is the system with highest rate and highest cost.
2. Anaerobic methods – no need of oxygen and presence of oxygen is inhibitory
• Anaerobic digester - high rate
• Anaerobic ponds - low rate
From all on this slide, anaerobic digester has the highest rate.
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
43. ACTIVATED SLUDGE PROCESS
• The conventional activated sludge system contains;
• A tank for wastewater aeration - bioreactor/aeration tank
• A settling tank - clarifier
• Solid recycle line - Return Activated Sludge (RAS) line
• In an aeration tank, water is constantly aerated using bottom aeration systems and
mixed using large impeller systems in order to establish a uniform oxygen
concentration.
• Aeration should be maintained at 1-2 mg/L.
• Aeration above 2 mg/L is considered as a waste of energy.
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
44. ACTIVATED SLUDGE PROCESS CONT.
• Oxygen concentration
• Maximum concentration of oxygen in pure water is around 8 mg/L (20%). But as dissolved organic matter
content rises, maximum oxygen content that can be retained within water drops gradually. As activated
sludge system depends on aerobic decomposition, any lowering of oxygen below to the level required by
associated microbes is not favorable. Therefore, aeration is a must
• In the aeration tank, aerobic microbial decomposition of organic particles take place.
• Generally, the wastewater flows through under constant aeration in the presence of activated
sludge and exits at the end of the tank after 4-8 hours of residence/retention time.
• During the retention time; aerobic microbes aggregate together and form small particles known as
floc.
• These flocs carryout decomposition of organic matter.
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
45. MICROBIAL CONSORTIUM IN FLOCS
• Generally and essentially dominated by bacteria.
• But may also include protozoa, fungi, nematodes, rotifers etc.
• Dominant non-filamentous bacterial species include;
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
Zooglea spp. Achromobacter spp.
Pseudomonas spp. Corynebacterium spp.
Flavobacterium spp. Comamonas spp.
Alcaligenes spp. Brevibacterium spp.
Bacillus spp. Acenitobacter spp.
46. MICROBIAL CONSORTIUM IN FLOCS CONT.
• Dominant filamentous bacterial species include;
• Sphaeriolitus (sheathed bacteria)
• Beggiotoa
• Actinomycetes
• Norcardia spp.
• All these heterotrophic bacteria are primary consumers of organic matter present in
incoming wastewater.
• All other heterotrophs such as protozoa and fungi are secondary consumers.
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
47. FUNGI AS INDICATORS
• In activated sludge, fungal growth is not very common.
• Sludge system is not very favorable for them.
• Accidental fungal growth can occur due to;
• Low pH
• Toxic waste
• Nitrogen deficient waste etc.
• Hence, fungal growth in an activated sludge system is considered to be an indication of a system error.
• Predominant fungal species grow on activated sludge includes;
• Penicillium,
• Cephalosporium,
• Cladosporium,
• Alternaria and Geotrichum.
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
48. FLOC FORMATION AND IMPORTANCE
• Formation of flocs with correct structure is important for both;
• Biodegradation
• Sludge settling
• In the aeration tank, aerobic microbes feed on dissolved organics and convert them in to;
• Carbon dioxide
• Water and;
• Biomass
• These microbes then aggregate together in to structures called flocs.
• Flocs contain live and dead microorganisms and products of microbial metabolism.
• Correctly structured flocs are easily settled and hence, enable the separation of treated effluent
from sludge.
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
49. FLOC FORMATION CONT.
• Flocs with correct structure have two parts;
• Core
• Filamentous mesh
• Some non-filamentous bacteria (e.g. Zoogloea ramigera) which produce EPS are
responsible for forming the core structure.
• EPS will enable such bacteria to aggregate together forming a sticky center.
• The core will then get covered by several species of filamentous bacteria forming a
filamentous mesh around them.
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
50. FAVORABLE CONDITIONS
• Activated sludge process is more or less completely dependent upon correctly structured flocs.
• Formation of such flocs require;
• Presence of right microbes
• High oxygen concentration (for both formation & survival. Hence, continuous aeration is a must.)
• Good phosphorous content and C: N ratio.
• Correct pH (around 6.5-7.5)
• Apart from that, for proper biodegradation and sludge settlement sludge age is important.
• Eukaryotes such as protozoa feed on flocs and act as a biological control system.
• Bacteriophages are problematic as they attack floc formers destroying floc structures.
• Fungal growth is an indication of lowering of pH, presence of toxic waste or low nutrient waste.
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
51. MONITORING ACTIVATED SLUDGE
SYSTEMS
• Is a complex procedure. Includes several parameters that must be closely studied.
• Important to maintain the correct operation of the plant in order to achieve
objectives.
• Parameters include;
• Mixed Liquor Suspended Solids - MLSS
• Food-to-Microorganism ratio - F/M ratio
• Hydraulic Retention Time - HRT
• Sludge Volume Index - SVI
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
52. MIXED LIQUOR SUSPENDED SOLIDS
• Concentration of total suspended solids in the aeration tank.
• Includes all the suspended organic material and microbial biomass and minerals.
• Determined experimentally using gravimetric methods mainly which include
filtrations et. at a temperature of 105 Celsius.
• Units – mg/L
• The typical control band for the concentration of MLSS in wastewater is 2,000 to
4,000 mg/L for conventional activated sludge
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
53. WHAT IF..
MLSS is too high
• Process is prone to bulking and over
loading.
• DO will drop.
• Reduced nitrification efficiency and
sludge settleability.
• Requirement of excessive aeration.
• This will be a will be a waste of energy
MLSS is too low
• Process may not remove sufficient
amount of organic matter.
• The sludge age may be too low to
enable nitrification
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
54. FOOD-TO-MICROORGANISM RATIO
• An indication of the biomass available to consume the applied quantity of organic pollutant at any time.
• Helps to have a balance between substrate consumption and biomass generation to keep the system at an
equilibrium.
• Calculated using the equation;
𝑭
𝑴
𝒓𝒂𝒕𝒊𝒐 =
𝑸 × 𝑩𝑶𝑫 𝟓
𝑴𝑳𝑽𝑺𝑺 × 𝑽
Where;
Q - influent flow rate - m3 per day
BOD5 - five-day biological oxygen demand
MLSS - mixed liquor suspended solids - mg/L
V - volume of the biological reactor - m3
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
55. HYDRAULIC RETENTION TIME
• The average resident time of wastewater in the aeration tank.
• Average HRT usually ranges from 3 to 8 hours but can be higher with high BOD5 wastewaters.
• Calculated using the equation;
𝐻𝑅𝑇 =
1
𝐷
=
𝑉
𝑄
Where;
D - dilution factor
V - volume of the biological reactor
Q - flow rate of the wastewater influent
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
56. SLUDGE VOLUME INDEX
• The volume (in ml) occupied by 1 gram of activated sludge after settling the aerated liquor for 30
minutes.
• Used to describe the settling characteristics of sludge.
• Good settling sludge - SVI below 100 mg/L
• Poor settling sludge - SVI above 150 mg/L
• A process control parameter to determine the recycle rate of sludge.
• Equation;
𝑆𝑉𝐼 =
𝑉 × 1000
𝑀𝐿𝑆𝑆
• For a 1 liter of sludge, minimum of 1/3 of its volume must settle. If not, the system is not working
at all.
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)
57. SLUDGE SETTLING PROBLEMS
• Due to poor settling sludge formation;
• Suspended solids pass to the effluent in concentrations that often exceed regulatory standards.
• Desired SRT cannot be maintained.
• Effluent BOD limitations are often exceeded
• Such settling problems may be due to;
• Sludge bulking
• Rising sludge
• Foam formation etc.
10/20/2015H.G.D.A.P.JAYASINGHE. BSc. (undergraduate)