- Aerobic Bacteria. Aerobic bacteria are mostly used in new treatment plants in what is known as an aerated environment.
- Anaerobic Bacteria. Anaerobic bacteria are used in wastewater treatment on a normal basis. ...
- Facultative. Facultative microorganisms in sewage treatment are bacteria that can change between aerobic and anaerobic depending on the environment they are in. ...
What are the types of microorganisms used in wastewater treatment?
Common Microorganisms Used in Wastewater Treatment 1 Aerobic Bacteria. Aerobic bacteria are mostly used in new treatment plants in what is known as an aerated environment. 2 Anaerobic Bacteria. Anaerobic bacteria are used in wastewater treatment on a normal basis. ... 3 Facultative. ...
Are bacteria in wastewater treatment plants aerobic or anaerobic?
The nature of individual bacteria is dependent upon the environment in which they live. Usually, facultative bacteria will be anaerobic unless there is some type of mechanical or biochemical process used to add oxygen to the wastewater.
What is the role of bacteria in wastewater treatment?
This bacterium uses the free oxygen within the water to degrade the pollutants in the wastewater and then converts it into energy that it can use to grow and reproduce. For this type of bacteria to be used correctly, it must have oxygen added mechanically.
Which organisms will dominate in the future of wastewater treatment?
The organisms that will dominate will be the ones that are best suited to the environment.1 Microorganisms that are natural to the wastewater environment play a vital role in the wastewater treatment process. Beneficial bacteria, protozoa, metazoa, algae, and fungi feed on organic material in wastewater, breaking it down.
What types of bacteria are used in wastewater treatment?
Anaerobic bacteria are used in wastewater treatment on a normal basis. The main role of these bacteria in sewage treatment is to reduce the volume of sludge and produce methane gas from it.
How is bacteria used in sewage treatment?
When this methane gas is cleaned and handled properly it can and is commonly used as an alternative form of energy. Aerobic bacteria- Aerobic bacteria work by using the oxygen that is in the water to break down the pollutants as a food source.
What bacteria is in sewage water?
Pathogenic Bacteria Pathogens typically found in sewage include Salmonella, Shigella, E. coli, Streptococcus, Pseudomonas aeroginosa, mycobacterium and Giardia Lamblia, according to the Water Quality and Health Council website.
Which bacteria is used in STP?
Biological treatment of sewage treatment plant (STP) sludge by potential pure bacterial culture (Bacillus sp.) with optimum process conditions for effective biodegradation and bioseparation was carried out in the laboratory.
What is the role of bacteria in the treatment of wastewater Class 7?
It helps aerobic bacteria to grow which decompose organic matter like human waste. After several hours, the suspended microbes settle at the bottom of the tank as activated sludge. The water is then removed from the top. The dried activated sludge is used as manure.
Why are microorganisms used at a wastewater treatment plant?
Microorganisms are the workhorses of wastewater treatment systems and anaerobic digesters, where they are responsible for removal of pollutants and pathogens, recovery of nutrients and energy, and producing clean water.
Which bacteria is commonly found in anaerobic sludge during sewage treatment?
Correct answer is (a) MethanobacteriumAll India Exams.KVPY.
What is the role of bacteria in the water purification process?
Bacteria play an important role in water purification in drinking water treatment systems. On one hand, bacteria present in the untreated water may help in its purification through biodegradation of the contaminants. On the other hand, some bacteria may be human pathogens and pose a threat to consumers.
Which bacteria is used to treat sewage and refuse?
BioVolt uses strains of Geobacter and another microbe called Shewanella oneidensis to process the sludge. Its proprietary mix of organisms has one key advantage – the bacteria liberate some electrons as they respire, effectively turning the whole set-up into a battery.
What genus of bacteria is used for cleaning industrial organic waste?
Bacillus only blends are effective for municipal or industrial waste streams with minimal oil and grease. For waste streams with oil and/or grease applications (non-synthetic), blends with pseudomonas are preferred.
What are the roles of microorganisms in wastewater treatment?
The role of microorganisms in wastewater treatment helps to treat and purify wastewater and make it less harmful to the environment. While there are many different microbes used in sewage treatment, there are three well-known microbes that play an instrumental role in keeping sewage clean. Each of these types of bacteria help ...
Why are microorganisms important in wastewater treatment?
That’s because waste from humans and pets are a source of several types of waterborne diseases and bacterial contamination. Thanks in part to microorganisms, treating wastewater and sewage is possible.
What is aerobic bacteria?
Aerobic Bacteria. Aerobic bacteria are mostly used in new treatment plants in what is known as an aerated environment. This bacterium uses the free oxygen within the water to degrade the pollutants in the wastewater and then converts it into energy that it can use to grow and reproduce.
Why are aerobic bacteria used in sewage treatment?
The main role of these bacteria in sewage treatment is to reduce the volume of sludge and produce methane gas from it. The great thing about this type of bacteria and why it’s used more frequently than aerobic bacteria is that the methane gas, if cleaned and handled properly, can be used as an alternative energy source.
What is the purpose of wastewater treatment?
Many industrial and municipal wastewater treatment plants use bacteria and other microorganisms to help with the process of cleaning sewage. Picking the right bacteria can be tricky since your selection depends on the condition of your area for effective use. Wastewater treatment can also provide a great source for alternative energy if the anaerobic bacteria are handled correctly.
Do aerobic bacteria need oxygen?
Unlike aerobic bacteria, this type of bacteria is able to get more than enough oxygen from its food source and will not require adding oxygen to help do its job. Phosphorus removal from wastewater is another benefit of anaerobic microbes used in sewage treatment.
Is wastewater treatment an alternative source of energy?
Wastewater treatment can also provide a great source for alternative energy if the anaerobic bacteria are handled correctly. Learning the names of microbes used in sewage treatment and the role bacteria in sewage treatment plays doesn’t have to be a solo job.
What is the presence of bacteria and other microorganisms in wastewater?
The presence and activities of bacteria and other microorganisms indicates the condition of wastewater throughout the stages of treatment. Check in next week to learn about wastewater bioindicators.
What are the microorganisms that are natural to the wastewater environment?
Microorganisms that are natural to the wastewater environment play a vital role in the wastewater treatment process. Beneficial bacteria, protozoa, metazoa, algae, ...
How do bacteria break down organic material in wastewater?
Bacteria break down organic material in wastewater and form the floc that settles and separates solids from liquids. Controlling F/M ratio–a vital component to creating a favorable environment for wastewater bacteria–can be accomplished through the use of bioremediation products.
What are the phases of bacteria?
Five Phases of Bacteria Growth 1 During the lag phase, bacteria adapt to the environment, developing the required enzymes to digest nutrients. Bacteria break down nutrients with enzymes that only work in favorable conditions. Bacteria cannot survive if enzymes are not working properly. 2 Influent wastewater contains high levels of nutrients that bacteria use for growth and energy. Bacteria begin to grow and reproduce during the accelerated growth phase. Growing bacteria move about in search of nutrients, quickly multiplying. They do not settle to form floc. 3 During the declining growth phase, nutrient levels begin to drop and bacteria compete for nutrients. When food levels are low, bacteria slow down to conserve energy and do not grow or reproduce. Nutrients are used for energy and cell maintenance. 4 Bacteria levels remain constant during the stationary phase. They form a thick slime layer of waste products on the outside of the cell wall. This slime layer causes bacteria to clump together to form floc. 5 The number of bacteria reduces during the death phase. 1
How do aerobic bacteria use oxygen?
Aerobic bacteria use oxygen, which is added mechanically, to break down wastewater contaminants, converting it into energy. Bacteria use this energy to grow and reproduce. Anaerobic bacteria obtain oxygen from their food source. As anaerobic bacteria break down sludge, they produce methane gas.
How many phases of growth are there in aeration?
Five Phases of Bacteria Growth. The mixture of microorganisms and wastewater in the aeration tank is called “mixed liquor.”. Bacteria goes through 5 phases of growth in the mixed liquor. During the lag phase, bacteria adapt to the environment, developing the required enzymes to digest nutrients. Bacteria break down nutrients with enzymes ...
What is the name of the mass of bacteria that settles in wastewater?
Bacteria clump together, or floc, forming masses that settle and separate from wastewater liquids. This settled mass is called sludge. This week, we’re going to talk specifically about wastewater bacteria.
What are the different types of bacteria in sewage?
The qualitative analysis of sewage and sludge samples showed the presence of 12 bacterial species belonging to 5 genera: Actinomyces, Bifidobacterium, Clostridium, Propionibacteriumand Staphylococcus. In the sewage sludge, among isolated species, Clostridium perfringenswas identified. Qualitative analysis of bioaerosol showed the presence of 16 bacterial species belonging to 8 genera (Table 4). It was found that all 16 species were solely identified in the air at mechanical wastewater treatment workplaces (bar screens, containers with solids, primary settling tank). Taxonomical diversity within the abovementioned workplaces was significantly higher compared to background samples (χ2 = 11.8, p < 0.001), the biological treatment stage (χ2 = 5.1, p < 0.05), and the incineration of sewage sludge (χ2 = 6.6, p < 0.05). However, no differences in qualitative composition of bacterial biota were found between sewage and sludge and the air at the workplaces (χ2 = 0.96, p > 0.05). Qualitative analysis of air samples also showed that some of the identified species, such as Actinomyces meyeri, Bifidobacteriumspp., Clostridium perfringensor Peptostreptococcusspp., occurred across the whole treatment plant. In turn, the species of the genera Propionibacterium, Bacterioidesor Fusobacteriumwere characteristic for the primary treatment stages only.
What bacteria are in sewage?
Anaerobic bacteria were widely present both in the sewage and in the air at workplaces from the WWTP, especially when the technological process was performed in closed spaces. Anaerobic bacteria formed small aggregates with both wastewater droplets and dust particles of sewage sludge origin and as such may be responsible for adverse health outcomes in exposed workers.
What is the average concentration of anaerobic bacteria in sewage samples?
The average concentration of anaerobic bacteria in the sewage samples was 5.49 × 104CFU/mL (GSD = 85.4) and in sludge—1.42 × 106CFU/g (GSD = 5.1). In turn, the average airborne bacterial concentration was at the level of 50 CFU/m3(GSD = 5.83) and the highest bacterial contamination (4.06 × 103 CFU/m3) was found in winter at the bar screens. In total, 16 bacterial species were determined, from which the predominant strains belonged to Actinomyces, Bifidobacterium, Clostridium, Propionibacteriumand Peptostreptococcusgenera. The analysis revealed that mechanical treatment processes were responsible for a substantial emission of anaerobic bacteria into the air. In both the sewage and air samples, Clostridium perfringenspathogen was identified.
How many sampling points were used for sewage?
Samples of both sewage and sludge were collected at six sampling points and bioaerosol samples were additionally collected (with the use of a 6-stage Andersen impactor) at ten workplaces covering different stages of the technological process. Qualitative identification of all isolated strains was performed using the biochemical API 20A test. Additionally, the determination of Clostridiumpathogens was carried out using 16S rRNA gene sequence analysis.
Is water contaminated with bacteria?
Wastewater is always contaminated with different biological agents such as bacteria, viruses, protozoa, fungi, flatworms or roundworms (Sorber and Sagik 1980). Among them, pathogenic bacteria pose the most serious epidemiological risk. Wastewater can carry many opportunistic pathogens (e.g., Enterobacter cloacae, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Proteus vulgarisor Pseudomonas aeruginosa), which can cause different systemic infections, especially among people with a weakened immune system. In wastewater can be also found obligate pathogens from Salmonellaand Shigellagenera or enteropathogenic strains of Escherichia coli, which are responsible for salomonellosis, shigellosis or gastroenteritis, respectively (Cyprowski et al. 2005; Gerardi and Zimmerman 2005).
Which organisms have the most sentient wastewater?
Metazoa (animals) are in my opinion the most sentient wastewater organisms per unit of metabolism, but this is debatable, and I'm uncertain how I feel about the sentience of protozoa. Metazoa, unlike protozoa, have nervous systems.
What is the source of food for microorganisms?
One source of food for microorganisms is human wastewater, which contains, inter alia, excrement and, in some cases, ground-up food scraps. There are many types of wastewater-treatment systems, and I'll only discuss a few common ones here.
Why is incineration the best way to reduce bacteria?
Insofar as we also want to reduce bacteria populations in addition to invertebrate-animal populations, incineration seems best because it releases the energy the sludge contains in a non-sentient way, while digesting or composting sludge creates large numbers of bacteria. A downside of incineration is that, if sludge contains invertebrates (does it?), incinerating to death may be painful for those animals. The idea that heating to death may be painful for nematodes is not purely speculation, since "upon exposure to noxious temperature, Caenorhabditis elegans reacts by a withdrawal reflex. [...] the nociceptive response of C. elegans to heat resembles, in several aspects, that of higher organisms" ( Wittenburg and Baumeister 1999 ).
How much land use is 100 kg of food waste?
Diggelman and Ham (2003) report (Table 2, p. 505, "POTW" column) that disposing of 100 kg of wet food waste down the drain is responsible for 2.4 * 10 -4 m 2 of land use due to wastewater infrastructure. e I'm not sure if vegetation is prevented on all of this land area, since wastewater-treatment plants can have grass between the different buildings, but let's conservatively assume that vegetation is prevented on this entire land area. Since a wastewater-treatment plant is designed to last 30 years (p. 507), this is actually (2.4 * 10 -4 m 2) * (30 years) = 7 * 10 -3 m 2 -years of land use, which I'll round to 10 -2 for convenience.
What is activated sludge?
The activated-sludge process is a common type of large-scale secondary wastewater treatment.
How many micrometers are a rotifer?
To see this, consider that bacteria are typically 0.5 to 5 micrometers, while rotifers are typically 0.1 to 0.5 millimeters. Even if we conservatively assume a bacterium is 5 micrometers and a rotifer is 0.1 millimeter = 100 micrometers, that implies a difference in volume and mass of roughly (100/5) 3 = ~10 4.
What is the purpose of a biofilm filter?
Biofilms of bacteria, protozoa and fungi form on the media’s surfaces and eat or otherwise reduce the organic content. The filter removes a small percentage of the suspended organic matter, while the majority of the organic matter supports microorganism reproduction and cell growth from the biological oxidation and nitrification taking place in the filter. With this aerobic oxidation and nitrification, the organic solids are converted into biofilm grazed by insect larvae, snails, and worms which help maintain an optimal thickness.
What is the nature of bacteria in wastewater treatment?
Most of the bacteria that absorb the organic material in a wastewater treatment system are facultative in nature. This means they are adaptable to survive and multiply in either anaerobic or aerobic conditions. The nature of individual bacteria is dependent upon the environment in which they live. Usually, facultative bacteria will be anaerobic ...
What are the two organisms that are involved in wastewater treatment?
These single-celled animals perform three significant roles in the activated sludge process. These include floc formation, cropping of bacteria and the removal of suspended material. Protozoans are also indicators of biomass health and effluent quality. Because protozoans are much larger in size than individual bacteria, identification and characterization is readily performed. Metazoans are very similar to protozoans except that they are usually multi-celled animals. Macroinvertebrates such as nematodes and rotifers are typically found only in a well developed biomass. The presence of protozoans and metazoans and the relative abundance of certain species can be a predictor of operational changes within a treatment plant. In this way, an operator is able to make adjustments and minimize negative operational effects simply by observing changes in the protozoan and metazoan population.
How do anaerobic bacteria live?
Anaerobic bacteria live and reproduce in the absence of free oxygen. They utilize compounds such as sulfates and nitrates for energy and their metabolism is substantially reduced. In order to remove a given amount of organic material in an anaerobic treatment system, the organic material must be exposed to a significantly higher quantity of bacteria and/or detained for a much longer period of time. A typical use for anaerobic bacteria would be in a septic tank. The slower metabolism of the anaerobic bacteria dictates that the wastewater be held several days in order to achieve even a nominal 50% reduction in organic material. That is why septic tanks are always followed by some type of effluent treatment and disposal process. The advantage of using the anaerobic process is that electromechanical equipment is not required. Anaerobic bacteria release hydrogen sulfide as well as methane gas, both of which can create hazardous conditions. Even as the anaerobic action begins in the collection lines of a sewer system, deadly hydrogen sulfide or explosive methane gas can accumulate and be life threatening.
Why do filamentous organisms need to be in low concentrations?
When filamentous organisms are in low concentrations in the process, they serve to strengthen the floc particles. This effect reduces the amount of shearing in the mechanical action of the aeration tank and allows the floc particles to increase in size. Larger floc particles are more readily settled in a clarifier.
Why is wastewater held for days?
The slower metabolism of the anaerobic bacteria dictates that the wastewater be held several days in order to achieve even a nominal 50% reduction in organic material. That is why septic tanks are always followed by some type of effluent treatment and disposal process. The advantage of using the anaerobic process is that electromechanical equipment ...
What are the by-products of aerobic bacteria?
The by-products of aerobic bacteria are carbon dioxide and water. Aerobic bacteria live in colonial structures called floc and are kept in suspension by the mechanical action used to introduce oxygen into the wastewater. This mechanical action exposes the floc to the organic material while treatment takes place.
What is the primary reduction of organic material within a wastewater treatment plant?
The primary reduction of organic material within a wastewater treatment plant is performed by a number of different types of microorganisms. Most of the organisms can be categorized as either bacteria, protozoans or metazoans. These organisms are present in the air, the soil and most, if not all, warm blooded animals, including man.
What is biological waste treatment?
Biological waste treatment processes the process by which any waste treated biologically includes micro-organism for final discharge within the permissible limit specified by World Health Organisation (WHO).
Which group of bacteria is responsible for hydrolytic degradation of macromolecules in to soluble products such as sugars,?
These bacteria belong to genera – Actinonyces, Aerobactorbacter, Escherichia, Klebsiell, Lactobacillus, Pseudomonos, Streptococcus, Streptomyces, etc.
Why are methanogenic bacteria important in anaerobic digestion?
The methanogenic bacteria perform an important role in anaerobic digestion because their unique metabolism controls the rate of organic degradation. They also direct the flow of carbon and electrons, by removing toxic intermediary metabolites, and by enhancing thermodynamic efficiency of interspecies metabolism.
Why is reuse of wastewater important?
Thus, the reuse of wastewater has become an attractive option for increasing water resources . Effluents from biological wastewater treatment plants may lack the characteristics required for direct reuse.
What is the purpose of biological treatment systems?
To accelerate the forces of nature under controlled conditions in such facilities of comparatively small size that was the purpose of treatment of such waste. There is a wide range of biological treatment systems in use presently for the purification of liquid effluents based on the apparently simple processes by which mixed populations of micro-organisms degrade organic material, using it as a source of nutrients.
What is aerobic treatment?
Aerobic treatment may follow some form of pretreatment such as oil removal, involves contacting wastewater with microbes and oxygen in a reactor to optimise the growth and efficiency of the biomass.
How many cells are in a microorganism?
Bacteria are the most common type of micro-organisms and their number may be more than 10 12 cell/ml. They are responsible for the removal of about 85-90% of the BOD remaining after primary treatment of liquid waste.
Aerobic, Anaerobic and Facultative Bacteria
Food-To-Microorganism Ratio
- The amount of food available to microorganisms is calculated by the food-to-microorganism (F/M) ratio. The F/M ratio is the measurement of incoming food divided by the microorganisms (in lbs.) in the system. This is determined by dividing results of the BOD/COD testby the mixed liquor volatile suspended solids (MLVSS). If the mixed liquor is not held long enough for nutrient level…
Bioremediation
- The F/M ratio can be adjusted with bioremediation, which is a process of treating wastewater to encourage the growth of existing microorganisms. With biostimulation, supplemental nutrients, vitamins, minerals, organic acids, and pH buffers are introduced into wastewater to create a hospitable environment that stimulates naturally occurring microorganisms. Bioaugmentation, t…
Conclusion
- Bacteria break down organic material in wastewater and form the floc that settles and separates solids from liquids. Controlling F/M ratio–a vital component to creating a favorable environment for wastewater bacteria–can be accomplished through the use of bioremediation products. The presence and activities of bacteria and other microorganisms indicates the condition of wastew…
Citations
- T Glymph (2005). Wastewater Microbiology: A Handbook for Operators, https://www.iowaruralwater.org/tools_tips/toni_glymp/Bacteria-Protozoa.pdf
- Kentucky Department for Environmental Protection (2012). Types of Bacteria Used in Wastewater Treatment, https://kyocp.wordpress.com/2012/06/14/types-of-bacteria-used-in-wastewater-treatment/
- T Glymph (2005). Wastewater Microbiology: A Handbook for Operators, https://www.iowaruralwater.org/tools_tips/toni_glymp/Bacteria-Protozoa.pdf
- Kentucky Department for Environmental Protection (2012). Types of Bacteria Used in Wastewater Treatment, https://kyocp.wordpress.com/2012/06/14/types-of-bacteria-used-in-wastewater-treatment/
- R Fuller (2017). Food-to-Mass (F:M) Ratio, The Wastewater Blog, https://www.thewastewaterblog.com/single-post/2016/12/19/Food-to-Mass-Ratio
- LM Coelho, HC Rezende, LM Coelho, PAR de Sousa, DFO Melo, and NMM Coelho (2015). Bioremediation of Polluted Waters Using Microorganisms, https://www.intechopen.com/books/advances-in-bioremediation-...
Summary
Introduction
Septic System
Activated Sludge
Attached-Growth Systems
Vermifilters
- Possibly the worst form of waste treatment I've seen from the perspective of invertebrate suffering is vermifilters, which use bacteria and earthworms to decompose organic matter from wastewater. Wikipedia ("Vermifilter")reports: "Vermifilters are most commonly used for sewage treatment (either at a centralized level or in an on-site sewage treatme...
Lagoons
Stabilization Ponds
Other Information
Eutrophication