The role of microorganisms in wastewater
Wastewater
Wastewater, also written as waste water, is any water that has been adversely affected in quality by anthropogenic influence. Wastewater can originate from a combination of domestic, industrial, commercial or agricultural activities, surface runoff or stormwater, and from sewer inf…
What is the role of microbes in sewage treatment?
Microbes in Sewage Treatment: Indeed, microbes cause numerous diseases to animals and even plants but these tiny creatures are a lot more important to us in several ways. One such important use is in sewage treatment. Microbes play an important role in sewage treatment.
Why are microorganisms used in sewage treatment considered heterotrophic?
The microorganisms used in such a process are heterotrophic in nature; that means they do not synthesize their own organic materials and thus consume the organic constituents of sewage. You might think we could treat the wastewater with the utilization of chemicals.
What is the importance of microorganisms in waste management?
Yet, they are critical to how our modern societies deal with and dispose of unwanted waste from municipalities, agriculture and industry. These microorganisms, composed primarily of naturally occurring bacteria, play a vital role in breaking down organic matter, thereby reducing the presence of unwanted oils, sludge, and noxious smells.
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. ...
What is a sewage treatment plant and how does it work?
A semi-solid waste or slurry byproduct of sewage treatment is called sewage sludge. Different processes like physical, chemical and biological meth...
What are the main steps in sewage treatment?
a. Primary treatment or Physical process b. Secondary treatment or Biological process
What is the major function of Microbes in Sewage Treatment?
Sewage is treated in sewage treatment plants (STPs) by the heterotrophic microbes present in the sewage before being disposed of in water bodies. M...
Explain types of microbes used in sewage treatment?
Aerobic Bacteria: These bacteria degrade the contaminants in the wastewater using free oxygen in the water, then turn into the energy that can be u...
Why is sewage treatment important?
Sewage treatment helps in reducing the rate of harmful contaminants that cause pollution of water and soil. Wastewater that is treated in these STP...
What is sewage treatment?
Sewage treatment is a process in which the pollutants are removed. The ultimate goal of sewage treatment is to produce an effluent that will not impact the environment [1] . In the absence of sewage treatment, the results can be devastating as sewage can disrupt the environment. The general processes of sewage treatment are primary, ...
Why is the environment of sewage treatment plant controlled?
The environment of the sewage treatment plant has to be controlled precisely because bacteria are sensitive to the oxygen level, pH level, temperature, and level of nutrient. In order for efficient degradation of biological matter to occur, these factors are controlled manually.
Why is oxygen important?
Oxygen level. Oxygen level is an important factor to secondary and tertiary treatment processes. Secondary treatment, oxygen is required as a terminal electron acceptor in organic matter degradation. For example, nitrification by Nitrosomonas and Nitrobacter species requires dissolved oxygen to occur [4].
What are the two processes that occur after primary treatment?
The liquid phase is treated with aeration to allow aerobic degradation of the nutrients. The two important microbial processes at this stage are nitrification and phosphorous removal. Nitrification occurs in two discrete steps.
Why do bacteria have higher enzymatic activity at higher temperatures?
However, bacteria are known to have higher enzymatic activity at higher temperature because of increased thermal energy. For example, when thermophilic sludge treatment is compared to mesophilic treatment, the sludge biodegradability is higher with thermophilic degradation [9].
How is oxygen provided in secondary treatment?
Oxygen in secondary treatment is provided manually by pumping oxygen into the sewage continuously which occurs in an aeration tank [5]. In tertiary treatment, the removal of excess organic matter is enhanced by settling the sewage in a lagoon. This process is also aerobic, but it depends on the diffusion of oxygen because most organic matter has ...
How is sewage transferred to secondary treatment?
The liquid sewage is then transferred to secondary treatment which focuses on removing the dissolved biological compound by the use of micro-organisms. The micro-organisms usually use aerobic metabolism to degrade the biological matter in the liquid sludge. Then tertiary treatment is required to disinfect the sewage so that it can be released ...
How does sewage treatment help the environment?
Wastewater that is treated in these STPs can be reused for several purposes. Thus, sewage treatment helps in conservation of water as well as the environment.
How is sewage treated?
Sewage sludge is treated in a separate process called sludge digestion.
What is the name of the tank that sludge is pumped back into?
The remaining part of the sludge is pumped back into large tanks called anaerobic sludge digesters. Here, other anaerobic bacteria like methanogens are also present. Along with organic mass, these microbes also digest aerobic microbes (bacteria and fungi) of the sludge.
What are the most common forms of anaerobic bacteria?
Most common anaerobic forms belong to Actinomyces, Bifidobacterium, Clostridium, Propionibacterium and Peptostreptococcus genera. Facultative Bacteria: In sewage treatment, facultative microorganisms are bacteria that can switch between aerobic and anaerobic states depending on their surroundings.
What are the different types of bacteria in wastewater treatment?
Which Microbes are Used in Sewage Treatment? 1 Aerobic Bacteria: Aerobic bacteria are most commonly used in aerated environments in modern treatment plants. These bacteria degrade the contaminants in the wastewater using free oxygen in the water, then turn into the energy that can be used to grow and reproduce. This helps the bacteria to complete their tasks, continue to grow and reproduce. 2 Anaerobic Bacteria: Anaerobic microorganisms are commonly employed in wastewater treatment. Primary function of these bacterias in sewage treatment is to reduce sludge volume and create methane gas from it. This gas can be used as an alternative energy source when properly cleaned and managed. This type of bacterias can utilize enough oxygen from its food supply and does not require additional supply of oxygen. Another advantage of anaerobic microorganisms in sewage treatment is that they remove phosphorus from wastewater. Most common anaerobic forms belong to Actinomyces, Bifidobacterium, Clostridium, Propionibacterium and Peptostreptococcus genera. 3 Facultative Bacteria: In sewage treatment, facultative microorganisms are bacteria that can switch between aerobic and anaerobic states depending on their surroundings. These bacteria like to reside in an aerobic environment.
Why is sewage mixed with air?
The sewage is often mixed with air to facilitate decomposition as oxygen is critical for the growth of bacteria. This air helps in the growth of useful aerobic microbes into flocs (masses of bacteria associated with fungal filament to form mesh-like structures).
What is sewage water?
Sewage refers to the municipal wastewater that is generated in cities and towns on daily basis. Researchers estimate the indicator species, such as coliform bacteria or Pseudomonas aeruginosa in the sewage water.
Why are microbes important in sewage treatment?
In today’s world, microbes became essential for any kind of industrial process, and thus, various techniques are discovered where microorganisms are utilized for solving multiple problems. In that way, the role of microbes in sewage treatment is critical.
What is the purpose of sewage treatment?
Purpose of Sewage Treatment 1 To remove pollutants 2 Destruction of the deadly pathogens 3 To counterbalance coarse particles. 4 Elimination of poisonous substances
What is the most exciting part of sewage treatment?
However, the most exciting part of sewage treatment is that those microbes we need to eradicate ...
What is secondary treatment?
Secondary Treatment. So after the preliminary and primary wastewater treatment , let’s move to the actual point that is secondary treatment. Secondary sewage treatment is otherwise known as the biological process as microorganisms are utilized to treat the sewage.
How many steps are there in sewage treatment?
And the large-scale treatment involves lots of other physical, chemical, and biological processes. Besides these two parts, the entire sewage treatment process comprises four significant steps and various sub-steps. These four steps are: Also Check: Ways to prevent ocean acidification.
What are the three types of microbes?
Generally, three types of microbes, bacteria, fungi, and protozoa, are utilized for different functions. Bacteria decompose the sewage and convert them into settleable solids; fungi can degrade some constituents that cannot decompose by bacteria, and protozoa are the predators that help control the bacterial population.
What is tertiary wastewater treatment?
Tertiary wastewater treatment. Tertiary or the final step is concerned with subtracting non-biodegradable organic materials, heavy metals, and minerals. After processing in the secondary treatment plant, the effluent undergoes into the tertiary wastewater treatment, where mostly chemicals are used.
Why is wastewater treatment important?
Wastewater treatment is as essential to human health as it is to the protection of the environment. The use of these bacteria accelerates the process of treating pollution on a small surface: the wastewater treatment plant.
What is biological wastewater treatment?
Biological wastewater treatment is the most common sanitation method in the world. This technology uses different types of bacteria and other microorganisms for the treatment and purification of polluted water. Wastewater treatment is as essential to human health as it is to the protection of the environment.
How does floc work?
The technique consists in recirculating a well-adapted combination of substrate and selected bacteria so that they settle very quickly. Under these favorable conditions, bacteria develop flocs or biofilms very quickly. Under these favorable conditions, bacteria develop flocs or biofilms very quickly.
How long does it take for bacteria to colonize the environment?
The colonization of an environment by the needed bacteria and microorganisms necessary for the purification generally lasts between 4 and 8 weeks. Once again, it is the temperature that has the most influence on this growth time.
What is lipophilic bacteria?
Lipophilic bacteria are specialized in the decomposition of animal and vegetable fats and oils in urban WWTPs and industrial treatment plants. These bacteria are easily adaptable to all current treatment systems.
How to solve the presence of undesirable bacteria?
First, the solution consists of extracting as much sludge as possible and increasing aeration. The good bacteria can take several days to recover the environment.
What are the parameters that influence a plant's growth?
First, before we know who they are, we need to understand the parameters that influence their growth. Firstly, geographical location. Secondly, the type of pond in which bacteria will be grown. Thirdly, the characteristics of the wastewater entering the plant.
Introduction
Physical Environment
- The environment of the sewage treatment plant has to be controlled precisely because bacteria are sensitive to the oxygen level, pH level, temperature, and level of nutrient. In order for efficient degradation of biological matter to occur, these factors are controlled manually.
Microbial Processes
- There are several microbial processes, and the microbial processes can be catergorized into aerobic and anaerobic.
Current Research
- A research has shown the correlation between nutrient removal efficiency, light wavelength and light intensity. Xu et al. discovered that red and high intensity light maximizes the nutrient removal efficiency . Also, the use of pre-treated sludge is found to generate electricity in a microbial fuel cell . This can potentially lead to production of renewable energy.
References
- (1) Zhao, H., Duan, X., Stewart, B., You, B., Jiang, X., “Spatial correlations between urbanization and river water pollution in the heavily polluted area of Taihu Lake Basin, China.” Journal of Geographical Sciences, 2013, 23(4):735-752.(2) Canler, J.P., Perret, J. M., “Biological aerated filters: assessment of the process based on 12 sewage treatment plants.” Water Science and Te…