What is the role of biological treatment in water treatment?
Biological treatment has played an important role historically in drinking-water preparation in processes such as slow sand filtration, bank filtration, and underground passage.
What are the different types of biological wastewater treatment?
Typically broken out into three main categories, biological wastewater treatment can be: aerobic, when microorganisms require oxygen to break down organic matter to carbon dioxide and microbial biomass anaerobic, when microorganisms do not require oxygen to break down organic matter, often forming methane, carbon dioxide, and excess biomass
What are the processes used for water treatment?
The processes employed for water treatment depend on the quality of the water supply. In all cases, water has to be disinfected in order to deactivate any existing microorganisms present in water. So far, this technique was proved to be the most important for the protection of human life.
What is the difference between mechanical and biological water treatment?
Mechanical treatment allows removing insoluble coarse particle from the water. Biological water treatment is used for the degradation of nonrefractory organic compounds and some inorganic salts.
What is the biological treatment of water?
The principle of biological water treatment methods is on the degradation of organic compounds present in the effluent by microorganisms (aerobic and/or anaerobic). On one hand, to develop them, they will consume the dissolved organic pollution.
Which treatment is biological treatment?
Biological treatments include two main technologies: bioremediation and phytoremediation. Bioremediation exploits the ability of microorganisms to degrade and detoxify organic contaminants. Two general approaches are commonly used: biostimulation and bioaugmentation.
What are biological methods of wastewater treatment?
The presented biological wastewater treatment processes include: (1) bioremediation of wastewater that includes aerobic treatment (oxidation ponds, aeration lagoons, aerobic bioreactors, activated sludge, percolating or trickling filters, biological filters, rotating biological contactors, biological removal of ...
What is a secondary or biological treatment?
Secondary treatment removes the dissolved organic matter by the use of biological agents and hence, known as biological treatment. This is achieved by microbes which can consume and degrade the organic matter converting it to carbon dioxide, water, and energy for their own growth and reproduction.
Current Methods for the Remediation of Acid Mine Drainage Including Continuous Removal of Metals From Wastewater and Mine Dump
Opeyemi A. Oyewo, ... Mokgadi F. Bobape, in Bio-Geotechnologies for Mine Site Rehabilitation, 2018
Aquatic Chemistry and Biology
Biological treatment has played an important role historically in drinking-water preparation in processes such as slow sand filtration, bank filtration, and underground passage.
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New directions and challenges in engineering biologically-enhanced biochar for biological water treatment
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Review on discharge Plasma for water treatment: mechanism, reactor geometries, active species and combined processes
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What is biological water treatment?
Biological water treatment processes rely partially or entirely on biological mechanisms to achieve treatment objectives. These processes broadly include natural (e.g., riverbank and aquifer filtration) and engineered (e.g., fluidized bed as well as slow sand and rapid-rate filtration) processes. In drinking water treatment, ‘biofiltration’ processes in North America typically involve rapid-rate, granular media filters that are similar in design to conventional, physico-chemical filtration processes [1–3 ], whereas slow sand filters see continued use internationally. Biofilters differ from conventional filters through key operational practices that promote and maintain biological activity on the filter media, which enhances the transformation of organic and inorganic constituents before treated water is introduced into the distribution system (American Water Works Association Biological Drinking Water Treatment Committee, J. Carter, personal communication). In this Current Opinion, we draw heavily on the literature from the past three years to review advancements in the science and practice of drinking water biofiltration as well as to discuss the potential role of modern biotechnological tools to further this advancement.
What are biofilms used for?
Apart from the negative effects of biofouling in filtration, biofilms are used in biological water treatment, e.g. removal of carbon and nitrogen compounds in municipal and industrial wastewater treatment [194]. Increasingly, biofilms are discussed as dedicated reactors of basic chemicals. The biomass can be organized as biofilms, granules or sludge flocks in the diverse reactor designs. The strong correlation between biomass structures and water diffusion was discussed in Sections 3.1 and 3.2. For the technical applications, those findings are of high relevance. Most technically used biomass is characterized by physico-chemical parameters, such as TSS (total suspended solids), VSS (volatile suspended solids), and biomass density or settling ability. However, these parameters do not sufficiently or comprehensively describe the biomass to estimate mass transport as shown for example in Ref. [69]. By using the already mentioned NMR methods, it was shown that the physico-chemical parameters for completely different biomass systems (e.g. carrier-based biofilms and sludge flocks) differ, but their water diffusion properties can be very similar. The knowledge gained by the diverse NMR modalities helps to better understand the performance of the biological systems and gives indications for process improvements regarding biofilm thickness control or mixing. One example for a bioreactor is the concept of a moving bed biofilm reactor (MBBR) where carrier-based biofilms are continuously circulated by mechanical or hydrodynamic mixing to ensure sufficient mass transport of substrates to the biofilm surface [13,14,195,196]. An equally distributed thickness of the biofilm is favoured by shear forces and turbulence in the MBBR [197]. Uncertainties in hydrodynamics in the reactor regarding the mass transport of solutes from bulk to biofilm and reactor design have been reported [198]. MR flow velocity maps in real biofilm carriers revealed that the biofilm thickness and coverage on the carrier material are critical for the local flow regimes: some regions might be blocked by biofilm and therefore the transport of solutes is limited [47,199]. Stagnating conditions have been observed which might lead to a decreased overall performance of the biological water treatment system. By NMR methods, process parameters influencing the biofilm structure can be studied to give indications for improvement of the engineered biofilm system.
What is the sonochemical process?
In addition to the chemical synthesis processes, the sonochemical method has a wide application area in the conversion of biomass to biofuels. Sonochemical processes in biofuel and related fields are numerous. These processes include pretreatment of lignocellulosic structures, sonochemistry of carbohydrates, natural product extraction, fermentation, organic waste pretreatment, biological water treatment, and biotechnology/bioengineering [37–39]. In these mentioned applications with ultrasonic support, the future advantages of the ultrasonic reaction mechanism, ultrasonic condensation, and ultrasonic pretreatment applications need to be evaluated very well. In the studies examined to date, the effects of lignocellulosic structures, microwaves, and biodiesel on sonochemical pretreatment applications and biomass conversion rates have been studied and explained. The conversion of biomass into biofuel contains some difficulties to be overcome. In order to overcome these difficulties, the structures in the structure of the biomass should be illuminated. Raw biomass contains various structures containing lignin, cellulose, hemicellulose, free sugar, beeswax, proteins, trace organic-inorganic, and alkaloids, such as a large number of complex structures. Almost the whole of these structures in biomass are indefinite chemical structures. Cellulosic structures in biomass have a continuous repetitive structure, and lignin complex has a reticular connection structure [9]. The degradation of the lignin-carbohydrate structure in the raw biomass requires a high temperature-pressure environment, namely, harsh conditions. The selection of the appropriate solvent for the degradation of the structures in this biomass is one of the issues that should be considered carefully in biomass conversion. Ultrasonic energy can be an appropriate tool for overcoming these troublesome problems, because it provides suitable physicochemical conditions in the processing of complex structures in biomass. Compared to thermochemical methods with the introduction of high-intensity ultrasonic energy into the biomass, the conversion of biomass under lower valence conditions leads to degradation and high-efficiency catalytic reactions. With the applied ultrasonic energy, heat and mass transfer in the reactions take place at high intensity. The intermediate causes the contact of reagents and products to increase, and the reaction kinetics accelerate [9].
Can antibiotics be metabolized?
The extent to which antibiotics can be metabolised by human beings and animals is variable. Depending on the quantities of antibiotics used and their rates of excretion, antibiotics can be released into effluents and can reach sewage treatment plants [1–3]. Data available on antibiotics (from the ampicillin, erythromycin, tetracycline and penicilloyl groups) indicate their capability to exert toxic effects on living organisms, such as bacteria and algae, even at very low concentrations. These antibiotics are practically non-biodegradable and have the potential to survive sewage treatment, which leads to the persistence of these compounds in the environment and the potential for bio-accumulation [4]. The presence of antibiotics in the environment has favoured the emergence of antibiotic-resistant bacteria, increasing the possibility of infections, as well as the need to find new and more powerful antibiotics. As expected, antibiotic-contaminated water is incompatible with conventional biological water treatment technologies [5].
How does biological wastewater treatment work?
Biological wastewater treatment is designed to degrade pollutants dissolved in effluents by the action of microorganisms. The microorganisms utilize these substances to live and reproduce. Pollutants are used as nutrients. A prerequisite for such degradation activity, however, is that the pollutants are soluble in water and nontoxic. Degradation process can take place either in the presence of oxygen (aerobic treatment) or in the absence of oxygen (anaerobic treatment). Both these naturally occurring principles of effluent treatment give rise to fundamental differences in the technical and economic processes involved (Table 2 ).
What is biological method?
Biological method requires large land area, diurnal, and greater time for their functioning. (d) The process provides little flexibility in design and operation. Numerous studies depict the use of micro-organisms and leads to the removal of dye via a biosorption process.
What is phytoremediation in wastewater treatment?
Phytoremediation method: This is another biological method for wastewater treatment. The combination of two Latin words―plant and remedy―gave rise to the term phytoremediation. The plant, plant origin microbes, or associated microbiota are used to take up the contamination from soil or water.
Why do aerobic microorganisms need oxygen?
Aerobic microorganisms require oxygen to support their metabolic activity. In effluent treatment, oxygen is supplied to the effluent in the form of air by special aeration equipment. Bacteria use dissolved oxygen to convert organic components into carbon dioxide and biomass.
How is phytoremediation achieved?
The remediation is achieved either by retaining, elimination, or degradation in a natural way as it happens in an ecosystem. Phytoremediation is a cheaper, eco-friendly, and feasibly sustainable method for removal of dye pollutants. Moreover, the process requires little nutrient cost and also has aesthetic demand.
How is oxygen supplied to wastewater?
In conventional aerobic biological wastewater treatment processes, oxygen is usually supplied as atmospheric air, either via immersed air-bubble diffusers or surface aeration. Diffused air bubbles (via fine-bubble aeration) are added to the bulk liquid (as in an ASP, biological aerated filters (BAFs), fluidised bioreactors, etc.), or oxygen transfer occurs from the surrounding air to the bulk liquid via a liquid/air interface (as for a TF or rotating biological contactor (RBC)).
How does biogas replace fossil fuels?
In its function as a regenerative energy carrier, biogas replaces fossil fuels in the generation of process steam, heat, and electricity. The composition and quality of biogas depend on both effluent properties and process conditions such as temperature, retention time, and volume load.
What is biological treatment of drinking water?
Biological Treatments of Drinking Water. Systems that use bacteria to treat drinking water have been shown to be highly efficient and environmentally sustainable. Microbial biomass has been used since the early 1900s to degrade contaminants, nutrients, and organics in wastewater.
What is biological treatment?
Numerous forms and configurations of biological treatment processes are used to degrade contaminants in drinking water. Most are operated as fixed biofilm systems, meaning that the process includes a biogrowth support medium on which bacterial communities attach and grow (e.g., granular media).
What is a fluidized bed reactor?
Fluidized-bed reactors (FBRs) also use granular media to support biogrowth. Contaminated water is pumped up-flow through the reactor at a high rate to fluidize the granular media bed and reduce resistance to flow.
What is the purpose of a reactor basin?
The reactor basin provides the detention time necessary to achieve effective biological treatment. Treated water is drawn through the membranes by vacuum and pumped out to permeate pumps for further processing. Airflow introduced at the bottom of the reactor basin performs several functions.
How long has bank filtration been used?
Bank filtration, which has been used for more than 130 years in Europe, has aroused a great deal of global interest for use in reducing organic and particulate loads to drinking water treatment plants.
How do membranes help water?
Membranes can also be coupled with biological systems to improve the treatment of drinking water. In one approach, ultrafiltration membranes are submerged in a reactor basin that contains suspended biomass. The reactor basin provides the detention time necessary to achieve effective biological treatment.
Is biological water treatment harmful?
Consequently, well designed biological treatment systems pose no significant, inherent threats to the health or safety of distributed water.
What are the different types of wastewater treatment?
Typically broken out into three main categories, biological wastewater treatment can be: 1 aerobic, when microorganisms require oxygen to break down organic matter to carbon dioxide and microbial biomass 2 anaerobic, when microorganisms do not require oxygen to break down organic matter, often forming methane, carbon dioxide, and excess biomass 3 anoxic, when microorganisms use other molecules than oxygen for growth, such as for the removal of sulfate, nitrate, nitrite, selenate, and selenite
What is a fixed bed wastewater system?
A well-engineered fixed-bed will allow wastewater to flow through the system without channeling or plugging. Chambers can be aerobic and still have anoxic zones to achieve aerobic carbonaceous removal and full anoxic denitrification at the same time.
How are suspended flocs removed from wastewater?
The suspended flocs enter a settling tank and are removed from the wastewater by sedimentation. Recycling of settled solids to the aeration tank controls levels of suspended solids, while excess solids are wasted as sludge.
How does a biological trickling filter work?
They work by passing air or water through a media designed to collect a biofilm on its surfaces. The biofilm may be composed of both aerobic and anaerobic bacteria which breakdown organic contaminants in water or air.
What is aerobic microbiology?
aerobic, when microorganisms require oxygen to break down organic matter to carbon dioxide and microbial biomass. anaerobic, when microorganisms do not require oxygen to break down organic matter, often forming methane, carbon dioxide, and excess biomass. anoxic, when microorganisms use other molecules than oxygen for growth, ...
When was the moving bed bioreactor invented?
Moving bed bioreactors, or MBBRs, invented in the late 1980s in Norway, already has been applied in over 800 applications in more than 50 countries, with approximately half treating domestic wastewater and half treating industrial wastewater.
When was activated sludge first used?
Activated sludge was first developed in the early 1900s in England and has become the conventional biological treatment process widely used in municipal applications but can also be used in other industrial applications.
What are the main objectives of biological treatment?
The main objectives of biological treatment is to remove or reduce the concentration of organic, inorganic compounds and nutrients, especially nitrogen and phosphorus. Also denitrification of common terminology used for biological treatment process.
Why is water important to humans?
Due to continuous technological growth and industrialization, water has been fully polluted. This is categorized as water pollution. The outlet water of industries and human which accedes the limit of organic and inorganic components in the water is called wastewater (polluted water).
What is attached growth treatment?
Attached growth biological treatment process in which the microorganisms responsible for the conversion of the organic matter or other constituents in wastewater to gases and cell tissue are attached to same inert medium, such as rocks, slag etc. attached growth treatment process is also called fixes growth system.
What is biological waste water treatment?
Biological waste water treatment is the primary method of preparing food-processing waste water flows for return to the environment. Increasing waste water loads on existing plants and more stringent government discharge requirements have put considerable pressure on the food-processing industry to refine and understand better the design and management of biological waste water treatment processes. Though activated sludge and other biological treatment processes are still frequently operated by general guidelines and ‘rules of thumb,’ facility design and operation must be guided by consideration of both the physical and biological aspects of waste water treatment. Various modifications and combinations of aerobic and anaerobic biological treatment processes are commonly used in the food-processing industry.
Why is water treatment important?
Water treatment is performed in order to improve water quality. The processes employed for water treatment depend on the quality of the water supply. In all cases, water has to be disinfected in order to deactivate any existing microorganisms present in water. So far, this technique was proved to be the most important for the protection ...
What are the most important problems in water?
If the water originates from a surface water supply such as a river, lake, or dam, then the suspended particles are the most important problem. Different techniques to remove suspended particles include the addition of coagulants and the use of membranes.
What is the most effective method of removing bacteria and viruses from raw water prior to conventional treatment?
zooplankton) and macro-invertebrate filter feeders also reduce pathogen numbers. Apart from pre-chlorination, storage is the most effective method of removing bacteria and viruses from raw water prior to conventional treatment.
What is MF water treatment?
MF is used to remove turbidity and larger microorganisms. Water treatment in existing installations uses immersed membrane modules that are simply placed in water tanks where a vacuum at the permeate side drives the collection of purified water.
How to improve the taste of water?
1. Understand the treatment need: For many consumers, simply improving the taste of the water is their primary treatment need. For some, there may be health contaminants that must be treated. And others may have very hard water, causing issues with lime scale around fixtures and possibly damaging appliances. 2.
What will the future of brewing water systems be like?
Brewery water treatment systems of the future will be very flexible, allowing breweries to tailor-make their water for different products. At the same time, these future water treatment systems will aim to achieve optimum efficiency in terms of operating cost and especially wastewater produced. The advances in analysis techniques will inevitably lead to further challenges, as it will be possible to detect certain components that are not an issue today but will then need to be removed. It will also continue to be vital for brewers to pay attention to their water supply to avoid surprising and unexpected quality defects in the finished product.
