In secondary treatment, biological treatment is done on the wastewater to remove the organic matter present. This treatment is performed by indigenous and aquatic micro-organisms like bacteria and protozoa which consume biodegradable soluble contaminants like sugar, fat, detergent, and food waste.
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What is secondary treatment of wastewater?
In secondary treatment, biological treatment is done on the wastewater to remove the organic matter present. This treatment is performed by indigenous and aquatic micro-organisms like bacteria and protozoa which consume biodegradable soluble contaminants like sugar, fat, detergent, and food waste.
How is wastewater treated and treated?
SECONDARY TREATMENT Anaerobic Process So, less sludge is produced in anaerobic process. Bacteria that work in the absence of oxygen are Anaerobic Bacteria. The end products of an anaerobic process are odorous (due to the formation of …
What are the by-products of wastewater treatment?
Oct 16, 2009 · The activated sludge process (ASP) is an aerobic biological wastewater treatment process that uses microorganisms, including bacteria, fungi, and protozoa, to speed up decomposition of organic matter requiring oxygen for treatment.
What are the available options in the biological treatment processes of sewage?
Secondary wastewater treatment processes use microorganisms to biologically remove contaminants from wastewater. Secondary biological processes can be aerobic or anaerobic, each process utilizing a different type of bacterial community. Coupled anaerobic–aerobic processes may also be employed under certain circumstances. Aerobic – Aerobic biological …
Which bacteria is used in secondary sewage treatment?
Common Microorganisms Used in Wastewater TreatmentAerobic 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.Jul 23, 2018
What are some microorganisms used in secondary treatment?
Microorganisms used in a secondary treatment system include: bacteria, fungi, algae, and protozoa. These play an essential role in natural systems, and are harnessed in technologies such as activated sludge and fixed biofilm technologies such as roughing filters and slow sand filters.Mar 2, 2022
What is used in secondary treatment to consume waste?
A rotating biological contactor or RBC is a biological fixed-film treatment process used in the secondary treatment of wastewater following primary treatment. The primary treatment process involves removal of grit, sand and coarse suspended material through a screening process, followed by settling of suspended solids.
How is secondary wastewater treated?
Secondary treatment involves the removal of biodegradable organic matter (BOD) and suspended solids (TSS) through the processes of aeration and filtration. Secondary treatment is typically characterized as producing a treated wastewater effluent with a BOD of 25 mg/L or less and TSS of 30 mg/L or less.
How anaerobic bacteria are beneficial in secondary sewage treatment?
As anaerobic bacteria break down sludge, they produce methane gas. This methane gas can be used as an alternative energy source, called biogas, to fuel the wastewater treatment process. Anaerobic bacteria can also be used to lower the amount of phosphorus in the effluent.May 7, 2019
What are anaerobic bacteria?
Anaerobic bacteria are bacteria that do not live or grow when oxygen is present. In humans, these bacteria are most commonly found in the gastrointestinal tract. They play a role in conditions such as appendicitis, diverticulitis, and perforation of the bowel.Mar 5, 2021
What is a secondary treatment system?
Secondary treatment systems(STS) are wastewater treatment systems which produce treated effluent of secondary standard, i.e. 20 mg/L of Biochemical Oxygen Demand (BOD), 30 mg/L of Total suspended solids (TSS) and 10 cfu/100 mL of Escherichia (E) coli.Dec 7, 2021
What is secondary treatment of water?
Secondary treatment is a step in wastewater treatment that involves the use of biological processes in order to capture all the dissolved organic materials that were not caught during the initial treatment. Microbes take these organic substances as food, transforming them to water, energy and carbon dioxide.Oct 29, 2017
Which of the following is used in secondary treatment of sewage water?
Secondary sewage treatment is mainly a biological process. In secondary treatment primary effluent is passed into large aeration tanks, where it is constantly agitated mechanically and air is pumped into it. This allows vigorous growth of useful aerobic microbes into floes.
Why secondary treatment is called 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.
What is secondary waste?
Secondary waste is waste generated from different sources and of different nature, i.e. waste generated in a process that is known as a waste treatment operation; it includes residual materials originating from recovery and disposal operations, such as incineration and composting residues.Jun 8, 2015
What is the role of microorganisms in the secondary treatment?
Secondary wastewater treatment processes use microorganisms to biologically remove contaminants from wastewater. Secondary biological processes can be aerobic or anaerobic, each process utilizing a different type of bacterial community.
What is the purpose of sewage treatment?
The purpose of the sewage treatment is to remove the solids present in the sewage. ROLE OF MICROORGANISMS. Microorganisms are unicellular microscopic living things. They multiply by binary division of cells within 10 to 20 minutes. They require oxygen for their respiration.
What is secondary treatment?
The secondary treatment is designed to remove soluble organics from the wastewater. Secondary treatment consists of a biological process and secondary settling is designed to substantially degrade the biological content of the sewage such as are derived from human waste, food waste, soaps and detergent.
What are the objectives of biological treatment?
The overall objectives of the biological treatment of domestic wastewater are: 1 To oxidize or transform dissolved and suspended biodegradable substances into acceptable end products; 2 To capture and incorporate suspended non-settleable colloidal solids into biological floc or bio film, and 3 To transform and remove nutrients such as nitrogen and phosphorous.
What is activated sludge?
The activated sludge process (ASP) is an aerobic biological wastewater treatment process that uses microorganisms, including bacteria, fungi, and protozoa, to speed up decomposition of organic matter requiring oxygen for treatment.
What are some examples of organic solids?
Organic solids are the substances derived from living things like produces from plant and animal. Examples of organic solids are carbohydrate, protein, and fat. The organic solids undergo decomposition by the microorganisms. Inorganic solids are inert materials and they do not undergo decomposition. Examples of inorganic solids are grit, salt etc.
What are the end products of decomposition?
The end products of the decomposition are water, CO 2 and Cell tissues. Anaerobic bacteria use oxygen derived from chemical substances for their respiration. They multiply in the absence of DO in the water bodies. They oxidize the organic matter under septic conditions.
What are the two types of biological processes?
TYPES OF BIOLOGICAL PROCESSES. There are two types of biological treatment process; aerobic and anaerobic. Aerobic process means that oxygen is present for the microbes for respiration. Anaerobic process means that the process proceeds in the absence of DO.
What is secondary wastewater treatment?
Secondary Wastewater Treatment. Secondary wastewater treatment processes use microorganisms to biologically remove contaminants from wastewater. Secondary biological processes can be aerobic or anaerobic, each process utilizing a different type of bacterial community.
What is anaerobic process?
Anaerobic processes are generally used to treat high-strength wastewaters where it is impractical to utilize aerobic processes or where producing a biofuel gas is desired .
What are the components of aerobic systems?
In an aerobic system, the organic contaminants are converted to carbon dioxide, water, additional microorganisms, and other end products . Aerobic lagoons – Lagoons are typically large, shallow earthen basins that provide adequate residence time for the wastewater to be treated naturally by both bacteria and algae.
Where do microorganisms grow?
Microorganisms grow on the surface of the discs where aerobic biological degradation of the wastewater pollutants takes place. Trickling filter – An attached-growth process where wastewater is distributed over a fixed bed of media such as rocks, gravel, plastic substrate, etc.
What is the most effective method of secondary treatment of wastewater?
This method of secondary treatment of wastewater employs sand filters, contact filters, or trickling filters to ensure that additional sediment is removed from wastewater. Of the three filters, trickling filters are typically the most effective for small-batch wastewater treatment.
What is primary treatment of wastewater?
Primary treatment of wastewater involves sedimentation of solid waste within the water. This is done after filtering out larger contaminants within the water. Wastewater is passed through several tanks and filters that separate water from contaminants.
What is the third step in wastewater management?
This third and last step in the basic wastewater management system is mostly comprised of removing phosphates and nitrates from the water supply. Substances like activates carbon and sand are among the most commonly used materials that assist in this process.
How long does it take for a wastewater solution to be aerated?
The resulting mixture is then aerated for up to 30 hours at a time to ensure results.
What is stage 2 of wastewater treatment?
Stage 2. – Includes Secondary Treatment using different methods of Biological Oxidation to further purify wastewater. The Conventional Activated Sludge Process is the most popular, using Aeration in a long, but effective process that entails mixing and aerating wastewater in a solution of microorganisms grown in the system that breakdown organic material and separates dissolved solids. This can be accomplished by:
How does secondary treatment remove organic matter?
The secondary stage of treatment removes about 85 percent of the organic matter in sewage by making use of the bacteria that is naturally found in it. Increased oxygen encourages the growth of bacteria, which consume and breakdown the complex organic compounds.
What is the main objective of wastewater treatment?
The main objective of Wastewater Treatment is to separate solids from liquid then to treat both turning the solids into nonhazardous Bio-solids and water into non-threatening environmentally safe water to add back to the environment where it came from with the intention of using it again. 1. Primary Wastewater Treatment.
How much BOD is removed from sewage?
Weekly averages may be up to 50 percent higher. A sewage treatment plant providing both primary and secondary treatment is expected to remove at least 85 percent of the BOD and suspended solids from domestic sewage.
What is secondary treatment?
Secondary treatment is the part of the Wastewater Treatment process that breaks down organic matter, removes dissolved and colloidal solids. This organic waste material would create a high Oxygen demand on the receiving stream if it were let go into the environment. Secondary treatment is traditionally applied to the liquid portion of sewage after initial Preliminary and Primary treatment has removed settleable solids and inorganic floating material.
What is anaerobic digestion?
Anaerobic Digestors. Most large Wastewater Treatment Plants use 2 Stage Anaerobic Digestion to treat the solids removed from the Primary and Secondary Treatment facilities. Treatment is needed for the Solids to be deemed safe for landfills.
What is the purpose of sludge treatment?
The basic goals of treating sludge before final disposal are to reduce its volume and to stabilize the organic materials.
What is the main objective of secondary treatment?
The main objective of secondary treatment: To remove most of the fine suspended and dissolved degradable organic matter that remains after primary treatment, so that the effluent may be rendered suitable for discharge. Conventional secondary treatment can reduce the BOD's to below 20mg/l and Suspended Solids to below 30mg/l which is acceptable in ...
What is aerobic biological process?
Aerobic Biological Processes. Are those where sufficed amount of dissolved oxygen is required into the wastewater to sustain aerobic action, as one of the major polluting effects of wastewater on streams results form the depletion of dissolved oxygen by the action of aerobic organisms in degrading the organic content of the waste.
What is nitrification in biology?
Nitrification: Means the oxidation of ammonia to nitrate. Nitrification is possible with aerobic biological processes. If they are operated at low organic load rates-hence the units must be large than those which would be required for oxidation of carbonaceous matter alone.
What is a trickling filter?
It is the most common attached growth process. The trickling filter is like a circular well having depth up to 2 meter filled with granular media like stone, plastic sheets and redwood, slag, slate. The first tricking filter was placed in operation in England in 1893. the concept of a tricking filter was grew form the of contact frets which were water tight basins filled with broken stones. The limitation the contact filters included a relatively.
What is primary treatment?
Primary treatment removes about 60 percent of floating solid bodies, 30 percent of oxygen demanding wastes, 20 percent of nitrogen compounds, and 10 percent of phosphorous compounds. 2. Secondary Treatment: It is a biological oxidation of organic matter. It is achieved by filter method or by sludge process.
What is the purpose of algae and bacteria?
These all are very useful for waste liquid purification. Algae and bacteria used together is an efficient method for recovery of waste water over bacterial action. This process is also very inexpensive. In the algae-bacteria combination, an alga provides oxygen to remove nutriensy and other toxic elements. Bacteria on the other hand degrade organic matter aerobically.
What percentage of water is sewage?
Sewage water mainly has 99.9 percent of water and rest 0.1 percent of organic and inorganic substances. This waste water carries many bacteria which cause diseases. Organic matter decomposes to give different colour to the water and it also gives bad odour to the liquid.
What is metal screening?
It is the process of mechanically removing the solid materials present in water through metal screening. Grit chambers and sedimentation. Metal screening removes large floating objects such as small piece of woods, rags, masses of garbage and death insects and animals.
How is sludge reduced?
The volume and characteristics of the sludge is reduced through anaerobic (devoid of oxygen) auto digestion. In this process, complex compounds are broken down into water, carbon dioxide, methane and ammonia. This substance works as a good fertiliser. 3.
How are aquatic plants used?
The aquatic plants are also used in the treatment of wastewater. These plants when grown in high nutrient water grow well and double their population in two weeks time. It thus able to clean waste water containing various organic materials.
What is activated sludge?
This sludge is called activated sludge as it is rich in aerobic bacteria (bacterial which can survive only in presence of oxygen). This activated sludge is then subjected to aeration.
What is liquid waste management?
Liquid waste management. 1. WASTE WATER MANAGEMENT AND TREATMENT JIJEESH V. 2. WASTEWATER Wastewater is a mixture of sewage; water from household use; water used in commercial and industrial applications etc… Wastewater contains a variety of biological and chemical pollutants which make it unsafe for humans and the environment. 3.
What is tertiary treatment?
Tertiary treatment Removal of further nutrients and pathogens, using methods such as filtration, passage through wetlands, or disinfection by treatment with chlorine, ozone or ultraviolet light. Tertiary treatment is not always included in wastewater treatment systems. 8.
What is phosphorus removal?
PHOSPHORUS REMOVAL Phosphorus is a nutrient which makes the growth of algae possible. Chemicals including: ferric chloride, alum, or lime are added to the wastewater, which allow the smaller particles including phosphorus to group into larger masses. Then are removed through the sedimentation tanks. 45.
