What is meant by secondary treatment of wastewater?
Secondary treatment is the second step in most waste treatment systems during which bacteria consume the organic parts of the wastes. This is accomplished by bringing the sewage, bacteria and oxygen together in trickling filters or within an activated sludge process.Mar 13, 2003
What is secondary treatment process?
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
What happens in the secondary stage of wastewater treatment?
The secondary stage of treatment removes about 85 percent of the organic matter in sewage by making use of the bacteria in it. The principal secondary treatment techniques used in secondary treatment are the trickling filter and the activated sludge process.
What is primary and secondary wastewater treatment?
The main difference is the way each respective treatment is processed. Primary treatment works on sedimentation, where solids separate from the water through several different tanks. In contrast, secondary treatment uses aeration, biofiltration and the interaction of waste throughout its process.Nov 19, 2020
Which of the following are examples of secondary wastewater treatment processes?
There are a variety of secondary treatment processes; the following are conventional processes used by treatment plants:Activated sludge.Trickling filter.Non-electric secondary filtration (FilterPod)Oxidation ponds.Mar 2, 2022
What is secondary treatment 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.
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 purpose of secondary wastewater treatment quizlet?
The purpose of secondary treatment is to remove the suspended solids that did not settle out in the primary tanks and the dissolved BOD that is unaffected by physical treatment.
What do you understand by secondary treatment of wastewater enumerate various processes employed for this purpose?
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 secondary and primary treatment?
The initial and primary water treatment process removes large matter from wastewater while the secondary treatment will remove smaller particles already dissolved or suspended.Jun 26, 2018
What is primary secondary and tertiary treatment?
Wastewater is treated in 3 phases: primary (solid removal), secondary (bacterial decomposition), and tertiary (extra filtration).Jan 3, 2021
Which is the secondary treatment of sewage water Mcq?
Sewage treatment plant is a part of secondary treatment.
What is secondary wastewater treatment?
Secondary Wastewater treatment is the second stage of wastewater treatment. In primary treatment, suspended solids, colloidal particles, oil, and grease are removed. 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 ...
What is the process that uses oxygen to break down organic matter and remove other pollutants?
These processes are sensitive to temperature and with an increase in temperature, the rate of biological reactions increases. 1. Aerobic Treatment: Aerobic wastewater treatment is a biological treatment that uses oxygen to break down organic matter and remove other pollutants like nitrogen and phosphorus.
What is SBR treatment?
It is used to reduce the organic matter (BOD and COD), oxygen is bubbled with a mixture of wastewater and activated sludge. After this treatment, the treated water can be discharged on surface water.
Why is the sludge digestion system rendered simple?
However, the operation is rendered simple due to the elimination of primary settling and separate sludge digestion.
What is a membrane bioreactor?
Membrane Bioreactor – MBR is the combination of ultrafiltration (UF) and activated sludge process. MBR produces effluent of high quality which can be discharged to surface water for reuse. It can be retrofitted in existing installations.
Aerobic Processes
Aerobic secondary treatment of wastewater occurs when various types of electron acceptors are present in the medium then the bacterial cells will utilize the one that produces the highest quantity of energy. Thus aerobic processes will utilize oxygen first.
Anoxic Processes
If the nitrates are present then the microorganisms which are capable of utilizing nitrogen will prevail. during respiration, they will convert nitrate to nitrogen gas (Denitrification) and the processes are collectively called anoxic processes.
Anaerobic Processes
When nitrates are consumed then anaerobic processes start to prevail and other nutrients such as sulfates are utilized. During this process, the sulfates will be converted to sulfites and Carbon-d i-oxide to methane.
Suspended Growth Process
In this growth process, the microorganism which is responsible for the conversion of waste organic matter is maintained into suspension of the liquid phase. Aerobic suspended growth processes include Activated Sludge Processes, Aerated Lagoons, and Sequential Batch Reactors.
Attached Growth Processes
In attached growth processes the microorganisms are attached to the surfaces (such as stones, inert materials) or are self immobilized on flocs or granules in the system. Aerobic Attached Growth Processes include Trickling Filters, Roughing Filters, Rotating Biological Contractors, and Packed Bed Reactors.
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 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 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 the end products of anaerobic and aerobic processes?
Under aerobic conditions, if completely oxidized, organic matter is transformed into non-hazardous products. But an anaerobic process can produce methane (CH 4 ), which is explosive, and ammonia (NH 3) and hydrogen sulfide (H 2 S), which are toxic.
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 the activity of the WSPs?
The activity in the WSPs is a complex symbiosis of bacteria and algae, which stabilizes the waste and reduces pathogens. The algae produce oxygen during photosynthesis by utilizing carbondioxide and solar energy derived from sun light.
What are the two types of solids in sewage?
SOLIDS IN SEWAGE. The solids present in the sewage are of two types viz., Organic solids, and. Inorganic 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.
What is secondary treatment?
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.
Is wastewater a solid?
Total solids in wastewater can be categorized as inorganic and organic. When it comes to the size, it can be divided into suspended, colloidal and dissolved solids. The main purpose of the initial or primary treatment is to eliminate the suspended solids as much as possible.
What is package sewage treatment?
Commonly known as package sewage treatment plants, these units are commercially available and come in a prefabricated form for use to treat the wastewater flows from individual residences or small rural businesses.
What is a biofiltration system?
Biofiltration systems involve the use of peat or synthetic media to treat the wastewater. A peat fiber biofiltration system functions much like a conventional system with the exception that the wastewater is filtered through a layer of peat before being discharged to the disposal field. Several designs of peat filters are on the market; however the most common system installed in Manitoba is the modular system. The modules contain pre-compacted peat. This is a passive system whereby the effluent slowly trickles through the peat and drains directly to the disposal field. Peat treats the wastewater through physical filtration, adsorption and microbial activity.
