Typically, a complete-mix suspended growth aerobic treatment system is composed of a main treatment basin (aeration chamber) where the bacteria, organic matter, and effluent are mixed by the turbulence created by air injection. A second chamber (clarifier) provides quiescent conditions to allow the biomass to settle.
What is an aerobic treatment system (ATS)?
An aerobic treatment system or ATS, often called (incorrectly) an aerobic septic system, is a small scale sewage treatment system similar to a septic tank system, but which uses an aerobic process for digestion rather than just the anaerobic process used in septic systems.
What is an aerobic septic system?
From Wikipedia, the free encyclopedia An aerobic treatment system (ATS), often called an aerobic septic system, is a small scale sewage treatment system similar to a septic tank system, but which uses an aerobic process for digestion rather than just the anaerobic process used in septic systems.
How does an aerobic system work?
One thing that makes an aerobic system different is the addition of an aerator unit (basically air compressor or blower). The aerator unit forces oxygen into the main treatment tank. It is powered by electricity.
What is an aerobic treatment unit?
Aerobic treatment units, also called activated sludge tanks, are a common method of biological treatment used in municipal wastewater treatment facilities. According to Chapter 73 of the PA Rules and Regulations, traditional septic tanks can be replaced with aerobic treatment tanks.
What is an aerobic treatment septic system?
An aerobic treatment system (ATS), often called an aerobic septic system, is a small scale sewage treatment system similar to a septic tank system, but which uses an aerobic process for digestion rather than just the anaerobic process used in septic systems.
How does an aerobic treatment system work?
The Aerobic Waste Removal Process In an aeration system, the bacteria live either in sludge or in basins. Then a surface aerator or diffusion aerator sends extra oxygen into the system at the same time as organic waste. The bacteria eat the waste, breathe the air, and give off carbon dioxide as a waste product.
What is aerobic treatment unit?
Aerobic Treatment Units (ATUs) are similar to standard septic systems in that they use natural processes to treat wastewater. But unlike conventional systems, ATUs also use oxygen to break down organic matter, much the same as municipal wastewater treatment systems, but in a scaled-down version.
What is the difference between an aerobic system and a septic system?
Aerobic Septic Systems Aerobic treatment systems (ATS) include fixed film systems, continuous flow systems, retrofit systems and composting toilets. The main difference between an ATS and a traditional septic system is that it produces a higher quality effluent and requires a smaller leach field.
Do aerobic septic systems smell?
A common myth is that aerobic systems smell. Well, some do, but they shouldn't! A smelly septic system is a sign of a problem, one that needs to be fixed sooner instead of later.
What are the disadvantages of an aerobic septic system?
Increased cost: An aerobic septic system can cost up to three times as much as a traditional septic tank. The cost varies by design and location, but they are almost always more expensive than a traditional system. Property owners must weigh this cost with potential conveniences, such as space-saving measures.
Are aerobic septic systems good?
Aerobic bacteria break down waste solids faster than their anaerobic counterparts. The treated water that flows out of an aerobic septic system is cleaner, making an aerobic system a good choice if your property has a higher water table or other environmental challenges.
How much electricity does an aerobic septic system use?
Daily operating electrical usage: 86 Watts/Hr x 24 hrs/day = 2,064 Watt-hours/day.
How do septic systems work in the winter?
During winter, the freezing temperature outside makes the various components of your septic system freeze up. With the septic tank being frozen, the waste does not break down quickly, which causes problems for the residents.
Which is better conventional or aerobic septic system?
Conventional septic systems are generally less expensive than aerobic systems, though this is not always the case. Conventional systems involve much less maintenance than aerobic systems. Both conventional septic systems and aerobic systems are environmentally friendly when designed, used, and maintained properly.
How often should aerobic septic sprinklers go off?
We normally recommend you to pump out all your tanks/compartments when the sludge level reaches approximately 50% or higher in the aerobic unit or if excessive sludge builds up in the pump tank. (The average household will need to have the system pumped every 2-5 years).
How do I know if I have an aerobic or anaerobic septic system?
The basic difference between aerobic and anaerobic septic systems is the presence or absence of oxygen. Traditional anaerobic septic systems operate in underground tanks and in the relative absence of oxygen. This means that the bacterial colonies that break down sewage must be able to live without oxygen.
Where are aerobic treatment systems used?
These systems are commonly found in rural areas where public sewers are not available, and may be used for a single residence or for a small group of homes. Unlike the traditional septic system, the aerobic treatment system produces a high quality secondary effluent, which can be sterilized and used for surface irrigation.
What is a small scale aerobic system?
Small scale aerobic systems generally use one of two designs, fixed-film systems, or continuous flow, suspended growth aerobic systems (CFSGAS). The pre-treatment and effluent handling are similar for both types of systems, and the difference lies in the aeration stage.
What is the difference between a septic system and an aerobic system?
Comparison to traditional septic systems. The aeration stage and the disinfecting stage are the primary differences from a traditional septic system; in fact, an aerobic treatment system can be used as a secondary treatment for septic tank effluent. These stages increase the initial cost of the aerobic system, and also the maintenance requirements ...
What is an ATS system?
Jump to navigation Jump to search. A small scale sewage treatment system which uses an aerobic process for digestion. An aerobic treatment system ( ATS ), often called an aerobic septic system, is a small scale sewage treatment system similar to a septic tank system, but which uses an aerobic process for digestion rather than just ...
What is the disinfecting stage?
Disinfecting stage, where chlorine or similar disinfectant is mixed with the water, to produce an antiseptic output. Another option is UV disinfection, where the water is exposed to UV light inside of a UV disinfection unit. The disinfecting stage is optional, and is used where a sterile effluent is required, such as cases where ...
How does a fixed film system work?
Fixed film systems use a porous medium which provides a bed to support the biomass film that digests the waste material in the wastewater. Designs for fixed film systems vary widely, but fall into two basic categories (though some systems may combine both methods). The first is a system where the media is moved relative to the wastewater, alternately immersing the film and exposing it to air, while the second uses a stationary media, and varies the waste water flow so the film is alternately submerged and exposed to air. In both cases, the biomass must be exposed to both wastewater and air for the aerobic digestion to occur. The film itself may be made of any suitable porous material, such as formed plastic or peat moss. Simple systems use stationary media, and rely on intermittent, gravity driven wastewater flow to provide periodic exposure to air and wastewater. A common moving media system is the rotating biological contactor (RBC), which uses disks rotating slowly on a horizontal shaft. Nearly 40 percent of the disks are submerged at any given time, and the shaft rotates at a rate of one or two revolutions per minute.
Does ATS sewage smell?
ATS effluent is relatively odorless; a properly operating system will produce effluent that smells musty, but not like sewage. Aerobic treatment is so effective at reducing odors, that it is the preferred method for reducing odor from manure produced by farms.
What is aerobic treatment?
As mentioned throughout this article, aerobic treatment converts organic materials into carbon dioxide and new biomass. It does this with aerobic bacteria which require an oxygen-rich environment to thrive. Because of this, you must constantly pump air into them for them to work properly.
What treatment system can you use if you can't use aerobic?
If you cannot use an aerobic system, you could opt for an anaerobic treatment system. Anaerobic systems also use bacteria to break down wastewater but do not require an air supply.
What is aerobic wastewater treatment?
Aerobic wastewater treatment uses naturally-occurring, living microorganisms to break down containments. The bacteria eat complex organic substances and turn them into simpler materials. However, it is not the only biological treatment process available.
What is the air in the water system called?
In the main compartments, called an aeration chamber, air mixes with the wastewater. An air blower or compressor forces the air into the chamber to supply the oxygen needed for the bacteria to digest the solids and other containments in the water.
What happens when aeration is finished?
Once the aeration process ends, the solids sludge start settling out of the water, forming sludge. This happens either in the aeration chamber or in a secondary chamber called a settling chamber or clarifier, if present.
How many gallons of water do you need for an aerobic system?
Because of this, most aerobic systems range from 300 to 1500 gallons. Also, most local regulations require systems that can push 500 gallons per day.
What is an ATU in sewage?
Aerobic treatment systems or units (ATU) bring the process and efficiencies of municipal sewage plants to your home. Their key component is the oxygen they inject into the tank to increase the effluence of the natural bacteria in the tanks.
What is a complete mix aerobic treatment system?
Typically, a complete-mix suspended growth aerobic treatment system is composed of a main treatment basin (aeration chamber) where the bacteria, organic matter, and effluent are mixed by the turbulence created by air injection. A second chamber (clarifier) provides quiescent conditions to allow the biomass to settle. The two chambers are typically connected at the bottom, which allows the treated effluent to pass to the clarifier, and settled biomass to flow back to the aeration chamber.
What is SBR treatment?
An SBR provides treatment using one chamber. As the name suggests, processes occur in a particular order to provide aeration and biomass separation. These include filling the chamber, aerating the effluent, allowing the biomass to settle, pulling out the clarified effluent (decanting), and then removing a portion of the biomass. This is a batch operation, which means that storage must be provided for the effluent that arrives while the sequential operations are in progress.
What is the BOD 5 test?
This “extra treatment” leads to the development of a robust population of nitrifying bacteria (nitrosomonas and nitrobacter), which are present in the treated effluent. Consequently, when samples of the treated effluent are placed in BOD bottles, nitrification of ammonia (including that introduced with the dilution water) takes place during the five-day BOD test. The result is that the BOD 5 test will include both CBOD from the treated wastewater and an amount of nitrogenous oxygen demand (NBOD) (about 4.6 mg of oxygen are required to oxidize 1 mg of ammonia). Experience shows that a treated effluent with a CBOD of less than 10 mg/L can exhibit a BOD 5 of more than 50 mg/L using the standard five-day BOD test. For this reason, an alternative test has been developed, in which nitrification inhibitors are added to the BOD bottle in the standard five-day BOD test. This test is referred to as the CBOD test. The EPA and, essentially, all state environmental agencies can authorize this test to be used instead of the standard BOD 5 test, on a case-by-case basis. In fact, some state agencies have authorized the CBOD test to be used at the analyst's option.
How does suspended growth work?
A typical suspended growth aerobic treatment system contains basins filled with effluent into which air is injected. Air injection causes oxygen to become dissolved in the effluent and mixes the contents of the tank. The mixing action brings the suspended microorganisms into contact with the organic matter (food) and dissolved oxygen (fuel). As there is plenty of food and dissolved oxygen, the microorganisms thrive and become very concentrated within the basin (Davis and Cornwell, 1991 ). Microbes complete their life cycle while suspended in the effluent. The microbes oxidize the organic matter into carbon dioxide, new microbes, and insoluble matter (residuals). After several hours of detention in the aeration basin, the effluent moves into a settling basin or clarifier. The clarifier provides a quiet environment that allows the concentrated biomass to settle out of the effluent. The clarified effluent then proceeds to the next phase of treatment. As biomass accumulates in the clarifier, it is periodically removed (either automatically or manually).
What is an MBR system?
MBRs are activated sludge components that use membrane filtration units to separate the biomass from the effluent (see Section 3.8.4.6 in Chapter 3.8 for details of MBRs). Unlike the suspended growth configurations previously mentioned (see Section 3.13.5.3.2.2.1), MBRs do not depend on gravity (settling) to separate the biomass and effluent. With membrane filtration, time and space required for biomass separation is less of a constraint. MBR systems can thus treat a greater volume of water and occupy less space than the conventional suspended growth systems. However, the increased treatment capacity is accompanied by an increased electrical cost because greater aeration capacity and pressurization is needed to operate an MBR at its full potential. To accomplish nitrogen and phosphorus removal, additional unit processes must be added to the MBR process.
What happens to the microbes in the effluent?
Microbes complete their life cycle while suspended in the effluent. The microbes oxidize the organic matter into carbon dioxide, new microbes, and insoluble matter (residuals). After several hours of detention in the aeration basin, the effluent moves into a settling basin or clarifier.
Why is oxygen important in wastewater treatment?
In particular, aerobic treatment systems need a specific control on dissolved conditions. A significant variation can affect the enzymatic activity as well as separability of biomass from treated wastewater.
What is an aerobic treatment unit?
While a conventional septic system uses only the septic tank to separate solids, fats and grease, an aerobic treatment unit (ATU) uses Oxygen infusion for digestion rather than the anaerobic process. Just as in the case of conventional (or standard) systems, an aerobic septic system uses natural processes to treat wastewater.
How does aerobic septic work?
As mentioned, aerobic septic systems differ from conventional systems because the aerobic treatment process requires air to be injected and circulated inside the treatment tank. Hence, your aerobic septic system is made up of a greater number of parts than a conventional system, including electrical components and extra tanks. Specifically, your system will have a trash tank (got one), an aerobic treatment unit (tick) and a pump tank (yep, there it is). An air compressor infuses the treatment unit with air through diffusers in the tank and the cycle begins.
Why are aerobic septic systems more expensive than standard systems?
Aerobic septic systems are more complex than standard systems because of this they are also more costly. The value lies in the speed and the advanced level of treatment that you can expect from an aerobic septic system.
How to maintain aerobic septic system?
The most effective and efficient way to maintain your aerobic septic system is to have the details of your maintenance provider on hand for emergencies and to have a professional make the appropriate system checks and cleans as regularly as the maintenance schedule recommends.
What happens to solid waste in a septic tank?
In this kind of system, solid waste enters your septic tank and settles at the bottom. This, over time, turns into sludge. Meanwhile, the liquid waste that ends up inside your septic tank rises to the top.
What is the final treatment for water?
If you are dispensing the water as a spray, a final treatment is performed before the water enters the pump tank (commonly with a tablet or liquid chlorinators) or an individual tank just prior to the pump tank for the water chlorination, to eliminate any remaining pathogens.
Is aerobic septic maintenance good?
Aerobic septic system maintenance is not the best place to start if you are testing out your do-it-yourself skills. A well-functioning septic system keeps your home running smoothly and keeps your family healthy.
What is an aerobic treatment unit?
Aerobic treatment units, also called activated sludge tanks, are a common method of biological treatment used in municipal wastewater treatment facilities. According to Chapter 73 of the PA Rules and Regulations, traditional septic tanks can be replaced with aerobic treatment tanks.
How to prevent aerobic system from overloading?
Conserve water to avoid overloading the system. Be sure to repair any leaky faucets or toilets. Divert all non-wastewater sources of water , like roof drains, house footing drains, and sump pumps, away from the aerobic system.
What does it mean when the water in the aeration chamber is grayish brown?
Alarms or lights going off. Any changes in the system's normal operating sound. Any changes in the normal color of the wastewater in the aeration chamber (for example, if the color is grayish brown rather than chocolate brown, this can sometimes indicate problems). Excessive solids, foam, or scum in the unit.
What is the middle of an aeration chamber?
The middle, or aeration chamber, is where air is pumped into the chamber to provide oxygen for the aerobic bacteria. The air is brought into the aeration chamber at the bottom and either flows freely throughout the chamber "suspended growth" (Fig. 2.) or flows through a "fixed film media" (the black block in Fig. 1). Figure 2.
Why are ATUs not used?
A major reason that ATUs are not more widely used is concern about operation and maintenance by homeowners. ATUs are not passive and therefore require regular maintenance, and inspection. Abuse or neglect can easily lead to component failure or unsatisfactory performance.
Can a septic tank be replaced with an aerobic tank?
According to Chapter 73 of the PA Rules and Regulations, traditional septic tanks can be replaced with aerobic treatment tanks. In some cases, where the treated wastewater must be discharged into shallow soils, an ATU may make it possible to eliminate further pretreatment units within the system. Aerobically treated wastewater permits ...
Is ATU better than septic?
The quality of effluent leaving an ATU is considerably better than that discharged from a septic tank. Therefore, owners of on-lot systems with an ATU may reduce the size of their absorption fields by one-third, thus requiring a smaller absorption field than would be required if a septic tank had been used.
What is aerobic treatment system?
The aerobic septic system or aerobic treatment system injects oxygen (O2) inside the processing tank. The extra O2 increases the natural bacterial activity in the system and ensures further nutrient processing in the sewage.
What is the advantage of aerobic septic system?
The main advantage of the aerobic septic unit is that it may use on all kinds of terrain. While conventional septic tank systems can’t use on lands with high groundwater. An aerobic treatment system has been carefully manufactured to work well and is friendly with all types of soils.
How does a septic tank work?
The conventional septic tank system works in the following way: With the drain field, the sewage from septic tanks is channeled into underground trenches made of flat gravel or stone. After this, place a geo-fabric material on the trench top to keep dust, sand, or other debris away from the clean stone.
Why are aerobic bacteria called aerobic bacteria?
These aerobic bacteria are named because they use O2 (the “aero” part of “aerobic”) to process organic matters that pass by the septic system. These bacteria can’t make alive and perform treatment without organic matter and oxygen.
What is the pre treatment step in a septic system?
This pre-treatment step separates the solids from the sewer water.
Is aerobic septic good for lawns?
With an excellent aerobic septic unit, the wastewater used for cleaning or showering can be easily recycled and reused to supply water to the lawn. The water flows through the system, is treated, and then reprocessed. If you want an environmentally friendly system, then an aerobic septic system is the best choice.
Can you do it yourself with an aerobic septic system?
If you are checking your DIY (do-it-yourself) skills by maintaining your aerobic septic system, then it isn’t a suitable place to start. A well-operating aerobic septic system can keep your family healthy and keep your home’s working smoothly.
What makes an aerobic system different from an aerobic system?
One thing that makes an aerobic system different is the addition of an aerator unit (basically air compressor or blower). The aerator unit forces oxygen into the main treatment tank. It is powered by electricity.
How does anaerobic septic work?
Anaerobic septic systems consist of a treatment tank and a leach field. Wastewater is sent into the tank where solid waste settles at the bottom, effluent in the middle, and scum at the top. The effluent is relatively the cleanest. It flows through a series pipe buried under a leach field. Some systems add a separator box between the tank and pipes to distribute effluent more evenly. The last filtration process before treated wastewater is sent back to the environment happens in leach field.
Why do we need a moving paddle in a septic system?
Even solid waste, which otherwise settles at the bottom in anaerobic septic system, is exposed to aerobic bacteria.
Why do septic tanks have a separator box?
In an aerobic septic system, the aerator keeps on feeding oxygen to the bacteria inside the tank.
What are the two types of septic systems?
Septic Systems: Aerobic and Anaerobic. In locations where connection to a public sewer is unavailable, septic systems are the norm. Septic systems come in many different types. With that said, they generally fall just under two different categories based on how wastewater is treated: aerobic and anaerobic.
Is aerobic septic system good for a home?
An aerobic septic system is a good option for homes located close to surface water bodies. Surface bodies of water, such as lakes, ...
Do aerobic septic systems need leach fields?
Both aerobic septic systems and anaerobic systems require underground tanks to contain wastewater. They also need leach fields. Leach fields are used to send partially treated wastewater for a further filtration process. But that is where the similarities stop.
The Trash Tank
- Trash tanks permitted for installation should meet requirements of the American National Standards Institute (ANSI)/NSF Standard 40. The trash tank must have a minimum liquid capacity of 300 gallons or the average daily flow, whichever is greater. The main function of the trash tan…
Aeration Tank/Aeration Chamber
- The aeration tank must meet the most current ANSI/NSF Standard 40 and accommodate the projected daily flow. It also must have an opening of sufficient size to allow for maintenance. Since atmospheric air is forced into the chamber by a compressor or aerator, a venting mechanism for proper airflow through the aeration tank is required. The main function of the aer…
Clarifier Or Settling Chamber
- Treated wastewater exiting the aeration chamber enters the clarifier or the settling chamber. For most systems in Oklahoma, the clarifier is in the same tank as the aeration chamber (see Figure 2). The effluent entering the clarifier contains suspended solids (cell masses and non-degradable materials). The solids must be removed to prevent clogging caused by carryover of the solids to …
Disinfection
- If spray irrigation is used as the mode of dispersal, then the effluent needs to be disinfected. If the effluent is dispersed by subsurface drip irrigation, disinfection is not required. Disinfection is performed after the effluent has gone through the clarifier, but before it is pumped for dispersal. The most common method of disinfection is by chlorination. Manufacturer instructions about c…
Dispersal
- Effluent from the clarifier flows into a pump tank, where it is channeled through subsurface lines and eventually land-applied by either surface spray or subsurface drip irrigation. No biological treatment process takes place in the pump tank. The pump tank should meet ANSI/NSF Standard 40 and have a minimum liquid capacity of 700 gallons or, for systems with an average flow capa…
Maintenance
- The aerobic treatment system has components requiring regular maintenance. Maintenance starts by following manufacturer’s guidelines. Take the following as suggestions to keep your system in working order: 1. Know your installer. Know your installer and request that you be oriented to the operation and maintenance of your system. If you bought a used house, determin…
References
- Consortium of Institutes for Decentralized Wastewater Treatment (CIDWT). 2009. Installation of Wastewater Treatment Systems. 1st Ed. 454 pp. Oklahoma Department of Environmental Quality (DEQ). 2012. Individual and Small Public On-site Sewage Treatment Systems. Title 252: Oklahoma Admin Code Chapter 641. Lesikar, B. 2008. Aerobic Treatment Unit. Texas A & M AgriLife Extens…
Overview
An aerobic treatment system (ATS), often called an aerobic septic system, is a small scale sewage treatment system similar to a septic tank system, but which uses an aerobic process for digestion rather than just the anaerobic process used in septic systems. These systems are commonly found in rural areas where public sewers are not available, and may be used for a single residence or for a small group of homes.
Process
The ATS process generally consists of the following phases:
• Pre-treatment stage to remove large solids and other undesirable substances.
• Aeration stage, where aerobic bacteria digest biological wastes.
• Settling stage allows undigested solids to settle. This forms a sludge that must be periodically removed from the system.
Types of aerobic treatment systems
Small scale aerobic systems generally use one of two designs, fixed-film systems, or continuous flow, suspended growth aerobic systems (CFSGAS). The pre-treatment and effluent handling are similar for both types of systems, and the difference lies in the aeration stage.
Fixed film systems use a porous medium which provides a bed to support the biomass film that digests the waste material in the wastewater. Designs for fixed film systems vary widely, but fal…
Comparison to traditional septic systems
The aeration stage and the disinfecting stage are the primary differences from a traditional septic system; in fact, an aerobic treatment system can be used as a secondary treatment for septic tank effluent. These stages increase the initial cost of the aerobic system, and also the maintenance requirements over the passive septic system. Unlike many other biofilters, aerobic treatment systems require a constant supply of electricity to drive the air pump increasing overa…
See also
• List of waste-water treatment technologies
External links
• Aerobic Treatment Units at Northern Arizona University