Advanced Wastewater Treatment

State Design Flow Library

Our Growing Design Flow Library

Most states in the US publish design flow charts to stipulate the capacity of wastewater systems. Here’s a list of residential and commercial design flow charts for new construction organized by state.

These documents have been downloaded from various regulatory agencies. Jurisdictions for any particular job will vary. Aqua Tech makes no certifications regarding the veracity, applicability, or relevance of the documents listed below.

Contact us for more on how to plan the wastewater component of your particular project:

Biological Sewer Sludge Treatment and Reduction

Aqua Tech’s biological process carries out complete sewer sludge treatment eliminating the need for a clarifier.

This sewer sludge treatment is based on biofilm technology. Biofilm is a dense community of attached-growth microorganisms living on specially designed plastic media. Having direct contact with wastewater, biofilm absorbs and oxidizes pollutants thus providing treatment. Multiple biozones ensure that an appropriate biological system develops according to the nature of wastewater composition. It supports dynamic balance on its own both in mass and qualitative composition according to variations of wastewater parameters (within the range of optimal adaptation rates and allowable values of design loadings).

depiction of three layer biofilm on plastic media

Multi-Chamber Design

Multiple chambers in our bioreactor create a series of ecosystems in which the excess biomass is digested and mineralized in successive chambers by higher level microorganisms. This process converts organic sludge into carbon dioxide, water and inorganic elements.

Each chamber houses specialized media to host the required microorganisms.

Specialized Bio-Film Media

floating media for wastewater biofilm

The first chamber of the bioreactor houses a smooth-surface floating media. The smooth surface coupled with high turbulence in the first chamber prevents high biofilm accumulation on the media.

Sloughed biofilm travels into the next chamber to be consumed by protozoa inhabiting porous media (Bio-Chip).

Floating media for biological film wastewater treatment plant

The Bio-Chip media mitigates biofilm overgrowth as the chips rub against each other under aeration. These unfavorable conditions on the outside of the Bio-Chip cause microorganisms to inhabit primarily the protected interior of the media. Treatment in this chamber is provided by slow-growing bacteria such as ANAMMOX which produce negligible biomass.

wastewater treatment biological reactor static media

Subsequent chambers facilitate the development of a complete trophic system with all four trophic levels. This means that the amount of bacteria are controlled by Protozoa and Metazoans that consume any surplus bacterial biomass.

The last chamber utilizes static media and minimal aeration intensity to ensuring high efficiency adsorption and mineralization of any residual suspended matter.

Nota Bene:

The above described is the conceptual model or ideology of the bioreactors which does not change if a bioreactor has just two or three chambers. Thus, any our biological process is designed so that effluent biomass amount is within the required effluent limit for TSS.

Whitepaper for BioTank biological reactor in wastewater treatment.

BioTank, Aqua Tech’s biological reactor, is the best value in wastewater treatment for residential and commercial development as well as for small to midsized communities. The following product details demonstrate BioTank’s durability, versatility, and efficiency.

Moving bed biological reactor with transparent background
A BioTank hot off the manufacturer’s floor

Aqua Tech’s BioTank bioreactors range in capacity from 160 GPD to 80,000 GPD. They can be installed modularly to build systems with a capacity over 1 million GPD.

Our stainless-steel package systems operate with minimal maintenance for decades. They provide a timely and cost-effective alternative to site-built treatment facilities.


The BioTank is a factory-made, multi-chamber aeration tank made of stainless steel AISI-304. It is equipped with fixed and floating media and an aeration system comprised of an air compressor, snorkel, regulator valves, hoses, and oxygen diffusers.

The various chambers facilitate the growth of stage-specific microbes ensuring progressively higher levels of treatment through each chamber.

AISI-304 stainless steel construction allows for above ground and inground installation.

State of the art media provides maximum biofilm surface area which results in smaller bioreactors that treat up to municipal standards.

The aeration system ensures optimal oxygen conditions for advanced biological wastewater treatment.

Biological Reactor Applications in Wastewater Treatment

As a biological reactor, BioTank isn’t suitable for treating water from sources with high concentrations of chemical contaminants such as storm water, drinking water treatment centers, boiler houses or factories.

The BioTank treated effluent quality allows its safe discharge into the environment or reuse for irrigation or other technical needs.

The BioTank can be designed to meet any effluent standards including advanced treatment required for sensitive areas.

A pristine waterfall at an RV and cabin resort with over 200 units serviced by a biological wastewater reactor
A pristine waterfall at an RV and cabin resort with over 200 units serviced by one little BioTank.

General Provisions

Installation of an Aqua Tech system with BioTank biological reactor will require:

  • Site prep including a poured concrete pad for the BioTank, drainage areas and access roads
  • Dedicated electrical power supply (usually 3-phase)
  • Specialized onsite treatment systems for all local sources of wastewaters which do not correspond to the BioTank application terms

Wastewater should be primarily treated prior to be pumped to the BioTank. The primary treatment should include mechanical treatment (coarse solids and grit removal), FOG (fats, oils and greases) removal, wastewater settling and flowrate equalization.*

Process Specifications

FOG (fats, oils, and grease) Removal

FOG level should be constantly monitored, preferably by means of sensors.*

Amount of FOG enter the BioTank should not exceed 50 mg/l.

If FOG concentration is permanently higher than 50 mg/l in any of local discharges, then it is necessary to apply specially selected biopreparation for FOG decomposition, for example, BioEaseTM4210.

If FOG concentration exceeds 100 mg/l, then it is necessary to build a local grease trap and use the biopreparation for FOG degradation.

Overhead diagram of a wastewater treatment system with methanol doser
Overhead diagram of a wastewater treatment system for mixed-use featuring two BioTanks operating in tandem.

Coarse Solids Removal

The feed pumps should be protected from coarse solids present in wastewater. Depending on a primary treatment technology Aqua Tech Systems offers a solution for the removal of coarse solids.

Grit Removal

Wastewater usually contains certain amount of grit and other mineral substances, which should be removed before wastewater feeding to the BioTank.

Primary Settling

Suspended solids (SS) concentration limit for biological treatment based on the biofilm process is 105 mg/l. As raw wastewater usually has higher SS content (> 105 mg/l), primary settling should be introduced.

Primary Sludge Accumulation and Digestion

Primary sludge volume and odor are significantly reduced through the addition of a biopreparation such as Bacti-Bio 9500.

The sludge level should be constantly monitored by means of an automatic sludge level sensor or manual Sludge Judge device. Sludge removal and disposal should be handled by a certified contractor as needed (usually every 3-5 years).

Flowrate Equalization and Feeding

Aqua Tech installs flowrate equalization systems to minimize BioTank size and maximize performance.

Wastewater equalization enhances biological treatment by minimizing shock loads, diluting inhibiting substances, and stabilizing pH.

The assumed wastewater feeding duration to the BioTank is at least 18 hours/day.

The assumed feeding volume is:

v = Qday / 18, m3/hour, where Qday is wastewater amount per day

Aqua Tech Systems provides necessary settling-digestion and wastewater flowrate equalization tanks of the required volumes which are plastic or ferro-concrete.

Installation of precast concrete tank for wastewater settling and equalization
A combination settling and equalization tank being installed in Alabama

Phosphorus Removal

If required, phosphorus is removed during primary settling through the addition of coagulant.

Biofilm cannot remove more than 1-1.5 mg/l of phosphorus. The formed biocenosis of the biofilm, being in a state of dynamic equilibrium, does not produce biomass and, accordingly, does not consume phosphorus.

Wastewater processing with coagulant ensures efficient organics reduction and reduces the phosphorus below 1.0 mg/l.

Where required, Aqua Tech provides a coagulant dosing apparatus at the primary treatment step.

Biological Treatment

Process Characteristics

BioTank’s biological wastewater treatment process is based on the biofilm technology. Biofilm is a dense community of attached-growth microorganisms living on specially designed plastic media. The surface of the biofilm treats wastewater by absorbing and oxidizing pollutants. Multiple biozones within the layers of the biofilm create a self-cleaning, self-sustaining ecosystem. The biofilm develops the microorganism diversity necessary for maximum treatment in each application. Due to efficient ecosystem development in the BioTank there is no excess biomass growth.


Incoming organics are sequentially oxidized by isolated biocenoses of microorganisms living on media retained within the borders of each aeration chamber. The media is submerged in water.

Oxygen supply and mixing are provided by aeration.

Due to change of oxidation rate at each process stage – from high on the first stage to low on the last stage – the loads on biocenoses and water saprobity vary from high to low accordingly.

In response to changing environmental conditions and amount of dissolved oxygen, the treatment process occurs as follows:

  • Stage One – sorption and oxidation of dissolved organic matter, adsorption of suspended solids and colloids and hydrolysis (fermentation) of suspended solids and colloids
  • Stage Two – sorption and oxidation of dissolved organics,
  • Stage Three – biofiltration (biosorption)
process flow wastewater package plant diagram for commercial sewage treatment system
Process flow diagram for a commercial application with heavily contaminated influent.

Oxygen Conditions

Oxygen supply is provided by aeration. The oxygen mode is a function of organic load, biofilm density and thickness, and wastewater temperature.

The required amount of dissolved oxygen for each process stage should be optimized and adjusted according to the Aqua Tech Systems recommendations at start-up and follow-up analysis.


The Biotank’s biofilm process configuration creates conditions for simultaneous nitrification and denitrification.

The corresponding environment allows formation of layered biocenosis. The layers are determined by the amount oxygen diffusion into the biofilm.

The biofilm surface is the aerobic layer which creates conditions for heterotrophic microorganisms to partially oxidize and reduce ammonium along with oxidation of organic matter.

The internal mass of the biofilm is the anaerobic layer that creates conditions for development, growth and accumulation of specific autotrophic microorganisms (ANAMMOX) which oxidize and reduce the main part of incoming ammonium.

Biofiltration (Biosorption)

Biofiltration or biosorption occurs in the BioTank on a static media.

In low load conditions bacteria release a significant amount of exopolymers capable to capture and retain solids during contact. In turn, solid substances captured by the biofilm (bacteria, organic matter) serve as a food for predators and detritophages that results in reduction of suspended solids amount.

It should be noted here that bacteria and predators create symbiotic relationship after a number of successions, under which predators regulate their quantitative and qualitative composition in a strict accordance with incoming food amount.

Also the significant input in clarification comes from attached stalked ciliates (Peritrichia). The peritrichs provide themselves with food by filtering large amounts of water. One individual is able to consume up to 30,000 bacteria per hour. This way peritrichia provide a high degree of biological disinfection, destroying pathogenic microorganisms.

Low organic load and high amount of dissolved oxygen in the biofilter provide partial ammonium removal.

Ammonium bio-oxidation is carried out in two stages, by two types of chemoautotrophic bacteria:

2NH4+ + 3O2Nitrosomonas = 2NO2- + 2H2O+4H+

2NO2- + O2Nitrobacter = 2NO3

man at advanced wastewater treatment system testing effluent levels


Formation of the biofilm occurs spontaneously based on the set and maintained level of dissolved oxygen in each chamber. The biofilm reaches dynamic equilibrium as it develops through the initial operating period. Once this happens treatment process performance meets the project requirements.

Under conditions of actual loadings correspondent to the design specifications biocenoses fully mature:

  • For “B” bio-oxidation process – within four weeks
  • For “N” bio-oxidation and nitrification process – within one year.

The actual treatment efficiency should be at least 95.99% of the calculated one.

If necessary, the achievement of treatment quality for the process “N” can be accelerated by the use of methanol. Methanol provides an additional food source for heterotrophs which thereby multiplying their population. Due to lack of oxygen, heterotrophic microorganisms use oxygen from nitrates, thus reducing oxidized nitrogen. In this case it is possible to reach at least 90% of all required parameters within 60 days from start-up.

*Sold and supported by Aqua Tech Systems.

What is Eutrophication?

Eutrophication is plant overgrowth in domestic waterways.

green grass on water
Photo by cottonbro on

Wastewater contains nitrate and phosphorus which are nutrients that plants need to grow. Usually, nutrients are good things, but growing population density can result in too much of a good thing being deposited into streams, rivers, and other waterways. When this happens, plant life takes over – crowding out the habitats of fish and other aquatic life. As these plants die and rot, they can change water PH and bacterial levels.

To stop eutrophication, wastewater treatment systems need to greatly reduce or eliminate the amount of nitrate and phosphorus which they return to the watershed in their effluent. Governmental agencies set concentration maximums and enforce them through regular testing.

For the most part, nitrate and phosphorus can be reduced below regulatory thresholds through biological processes known as denitrification and mineralization. Advanced wastewater treatment systems use highly concentrated populations of beneficial bacteria to digest nitrate and phosphorus. The former is then released as nitrogen gas and the latter, collects in the tank as part of the sludge.

Even after advanced treatment, trace amounts of nitrate and phosphorus can frequently be found in wastewater effluent. Where mandated, further treatment can completely prevent even these from reaching the watershed.

If you’re in need of a wastewater system that will prevent eutrophication, let’s talk!

Drip irrigation systems are an efficient and proven technology many communities use to recycle and dispose of treated wastewater. The effluent is applied to the soil slowly and uniformly from a network of narrow tubing, placed in the ground at shallow depths of 6 to 12 inches in the plant root zone.

Because water is such a precious commodity, recycling wastewater can have both economic and environmental benefits for communities. Reusing wastewater to irrigate land can help protect surface water resources by preventing pollution and by conserving potable water for other uses. This is particularly important where community water supply sources rely on wells. The more water that is pumped from wells and discharged as effluent into a stream or other surface water, the less will be available to recharge aquifer or groundwater sources upon which future well water supplies rely.

Another benefit of applying wastewater to the land is that the soil provides additional treatment through naturally occurring physical, biological and chemical processes. Irrigating with wastewater also adds nutrients and minerals to soil that are good for plants and it helps to recharge valuable groundwater resources.

Residential developments with low building density required by septic drain fields contribute to an undesirable sprawl and limit land available for playgrounds, hiking trails, and other open space amenities. Spray systems, while superior to septic, can also limit land use since they produce aerosols that require large buffer zones.

Community sewers that use drip irrigation consolidate undersoil treatment into one region of the subdivision. This region can provide a visually appealing common area for the development. Achieving higher land use densities with desirable open spaces are important and shared goals of land use planners, environmentalists, and developers alike.

Soil reuse systems require less monitoring and thus lower operating costs when compared to surface discharge.

Additionally, subsurface discharge expedites the acquisition of state and county permits by addressing potential concerns of downstream property owners removing any reason for them to contest approval.

Beneficial reuse through drip irrigation is just another way we’re equipping responsible growth. Click the button below to see how we can equip you.
architecture backyard brickwalls chimney
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Advantages over septic:

  • Increased building density. They don’t require big drain fields on each lot.
  • Longer lasting. Land disposal through drip irrigation doesn’t become spent through built-up solids like septic leach fields.
  • Much better for the environment. Decentralized systems treat wastewater through accelerated natural processes, thereby eliminating water-borne pollution.

Advantages over municipal systems:

  • Sooo much cheaper! Decentralized systems reduce or eliminate the need for miles of large diameter pipe and lift stations.
  • No smell. Designed to be small and efficient, they treat so fast that there’s no detectable odor outside of a few feet from the system.
  • They facilitate development in growth areas without increasing tax burden or contributing to suburban sprawl.
  • They keep water in local aquifers rather than sending it downstream.

Talk to an expert!

(479) 530-7922

One of the biggest challenges to implementing comprehensive land use plans is how to accommodate new development in locally designated growth areas that do not have public sewers. Many rural and suburbanized towns in the US face this question.

They want to direct growth to the most suitable areas of town – near existing services, such as fire stations and schools, for example – but have no prospect of gaining access to public sewer lines. New development must rely on soils, usually on a lot by lot basis, to handle wastewater. The conventional wisdom says that means low densities of development, negating the effectiveness of a growth area. However, towns and counties without public sewer systems have options that they may not realize.

four tank wastewater system behind green metal fence

Additionally, watersheds in the United States reflect tremendous diversity of climatic conditions, geology, soils, and other factors that influence water flow, flora and fauna. There is equally great variation in historical experience, cultural expression, institutional arrangements, laws, policies and attitudes. With regards to wastewater issues, it would be a mistake to impose a standard model from the federal level to address the needs on a local level. Correspondingly, centralized
sewer systems are aging, frequently underfunded with respect to replacement costs and expensive to maintain. In addition, centralized sewer strategies are increasingly challenged by environmental and social considerations such as inter-basin transfer issues, aquifer depletion, nutrient loading and urban sprawl.

blue and gray concrete house with attic during twilight
Photo by Binyamin Mellish on

Decentralized wastewater management has the potential to be the catalyst for the re-creation of our institutions, to support a new agenda, and for rapidly building a flexible infrastructure to sustain the integrity of the natural systems that are essential to a healthy economy.

Tom Bartlett – founder and Ceo of aqua Tech

The new emerging civic agenda of smart growth, community preservation, open space planning, ecologically sound economic development, resource conservation, and watershed management demands that we rethink what constitutes assets and liabilities. With a capacity of roughly 200,000 gallons per day, these off-grid plants can be constructed at a cost of well under $3,000 per home. These are economic, environmental and quality of life issues and they do not lend themselves to single purpose solutions. They require local community based consideration within the context of flexible multipurpose planning.

Statistics have shown us that within the U.S., twenty-five percent of existing residential real estate and forty-seven percent of new construction are served by onsite treatment systems. Many of these systems are acknowledged to be inadequate with respect to soil absorption, nutrient removal, resource protection and public health. Ironically, despite these statistics and EPA policy changes, most regulatory codes as well as most municipal and commercial planning continue to consider onsite systems to be temporary solutions awaiting a centralized sewer hookup.

male constructor drawing draft on paper roll
Photo by Andrea Piacquadio on

Looking beyond the traditional assumption that wastewater is simply a matter of safe disposal and the public health; the real contemporary wastewater issues are the economic and environmental issues in which the public has a primary interest:

  1. Drinking water quality
  2. Deterioration of recreational water resources and other natural systems services
  3. Property Values
  4. Economic development in small and rural communities
  5. Urban sprawl

Beyond just disposal, decentralized wastewater management has the potential to contribute to the formation of an infrastructure to sustain watershed integrity. Decentralized wastewater treatment serves the “watershed agenda” and the principles of “community preservation” and “sustainable development.”

When approaches to the larger wastewater issues are successfully accomplished everyone benefits:

  1. Local communities win open space zoning, water quality and supply protection, increased development capacity and an expanding tax base.
  2. Natural systems are sustained through prudent zoning and reduction of non-point pollution.
  3. Developers win additional lots for development and higher margins typically associated with conservation subdivision design and municipal infrastructure.
  4. Regulatory agencies win because they gain partners in compliance management such as the municipality and perhaps a watershed authority.
  5. Citizens and homeowners win because property values are enhanced as schools, healthcare providers, and retail outlets crop up around the new infrastructure which decentralized systems provide.
clouds country countryside dirt road
Photo by Pixabay on

There are no major obstacles to a decentralized infrastructure for wastewater treatment.

New technologies in a properly managed context provide the opportunity for a land based watershed initiative that could significantly reduce small flow point source discharges such as those associated with onsite treatment systems. A decentralized wastewater management infrastructure should include:

  1. Clustered, performance-based, decentralized wastewater management systems
  2. Industrial & commercial pretreatment prior to discharge to existing sewage treatment systems
  3. Wastewater reuse systems

Estimates suggest that this infrastructure is achievable with technologies that require 50% to 70% less space with corresponding reductions in cost of 40% to 50%. For citizens in small and rural communities these reductions represent opportunities to preserve water quality, to stimulate economic development and job formation and to restore property values. Essentially, we are shifting from large sewage collection systems and centralized treatment plants to small and decentralized management systems. Keep in mind also that this is not an alternative to centralized sewer. Rather, it is a complimentary adjunct to the existing infrastructure.

Moreover, the decentralized solution is coming from local community and watershed needs. It is not coming from the bureaucracy. It is essentially good old bottom-up American pragmatism. It is important, therefore, that the general population becomes informed about the benefits of the decentralized approach. We must find a suitable mechanism to accelerate the progress to support watershed management. If we can not find such a mechanism, we run the risk of letting the limited existing strategies (centralized and onsite) dominate the next 20 to 30 year cycle.

Same Destination – Different Paths

With every project being considered for an Aqua Tech System, planners must consider many factors in the selection of an appropriate site specific wastewater collection system.

Such as:

  • Housing density and road frontage
  • Size of the project and wastewater volume to be conveyed
  • Topography and sensitive natural resources
  • Depth to bedrock or groundwater
  • Distance to the wastewater treatment and dispersal site
The Settling Tank getting a final inspection

During the design process of your system the following methods should be considered:

  • Conventional gravity systems (with lift stations as required)
  • Septic Tank Effluent Gravity (STEG) system (AKA small diameter gravity sewers)
  • Septic Tank Effluent Pump (STEP) pressure system
  • Grinder pump pressure sewer system
  • Vacuum

These collection or conveyance systems often represent the major portion of the total capital cost associated with any wastewater system, so careful consideration should be made to avoid extraneous expense while also ensuring reliability and environmental compliance.

Let us help you design a system that takes everything into account.

Several places around the US are currently experiencing a construction boom and we’re delighted to be a part of it. Here’s a mixed use system that our engineers have just designed.

This system is designed to treat 37,000 gallons of wastewater per day.

This particular system was designed to treat residential and commercial wastewater at the same time. Notice that the effluent (outflow) discharges at ground level. This is a septic system with no leach field!

Here’s the secret:

This private wastewater treatment plant removes nearly all of the Biological Oxygen Demand (BOD), Total Suspended Solids (TSS), and Total Nitrogen (TN).

Got an enquiring mind? Here’s an overhead view of the same sewer system design:

Here’s what a similar system looks like in real life:

Wastewater treatment plant overhead view
A 3-tank in-ground system with a methanol doser and all-weather controls

Whether you’re an engineer or a real estate developer, we can help you put together a system to meet your needs. Just click the button below!

“STEP” stands for Septic Tank Effluent Pump

We put this Effluent Pump…

…into this Septic Tank (not to scale).

Here’s a video:

A video slideshow on the benefits of STEP Collection

Here are the gory details:

Technical schematics for STEP collection

Here’s how it looks when we’re done.

STEP tank installed

Our STEP system creates a pressurized, small pipe influent delivery structure to the treatment plant which eliminates the need for the expensive piping and lift stations that gravity systems require. This means that developers can cut their cost as well as defer some of that reduced cost of the community wastewater system until lots are sold. Since each home shoulders some of the load associated with wastewater treatment, the initial cost and maintenance can be distributed to the homeowners as well.

Beyond reducing development cost, STEP technology further enhances effluent water quality by leaving the majority of the solids at the point of origin where they can degrade through anaerobic processes. The effluent leaving the tank at the home then becomes the influent which the next component in the Aqua Tech system will treat through aerobic processes.

STEP Over to Treatment

A process flow diagram for a 25000 gallon per day wastewater treatment system using STEP Collection
After STEP Collection, the effluent travels under low pressure to a system like this.

When we say that our systems are the best, here’s a bit of what we mean.

Major components of the BioTank system are constructed of carbon steel or stainless steel, with plastic or zinc coated steel for railings and fences. The unit provides ready access to each treatment compartment facilitating operation and maintenance procedures. The media blocks are easily removed from each treatment compartment for inspection or plant maintenance.

Random packed media that is biologically inert and mechanically durable enhances oxygen transfer.

The oxygen delivery system comes self-contained within each BioTank.

An efficient oil-less compressor with few moving parts supplies dissolved oxygen to the treatment process. Low noise and vibration is a positive design characteristic associated with these

A 304 stainless steel exterior or NEMA 4X mountable control cabinet is provided with each
BioTank. Each cabinet contains the control logic to automate the function of the compressor, sludge airlift, coagulant dosing pump and cabinet heater if necessary.

The BioTank treatment plants can be supplied with separate or attached offices, laboratories and mechanical equipment rooms.

wastewater treatment system inside large building
BioTank installed in a metal building

The BioTank treatment plants may also be supplied with bar racks or screens, grit chambers, flow meters, chemical dosing equipment, UV disinfection modules and sludge dewatering systems.

All of our systems are completely customizable to perfectly fit your needs. Click the button below to speak with a member of our sales team.

Removing ammonia nitrogen from wastewater is a well-established and quantifiable
biological process. Nitrogen exists in the influent primarily in the form of organic nitrogen
and ammonia nitrogen (Total Kejldahl Nitrogen + TKN). The principal part of the organic
nitrogen is mineralized to ammonia nitrogen through bacterial activity. Therefore,
ammonia-N is commonly regarded as the starting point in the nitrogen reduction process.

A diagram of showing the process of ammonium in wastewater being converted to nitrogen gas.
Wastewater nitrification and denitrification take place in our BioTank

Nitrification: the conversion of ammonia nitrogen (NH3-N) to nitrate nitrogen (NO3-N) is a
biological process accomplished in the presence of dissolved oxygen. Typical
requirements for effluent ammonia-N are from 1 to 3 mg/l, which is reliably accomplished.
Successful nitrification is accomplished with a healthy microorganism population and an
environment where PH, temperature, alkalinity, organic loading and dissolved oxygen are

In the BioTank system the pH is generally buffered by the carbonate system
associated with the wastewater; the temperature remains consistent due to the biological
activity in the plant; the organic loading is relatively constant because the wastewater has
been treated in the first compartment(s) of the plant; and the compressor provides an
adequate supply of dissolved oxygen.

Nitrification/Denitrification Table

Facultative heterotrophic organisms under anoxic conditions accomplish biological
denitrification. In this process bacteria convert the nitrate-N to nitrogen gas
that is released into the atmosphere.

Denitrification occurs by several different means and though process control adjustments.
As the microorganisms multiply, the biological film thickens on the submerged media and
the diffused oxygen is consumed before penetrating the full depth of the slime layer.
Consequently the film develops aerobic, anoxic and anaerobic zones. This process accounts for significant nitrogen removal via simultaneous nitrification and denitrification.

Denitrification utilizing septic tank carbon is widely considered to be the most economical
and efficient method for nitrogen removal. Utilizing prescribed recirculation rates this
method of returning BioTank nitrified wastewater to the carbon source in the anoxic zone
of the primary tank has achieved reductions of nitrogen of approximately 80 percent.

Nitrogen removal may be enhanced further in a tertiary anoxic zone located after the
aerobic treatment.

To learn more about this critical process and how Aqua Tech can help you utilize it, click the button below.

As these media get smaller, their treatment capacity goes up.

Biofilm. It’s not a documentary narrated by David Attenborough; it’s the organic factory that cleans wastewater in our BioTank biological reactors. Biofilm is a population of microorganisms that attach to a filter media and form a biological slime layer. As wastewater flows over the biofilm, the microbes consume the organic material. This means that the more square meters (m2) of biofilm present within a treatment system, the more treatment can take place. Earlier aerobic treatment tanks used suspended growth and fixed film systems which could treat wastewater down to TSS (Total Suspended Solids) and BOD5 (Biological Oxygen Demand) concentrations as low as 20mg/L. Those are impressive numbers compared to traditional onsite system effluent, but those older systems had to be especially large to accommodate a large enough population of microbes to get the job done. Also, treatment was quite slow requiring several days.

But those days are over!

example of a floating biofilm medium
Our treatment systems feature hundreds of these floating media

Aqua Tech’s BioTanks feature one or more* chambers filled with floating biofilm media. These media hold the slime layer rather than allowing the microorganisms to contribute to the suspended solids as with suspended growth systems. Because they move around through the wastewater, they treat more efficiently than fixed film.

How efficiently?

We actually have numbers to answer that question. Remember that when it comes to biofilm, more square meters means more treatment. More square meters per cubic meter (m3) means more treatment in less space – greater efficiency. Our floating media incorporates an incredible amount of surface area per cubic meter. With highly advanced production methods, we can now offer very small media with very high m2/m3 (square meters per cubic meter).

The evolution of floating biofilm media…

Five sizes of wastewater biofilm media
As the media get smaller, the biofilm gets larger.

The photo above shows five generations of floating biofilm media. Let’s look at the m2/m3 for each of them.

This one is a little smaller than a shot glass. It can host 440 square meters of biofilm to every cubic meter of treatment tank.

This one is about the size of a thimble. It’s surface area per cubic meter is over twice the amount of the first one.

This one could fit in a half teaspoon. It’s surface area is 2200 m2/m3.

Now get ready for an evolutionary jump!

Talk about biological engineering. Look at that thing! This little Pringle-shaped wafer boasts 4000 square meters per cubic meter.

It’s this kind of technology that enables Aqua Tech systems to treat down to <10mg TSS & BOD5 within a tiny footprint. And now, with a demand for high efficiency Single Family systems, we’re pushing the boundaries even further.

This little guy is smaller than a nickel. All of those tiny holes translate into a whopping 5000 square meters of biofilm per each cubic meter.

But the Biochips aren’t just pretty to look at. See them at work below!

Let us put one of our high tech wastewater treatment systems to work for you today! Just click the button below to get started.

*Number of chambers containing floating media varies by model and application