Biological Processes for COD, Ammonium, and Nitrogen Removal
Have a biological wastewater treatment system designed
Maksim Neubauer
Head of International Project Development
What is aerobic biological wastewater treatment?
In aerobic biological wastewater treatment, microorganisms use oxygen to reduce biodegradable organic compounds in industrial wastewater. Depending on the process conditions, in addition to COD and BOD, ammonium and nitrogen can also be treated biologically.
Under aerobic conditions, microorganisms biologically break down available organic carbon compounds. With proper process control, ammonium is additionally oxidized through nitrification, first to nitrite and then to nitrate.
For further nitrogen removal, aerobic process stages can be combined with anoxic phases or reactor zones. Under anoxic conditions, previously formed nitrate is reduced to elemental nitrogen through denitrification.
Aerobic biological wastewater treatment uses microorganisms and oxygen to remove biodegradable organic matter from wastewater. Through nitrification and supplementary anoxic denitrification, additional amounts of ammonium and nitrogen can be reduced.
Which substances can be removed biologically from industrial wastewater?
Which substances can be biologically reduced depends on their biodegradability, the composition of the wastewater, and the process configuration selected. The primary functions of aerobic biological treatment plants are carbon removal and nitrogen treatment.
CSB and BSB
Biologically available organic carbon compounds are metabolized by heterotrophic microorganisms. This helps reduce the COD and BOD loads in the wastewater .
Ammonium
Nitrifying microorganisms oxidize ammonium under aerobic conditions, first to nitrite and then to nitrate.
Total nitrogen
During anoxic process phases or in reactor zones, nitrate can be reduced to elemental nitrogen through denitrification and thus removed from the wastewater.
Biodegradable trace substances
Depending on the composition of the wastewater, biological systems can also reduce other biodegradable organic compounds . The actual biodegradability is evaluated on a project-by-project basis.
Technical Comparison of Aerobic Biological Processes
SBR, MBBR, MBR, activated sludge, and biofiltration differ primarily in terms of biomass retention, operating mode, solids separation, and reactor design. The technical comparison highlights the fundamental differences between the processes, regardless of the ultimate project-specific selection.
| Procedure | Biomass Principle | Mode of operation | Solid-Liquid Separation | Technical Feature |
|---|---|---|---|---|
| SBR | Suspended activated sludge | Discontinuous / cyclical | Sedimentation directly in the SBR reactor | Biological reaction and sedimentation occur sequentially in the same reactor |
| MBBR | Biofilm on freely moving carriers | Continuously | Separate removal of discharged biomass | High active biomass density due to biofilm on movable growth substrates |
| MBR | Suspended biomass | Usually continuously | Membrane Filtration / External UF | Biological treatment and external ultrafiltration are combined |
| Activated sludge | Suspended activated sludge | Continuously | Secondary clarification with biomass recirculation | Spatial separation of the biological reaction and sludge removal |
| BAF / Biofiltration | Biofilm on a solid filter or support material | Continuously | Filtration within or across the filter bed | Biological biofilm treatment and filtration are combined in a single process step |
Aerobic processes differ primarily in terms of how the biomass is retained within the system and how the treated water is separated from solids. The final choice of process also depends on COD/BOD load, nitrogen load, temperature, load profile, space requirements, and required effluent quality.
Our Aerobic Biological Wastewater Treatment Plants
ALMAWATECH offers various biological treatment processes for industrial wastewater. The selection and design are determined on a project-by-project basis based on wastewater analysis, load profile, and required effluent quality.
ALMA BIO SBR
The ALMA BIO SBR is a cyclically operated biological reactor for industrial wastewater streams with varying loads and intermittent wastewater inflow. Filling, biological reaction, sedimentation, and clear water discharge occur sequentially within the same reactor.
- Fluctuating Production Wastewater
- Batch-wise wastewater generation
- CSB and BSB Degradation
- Nitrification and Denitrification
- Compact biological treatment plants
ALMA BIO MBBR
In the ALMA BIO MBBR system, the active biomass grows on freely movable plastic carriers. The large biologically active surface area enables a compact biofilm technology for organic degradation, nitrification, and nitrogen removal.
- High or fluctuating COD loads
- Ammonium Degradation
- Nitrogen elimination
- Expansion of Existing Biological Treatment Plants
- Compact Biofilm Stages
ALMA BIO MBR
The ALMA BIO MBR combines biological wastewater treatment with external ultrafiltration. The biomass is retained in the biological stage, while the external UF handles solids removal, thereby ensuring a very low solids load in the effluent.
- High Standards for Process Quality
- Water Reuse Applications
- External UF for Biomass Retention
- Biology and Membrane Filtration Combined
- Industrial Process Water Reuse
ALMA BHU BIO
The ALMA BHU BIO is a custom-designed biological activated sludge system for large industrial wastewater flows. Depending on the treatment objective, aerobic and anoxic process stages are combined with sedimentation and biomass recirculation.
- Large industrial wastewater streams
- Continuous Production
- CSB and BSB Degradation
- Nitrification and Denitrification
- Custom-designed large-scale plants
ALMA BIO BBI
The ALMA BIO BBI is a compact biological wastewater treatment plant based on the activated sludge process. Biological reaction and solids separation are combined in a compact plant design for small- to medium-sized volumes of industrial wastewater.
- Compact Biological Treatment
- CSB and BSB Degradation
- Integrated Sedimentation
- Small and medium-sized wastewater flows
- Industrial wastewater containing biodegradable pollutants
ALMA BHU DEA
The ALMA BHU DEA is designed for the biological removal of nitrogen from ammonium-rich wastewater. The deammonification process combines partial nitrification with anammox-based nitrogen conversion.
- Industrial wastewater high in ammonium
- Advanced Nitrogen Removal
- Partial nitrification
- Anammox process
- Project-Specific Biological Design
Other aerobic biofilm processes
In addition to SBR, MBBR, MBR, and activated sludge systems, ALMAWATECH offers biofiltration systems for various hydraulic capacities, biological post-treatment, and water reuse applications.
ALMA BHU BAF
Biologically Activated Filtration for High Water FlowsThe ALMA BHU BAF combines biofilm processes with filtration and is suitable for the biological degradation of organic substances as well as for nitrification and denitrification.
ALMA BioFil Compact
Compact Biofiltration for Industrial Water Recirculation SystemsThe ALMA BioFil Compact is suitable for compact biological applications as well as the treatment of water recirculation systems or permeates, and can be used as a pretreatment for further membrane processes. ```
Have an aerobic wastewater treatment system designed:
Maksim Neubauer
Head of International Project Development
SBR, MBBR, MBR, or biofiltration—which process is the right one?
The selection of an appropriate biological process depends on the wastewater composition, the load profile, the hydraulic boundary conditions, and the required effluent parameters. Depending on the application, different biological technologies may be technically and economically viable.
| Initial situation | Technology That Is Often Suitable |
|---|---|
| Highly fluctuating or batch-based inflow | SBR |
| High process robustness combined with a compact design | MBBR |
| Very high-quality treated water or water reuse | MBR |
| Continuous large volumes of industrial wastewater | Activated sludge process |
| Biological Post-Treatment or Polishing | BAF / Biofiltration |
| Existing biological treatment plant to become more efficient | Often MBBR or an additional biofilm stage |
| Ammonium must be reliably nitrified | SBR, MBBR, BAF, or activated sludge – project-specific selection |
There is no single biological process that is equally optimal for every type of industrial wastewater. ALMAWATECH selects the appropriate technology based on the actual wastewater analysis, hydraulic and organic load profiles, and the required effluent parameters.
Aerobic or anaerobic wastewater treatment—what's the difference?
Both aerobic and anaerobic processes use microorganisms for biological wastewater treatment, but differ fundamentally in terms of oxygen requirements, process control, and applications.
Aerobic Wastewater Treatment
Aerobic microorganisms require oxygen for the biological conversion of organic compounds. Aerobic systems are particularly suitable for the advanced treatment of wastewater, the degradation of COD and BOD, the nitrification of ammonium, and—in combination with anoxic process stages—nitrogen removal.
Anaerobic wastewater treatment
Anaerobic microorganisms function without a supply of oxygen. Industrial wastewater with a high organic load can thus be biologically pretreated. In this process, part of the organic load is biologically converted into high-energy biogas.
Combining Aerobic and Anaerobic Processes
For heavily contaminated industrial wastewater, an anaerobic pretreatment can be combined with an aerobic post-treatment. The anaerobic stage first reduces a significant portion of the organic load. The downstream aerobic biological treatment stage then takes over further COD removal as well as—depending on the plant design—nitrification and nitrogen removal.
Anaerobic Wastewater TreatmentCase Studies on Aerobic Biological Wastewater Treatment
Sugar Industry, Pemuco, Chile
Nitrification and denitrification with integrated degassing and sedimentation for a wastewater flow rate of 120 m³/h.
Abraham Benelux S.A., Belgium
Compact biological wastewater treatment plant in a container design with a capacity of 35 m³/d.
Paper mill, Southern Germany
Removal of biologically difficult-to-degrade COD via biofiltration at a flow rate of 700 m³/h.
Sugar Industry, Germany
Anaerobic treatment and aerobic post-treatment for 220 m³/h from the sugar industry.
Dairy, process water, Germany
Biofiltration for further COD removal in the water reuse process, designed for 600 m³/d.
Top Harvest Yanchang Coal, China
Biological wastewater treatment for 1,500 m³/h with an upstream DAF stage for the pretreatment of refinery wastewater.
Automation of Biological Wastewater Treatment Plants
Biological treatment performance depends largely on oxygen supply, hydraulic load, temperature, and organic load. ALMAWATECH therefore combines aerobic biological processes with project-specific measurement and automation technology.
Typical Parameters in Biological Wastewater Treatment Plants
Typical Industrial Applications of Biological Wastewater Treatment
Aerobic biological wastewater treatment is used in numerous industrial sectors when organic pollutants, ammonium, or nitrogen need to be reduced biologically.
Food industry
Biological treatment of industrial wastewater with high and frequently fluctuating organic COD and BOD loads.
Beverage Industry & Breweries
Degradation of highly bioavailable organic pollutants as well as nitrification and further nitrogen removal.
Dairies
Treatment of highly organic wastewater with high COD/BOD loads and significant fluctuations in production.
Paper & Packaging Industry
Primary or secondary biological treatment of organically contaminated process wastewater from industrial production processes.
Chemical industry
Treatment of suitable biodegradable stream fractions following pretreatment tailored to the wastewater composition and potential inhibitors.
Pharmaceutical & cosmetics industry
Biological treatment of production and cleaning wastewater containing organic pollutants, following an assessment of its biological degradability.
What data do we need to design a biological wastewater treatment plant?
To select the appropriate process and ensure reliable design, we need information on the hydraulic load, biodegradable load, nitrogen load, and the desired effluent parameters.
Key Data for Initial Process Selection
- Average and Maximum Flow Rate
- Daily and Weekly Profiles
- COD
- BSB
- Dissolved and Total CSB
- Ammonium nitrogen
- Total nitrogen
- Phosphorus
- pH value
- Wastewater Temperature
- Solids content
- Conductivity
- Peak loads
- Production Times
- Existing Pretreatment
- Desired flow rates
- Known inhibitors or contaminants
- Existing pools and available installation space
Which biological wastewater treatment method is right for your wastewater?
Please send us your wastewater analysis, flow rate data, and desired discharge parameters. Our process engineers will determine whether SBR, MBBR, MBR, activated sludge, biofiltration, or a combination of several processes represents the technically and economically suitable solution.
Design and Construction of an Aerobic Wastewater Treatment Plant
Technical documentation and data sheets for aerobic wastewater treatment systems
Photos of aerobic wastewater treatment plants
Frequently Asked Questions About Aerobic Wastewater Treatment Systems
What is aerobic biological wastewater treatment?
In aerobic biological wastewater treatment, microorganisms use oxygen to break down biodegradable organic matter in the wastewater. Depending on the process configuration, ammonium can also be nitrified and nitrogen removed through anoxic denitrification.
Which biological wastewater treatment method is best suited for industrial wastewater?
This depends on the wastewater composition, load, flow rate, and effluent requirements. For example, SBR is well-suited for fluctuating or intermittent wastewater flows, while MBBR is a compact biofilm technology, and MBR is particularly suitable when effluent requirements are high.
What is the difference between SBR, MBBR, and MBR?
In an SBR, biological treatment and sedimentation occur sequentially within a single reactor. In an MBBR, the biomass grows on movable carriers. An MBR combines biological treatment with membrane filtration to separate solids.
Can a biological treatment system be used even when wastewater loads fluctuate significantly?
Yes. Processes such as SBR or MBBR can be specifically designed to handle fluctuating hydraulic and organic loads. However, the actual load profiles and potential production peaks are the decisive factors.
When is pretreatment necessary before the biological stage?
Pre-treatment may be necessary if the wastewater contains high levels of solids, grease, heavy metals, or other biologically inhibitory substances. Depending on the application, screening, flotation, neutralization, or physicochemical treatment may be performed as preliminary steps.
Can an existing biological wastewater treatment plant be expanded?
Yes. Depending on the tank geometry and treatment objective, existing biological treatment systems can be expanded, for example, by adding additional biofilm stages, MBBR carriers, biofiltration, or additional reactor lines.
How important is wastewater temperature for biological treatment?
Temperature has a significant impact on the activity and growth rate of microorganisms. Nitrification, in particular, is sensitive to low temperatures, which is why temperature must be taken into account when sizing the system.
Can aerobic biological wastewater treatment be used for water reuse?
Yes. Aerobic biological treatment can be a key component of water reuse concepts. In particular, MBR and biofiltration systems can be used as a biological pretreatment stage prior to further membrane processes such as ultrafiltration or reverse osmosis.
Our Anaerobic Wastewater Treatment Plants
ALMA BHU BIO
The ALMA BHU BIO System combines nitrification, denitrification, and sedimentation with biomass recirculation to increase conversion rates.
ALMA BIO BBI
The ALMA BIO BBI system is characterized by its integrated sedimenter, which makes it extremely space-saving compared to similar systems.
ALMA BAF
Biologically activated filtration (BAF) uses sessile microorganisms to remove organic compounds (BOD, COD) and nitrogen from wastewater.
ALMA BIO MBBR
Biological wastewater treatment using free-floating biofilters for the efficient reduction of carbon and nitrogen compounds.
ALMA BIO SBR
A sequentially operated bioreactor with distinct phases for biological treatment, sedimentation, and clear water discharge.
ALMA BHU BIO DEA
Biological deammonification process for energy-efficient nitrogen removal from wastewater with high ammonium content and low oxygen demand.
ALMA BIO Compact MBBR
Containerized MBBR system for biological wastewater treatment, offering high treatment capacity per unit area and rapid integration into operations.
ALMA BioFil Compact
Our compact biologically activated filtration in tank design, equipped with special growth bodies for effective biomass growth.
ALMA BIO MBR
Membrane bioreactor with submerged plate modules or an externally mounted ultrafiltration unit in a robust tubular module design.
Have wastewater data reviewed
Maksim Neubauer
Head of International Project Development