Biological Wastewater Treatment – DAS Offers Tailor-Made Systems for the Treatment of Industrial and Sanitary Wastewaters

Industrial enterprises and municipalities are always on a look out for optimal wastewater treatment solutions. However, the demands on biological wastewater treatment are unique to each individual project. DAS Environmental Expert systems are designed to adapt to the needs of each individual customer, whether we install a single biological purification stage, construct an entire treatment plant or equip an entire manufacturing facility with wastewater technology.

Individual Solutions for Biological Wastewater Treatment

Our biological methods for wastewater treatment support our clients’ compliance with legally-prescribed discharge values, thus avoiding heavy polluter surcharges, increasing the eco-friendliness of their products and 

rendering processes more efficiently through water recycling. Our systems for the treatment of industrial and sanitary wastewaters are as individual as our clients.

DAS Systems for Biological Wastewater Treatment Suitable for Diverse Industries

DAS Environmental Expert offers a wide range of wastewater treatment technologies to a vast spectrum of industries. Our solutions are successfully employed in the chemical and pharmaceutical industries, as well as the semiconductor and energy industry. In addition, biological treatment methods prove to be the best solution for the pulp-and-paper industry, laundry facilities, textile production, the food industry and agriculture. Biological wastewater treatment systems provide solutions for the removal of organic wastewater contents, ammonium and nitrate contaminations. DAS Environmental Expert wastewater technology treats wastewaters safely, reliably, ecologically-sustainably and efficiently.

Anaerobic Biological Wastewater Treatment Utilizing the UASB Process

The Upflow Anaerobic Sludge Blanket (UASB) method is often used for biological treatment of industrial wastewaters. This method removes large amounts of organic contents, dissolved sugars, proteins and fats from wastewater.  

Using microorganisms in a special reactor absent of atmospheric oxygen, the pollutants are chemically transformed into biogas. Biogas is a gaseous mixture that primarily contains methane and carbon dioxide and can be used as an energy source in production, typically in a cogeneration unit, to generate power and heat.

This particular version of a biogas plant is primarily used for the treatment of wastewaters in the food-and-beverage industry, as well as in the pulp-and-paper industry.


Anaerobic Biological Wastewater Treatment Methods

Biological Wastewater Treatment with the Membrane Bio Reactor (MBR)

The Membrane Bio Reactor (MBR) is another option to achieve the oxidation and nitrification of organic substances in wastewaters; the degradation of pollutants takes place in an aerated sludge tank with a very high sludge concentration.

Using membranes, the separation of the treated wastewater from the sludge is achieved via ultrafiltration. The membrane filter module can also be submerged and integrated into pre-existing biological treatment stages; however, a separate reactor is considerably easier to service.

The MBR process is suitable for the biological treatment of highly contaminated industrial wastewaters. In addition, it is often used for the purification of domestic or municipal wastewaters and for the treatment of grey-rain-and-surface water.

Due to the membranes’ very small pore diameter, bacteria and viruses cannot pass through the membrane filter, thus, germs are withheld. The water quality of the wastewater treatment plant’s effluent meets the EU Bathing Water Directive. With its compact design, the MBR system can even be designed in container form as a fully mobile solution to suit temporary applications.  

Wastewater Treatment with the MBBR Method

The Moving Bed Biofilm Reactor (MBBR) is a technology for biological wastewater treatment where the necessary microorganisms grow as a biofilm on a carrier medium.

The population of microorganisms growing on the spherically-shaped filling material creates a large and highly effective surface area. At the same time, aeration inside the reactor causes the inflowing wastewaters to continually intermix, thereby ensuring optimum contact of the wastewater contents with the microorganisms. In addition, it is possible to use the MBBR technology, also called the fluidized bed process, anaerobically; during anaerobic processing, intermixing is handled by pumps or a stirring unit.  

Shearing forces inside the reactor as well as the wastewater contents determine the thickness and quality of the biofilm on the carrier material. The higher the concentration of organic substances in the wastewater, the faster the biofilm grows.

The Biofilm Process Reduces the Amount of Excess Sludge  

Similar to other biological process for the degradation of organic carbon compounds, the MDDR method produces excess sludge. However, the amount occurring during the biofilm process is significantly lower than that of activated sludge processes of similar capacity. Still, after treatment, within the MBBR, the purified wastewater needs to be separated from resulting sludge, which can take place in a clarification tank via sedimentation. If wastewaters are directly released into another wastewater treatment plant, the sludge separating stage can be skipped if the facility’s design and capacity allows for later separation, and undesired sedimentation processes during transportation can be excluded.

Advantages of the MBBR-Process Compared to the Activated Sludge Process

One disadvantage of the activated sludge processes is that, when retrieving the excess sludge, part of the microorganisms that are suspended within the sludge are removed with it. Even when re-adding re-circulated sludge from the clarification stage, the microorganisms only have a short life span. Due to being immobilized on the carrier material, microorganisms in the MBBR method exhibit a much longer life span. Microorganisms that specialize in degradation-resistant compounds have very long life spans and, therefore, are able to establish themselves. In all, the MBBR purification process is significantly more stable than the activated sludge process, and load peaks are well-absorbed.

DAS Environmental Expert uses a carrier material that features a very large specific surface that allows extremely compact MBBR systems. The shape of the filling material prevents the carrier material from interlocking and ensures the system reaches a consistently high degradation capacity.

Our MBBR systems can be designed as a compact unit or as modular bioreactors. The modular reactors require much less space than traditional activated sludge facilities, and no civil engineering construction is necessary. Special process engineering and design make it possible to use our MBBR system as a denitrification reactor and operate it as such.

Biological Wastewater Treatment with the Trickle-Flow-Reactor

During treatment within a Trickle-Flow-Reactor (TFR) the wastewater is sprinkled over a fixed bed.  The system uses a very light, small-grain carrier material that, within days, is covered by a highly active mixed population of bacteria that have adapted to their respective conditions.

The constant inflow of wastewater that trickles down over the bed is aerated by ambient air that is supplied by a ventilator at a minimum pressure flowing in the opposite direction, allowing the TFR technology to operate with minimum effort.  In regular intervals, regeneration is initiated automatically, which rejuvenates the mixed microbial population and washes out excess biomass from the system without noticeably affecting the reactor’s capacity. The liquid sludge can be further drained and, depending on local conditions, can be passed on to facilities for composting or humification.

DAS Environmental Expert reactors are lightweight and low-maintenance. They require little space and are extremely energy efficient. Due to its highly active biomass, the TFR process reaches more than 90% of its required degradation capacity within the first 10 days.

Biological Wastewater Treatment with the SBR Method

The Sequenced Batch Reactor (SBR) is an activated sludge technology for the treatment of wastewater based on two separate systems. A pre-treatment stage is used for mechanical retention of coarse material and also functions as a collection tank from which the contaminated wastewater advances to a biological activation or secondary sedimentation tank, the so-called SBR-tank. 

Within the SBR tank, the inflowing wastewater is purified through a cyclic process and the aid of activated sludge containing a high concentration of microorganisms that remove organic substances from the wastewater. In order to ensure proper mixing and oxygen supply, the wastewater is circulated in regular intervals via air supply.  

The aeration phase is followed by a resting phase without aeration, which causes the activated sludge to settle at the bottom of the reactor. In the upper part of the SBR tank, however, a clear water zone is formed. Finally, the purified water, removed from this upper water zone, is discharged into a receiving tank or drainage system. The excess sludge is drained from the bottom of the reactor and re-added to the pre-treatment stage; and the process starts again.