AGARÂŽ FFAST

Combining the robust RF capabilities with Activated Sludge polishing The AGARÂŽ FFAST (Fixed Film Activated Sludge Treatment) configuration combines the advantages of both fixed-film and suspended biomass technologies. In this configuration, the wastewater is treated first in a RF reactor (see above), then in a conventional activated sludge process. This combination utilizes the RF capability to significantly reduce wastewater BOD in a relatively small reactor volume filled with Aqwise Biomass Carriers, followed by the high-quality effluent achievable in an activated sludge system. Wastewater is introduced into a single-stage roughing filter, with no sludge circulation. Following this treatment, soluble BOD in the wastewater is reduced by 45%-70% before entering the activated sludge process. The activated sludge system is considerably smaller, as it is required to deal with only a fraction of the organic load of an equivalent conventional plant; in effect, it acts to polish the RF effluent to extremely high qualities. Return Activated Sludge (RAS) from the secondary clarifiers is recirculated to the beginning of the activated sludge tank; provisions may be made for allowing a part of the RAS to return upstream to the RF, thereby creating a selector effect for control of filamentous organisms. Another advantage of the FFAST configuration is its ability to sustain shock loads as well as a certain amount of toxicity, thereby protecting the downstream activated sludge process from upsets. Due to the thickness of the biofilm on the Biomass Carriers, the bio-film is capable of rebounding more quickly from toxicity upsets than an equivalent suspended biomass. The FFAST process is optimal for plants with limited area, which require consistently high quality effluents coupled with an ability to withstand shock-loads, as well as for new plants or upgrades of high load wastewater treatment plants.

AGARÂŽ IFAS

Intensive Nitrogen Removal within new or existing plants The AGARÂŽ IFAS (Integrated Fixed film Activated Sludge) configuration utilizes the complex interactions between a bio-film on the Biomass Carriers and suspended biomass in the activated sludge. This co-existence creates a specialized and highly concentrated nitrifying bio-film on the Aqwise Biomass Carriers, acting simultaneously with the organic carbon oxidation by the activated sludge. This process principle is to introduce biomass carriers into the activated sludge, thereby allowing the activated sludge to remove most of the BOD, while allowing the biofilm to develop a microbiological population that oxidizes ammonium compounds. The AGARÂŽ IFAS is particularly well suited for retrofitting existing plants in order to add nitrification capacity, as well as increasing carbonaceous BOD removal, without any additional tank volume. The IFAS process can also be utilized in newly designed plants. An AGARÂŽ IFAS reactor is typically divided into a series of process stages that include aerobic, anoxic and anaerobic volumes, in a similar way to some well known BNR configurations. In AGARÂŽ IFAS biomass carriers are filled in the aerobic stages. The carriers are retained by screens located at the effluent end of the process stage, and by a hydraulic effect called a "carrier barrier" at the influent end. The heart of the IFAS process lies in the competition between microorganisms growing in the liquid sludge, and those growing on the Carriers. As the suspended biomass has an absolute advantage over the fixed biomass in soluble BOD assimilation, the biomass developing on the Carriers consists almost entirely of nitrifying bacteria. As a result, the same tank contains two different microbiological populations executing completely different functions, thereby greatly increasing the treatment potential within the same volume. By using advanced modeling and in-depth process design tools, the size, location and quantity of biomass carriers in each of the process stage can be accurately determined to achieve extremely precise nutrient removal. The AGARÂŽ IFAS process is the perfect solution for upgrading existing plants to Biological Nutrient Removal, without adding reactor volume. In addition, the IFAS process can be used to increase plant treatment capacity with no addition of tankage.

AGARÂŽ MBBR

A robust solution for intensive BOD and Nitrogen removal The AGARÂŽ Roughing Filter (RF) or Moving Bed Bio Reactor (MBBR) configuration offers a treatment process based on a bio-film which provides organic carbon removal, as well as nitrification and de-nitrification where needed, without circulation of activated sludge. The process is simple, robust, and requires minimal operator intervention. Wastewater is introduced into a single or multiple-stage system (depending on whether nitrogen removal is required), each of which contains the suitable volume of Aqwise Biomass Carriers. The process configuration designed for BOD removal only is a once-through design, with 1to 2 process stages in series. The number of stages is determined according to the required effluent quality. Wastewater enters the reactor, and effluent exits the reactor to a solids separation unit such as a clarifier, a DAF unit, media filtration, etc. In this configuration, there is no sludge recycle to the aeration tank, and all of the biological activity takes place in the bio-film on the carriers. When nitrogen removal is also required, the process will include a larger number of process stages, and an internal circulation of nitrified effluent to a pre-denitrification basin, but other than this, there is no sludge recycle from the solids separation unit. The RF/MBBR configuration is extremely well suited for a wide range of applications: from pre-treatment of industrial wastewater in order to cut down the organic load, to full treatment of municipal wastewater to the most stringent effluent requirements.

AGARÂŽ MBBR-BNR

The AGARÂŽ Roughing Filter for Biological Nutrient Removal (MBBR-BNR) configuration offers a treatment process based on a bio-film which provides organic carbon removal, followed by nitrification and de-nitrification, without circulation of activated sludge. Denitrification occurs in both pre-denitrification reactor, and in an innovative, patent pending, fixed/moving bed reactor in which intensive endogenous denitrification occurs. The process is simple, robust, and requires minimal operator intervention. Wastewater is introduced into a multiple-stage system, each of which contains the suitable volume of AqWise Biomass Carriers, followed by the fixed bed reactor. The MBBR-BNR configuration is extremely well suited for small and medium municipal applications, where nitrogen removal is required with a minimal operator intervention.