In the absence of oxygen, many groups of anaerobic microorganisms work together to decompose organic matter. The microbiology behind the process is more complex and delicate than that of aerobic processes, where most bacteria “work” individually. It is the main reason why anaerobic systems require greater control and monitoring in order to perform efficiently.
This type of treatment is very effective in the removal of biodegradable organic compounds. It is especially suitable for organic wastes and wastewater streams which are highly-loaded with organic contaminants. It effectively converts them to mostly methane gas and carbon dioxide, with very little excess sludge generation. Although the process leaves some organic pollution unremoved and cannot provide the level of effluent quality achievable with aerobic treatment, the significantly lower excess sludge production and valuable renewable energy generation in the form of biogas, are the reasons why it has become the favored approach to many industrial wastes and wastewater applications.
Wastewaters streams from food and beverage production, biofuels production, pulp and paper mills, and from the chemical industry, are highly-loaded with organic pollutants and can be treated advantageously by the means of various anaerobic processes.
However, varying wastewater components, the wide range of possible Chemical Oxygen Demand (COD) concentrations, and each client’s local conditions require a careful selection from the different anaerobic reactor types. A single anaerobic technology is not the best solution to all applications.
GWE has one of the most extensive portfolios of anaerobic technologies of any vendors, with thirteen (13) different configurations and concepts.
The ANUBIX™ reactor family are Upflow Anaerobic Sludge Blanket (UASB) reactors, typically used for wastewaters from breweries, beverage production, sugar mills, starch factories, paper mills, and many other industries. Volumetric organic loading rates of up to 25 kg COD/m³.d are used in these types of systems.
The group consists of three different reactor configurations B, C, and T model. Each has its own individual features and is ideally suited to a different group of wastewater types.
The high rate system, the ANUBIX™ – B is used for low to medium-strength wastewaters that are low in solids and FOG, which promote good sludge growth in an UASB. The ANUBIX™ – B can utilize both granular and flocculent biomass, giving it the most flexibility of the UASB reactor configurations.
Technology: UASB bioreactor, secondary treatment, COD to biogas, three-phase separator.
The ultrahigh rate system, the ANUBIX™ – T is used for medium-strength wastewaters with easily-degradable organic matters, which promote excellent sludge growth in an Expanded Granular Sludge Bed (EGSB) configuration. The ANUBIX™ – T is exclusively a granular-sludge form of anaerobic technology.
Technology: EGSB reactor, high-rate bioreactor, secondary treatment, COD to biogas.
In contrast to the conventional UASB reactor ANUBIX™ – CES system, with a built-in three-phase separator at the top of the reactor which diverts the biogas and retains solids, in this reactor, sludge separation is performed externally in a special lamella type separator, the GWE SUPERSEP™ – CF. The effluent of the sludge separator flows by gravity into any post-treatment that might be required.
Technology: secondary treatment, anaerobic treatment, UASB, organic waste to biogas.
The ANAMIX™ reactor is a continuously stirred (CSTR), long residence time digester for very high strength or high-solids wastewaters and slurries. It is available in both mesophilic and thermophilic (ANAMIX™ – M/T) configurations, the choice of which is made based on wastewater characteristics. Mixing can be performed with various devices, depending on the type of wastewater or waste treated, but is most typically done with a large top-entry mixer or via external pump mixing.
Technology: high COD content treatment, continuously stirred reactor, organic waste and sludge to biogas.
The ANAFIX™ reactor is an ‘anaerobic filter’ type of anaerobic system containing floating biomass carrier material to enhance biomass concentrations and retain biomass within the reactor. It is typically utilized for wastewaters from the chemical industry, where suboptimal conditions prevail that promote poor-settling biomass with very low growth rates.
Technology: upflow anaerobic filter reactor, low TSS/COD wastewater streams.
The FLOTAMET™ system is a unique GWE technology, consisting of a fully-mixed ANAMIX™ reactor, followed by our SUPERFLOT™ – AIR or – BIOGAS (DBF) technology for solids/liquid separation by flotation, to capture and retain high biomass concentrations within the system. It is typically used for wastewaters that are rich in FOG, salts and/or fibers.
Technology: secondary treatment, demanding wastewater treatment (high COD, FOG, TSS, and salt content).
The COHRAL™ system is a near-zero pressure Covered High Rate Anaerobic Lagoon system, used for large flow, very high strength wastewaters (e.g. molasses distilleries, palm oil mills), where space is not an issue or open lagoons already exist. COHRAL™ consists of an earthen basin with concrete ring walls, a floating, insulated membrane cover for biogas collection, and a full reactor distribution system.
Technology: low loading rate anaerobic treatment, fully covered lagoon, concentrated wastewater treatment, low TSS/COD wastewater streams.