The excess sludge formed during the biological treatment of wastewater must be removed from the system by the operator. The removed excess sludge is usually thickened, dewatered, then burnt, or transported to disposal sites. All steps above have high costs, which means the operators of WWTP’s are mostly interested in technologies capable of the reduction of excess sludge formation.
Usually the causes why the operators are keen on reducing excess sludge amount are:
1) Operational cost reduction (like described above)
2) Under designed or undersized excess sludge thickening, and/or dewatering units (the operator is unable to remove, and dewater the amount of excess sludge daily formed in the system)
3) The WWTP has an anaerobic sludge digester, where the reduction of the excess sludge part in the digester feed mixed sludge can be a subject of interest. Since the excess sludge part of the mixed sludge has lower biogas output potential, the lower excess sludge part can result a longer hydraulic retention time in the digester, with an optimized and more stable gas output both in quantity and quality.
Excess sludge production in activated sludge WWTP’s can be decreased significantly by our bioaugmentation technologies if we interact in the right processes:
1) The production of the excess sludge can be reduced by the improved biodegradation of hardly biodegradable particulate organic matter which aggregates to sludge flocs but they are not a part of the active biomass. The improved biodegradation of these organic substances can be achieved by bacterial (check our applied technology: Bioclean TM) or enzymatic technologies (check our applied technology: Vickzyme Block Pink).
2) The bigger part of the excess sludge is the active biomass which is produced by the reproduction of activated sludge bacteria due to their metabolism when degrading the wastewater (mostly organic) constituents. When the bacteria metabolise the organic matter in the wastewater they produce energy, CO2 and H2O from one part of it, and they use the other part for creating new cell material. The ratio which defines the part of the readily biodegradable (mostly organic) material converted into new cell material is called cumulated yield (Y). Every WWTP has its own representative cumulated yield but in every WWTP there is a possibility to interact in the microbial metabolism with the right biotechnological method to improve the metabolic processes in a way that the activated sludge converts a bigger portion of food source to energy, CO2 and H2O and cell production is minimised. That results a lower cumulated yield of the activated sludge by the bioaugmentation treatment (check our applied technology: Bioclean ALPHA).
The highest energy consumers of a WWTP are the blowers which are responsible for the aeration of the aerobic reactors. Due to the difference in physical and chemical characteristics of the Oxygen and the water molecule, this process is highly energy wasting. To ensure the necessary amount of dissolved Oxygen needed for aerobic respiration requires a continuous large amount of air pumped in. The reduction of the blowers’ energy consumption is a common interest for all WWTP operators around the world. If the blowers are equipped with frequency controllers, and the control of the blowers by dissolved Oxygen is provided, then the energy consumption of a WWTP can be achieved by our bioaugmentation technology.
As written above, dissolving Oxygen in water is generally difficult, which means a lot of air is needed to reach the desired concentration of DO in the water column. Moreover, the transportation of the dissolved Oxygen molecule within the bacterial cell is limited as well. Transportation process happens through the cell membrane then the Dissolved Oxygen molecules participate the biochemical processes within the cell. By our bioaugmentation method, we introduce selected bacterial species which has a membrane structure where the transportation of the dissolved Oxygen molecule is easier, it reduces the aeration requirement of the system. In addition, since these recently introduced species are more competitive than the naturally growing heterotrophs in the competition for food due to their higher metabolic rate, we are able to accelerate the metabolism of organic matter in the bioreactors. This effect has a great impact on energy consumption: in that particular area (usually at the end of aerobic reactors) where the DO probe is located at, less air will be needed for maintaining the desired DO. The concentration of organic substances, which result the highest DO consumption, will be way less than before at the bulk solution near the DO probe due to intensified metabolism, which results the bacteria consume less DO for their metabolism. As a result of the 2 factors above, considering a same cumulative load for the plant, the blowers operate on a lower daily average operational frequency than before in case of a well-bioaugmented activated sludge. As a result, bioaugmentation delivers massive energy cost savings for the operator
Check our applied technology: Bioclean TM!
Activated Sludge WWTP’s must face with more and more stringent discharge limits for their effluent in case of Total Nitrogen concentration. Biological Nitrogen removal is a multiple step process. After the oxidation of Ammonium ions in the aerobic reactors, heterotrophic bacteria in the activated sludge reduce the formed Nitrate to Nitrogen gas in Oxygen-free environment by the biodegradation of soluble organic substances (denitrification).
The process of denitrification happens both in anoxic and aerobic reactors. Anoxic reactors are located mostly prior to aerobic reactors in the technological scheme at continuous flow WWTP’s (pre-denitrification). The internal recirculation drives the mixture with high Nitrate concentration from the end of the aerobic zones into this anoxic reactor, where the bacteria in a DO free environment reduce the Nitrate to Nitrogen gas by organic biodegradation. Nitrogen gas escapes to the atmosphere at the end of the process. In case of SBR WWTP’s the anoxic phase is separated in time, not in space, but the essence of the process is the same.
The removable amount of Nitrate is limited in the anoxic reactors (or at anoxic times in SBR’s) even if the necessary amount of soluble organic matter is available in the raw wastewater. The improvement of Nitrogen removal capacity in the anoxic reactors technically can only be achieved by increasing the internal recirculation ratio, while the same at SBR plants can be done by increasing the frequency of anoxic times. Both actions have their own limits. Setting the internal recirculation to a too high rate or setting up too frequent anoxic times in SBR’s may result the deterioration of the activated sludge structure and can adversely affect the treatment capacity of the entire biology, without providing extra gain anymore in Total Nitrogen removal.
However, Total Nitrogen removal capacity of an activated sludge can be significantly improved without any risks by our bioaugmentation process. The goal of the process is on one hand providing more readily biodegradable COD for the anoxic reactors by improved hydrolysis of hardly biodegradable organic particulate matter, on the other hand the reinforcement of the sludge structure, enlarging the size of the activated sludge flocs, and increasing their density. As a result of bioaugmentation the activated sludge shows a significant improvement in Total Nitrogen removal capacity in the anoxic, and aerobic zones (at anoxic, and aerobic times in SBR reactors). In aerobic zones, denitrification is achieved at a way higher rate than before within the flocs where the DO concentration is not a limiting factor anymore like it is at the perimeter of the flocs (check our applied technologies: Bioclean TM, Vickzyme Block Pink, check also our related TN removal boosting machinery: GridBee AP mixers). The application of Bioclean TM and Vickzyme Block Pink for TN removal enhancement results a boost in Bio-P removal as well, see next chapter.
Our cutting edge bioaugmentation technologies are available for the intensification of Biological Phosphorus Removal (Bio-P) at every WWTP, where the technological and environmental conditions are given for this biological process in space or time (Dissolved Oxygen-free and Nitrate-free environment, continuously stirred tank reactor, presence of readily biodegradable organics in the bulk solution).
By the improvement of the Bio-P bacteria’s metabolism, Polyphosphate formation can be boosted by our technologies in the anaerobic reactor (or anaerobic time in case of SBR’s), as well as the excess Phosphorus uptake rate in the aerobic zone (or aerobic time in case of SBR’s). A well-executed bioaugmentation ensures Total Phosphorus concentrations constantly well below 1.0 mg/l in the effluent without any addition of Ferric or Alum salts. In case of those WWTP’s where the load varies at a high range, which has a negative effect on the floc structure of the activated sludge, the performance of Bio-P removal is not stable. By the application of our bioaugmentation technologies in such variably loaded WWTP’s Ferric or Alum addition cannot be avoided but can be significantly reduced by 40-80% compared to the amount used before the bioaugmentation. The application of Bioclean TM and Vickzyme Block Pink for Bio-P removal enhancement results a boost in TN removal as well, see previous chapter.
Check our applied technologies for boosting Bio-P removal: Bioclean TM, Vickzyme Block Pink! You may also be interested in how 100% complete mixing is able to boost Bio-P removal without any bioaugmentation: GridBee AP mixers.
Overloaded or under designed WWTP’s are mostly unable to meet with effluent parameters set by authorities. The common method for increasing the capacity of these WWTP’s is a costly investment for building new bioreactors, clarifiers, upgrading the plant’s mechanical and electrical parts etc. Our bioaugmentation technologies provide a solution for the owners and the operators of such plants to increase the biological treatment capacity of their plant without high cost investments. We are able to increase the plant’s treatment capacity by 30-40% by only interacting in the biological step. By bioaugmentation we modify the microbial community in a way that the WWTP will be able to treat way more load than before (check our applied technology: Bioclean TM), also we are able to add further upgrade in the treatment capacity by the acceleration of the metabolism of the activated sludge microbes (check our applied technologies: BioGuarde I, BioGuarde II, Vickzyme Block Blue).
By the application of our bioaugmentation technologies bad settleability of the activated sludge due to pin floc formation or EPS abundance can be adjusted. As a result, sludge washout from secondary clarifiers will stop or decline significantly. The effluent parameters of the overloaded plant can be optimised, moreover they may be brought down below the mandatory limits (COD, BOD, TSS, NH4-N, TN, TP).
The process of nitrification in the activated sludge is usually hurt or stopped by overload. By our bioaugmentation technologies the nitrifying ability of the overloaded plant can be optimised or totally restored (check our applied technologies: Bioclean TM, Ammonia Guarde).
Abundance of filamentous bacteria has a negative impact on the floc structure of the activated sludge, especially settleability of the flocs, which can lead to sludge washout from the secondary clarifiers. Sludge washout is an unwanted phenomenon because it results serious deterioration of effluent quality in case of multiple parameters. Filamentous blooming also has adverse effect on operational conditions of the plant by the foam and scum formation on the biological reactors and on the surface of secondary clarifiers. Causes of filamentous blooming can be multiple: quick rise or drop in the temperature of the bioreactors, seasonal turn of the biology in autumn and spring, underload or overload, high readily biodegradable organic fraction in the influent COD, high fat, oil or grease (FOG) load, lack of macronutrients, micronutrients or trace elements in the influent.
Our bioaugmentation technologies provide solutions to all causes of filamentous blooming shown above, they are able to restore the healthy flocculent/filamentous bacteria ratio in the activated sludge by eliminating the causes of the blooming:
- in case of high FOG load by the acceleration of FOG breakdown (check our applied technology: BioGuarde II)
- when the raw wastewater lacks macronutrients, we provide macronutrients (check our applied technology: BioBooster NOC)
- when the raw wastewater lacks micronutrients, we provide micronutrients, trace elements, biostimulants and vitamins (check our applied technology: BioBooster Micro).
The rest of the causes resulting filamentous blooms that usually happen at municipal or industrial wastewater treatment plants are quick rising or drop in the temperature of the bioreactors, seasonal turn of the biology in autumn and spring, underload or overload, high readily biodegradable organic fraction of the influent COD. These issues can also be adjusted by our suitable bioaugmentation technologies. Once we modify the microbial composition of the activated sludge, providing a competition for filamentous bacteria, species which are able to outpace them during the competition for food. As a result, filamentous bacteria numbers can be knocked down to a level, where they do not harm the floc structure, and settleability of the activated sludge (check our applied technologies: Bioclean TM, Bioclean ALPHA).
Our Bioclean STP bioaugmentation technology has been developed for the optimization of anaerobic digesters processing raw sewage sludge and excess activated sludge as main feed fraction in WWTP’s. By the intensification of the steps in the anaerobic degradation process the application of Bioclean STP is able to boost the biogas production of the digesters by 18-35%, which can be utilized in a gas engine to generate extra energy, or burnt in combustion to produce extra heat.
As a result, massive amount of savings/profit is about to come by our bioaugmentation technology on energy and/or gas costs. The application of Bioclean STP does not require any modification in the digester technology or reactor setup, just a simple dosage of the selected strains of the Bioclean STP bacteria.
Enzymes produced by the bacteria of Bioclean STP decompose the foaming agents rapidly, especially surfactants which source is cell lysis (mostly from filamentous bacteria). By treating with Bioclean STP, the resistance of the anaerobic digester against toxic and inhibitory slug loads is significantly improved. The stabilized acidogenesis and acetogenesis suppresses the formation of foam producing organic compounds which tend to accumulate under certain environmental conditions, and inhibit acetate formation.
After an increased dosage of Bioclean STP for about 2 weeks, the operator just needs to add a daily maintenance dosage to the system to ensure the optimum performance of the digester. Due to the continuous maintenance dosage of the microbes found in Bioclean STP, the stability of anaerobic digestion improves significantly, fluctuations in specific gas output will be reduced. A significant advantage of the continuous maintenance dosage is the improved adaptability and resistance of the microbial community. Digesters treated with Bioclean STP will also recover more rapidly from toxic and inhibitory shocks.
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Tertiary treatment ponds (also referred as maturation ponds, polishing ponds or stabilization ponds) are usually the final step of wastewater treatment in several municipal or industrial wastewater treatment plants. These ponds receive the effluent of the secondary treatment step, and they provide a high hydraulic retention time post biological treatment for the effluent of the secondary treatment in order to meet with strict regulations regarding effluent quality. Well-designed, and operated tertiary treatment ponds are naturally able to reduce the COD, BOD, TSS, and N,P nutrient concentrations of the secondary treated effluent.
However, it is a really tough job to operate tertiary treatment ponds. Since their operation is natural, Nature cannot be controlled so easily. The concentration of Nitrogen and Phosphorus compounds are multiple than a natural pond tolerates for stable operation, even if the secondary treatment provides complete nutrient removal steps. Since high hydraulic retention time is provided in the ponds, there are no biological limitations for aquatic weed and/or algae blooms. As a result of the above, photosynthesis boosts daytime which means pH increases if the water is not well-buffered. The tertiary effluent at the end of the system can become very alkaline, which can result effluent violation for pH. Overgrowth of vegetation, especially algae can deteriorate many parameters of the tertiary effluent compared to the secondary effluent (COD, BOD, TSS), preventing the pond to serve its primary role: improvement of water quality.
Sludge production, and sediment accumulation rate are usually very high in tertiary treatment ponds thanks to the TSS content of the secondary effluent, and the continuously reproducing/decaying algae communities and macrovegetation. The usual solution for sediment removal is physical interaction, dredging, which is a very expensive operation.
Our bioaugmentation technologies combined with our solar-powered SolarBee long distance circulators provide an ultimate solution for all the above mentioned biological problems tertiary treatment ponds can have: boosted organic breakdown (COD, BOD, TSS concentration optimization in the final effluent), algae and aquatic weed control, nutrient removal boost (N,P), pH control, significant reduction of yearly sediment production, significant decrease of the existing sediment layer by biodegradation to eliminate the need of dredging for a long time.
Nearly all activated sludge wastewater treatment plants struggle with sludge accumulation, and build-up at dead zones in anaerobic, and anoxic reactors where mechanical mixing is provided, as well as in aerobic reactors where sludge accumulates in dead zones of the corners, and below the diffuser system which is located far above the floor of the reactor. As a result, the tanks have to be emptied and cleaned by the operator periodically which is a very time consuming, hard, and expensive work for the operator company.
The source of the sludge accumulation problem is the same in every reactor type: the complete mixing which is actually the main operating principle of activated sludge wastewater treatment is not complete mixing in practice. In most cases neither mechanical mixers used for mixing anaerobic, and anoxic reactors, nor submerged aeration in aerobic reactors are able to provide 100% complete mixing. In order to eliminate sludge accumulation in dead zones, 100% complete mixing must be provided.
Our GridBee AP mixers generate a new flow pattern for the reactor, and provide 100% complete mixing in a few hours after their installation. Our mixers do not have any electrical, or moving parts, and due to their anti-clog structure, hair and fibre like solids cannot cause operational issues to our mixer, unlike they do to conventional mixers. The GridBee AP mixers are mixing with air. Air supply for our mixers are usually provided from the main air pipe of the blower, so additional blower is not necessary, however, small capacity custom blowers to provide air just for the mixers are available as an option. The diffusers of our mixers are coarse bubble diffusers, as a result their Dissolved Oxygen intake capacity is highly limited, so they can be applied successfully for mixing anaerobic, and anoxic zones as well without compromising the performance of the reactors. 100% complete mixing will bring you the following benefits:
- biological treatment capacity of the activated sludge increases, without any investment for reactor volume expansion (optimization of effluent COD, BOD, NH4-N, TN, TP values)
- sludge accumulation will stop, and accumulated sludge will be removed as dead zones are eliminated. No need for costly operations like draining reactors, removing the accumulated sludge etc. No more reduction of the reactor volumes because of accumulated sludge, no more capacity loss of reactors due to the above phenomenon
- 100% complete mixing optimizes the energy consumption of the WWTP
- if applied in aerobic zones, denitrification (TN removal) can be boosted
- better activated sludge floc structure, lower SVI
Click here for more information on GridBee AP mixers!
Raw wastewater deficiency in macronutrients, micronutrients, trace elements, and vitamins are mostly the symptom of industrial biological wastewater treatment plants.
The lack of the above-mentioned compounds, and ions can end up in a drop of biological treatment efficiency, deterioration of the sludge structure, and settleability, or filamentous bacteria blooming. As a result, effluent violation is quite common.
We developed BioBooster NOC which is a complex solution optimized for the macronutrient, micronutrient, trace element, vitamin, and biostimulant requirements of the microbial community in the activated sludge. The types of the constituents, and their ratio in the product is a perfect fit for every type of activated sludge processing the wastewater of any industries to restore its optimum treatment performance and sludge structure.
We have customized BioBooster NOC for those plants which do not lack macronutrients like Nitrogen, and Phosphorus sources, just micronutrients, trace elements, stimulants and vitamins. BioBooster Micro contains all constituents found in BioBooster NOC except for Nitrogen and Phosphorus sources. Due to the removal of these macronutrients, BioBooster Micro is way more concentrated with the rest, so its dosage is way lower than BioBooster NOC.
In municipal sewage systems where the residence time of the wastewater is high, pumping stations following these parts of the system may generate odor problems due to gases formed during the anaerobic degradation processes in the raw wastewater. In most cases, even if the pumping station is equipped with a biofilter, the filter material’s absorption capacity is not enough to prevent customer complaints.
Our new generation C-5 Odor Neutralizer product is successfully used to reduce odor in wastewater systems in many countries worldwide. The concentrated version of C-5 Odor Neutralizer is applied as prevention of odorous gas formation by its continuous dosage in pumping stations at the upper parts of the system before the high residence time sections where anaerobic breakdown generates the odorous gases. The strong smell in the wastewater can be derived from the decay of organic materials. These organic compounds typically contain function groups with Sulphur or Nitrogen (also including sulphur-based Mercaptan compounds, and short-chain fatty acids including amino group). In this case smell is caused mostly by the anaerobic bacteria, which break down proteins and other organic materials, because these microorganisms get to take the Oxygen from the amino groups of the proteins.
By its continuous dosage, C-5 Odor Neutralizer changes the environment to digest the proteins and fats in another biochemical pathway, significantly reducing odorous gas formation (H2S, NH3 and Mercaptans) in the pumping station following the long residence time section of the system.
Besides odour prevention the C-5 Odor Neutralizer has a massive direct odor removal ability. C-5 Odor Neutralizer is a botanical extract supplied in concentrated liquid form. By the 5-time dilution of the product with pure water, the diluted version is used for the regeneration of the biofilters, and for increasing their odour removal capacity to multiple. The biofilm on the filter surface absorbs and breaks down the Hydrogen Sulphide and Ammonia in an enzymatic pathway, and significantly boosts the odor elimination capacity of the biofilter.
Click here for more information on C-5 Odor Neutralizer!
We provide highly effective, cutting edge bioaugmentation technologies for the intensification of anaerobic biological processes in strict anaerobic systems (check our applied technologies: Bioclean Septic, Bioclean STP). Both technologies are GMO-free, the beneficial bacteria were isolated from the nature.
The species are strict, and facultative anaerobic bacteria partnered by enzymes and enzymatic substances responsible for the optimal metabolism. Bioclean Septic has a lower microbial count, and lower price, developed as a cost-effective solution for lower loads, and well-loaded but high residence time systems (more than 30 days of HRT), while Bioclean STP is a concentrated version for high loads, lower residence time systems (applicable even at 4-10 days of HRT), and for the hydrolysis of hardly biodegradable substances.
The application of Bioclean Septic and Bioclean STP technologies are developed for wastewater treatment or sludge reduction in strict anaerobic environment. Since the microbial composition of both products consist of psychrophilic or mesophilic bacterial species, they can be applied in cold weather/climate as well. The applicational window of the technologies is wide: raw, excess or combined sludge treatment (odour removal, supernatant quality optimization, and sludge volume reduction) in municipal or industrial wastewater treatment plants’ sludge storage ponds, optimization of the sludge structure, and improved pellet formation in UASB, EGSB, and IC anaerobic reactors, slurry and manure treatment (odour removal and slurry/manure volume reduction, quality optimization) in animal farms, domestic use in cesspool treatment, restaurants, food processing industries, etc.
Either Bioclean Septic or Bioclean STP can be used successfully for the reduction of the amount of raw and/or excess sludge in industrial or municipal WWTP’s which are not equipped with sludge dewatering units. In this case sludge storage and dewatering is done in sludge fields or sludge ponds in an anaerobic way. Domestic application of Bioclean Septic is also widespread in areas where wastewater canalisation has not been constructed yet, and houses collects their wastewater in cesspools or septic tanks.
By the application of our anaerobic bioaugmentation technologies:
- Sludge volume, and connected transportation, handling, disposal costs decrease significantly in case of sludge ponds and fields.
- Anaerobic stabilisation of the sludge is processed, as a result, the water content of the transported sludge decreases significantly, which is a massive reduction in sludge handling costs for the operator
- At wastewater treatment plants COD and BOD concentration drops in sludge field’s or pond’s filtrate/supernatant, which decreases the internal load of the entire plant since this water is driven back to the raw wastewater at the start of the plant.
- Odor of the sludge field/pond significantly decreases
- At domestic use odor of the treated cesspool significantly decreases, as well as suction and maintenance costs are about to drop.
In case of sludge storage ponds where the sludge is covered by at least 1 m high water layer, our long-distance solar powered circulation technology, SolarBee can be successfully applied as a supplemental element of bioaugmentation just like it is done at freshwater bioremediation, and wastewater treatment. By the application of SolarBee the following benefits can be expected:
- Biodegradation of organic materials in the sludge layer are carried out at multiple pace. As a result, the pace of the sediment amount, and layer height reduction happens at a way higher rate.
- The biological treatment, and quality optimization of the aquatic layer on the top are carried out with multiple pace.
Our high-end bioaugmentation technology, Grease Trap Guarde, is developed for the operational cost reduction, and maintenance of wastewater pumping stations, grease traps in restaurants, wastewater treatment plants, and industries.
Grease Trap Guarde is a microbial system made of only all-natural substances which has been developed for biological-enzymatic FOG removal in grease traps, and pumping stations. The basic concept of the technology is that fat, oil and grease molecules serve as food source for the bacteria present in Grease Trap Guarde, so the removal of these substances happen in a natural way. This means all pumping stations, industrial and restaurant grease traps can be operated with good performance at low cost, with no clogging and significantly reduced odor formation without the use of any harmful chemicals. Grease Trap Guarde is 100% biodegradable in nature, and the product has no by-products or constituents at health or ecological risk.
The advantages of Grease Trap Guarde application:
- Maintenance, operational and cleaning costs of the pumping stations, and grease traps are significantly reduced
- The health and environmental risks by using harmful chemicals can be avoided at all during the everyday maintenance of the pumping stations, and grease traps
- Environmentally friendly, 100% biodegradable, all-natural
- Odor formation in the pumping stations, and grease traps is significantly reduced
Click here for more information on Grease Trap Guarde!
High FOG load in raw wastewater influent can happen frequently in municipal and industrial wastewater treatment plants, which means the activated sludge has to cope with a higher, and different organic load. This can deteriorate the sludge structure, or it can cause filamentous bacteria blooming, which can lead to effluent violations, and operational issues. By our bioaugmentation technologies the FOG biodegradation capacity of the activated sludge can be improved to level where the extra FOG load is biodegraded by the activated sludge without hurting its structure or microbial composition (check our applied technologies: Bioclean TM, Bioclean FOG, BioGuarde II).