bioTEC BAC products
bioTEC BAC products
1. What does bioTEC BAC consist of?
bioTEC BAC consists of a carrier material made of phyllosilicates and embedded membrane effectors. The growing bacteria are in close spatial contact with the active substances, so that these (very expensive) substances can be used in the lowest concentration.
The membrane effectors (1) are:
- Nicotinate (inhibition of adenyl cyclase and fatty acid esterification with glycine-3-phosphate)
- Salicylate (incorporation into the lipid layer of the cell membrane, inhibition of the formation of unsaturated fatty acids, especially arachidonic acid)
- Anthraquinone (inhibits membrane-bound K + / Na + -ATPase)
- Alginic acid silyl ester (accelerates oxygen transport into the cell by phase transfer catalysis)
- Lithium carbonate (reduces the K + content of the cell)
- Urea / SDS adduct (impurity in membrane micelles)
- Guanidinium nitrate (increases transmembrane permeation, increases glucose oxidation)
- K-O-ethyldithiocarbamate (inhibits phosphodiesterase, the c-AMP content increases).
Due to long series of experiments, 144 mixtures have been developed to control microbial mixed biocoenoses. For the practical needs of sewage treatment plants, 9 products have been selected that can handle most problems. In special cases, however, there are another 135 products to choose from.
2. How does bioTEC BAC work?
Effect as a Growth Substrate
Most bacteria tend to settle on a solid surface. After colonization, their metabolic activity, lifespan, and resistance to toxins, pH surges, and other stress typically increase. The phyllosilicates represent a suitable growth substrate with 20-25 μ (bacteria 1-10 μ), which, however, can be treated technologically like a liquid.
By selection, the bacteria performing consecutive degradation steps are spatially adjacent. An intermediate does not have to search for its next partner for a long time, the reduction is accelerated.
Due to the higher age, the amount of living bacteria increases up to twice. If enough oxygen is available, the degradation rate will increase by 30-40%.
Acceleration of Oxygen Transfer
The utilization of the registered oxygen is usually bad (10-15%). Frequently, the transfer from the water phase (with its poor oxygen solubility) to the flake is often rate-determining. As studies have shown (2), this transfer can be accelerated by alginic acid or even better by alginic acid allyl ester.
Due to structural similarities with the red blood pigment hemoglobin, which is the oxygen transporter of many animals, a similar mechanism may be suspected.
Improvement of the sludge quality (bulking sludge, scum)
In activated sludge plants, there are three types of technologically undesirable sludge, all of which make the sedimentary separation of sludge and water difficult:
|bulking sludge:||The sludge has a low specific gravity (SVI 200-1000 ml / g). Most of the flake consists of many filamentous bacteria that are matted together.|
|floating sludge:||The sludge is lighter than water and therefore floats up. Actinomycetes (Nocardia) are often the cause. A common cause are fats, oils and detergents in wastewater. Often only a part of the mud consists of floating sludge (biphasic mud).|
|denitrations sludge:||Nitrate is denitrified in secondary settling tanks to gaseous nitrogen. The nitrogen bubbles drive up the mud. This can be counteracted by changing the process technology.|
The types of swelling and floating sludge can be combated by bioTEC BAC. It is necessary to determine the causative bacteria (3). An assignment of the different bacterial groups to bioTEC BAC products is shown in the table.
In addition to bacteriological analysis, the cause of swelling and floating mud formation must always be investigated.
The most common causes are:
|underload bulking sludge:||At a sludge load below 0.005 kg BOD5 / kg TS.d the bacteria compete for nutrients. Filamentous bacteria are preferred.|
|unfavorable wastewater composition:||A strong departure from the ideal C: N: P ratio of 100: 5: 1 results in the formation of filamentous bacteria. The cause is therefore a relative lack of nutrients (in contrast to the absolute lack of nutrients in Unterlastblähschlamm).|
|toxic substances:||Heavy metals such as copper, chromium (VI), zinc or cyanides, thiocyanate, phenols, mineral oils u.v.a. lead to poisoning or inhibition of bacteria. Resistant (often filamentous) species predominate. pH surges, especially acid, lead to similar phenomena. In this case, the flake structure can be destroyed, which even without filamentous bacteria leads to poor deductibility.|
|overload bulking sludge :||For sludge loads above 0.5 kg BSB5 / kg TS.d. there is a competition for oxygen. Here too, filamentous bacteria have advantages. A very bad oxygen supply leads to a similar picture.|
Certain combinations of membrane effectors promote floc-forming bacteria. Bloating and floating mud disappear. This applies to all common filamentous bacteria, which account for 85-90% of all problem cases.
For rare species, laboratory tests must be performed to select the appropriate product (including the total).
Promotion of fat loss
Animal and vegetable fats and oils (triglycerides) in larger quantities can be a problem during degradation. The cleavage into glycerol and fatty acid occurs through exoenzymes of certain bacteria. The further degradation of fatty acids can be a problem. If fatty acids accumulate, they can in turn inhibit further cleavage. Fats and oils like to frame as mono-substrates. The nutrient supply in this layer is just as inadequate as the oxygen supply (oxygen diffuses poorly by fat). By promoting fat loss (bioTEC BAC VIII) it is possible to overcome degradation inhibition.
bioTEC BAC VIII is not suitable for fats and oils based on mineral oils!
Influence of anaerobic wastewater and sludge treatment
During digestion, the wastewater constituents are degraded by hydrolysis to give organic acids and alcohols. Remains the digestion at this stage, it comes to significant odor nuisance.
In the methanation phase, the organic acids (if not already present as acetate) and the alcohols are first degraded to acetic acid (acetogenic bacteria) and then converted into methane by methanogenic bacteria. Both types of bacteria must be in close coexistence with each other. This community is promoted by Auswuchssubstrat.
Diverse inhibitions by heavy metals or by lack of trace elements hinder the methanation, less the hydrolysis. By promoting the acetogenic and methanogenic bacteria, this can be remedied.
In addition to membrane effectors, bioTEC BAC VIII also contains trace elements.
Control of thread-forming bacteria and scum bacteria
|Name||gefördert durch||bekämpft durch|
|Microthrix parvicella||long-chain fatty acids, low mud load||low oxygen concentration, bioTEC BAC II or IV|
|Sphaerotilus spec.||at low mud load:
readily degradable substrate, carbohydrates with high sludge load: fatty acids, detergents
|high nitrogen content
(Urea addition), intermittent
bioTEC BAC VI
|021||Carbohydrates, short chain fatty acids||bioTEC BAC II or IV|
|Haliscomenobacter hydrossis||high nitrogen content, low sludge load||bioTEC BAC II, IV or VI|
|0961||Protein, carbohydrates, oils, high nitrogen content||higher sludge load, short chain fatty acids, bioTEC BAC II or IV|
|„„Cyanobacteria“||high sludge load, long-chain fatty acids||Ammonium phosphate + bioTEC BAC VI|
|Nostoc limnicola||Lack of phosphorus and nitrogen, oils, detergents||Ammonium phosphate + bioTEC BAC IV or VI|
|0041||low sludge load, tolerant to oxygen deficiency||intermittent substrate addition, bioTEC BAC III|
|Thiotrix spec.||Oxygen> 0.1 g / l, sulphides,
Thiosulphates, digested wastewater
|intermittent substrate addition, bioTEC BAC II or IV|
|0675||low sludge load, oils, pH impact load||bioTEC BAC II or IV|
|1701||low sludge load||intermittent substrate addition, bioTEC BAC IV or VI|
|Nocardiforme (N. amarae)||Oils, fats, detergents||bioTEC BAC VIII|
Examples of the application of bioTEC BAC products
1. Thiotrix Bulking Sludge in a Dyeing plant (4), (5)
In the activation plant of a dyeing factory, bulking sludge appeared. The cause was high sulphide contents in the wastewater. Thiotrix dominated, the SVI was 213-263 ml / g. Previous experiments with hydrogen peroxide or polymers were unsuccessful. It came to the mud drive.
17 days after the addition of bioTEC BAC II Thiotrix disappeared abruptly. The SVI dropped to 53-90 ml / g. Mud down did not happen anymore.
Treatment was started with 25 g bioTEC BAC II per kg BSB5. A continuous dosage of 4 g bioTEC BAC II / kg BOD5 prevented swelling mud formation safely and sustainably.
2. Bulking Sludge (021 N) in a Municipal Sewage Treatment Plant
For unknown reasons, but presumably caused by a dairy, swelling sludge (SVI = 340 ml / g) almost always appeared in a sewage treatment plant. It was 021 N.
By adding 24 g bioTEC BAC VI / kg BSB5 for 10 days, the proportion of 021 N gradually decreased to a very low level (SVI approx. 90 ml / g). After completion of the dosage it took 6 weeks, until the old swelling picture was reached again. After renewed treatment and a subsequent continuous dose of 6 g / kg of BSB5 it was possible to safely achieve an SVI below 100 ml / g.
3. Floating Sludge (Nocardien)
In a sewage treatment plant with a predominantly industrial share (metal processing) occurred regularly Nocardien scum on. It was thought to be the influence of drilling and cutting emulsions.
After addition of bioTEC BAC IV (10 g / kg BOD5) the scum cover began to decrease after 4 days, was almost complete after 6 days and completely disappeared after 14 days.
4. Insufficient Oxygen Supply
In the sewage treatment plant of an animal body utilization, the oxygen content of the activation was very low after production expansion (0.2 mg / l). To do this, all 12 hollow shaft aerators had to be switched on. After addition of bioTEC BAC III (18 h / kg BOD5) it was possible within 3 days to achieve the same oxygen content (and the same degradation) with only 8 hollow wave aerators, which considerably reduced the energy input.
5. Insufficient Nitrification
In a municipal sewage treatment plant, it was not possible to nitrify despite a sludge load of 0.12 kg BOD5 / kg TS.d and a temperature of 12 ° C. Presumably, avivages from textile processing acted as nitrification inhibitors (nitrifying agents were present).
bioTEC BAC VI in an amount of 25 g / kg BOD5 almost immediately after 8 days led to a complete nitrification of the wastewater treatment plant. The continuous dosage could be reduced to 8 g / kg BOD5.
6. Bad Anaerobic Degradation
Wastewater was treated anaerobically in a sugar refinery. Gas production remained at 65% of the target value. There were large amounts of organic acids in the process, resulting in great odor nuisance.
12 days after treatment with bioTEC BAC IX, gas production even increased to 100% of the target value and stabilized. The smells disappeared.
7. Cold Digestion
In a cold digestion of sludge under strong odor always a separation in floating and sedimented sludge occurred. The intervening muddy water was green-black and stinking.
After treatment with bioTEC BAC IX, a good separation of the sludge and the muddy water resulted. The muddy water was clearer and less odoriferous.
How are bioTEC BAC products used?
1. Aerobic Treatment
After analyzing the causes, bioTEC BAC is added at the most turbulent point possible. With a sludge age of several days, a daily one-time addition is sufficient as bioTEC BAC is recycled with the return sludge.
It usually begins with 20-25 g / kg BOD5 up to 1 1/2 times the age of sludge, if the desired effect is not earlier declining again.
This dosage is maintained as a continuous dose. They compensate the bioTEC BAC discharge with the excess sludge.
2. Anaerobic Treatment
It starts with about 100 g of bioTEC BAC IX per m³ feed to about 1 1/2-fold residence time in the digester. Again, the dosage is reduced until the effect (gas production) begins to deteriorate.
List of standardized bioTEC BAC products
|Aerobic wastewater treatment:||bioTEC BAC I
bioTEC BAC II
bioTEC BAC III
bioTEC BAC IV
bioTEC BAC V
bioTEC BAC VI
bioTEC BAC VII
|Aerobic and anaerobic treatment of animal and vegetable fats and oils:||bioTEC BAC VIII|
|Anaerobic wastewater and sludge treatment:||bioTEC BAC IX|
From a further 135 products, the corresponding special product is available for the respective problem case.