Papermaking wastewater treatment bio-enhancement technology
Wastewater treatment has always been a stubborn problem in environmental governance. Bio-augmentation technology refers to adding specific microorganisms to traditional biological treatment technology, thereby increasing the concentration of microorganisms and increasing their decomposition rate, so as to better treat wastewater. deal with.
The specific performance of bioaugmentation technology
From the analysis of the main manifestations of bioaugmentation technology, it can be divided into three parts, one is the direct addition of specific degrading microorganisms, and the other is bioaugmentation preparations and immobilized bioaugmentation technology. The following three aspects will be elaborated.
1.1 Directly adding specific degrading microorganisms
Directly adding specific degrading microorganisms is more common in bio-augmentation technology. The operating principle is to directly put the cultured and domesticated microorganisms into the wastewater to be treated, and use the treated pollutants as the only carbon source and energy. The microorganisms form highly efficient biofilms by attaching to the carrier.
For some degraded organic substances that are more difficult to remove, they need to be treated by inputting biological co-metabolism substrates.
For example, when microorganisms form oxidase by degrading original substrates such as toluene, phenol, and dichlorophenoxy, the original structure of pollutants is changed, thereby achieving the purpose of degrading pollutants.
For this process, it is called biological co-metabolism. For example, resin acid, the main pollution source of papermaking wastewater, can be treated by the degradation of lignin by P. chrysosporium, and the derivation of various phenolic compounds after its degradation.
In this process, the structure of the microbial cell of resin acid is not changed, but it is removed by bio-enhancing the degradation of resin acid.
Therefore, when processing, first select a strain of lignin that is preferentially degraded. The degradation of this lignin needs to preferentially degrade its alkalophilic degrading bacteria. It needs to be cultured in an alkaline liquid for about 10 days, and then when the degradation rate After reaching 49%, it can be used to metabolize lignin and its derivatives.
1.2 Biofortified formulations
In the process of wastewater treatment in paper mills, this bio-enhanced preparation has a significant effect, one of which can effectively shorten the acclimation time of microorganisms, thereby increasing the concentration of microorganisms in biological treatment, thereby improving the efficiency of paper mill wastewater treatment.
On the other hand, its operation is relatively simple, and the pollution can be effectively treated, which can avoid some unnecessary waste of resources in the process of wastewater treatment.
And paper mill wastewater has a lot of carbohydrates and organic matter, which provides nutrients for the strengthening of microorganisms. Treating papermaking wastewater in this way can improve the removal rate of organic matter and improve the dephosphorization effect of sewage.
1.3 Immobilized bioaugmentation technology
Although the wastewater treatment method of directly adding specific degrading microorganisms has the advantages of simple operation and resource saving, it is still in the process of operation.
The special microorganisms put in are easy to cause loss, or they are directly swallowed by the original microorganisms after being put in, thus affecting the effect of wastewater treatment.
The immobilized bioaugmentation technology can solve this problem. Its mechanism of action is to fix the mixed dominant strains in a specific carrier, so that the bacteria fall off less, maintain the activity of the bacteria, and maximize the concentration of the dominant microorganisms. of improvement.
In the process of wastewater treatment, the survival time of bacteria can be increased.
And while the wastewater pollutants are treated, the conductivity of the wastewater can also be effectively reduced, and the recovery rate of the wastewater can be improved.
According to clinical literature research, the immobilized bioaugmentation technology was applied to P. chrysosporium, and it was found that the decolorization efficiency was significantly improved after application, which could effectively enhance the decolorization efficiency.
The specific application of bio-enhancement technology
The application of bio-augmentation technology is mainly to treat refractory substances, remove nutrients in wastewater, and speed up treatment efficiency.
2.1 Treatment of refractory substances
The main reason why bioaugmentation technology can be used in paper mill wastewater is that it is difficult to properly treat some difficult-to-degrade organic substances in the process of paper mill wastewater treatment.
Therefore, it is necessary to increase the concentration of microorganisms through bioaugmentation technology to improve the degradation effect. However, with the increase in the types of pollutants in the water environment pollution.
Compounds that require complex structures require a specific strain to explain, and these substances have a certain toxic effect on microorganisms, while the number of microorganisms with metabolic functions is small.
Therefore, these difficult-to-explain substances will exist in the discharged environment for a long time, causing stubborn pollution. Conventional wastewater treatment methods cannot achieve significant results, so bio-augmentation technology is required.
For example, if the microorganism such as sodium alginate is immobilized on white rot bacteria, because the domestication of the bacteria improves the adaptability of white rot bacteria, it has a higher survivability in an acid-alkali environment and better degradability of lignin.
The papermaking black liquor is digested and treated in an anaerobic environment. The papermaking black liquor is mainly a kind of lignin, which can be degraded by sodium alginate, chitosan and activated carbon microbial capsules. The bacteria died naturally, but the immobilized white rot bacteria still had a good ability to degrade lignin.
2.2 Removal of nutrients from wastewater
Industrial wastewater, especially wastewater from paper mills, will discharge a large amount of hemicellulose, lignin and other substances during the production process, making the nitrogen and phosphorus content in the wastewater too high, which is often referred to as eutrophication. during the treatment of this water body.
The use of biotechnology treatment will make the microorganisms used grow slowly. On the other hand, the microorganisms cannot maintain a high concentration state for a long time, so it is difficult to treat.
For example, in the application of nitrifying bacteria, due to its slow growth rate and low survival rate, the wastewater treatment effect is not good. Therefore, it is necessary to use bioaugmentation technology to strengthen the nitrifying bacteria. The enhanced nitrifying bacteria can promote the growth of bacteria in the biofilm and start quickly.
Microorganisms multiply rapidly in the biofilm, and in addition, the abundance of nitrifying bacteria on the surface of the biofilm is increased, resulting in an accelerated rate. After being used in papermaking wastewater, its denitrification effect is significantly improved.
And this nitrifying bacteria also has a good denitrification effect on low temperature papermaking wastewater after bioaugmentation.
2.3 Speed up processing efficiency
Although the method of directly inputting high-efficiency microorganisms is simple and effective, it is easily affected by factors such as water environment, water quality, water quantity, eutrophication, and bacterial injection during the treatment of papermaking wastewater. It may be engulfed by other microorganisms, thereby adding to the cost of sewage treatment.
Therefore, while speeding up the treatment efficiency, it is also necessary to ensure the treatment quality. In the process of papermaking wastewater treatment, it is necessary to invest a certain amount of dominant bacteria, and at the same time increase the proportion of effective bacteria, so as to achieve a rapid removal effect.
In addition, the stability of the system can be maintained by enhancing the ability to withstand load shocks.
Conclusion
With the concept of my country’s Scientific Outlook on Development and the proposal of sustainable development strategies, people’s awareness of environmental protection has been continuously enhanced, and the country has also stepped up efforts to rectify industrial pollution.
Bio-augmentation technology needs to be analyzed from two aspects in the treatment of papermaking wastewater, one is the performance of bio-augmentation technology, and the other is the application of bio-augmentation technology.
From the analysis of the main application methods of bioaugmentation technology, it can be divided into three parts, one is the direct addition of specific degrading microorganisms, and the other is bioaugmentation preparations and immobilized bioaugmentation technology.
The application of bio-augmentation technology is mainly to treat refractory substances, remove nutrients in wastewater, and speed up treatment efficiency.