MBFB process concept
The membrane biological fluidized bed process is based on a biological fluidized bed, using Pow-dered activated carbon (PAC) as a carrier, combined with a solid-liquid separation technology of Membrane bioreactor (MBR). The reactor integrates the physical adsorption, microbial degradation and high-efficiency separation of the activated carbon, so that the small molecular organic matter which is difficult to degrade in the water body is fully mass-massed and mixed with the activated carbon powder which is in a fluidized state under aeration conditions. Adsorption and enrichment on the surface of activated carbon, which forms a local contaminant concentration area on the surface of activated carbon; powdered activated carbon also provides a special surface for microbial reproduction, and its porous surface adsorbs a large number of microbial flora, especially with target pollutants as metabolism. The microbial flora of the substrate; at the same time, the powder activated carbon has a strong adsorption capacity for dissolved oxygen in the water body. Under the condition of high dissolved oxygen, the microorganism oxidatively decomposes the small molecular organic matter enriched on the activated carbon surface, and then utilizes the special purpose of the national The stainless steel filtration separation system suspends water and powdered activated carbon adsorbed with organic matter. Separated by crossflow filtration, further purifying contaminated water, to reach the water reuse standards. Studies have shown that MBFB can effectively remove ammonia nitrogen, COD and other toxic organic substances that are difficult to degrade small molecules in micro-polluted water.
MBFB mechanism
In the MBFB reaction system, powdered activated carbon (PAC) is a bioactive carbon (BAC) due to the adsorption of a large number of microorganisms, so that PAC not only has the adsorption and enrichment of small organic pollutants, but also the presence of PAC on microorganisms. Adsorption and protection, adsorption of dissolved oxygen by PAC, decomposition of small molecules by microorganisms under local high contaminant concentration and high dissolved oxygen, and bioregeneration of PAC. PAC, microorganisms, dissolved oxygen, pollutants and other elements under the action of high-intensity fluidization, mixing, mass transfer and shear, achieve efficient decomposition of micro-polluted small molecular organic matter.
1. PAC adsorption and enrichment of small molecular organic substances PAC can enrich pollutants to form local high concentration areas, which is beneficial to microbial growth and decomposition of micro-polluted small molecules organic matter;
2. Adsorption and protection of microorganisms by PAC;
3. The adsorption of dissolved oxygen by PAC, as the diameter of activated carbon particles becomes smaller, the specific surface area increases, and the adsorption of dissolved oxygen by PAC becomes stronger and stronger;
4. Microbial decomposition of small molecular organic matter, MBFB process adsorption and enrichment of microorganisms, pollutants and dissolved oxygen by PAC; through the protection of microorganisms by PAC, microbes can effectively utilize trace organic pollutants as the bottom The substance, dissolved oxygen as an electron acceptor, decomposes organic matter in the micro-polluted water body, and realizes deep purification of water quality;
5, PAC biological regeneration, activated carbon surface biofilm has oxidative decomposition of the adsorbed organic matter, can restore the adsorption capacity of activated carbon by biodegradation, achieve PAC biological regeneration, high-strength three-phase mass transfer, mixing, in MBFB system The turbulent flow, shearing and friction between the activated carbon particles cause the aging biofilm on the surface of the activated carbon to continuously fall off, so that MBFB maintains efficient adsorption and biodegradation functions.
MBFB features
1, long-term use of activated carbon powder, no need to replace or regenerate;
2. Three-phase mass transfer and mixing, high reaction efficiency;
3. The carrier is not lost;
4. The carrier fluidization performance is good;
5. High oxygen transfer efficiency;
6. The pollutants are highly enriched and the biomass is large;
7. Good effect on micro-polluted water treatment.
