Immobilization Mechanism Between Carbon Fiber And Microorganisms

Carbon fiber is a kind of special fiber which is characterized by a very good combination of overall properties with high strength, high modulus and high temperature resistance properties. At present, carbon fiber has became a emphasis of material research because of its excellent integrative performances. At the same time, carbon fiber is excellent in biological compatibility. The biological sewage treatment technology which uses carbon fiber as the biofilm carrier material is mainly using its good biological compatibility of forming activated sludge biofilm. The carbon fiber not only increases the contact area between wastewater and sludge, but also improves the capacity of digesting organic compounds in the water. This paper is mainly about carbon material, water environment and microbial compatibility.The experiments carried out were based on the previous research results. In this paper, carbon fiber was treated by anodizing the surface modification method.Then chose carbon fibers which showed good microbial compatibility to carry out adhesion experiments in the micro-environment. The content of Extracellular Polymeric Substances (EPS) in the sludge was measured, and the changes of polysaccharides and protein content in the EPS were investigated to identify whether the protein or polysaccharides plays a major role in the adhesion process. Study the immobilization mechanism between micro-organisms and carbon fiber deeply by the results.Selected 8 kinds of microorganisms from the activated sludge. At last, chose one kind of microorganism which the weight of bio-film is largest. Different concentrations of sodium iodide solution, different concentrations of trypsin solution and the same concentration of sugars such as glucose, lactose, L-sorbose, D-mannose and D-fructose were used to treat carbon fibers, then carried out the adhesion experiments. At the same time, carbon fibers were measured by X-ray photoelectron spectroscopy (XPS). Different concentrations of trypsin solution and bovine serum albumin solution were used to treat the microorganism, as well as high temperature treatment and use Phosphate Buffered Saline (PBS) to take the place of bacteria suspension supernatant and then carried out the adhesion experiments.It initially reveals that polysaccharide content of EPS is higher than protein, the protein plays the major role.The pH value is steady at 8.5-8.7 in adhesion process, therefore, it is supposed tha weakly alkaline environment may be more suitable for microbial immobilization process. Dominant microorganism is bacillus. It is inferred that the immobilization receptor is a kind of carbohydrate protein.The immobilization receptor is something like lactose protein. Microorganisms'capability of immobilization decreases with the increase of C-N bond.