| Bio-augmentation technology has attracted great attention in the current waste water treatment technology because it has great application potential in the treatment of refractory organic matter.In the process of application of bio-augmentation technology,carrier material will affect the operation cost and the strengthening effect of the system.At present,the mainstream carrier material is chemical product and due to their low biological activity,it can not fully fit with the biochemical system.Therefore,it has great significance to develop a biological carrier with biocompatibility,high efficiency and simple follow-up disposal.Recent years,biomass carriers such as bamboo silk and straw have attracted much attention from practitioners.Among them,mycelium pellets formed by filamentous fungi in a specific flow state have certain strength,large specific surface area,surface characteristics suitable for bacterial fixation and growth,and good biocompatibility,etc.,and their feasibility and technical advantages as new biological carriers have been confirmed.In this study,the culture conditions of mycelium pellets were optimized based on different filamentous fungal strains,and the surface was modified with biological flocculant.On this basis,the load performance of mycelium pellets as microbial carriers was further discussed.In this experiment,one newly screened and preserved strain of Aspergillus Niger,Penicillium citrinum and Rhizopus Oryzae in the laboratory were selected as the research object,and the optimal medium formulation and operating conditions of the three fungi in the process of forming mycelium pellets were investigated respectively.These three kinds of fungi grew fastest when glucose were used as carbon source and ammonium chloride was used as nitrogen source,with the addition of 10g·L-1 and 1g·L-1 respectively.When the rotational speed of shaking table and the volume of spore inoculation were changed,the growth of mycelium ball would be affected.When the rotational speed was 160r·min-1,the maximum dry weight of three fungi could be obtained.The dry weight of mycelium could be 110.3mg,118.2mg and 83.8mg respectively in 150 m L medium.0.8m L was the best spore suspension inoculation for all three strains.Through drawing the growth curve under the optimum conditions,it was found that the three mycelial spheres could reach maturity after 48 hours of growth.Put the cultured Aspergillus Niger mycelium pellets and Penicillium citrinum mycelium pellets into F2 bioflucculant to improve the content of extracellular polymer on the surface of mycelium pellets,so as to improve the surface adhesion performance of mycelium pellets and enhance the load capacity of mycelium pellets on microorganisms.The experimental results showed that the amount of polysaccharides and proteins in the surface bound extracellular polymer of the two kinds of mycelium pellets modified by bioflocculant were significantly increased,and the sedimentation performance of mycelium pellets was improved.Due to its loose structure and poor sedimentation performance,Rhizopus Oryzae mycelium pellets could not maintain its original shape under strong hydraulic impact,so it was not suitable for use as a carrier material.Loaded the modified Aspergillus Niger mycelium pellets with activated sludge to characterize the characteristics of mycelium pellets before and after the load,and investigatting the treatment efficiency of mycelium pellets on actual domestic sewage by beaker experiment and SBR reactor operation.The results showed that the mycelium pellets loaded with sludge had a good effect on the treatment of domestic sewage,with the removal rate of COD and ammonia nitrogen reaching 82% and over 89% respectively.But due to the absence of some functional bacteria and insufficient anaerobic time in the process of operation,the removal rate of total nitrogen in the system is very low,which needs to be further discussed and solved by subsequent studies. |
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