| Phenolic compounds are a kind of refractory compounds and have extensive distribution and source.Phenol is usually treated by physical or chemical or biological ways.But it will produce secondary pollution by physical or chemical ways.While it needs to add free functional bacterial in addition when using biological ways to treat phenolic compounds.So using carrier to immobilize free bacteria is a kind of solution.Mycelium pellet is a kind of novel carrier formed by fungal hyphae growing and twining,which possesses excellet adaptability and adsorbability even in estreme condition.However the use of mycelium pellets in bioreactors and bioreactor configuration is still limited.To study mycelium pellets as carrier of immobilized phenol-degrading bacteria on the feasibility of removing phenol,this paper regarded phenol synthetic water as the research object,and regarded phenol emissions(0.5mg/L)in the integrated wastewater discharge standard as goal,and designed experiments about preparation of mycelium immobilized bacteria,static tests,design and parameter optimization of reactors.It demonstrated that mycelium pellets immobilized with phenol-degrading bacteria can treat phenol wastewater effectively and developed two kinds of new reactor.Firstly,immobilize free phenol-degrading bacteria on mycelium pellets by cultureadsorption method.Investigate fundamental characteristics and stability of mycelium pellets immobilized with phenol-degrading bacteria.Through characterization of mycelium pellets,find that the diameter of pellets mostly distributed among 2~3mm with excellent settlebility,and the integrity coefficient was about 91.3% which indicated good integrity.Besides that,it demonstrated that there is a lot of hole in mycelium pellets and phenol-degrading bacteria can distribute uniformLy after absorption.After that conduct a static test by adding phenol-degrading bacteria into phenol wastewater.Firstly compare removing phenol efficiency by free phenol-degrading bacteria,mycelium pellets immobilized with bacteria and mycelium pellets.It demonstrated that in the same condion,mycelium pellets imbolized with phenoldegrading bacteria can remove phenol more efficiently.Then by static tests,it was studied that how phenol concentration,p H,temperature and rotate speed influence the phenol removing efficiency.And the result showed that the optimum conditions for the removal of phenolic compounds in conical flask were as follows: the concentration of phenol wastewater was about 200~400mg/L,p H was 7,the temperature was 30℃ and the rotate speed was 200r/min.At the same time,analyze the mechanism of removal of phenol by mycelium pellets imbolized with phenol-degrading bacteria in brief.Lastly,design and produce two different reactors: airlift and hybrid,which both use continus flow.Start and run this two reactors and conduct parameter optimization in phenol concentration,aeration rate and HRT.When influent phenol concentration was about 200mg/L,pH was 7,temperature was 25~30℃,HRT was 3 days and MLSS was 1300mg/L,this two different reactors both can reach steady state in ten days and the corresponding phenol concentration in effluent was about 0.5mg/L.Optimizing this two reactors’ operating parameters,the result showed that the optimum conditon of continus airlift reactor was 0.0513~0.103(kg phenol)/(kg mycelium pellets ·d),HRT was 5d;and as for continus hybrid reactor,the optimum condion was 0.103(kg phenol)/(kg mycelium pellets ·d),HRT was 3d. |
