Continuous Growth Mechanism Of Aerobic Filamentous Biofilm Of White-rot Fungus In The Treatment Of Refractory Organic Wastewater

It is a challenge for the effective,low-cost treatment of refractory organic wastewater.The white-rot fungi have great potential to treat it due to their unique ability to degrade refractory organic pollutants.However,white-rot fungal treatment system has been impeded owing to short-term fungal activities in reactor.For the first time,our research group has successfully achieved the long-term continuous growth of P chrysosporium aerobic filament biofilm in landfill leachate and coking wastewater under non-sterile conditions,which based on vascular carrier s and Zheng-Long reactors.But the mechanism involved the long-term continuous growth of P chrysosporium aerobic filament biofilm in wastewater remains to be studied.In order to solve this problem,the formation and growth process of P chrysosporium aerobic filamentous biofilm in wastewaterwas were investigated.The experimental results showed that:· In biofilm formation stage,the spores of P.chrysosporiumcan attached to vascular carrier,germinated in it to form P.chrysosporiumaerobic filamentous biofilm and then grew to cover the surface of vasc ular carrier.· When P.chrysosporium aerobic filamentous biofilms were added to wastewater,they first adsorbed pollutants and changed their colour.In addition,they maintained the continuous Li P production to remov e COD and ammonium nitrogen,which suggested that P.chrysosporium aerobic filamentous biofilm undergoe d adsorption,degradation and growth process.· In landfill leachate and coking wastewater,the outer layers of P.chrysosporium aerobic filamentous biofilms were torn open and gradually exfoliated,but their inner layer still fixed in vascular carrier and grew to increase the thickness of P.chrysosporium aerobic filamentous biofilm,and developed new outer layers of P.chrysosporium aerobic filamentous biofilm s.The new outer layers were torn open and gradually exfoliated.Based on those results,it proposed that the growth mechanism of P.chrysosporium aerobic filamentous biofilm in refractory organic wastewater was the cyclic growth process involving the exfoliation of outer layer-continuous growth of inner layer-the exfoliation of new outer layer.The continuous growth of P chrysosporium aerobic filament biofilm was attributable to(1)a vascular carrier designed to form aerobic filamentous fungal biofilm in/on its surface and to achieve the continuous supply of nutrient and oxygen for its inner layer to keep continuous growth of inner layer,(2)a Zheng-Long rector designed to achieve the layered,static culture of aerobic filamentous biofilm and to decrease some damages for biofilm,and(3)An appropriate reactor operation strategy(Sequencing Batch)used to decrease the influence of metabolites and bacteria on aerobic filamentous biofilm.