Study On Substrate Interaction During Aerobic Granular Sludge Degradation Of Chloroaniline

Aerobic granular sludge was successfully developed with flocculent activated sludge as the seeding sludge and chloroaniline as a sole carbon source via controlling the operation parameters.In the same time we developed a salt-tolerant chloroaniline sludge degradation system through a gradual increase in the salinity object to explore the domestication of chloroaniline degradation salt-tolerance sludge,finally bring out some suggestion to the high-slinity industrial wastewater management.The diameter for the matures aerobic granular sludge are 250?m,but sludge in 5g/L NaCl saliferous SBR only 138.4?m.For the two SBR the removal efficiencies of chloroaniline were 100%and the removal efficiencies of TOC were above to 90%when they were in stable phase with intial chloroaniline concentration 900mg/L.The PCR-DGGE fingerprints indicated that aerobic granules contained a wide diversity of microorganisms and had a stable community structure in this period.Change of the aerobic granular sludge load when the influent chloroaniline concentration at 1500mg/L,it could remove 3-chloroaniline and 4-chloroaniline 100%but the 2-chloroaniline removal efficiencies reduced to 90%.However when the chloroaniline concentration at 1800mg/L,it was ceased to degradation chloroaniline and the sludge activity declined.PCR-DGGE analysis indicated that microbial population structure and quantity differed obviously during this period,and it was based on the Bdellovibrio,Mycetocola,Mycetocola,Planctomycete,Delftia and other bacteria.For the saliferous SBR kept the chloroaniline load at 900mg/L to change its salinity.When the salinity at 30g/L it could remove 3-chloroaniline and 4-chloroaniline 100%but the 2-chloroaniline only about 27.6%,before this salinity all of the chloroanilines removal efficiencies were at 100%.But when the salinity of up to 35g/L this system failured.In the process,sludge activity continued to decline.On the other hand,PCR-DGGE fingerprints indicated that the main advantage flora did not significantly changed mainly about Pseudomonas,Planctomycete,Verrucomicrobia,Marine and other types of bacterias.The competitive inhibition interaction existed when the chloroaniline components were presented as a mixture for the aerobic granular sludge degradation.Besides,the presence of 2-CA slightly inhibited 3-CA and 4-CA degradation,while the interaction between 3-CA and 4-CA was more significant.The chloroaniline degradation by aerobic granular sludge had a good fit to the Luong kinetics model,and the highest specific chloroaniline degradation rate in the line:3-CA>4-CA>2-CA.Besides,the model indicated that the maximum talerated concentration of 3-CA and 4-CA were closed to 800mg/L but the 2-CA only about 670mg/L.Successed isolated a Delftia strain w1 capable of degrading chloroaniline from aerobic granular sludge.The bacteria degradation performance analysis show that it can growth with 3-chloroaniline or 4-chloroaniline as the sole carbon source and nitrogen source,but can't utilize 2-chloroaniline as the sole carbon source and nitrogen source,however 2-chloroaniline can degraded when coexist 3-CA or 4-CA.And the degradation of 3-CA and 4-CA will be inhibited when presence of other chloroaniline.In addition,The inhibition of 2-CA to 3-CA or 4-CA is weaker to 3-CA between 4-CA.The experimental results indicated that the degrading process of the 3-CA or 4-CA biodegradation by the strain still followed the Luong model,and the the maximum substrate concentration of 3-CA or 4-CA are all closed to 590mg/L.With the salinity experiment for the strain found that this strain can be adapted NaCl to lOg/L,shows that it has a potential value for practical use.