Analysis On Characteristic Of Treatment Technology For Gibberellin Wastewater With Combined Process Of Multi-Stage Anaerobic +A_O

There is a high concentration of organic matter,ammonia nitrogen and sulfate in the gibberellin production wastewater,and also has a certain chroma.It is a kind of difficult to deal with in pharmaceutical wastewater with its complex composition.A biochemical company in Jiangxi is mainly produced gibberellin by biological fermentation,three kinds of wastewater generated in the production process: raffinate wastewater,high concentration wastewater,comprehensive wastewater.In the raffinate wastewater,COD concentrations reached 25000-40000mg/L,the ammonia nitrogen concentrations between 200mg/L-350mg/L,sulfate content in 12000mg/L-28000mg/L.According to the characteristics of gibberellin production wastewater,the biochemical company was built the IC+UASB+Micro-aerobic+UASB+AO+biological contact oxidation processing to deal with.In this study,this wastewater treatment process of gibberellin production was studied as follow:(1)The removal effect and mechanism of sulfate were studied.In the actual operation process,the control pH is about 9.5,through the coagulation sedimentation tank and reaction tank 1 two-step reaction,the overall removal rate at about 85%.(2)The start-up state of the reactor was studied.After about 45 days of commissioning,all the reactors are start-up completed.Start initial stage,in anaerobic treatment unit,VFA increased,pH and ALK decreased,VFA slowly decreased,pH and ALK is relatively stable with the start.When start-up completed,anaerobic has a great removal in COD,sulfate,anaerobic sludge granulation.The sludge concentration increased significantly during AO start-up,sludge particles gradually,starting at the completion of MLSS,stable at 2g/L,SV30 increased to more than 20%,SVI remained at about 90ml/L.When the contact oxidation tank and the micro oxygen pool were started,there was a visible Brown biofilm on the carrier,and the two reactors could degrade some impurities in the water.(3)The operation effect and influencing factors of anaerobic reactor were studied.The run data of IC showed that the removal rates of COD and sulfuric acid were about 55% and 50% respectively,and the MLSS in 2m,4M,8m and 10 m of the reactor were increased in stable operation period.Analysis of the impact factors on IC reactor,the value of COD/SO42-control in 6-8,pH is about 7.3,the temperature is 30-35 DEG,control in these will make IC run better.The run data of UASB showed that the COD removal rate of UASB1 and UASB2 reached 50% and about 75% respectively,and the sulfate removal rate was up to 60% and 75% respectively.The influencing factors were analyzed,the optimal operating environment for the UASB1: the COD/SO42-value is higher than 7,more than 7 in pH;the best operation conditions for UASB2: more than 13 about the COD/SO42-value,pH is about 7.3.(4)The operation effect and influence factors of aerobic reactor were studied.AO results show that COD,NH3-N,TP can reach about 67%,93%,75% removal rate.To analyze the best operation conditions for AO: COD/SO42-value was more than 30,pH between 7.3-8 and DO in aerobic tank and anaerobic tank is 3mg/L and 0.5mg/L respectively,sludge return ratio is 0.6,the reflux ratio is about 2.Removal rate of COD,ammonia and sulfate in micro aerobic tank were about can reach 20%,15%,15%,and removal rates of COD in contact oxidation pool of were about 60%.(5)On the overall operation of the system effect,results show that the main IC+UASB+Micro-aerobic+UASB+AO+biological contact oxidation processing can treat gibberellin production wastewater effective,the effluent concentration of COD,sulfate,ammonia nitrogen and total phosphorus were 80mg/L,80mg/L,2.5mg/L,0.25 m.The effluent quality is able to meet the first class criteria specified in Integrated Wastewater Discharge Standard(GB8978-1996).The operation cost of the system of the calculation results show that the sewage treatment operating cost of 2.8 yuan /m3.Wastewater treatment process of gibberellin with IC+UASB+Micro-aerobic+ UASB+AO +biological contact oxidation processing has strong resistance to impact load,stable operation,good effluent quality,low cost,has a certain reference value for similar wastewater treatment engineering practice.