| Natamycin is a broad-spectrum and high efficient antifungal agent,which is widely used in fields of food and medicine.It is produced through microbial fermentation and multi stage separation as well as purification.Natamycin wastewater which is discharged in production process belongs to typical high concentration organic wastewater.Content of CODcr and TN are high,which are 20000mg/L-50000mg/L and 1000mg/L-3000mg/L respectively.According to requirements of discharge standard,two objectives of denitrogenation and decarbonization need to be completed. Study and report on denitrogenation and decarbonization technology of high concentration organic wastewater at home and abroad are relatively less.This study was based on the treatment project natamycin wastewate,combined with Anaerobic-Aerobic decarbonization technology and Nitrosation-ANAMMOX denitrogenation technology.We put forward a new technical route.We carrred out the research on engineering application and laboratory studies.The conculsions from this study are as follows:1.Anaerobic fermentation technology used could efficient removal organics of natamycin wastewater.Natamycin didn't inhibit methanogenic process.Natamycin wastewater could complete Nitrosation-ANAMMOX process when CODcr concentration of discharge water from anaerobic was low.Based on integrated technical route proposed,natamycin wastewater could realize targets of denitrogenation and decarbonization.2.Comparative study on treatmen effects for natamycin wastewater between bench-scale UASB reactor and field High-Rate Anaerobic Reactor showed that the latter had a better CODcr treatmen effect and more stable operation.The maximum CODcr concentration of influent was 11163mg/L during the running of UASB reactor,and the maximum organic volumetric loading of inflow was 9.05kgCOD/m3.d,the maximum removal loading and the average removal loading were 5.89kgCOD/m3.d and 2.59kgCOD/m3.d;The maximum removal rate of CODcr and the average removal rate of CODcr were 88.9% and 71.6%.The maximum CODcr concentration of influent was 28109mg/L during the running of High-Rate Anaerobic Reactor,and the maximum organic volumetric loading of inflow was 7.86kgCOD/m3.d,and the average organic volumetric loading of inflow was 3.06kgCOD/m3.d;The average effluent concentration of CODcr was 1141mg/L,and all of effluent CODcr was less than 2000mg/L.During the running of High-Rate Anaerobic Reactor,the maximum removal rate of CODcr and the average removal rate of CODcr were 95.5% and 87.3%,which showed that High-Rate Anaerobic Reactor had an excellent treatment ability of CODcr.3.Semi-Nitrosation—ANAMMOX process was used to treatment natamycin wastewater after anaerobic process under long sludge age and low concentration of dissolved oxygen.Nitrosation process was stable when CODcr concentration of discharge water from anaerobic was low.Nitrate accumulation occurred when CODcr concentration of discharge water from anaerobic was high,which had influence on nitrogen removal efficiency of ANAMMOX process.Denitrification reaction by adding Sodium Acetate into the system further improved removal rate of total nitrogen in the late stage.The average and the maximum removal rate of total nitrogen were 78% and 92.5%. During Nitrosation—ANAMMOX process,NH4+-N and TN concentration of influent were 150mg/L-350mg/L and 200mg/L-350mg/L respectively,average removal rate of NH4+-N and TN were 80% and 45% respectively;The average and the maximum total nitrogen volumetric loading of inflow in nitrosation reactor were 0.64kg/m3.d and 0.87kg/m3.d respectively,and the average and the maximum removal loading of total nitrogen were 0.28kg/m3.d and 0.69kg/m3.d respectively;Ammonia,nitrite nitrogen and nitrite nitrogen of the final effluent after 54 days were 8.38mg/L,9.37mg/L and 38.12mg/L.It was showed that various nitrogen concentration treated by this process combination can reach the national effluent standard.4.Membrane bioreactor was used to treatment natamycin wastewater after nitrogen removal process,CODcr treatmen effect was low.During the incipient operation,CODcr removal rate was only 22.2%.CODcr of influent was less than 350mg/L while CODcr of effluent was less than 300mg/L.Then ferrum carbon aeration micro electrolysis, adding powdered activated carbon to MBR, adding sodium acetate to MBR and shortening the sludge age were used,but evident effectiveness wasn't generated after a period of practice of run.In the whole experiment period,the average removal rate of CODcr was 23.5%,and the average organic volumetric loading of inflow and the average removal loading were 0.31kgCOD/m3.d and 0.08kgCOD/m3.d respectively.Therefore,it is infeasible to treatment natamycin wastewater with a feeble biodegradability using MBR.In membrane flocculation reactor experiment,dosing 200mg/L FeCl3 into the reactor,the effluent COD,total iron and chromaticity increased when the membrane pollution became serious.The maximum removal rate of CODcr was 67%.The removal effect of membrane flocculation reactor was superior to membrane bioreactor,but its membrane pollution was more serious than membrane bioreactor.In the experiment of sodium hypochlorite decoloration,the addition amount of sodium hypochlorite increased with the increasing of concentration of COD.When COD concentration was 251mg/L,the addition amount of sodium hypochlorite was 1/500 of volume of MBR effluent,the effluent chromaticity was less than 30degree;When COD concentration was 516mg/L,the addition amount of sodium hypochlorite was 1/250 of volume of MBR effluent,the effluent chromaticity was less than 30degree. |
