Research On Sponge Iron Inner Electrolysis Catalyzed By Manganese Mineral & MBR Technique Treating Dyeing Wastewater

A introduction to the source ,characteristics,and harm of dyeing wastewater was given in this dissertation as well as a introduction to present state of research on it. Sponge iron inner electrolysis and membrane bioreactor(MBR) both have their own advantages.This dissertation tried to combine these advantages together to form a new kind of technique for dyeing wastewater treatment.sponge iron inner electrolysis catalyzed by manganese mineral was used as pretreatment technique while MBR was the later biological treatment technique.This research proved it's feasibility.Synthetic dyeing wastewater was used in this dissertation.The study on sponge iron inner electrolysis catalyzed by manganese mineral showed that sponge iron/ manganese mineral could improve the biodegradable characteristic of the wastewater and had a good decolorization rate.However,the pH of the effluent was high while the removal rate of COD was low.Further treatment of the effluent was needed in order to fill the emission control regulations.4m/h was the best filtration velocity. Though it could not resume fully after the dynamic regenetation , sponge iron/ manganese mineral could still keep a better decolorization rate.Microorganism was found after a long reaction period.When the COD, BOD₅,chroma and pH of the influent were 700mg/L-800 mg/L, 230mg/L-250mg/L, 1000-1200 multiples, 8-11 respectively,the value of the effluent after sponge iron inner electrolysis catalyzed by manganese mineral were 570mg/L-670 mg/L , 200mg/L-320mg/L , 4-150 multiples , 8-11 respectively.The removal rates of the pollutants such as COD ,chroma and NH3 -N were observed as well as the characteristics of the sludge in MBR during its running for 106 days. When the COD, NH3-N,chroma and total iron of the MBR influent were 391mg/L-690 mg/L(577 mg/L on average), 12.08mg/L-49.79mg/L(29.43 mg/L on average),6-250 multiples(117 multiples on average), 0.27mg/L-17.9mg/L (4.31mg/L on average)respectively,the value of the supernatant fluid were 12mg/L-67 mg/L(23 mg/L on average), 0 mg/L-0.81 mg/L(0.3 mg/L on average),10-90 multiples(37 multiples on average), 0.02mg/L-0.96 mg/L (0.27 mg/L on average)respectively while the value of the effluent at last were 3mg/L-31 mg/L(8mg/L on average), less than 0.5mg/L, 5-80 multiples(27 multiples on average), 0.01mg/L-0.45mg/L (0.05 mg/L on average)respectively. The COD , NH3-N,chroma removal effciences of the microorganism were95.87%,more than 99% and 66.94%,while removal effciences of the MBR were98.61%,more than 99% and 76.29% respectively.MLSS in MBR was range from 5.6 g/L -12.4g/L,while MLVSS in MBR was range from 3.0 g/L -9.8g/L.SV increased at first and then decreased while the variety of particle size of sludge was on the contrary.The concentration of Fe in was below 3% all long and it would not restrain the microbial activity.Bioferric sludge was formed at last which could improve the characteristics of the sludge.The whole system's removal rate of COD was 98.95% while the decolorization rate was 97.27%.When the average of COD,chroma of the influent was 762mg/L and 1100 multiples respectively,the average of COD,chroma of the effluent at last was 8 mg/L and 27 multiples. The main contribution to decolorization was from the pretreatment taking up 87.6% while the main contribution to COD removal was from MBR taking up 86.6%.