Pretreatment Of Acrylic Fibre Wastewater By Sponge Iron-carbon Micro-electrolysis Combined With Fenton

This topic came from Water Related Issues in the National 12 th Five-year Plan,which is regarded as intensifying requirement to wipe off organic pollutants in acrylon wastewater.It combined actual situation of acrylon wastewater from Qifeng Co.,Ltd.of Jilin Chemical Fiber Group.Lab test of sponge iron to treat acrylon wastewater physically & chemically was performed in test base.Current situation of this factory is that COD in acrylon wastewater is not easy to be biodegradable.This study integrated technology of intensified treatment such as sponge iron/carbon microelectrolysis,sponge iron/carbon microelectrolysis coupling H₂O₂,Fenton of sponge iron & catalyzed metal.Influence of above physical & chemical technology to wipe off acrylon wastewater was investigated.COD was used as index of evaluation and conclusion is shown as below:1 To treate acrylon wastewater by sponge iron-carbon micro-electrolysis technology?1?Based on single-factor experiment,technological conditions of sponge iron-carbon microelectrolysis technology to pre-treat acrylon wastewater has been optimized through response surface analysis.Best factors combination is 2 for p H of inflow,0.5 for mass ratio of iron and carbon,dosage of sponge iron is 35 g/L and reaction time is 75 min.Under above situation,removal rate of COD gets 29.59%.?2?Micro-electrolysis pre-treatment by sponge iron-carbon to treat acrylon wastewater can improve removal efficiency of biochemistry.When average COD of inflow is 925.5mg/L,it could be reduced to 648.2mg/L by micro-electrolysis.Removal rate is 29.96%.And COD of final bio-chemical outflow is 231.8mg/L.Bio-chemical removal rate is 64.24% and accumulated removal rate is 74.95%,which is improved by 12.5% compared with bio-chemical treatment and accumulated removal rate is improved by 23.2%.?3?Average COD of outflow from catalytic oxidation ditch of wastewater treatment plant is 314.2mg/L.Micro-electrolysis may help to reduce it to 198mg/L.Then if the wastewater is sent to bio-chemical system,no COD will be removed,which means it has come to removal limitation.?4?Under basis of optimized conditions of response surface,ratio of iron and carbon is adjusted from 0.5 to 1,when sponge iron dosage is 35g/L,p H of inflow is 2 and reaction time is 75 min.Compared with time before adjustment,removal ratio of micro-electrolysis is reduced from 29.96% to 23.56%.Bio-chemical removal ratio if reduced from 64.23% to 59.32%.Total removal ratio is reduced from 74.95% to 68.91%.?5?Under basis of optimized conditions of response surface,p H of inflow is adjusted from 2 to 3,5 and p H of inflow is stable,when sponge iron dosage is 35g/L,mass ratio of iron and carbon is 0.5 and reaction time is 75 min.If average COD of inflow is 752mg/L and p H of inflow is 3,COD may be reduced to 574.9mg/L by sponge iron-carbon.When it is further treated through bio-chemical treatment,COD of outflow will be 258.6mg/L.When p H of inflow is 5,CODmay be reduced to 596.2mg/L through micro-electrolysis.When it is further treated through bio-chemical treatment,COD of outflow will be 275.4mg/L.When p H of inflow does not change,COD may be reduced to 618.6mg/L.When it is further treated through bio-chemical treatment,COD of outflow will be 288.7mg/L.Control group,that is acrylon wastewater which is not pre-treated by sponge iron/carbon,average COD of final bio-chemical outflow is 358.8mg/L.2 Sponge iron-carbon micro-electrolysis combined with H₂O₂ to pre-treat acrylon wastewater?1?Under the condition of sponge iron-carbon micro-electrolysis optimized by response surface,during which 35g/L sponge iron is used,mass ration of iron and carbon is 0.5,p H of inflow is 2 and response time is 75 min,coupling mode of H₂O₂ is a continuous addition from the beginning and the maximum dosage is 3ml/L.When H₂O₂ dosage is 1ml/L,2ml/L,3ml/L respectively and COD of inflow is 825.9mg/L,COD of outflow is 414.4mg/L,345.3mg/l and 261mg/L.Correspondingly,removal ratio is 49.8%,58.2% and 68.3%.?2?When average COD of inflow is 730.4mg/L and dosage of H₂O₂ is 1ml/L,2ml/L and 3ml/L,pretreatment may reduce COD to 385.3mg/L,3063mg/L and 243.2mg/L respectively.If it is further treated biologically by SBBR,average value of final COD is 159.2mg/L,126.4mg/L and 88.8mg/L.3 Pretreating acrylon wastewater by sponge iron combined by H₂O₂?1?Under the condition of continuous input of H₂O₂ at the beginning,when p H of inflow is 2,stirring speed is 50r/min,H₂O₂ dosage is 1ml/L,2ml/L and 3ml/L,corresponding sponge iron dosage is 15g/L,25g/L and 35g/L and reaction time is 90 min,120min and 150 min,removal rate is 36.1%,45.5% and 58.1% respectively.?2?When H₂O₂ dosage is 1ml/L,2ml/L and 3ml/L,with input of activated carbon into combined system of H₂O₂ and sponge iron,removal rate will be increased gradually.And when mass ratio of iron and carbon is 0.5,removal rate is intended to be stable,which is 45%,54.4% and 68.5% respectively.Removal rate is increased by 9.5%,9.5% and 8.7% compared to case without activated carbon.?3?When average COD of inflow is 921.1mg/L and H₂O₂ dosage is 1ml/L,2ml/L and 3ml/L,COD may be reduced to 590.9mg/L,505.1mg/L and 395.3mg/L by combined pretreatment of sponge iron and H₂O₂.If it has a further treatment by SBBR,average value of final COD is 234.6mg/L,179.7mg/L and 148.7mg/L respectively.4 Study of catalyzed metal's sponge iron physical-chemical reaction in acrylon wastewater?1?When dosage of sponge iron is 35g/L,mass ratio of iron and carbon is 0.5,reaction time is 75 min,dosage of Mn O₂ and Al₂O₃ is 1g/L respectively,under different p H of inflow,pretreatment of acrylon wastewater by sponge iron-carbon microelectrolysis is all strengthened.When p H of inflow is 2,removal rate is increased to 36.69% and 39.58% respectively.?2?When dosage of sponge iron is 10g/L,H₂O₂ is 1.5ml/L and it is used all together,reaction time is 105 min,dosage of Al₂O₃ is 2g/L,p H of inflow is 2,removal rate is increased from29.54% to 42.97%.p H of inflow may also be broadened to a large scale.In the same situation,when dosage of Si O₂ is 2g/L,p H of inflow is 2,removal rate is increased from 29.48% to 42.09%.?3?When dosage of sponge iron is 15g/L,reaction time is 90 min,dosage of Mn O₂ and Al₂O₃ is 2g/L,pretreatment of acrylon wastewater by sponge iron is all strengthened under different p H.When p H of inflow is 2,removal rate is increased from 21% and 21.6% to 25% and 31.44%.At the same time that Al₂O₃ strengthen sponge iron system by its own,it may also broaden scope of sponge iron to pretreat acrylon wastewater.Under the same p H situation of original water,removal rate may be increased from 3.6% to 17.17%.