Study On Treatment Of Acrylic Fiber Wastewater With Additional Carbon Source And Different Operation

At present,China has already been the largest country in the world which produces acrylic.In fact,if the acrylic wastewater,containing high organic pollutants and ammonia nitrogen concentration,pulls into waters without any disposition,our environment will be severely polluted.As a kind of industrial wastewater which is hard to degrade,the acrylic has been a key object of study.The wastewater,with low B/C,contains a large number of biodegradable organic matter and toxic and harmful substances,which will inhibit the growth and metabolism of the microorganism during the biochemical phase.Therefore,the discharge standards of acrylic wastewater are highly concerned by the environmentalists as difficult problems.This paper focuses on the wastewater from the regulating reservoir in Jilin Chemical Fiber Factory,including three experiments.Specifically,they are the research to the effect on coupling of acrylic wastewater and viscose wastewater,the strengthening effect on coupling by adding sponge iron and iron salt?FeSO4,FeCl3?and the effect on acrylic wastewater through different treatment processes.The conclusions are as follows.?1?Coupling treatment of acrylic wastewater and viscose wastewater?1?When comparing the individual coupling treatment of acrylic wastewater with the coupling treatment of acrylic fiber and viscose wastewater,the removal capacity of COD is larger than the theoretical volume removal load,and the removal capacity of ammonia volume is slightly smaller than the theoretical volume removal load.The degradation efficiency of COD was better and the degradation effect of ammonia nitrogen is nearly the same.?2?Study on the effect of adding viscose wastewater in different time periods to the coupling treatment.6# reactor?T=8 h,adding viscose wastewater?reaches the best degradation of COD;as for the ammonia removal,the effluent of the 6# ⁹# reactor is in 1.5 mg/L below,having a higher removal.Especially,the 8# reactor reaches the best,when T=14 h by adding viscose wastewater.The removal rate of nitrite nitrogen is in the range of 0.1 0.2 mg/L in each reactor.The accumulation of nitrate nitrogen in the 3# reactor was the least,that is,the addition of viscose wastewater meets T=0 h,the accumulation of nitrate nitrogen was the lowest and the effluent concentration was the lowest.The best removal efficiency of total nitrogen was 3# reactor.Namely,When the addition of viscose wastewater meets T=0 h,the lowest concentration of total nitrogen appears.?3?After changing the operation mode,the degradation of COD in each reactor did not strengthen.However,the effluent concentration increased slightly.This reaction plays a obvious role in the reinforcement of denitrification.After the change happens,when T=8 h by adding viscose wastewater,the COD degradation achieves the best.?4?Study on the change of the concentration of each index before and after changing the operation mode.The rate of degradation of ammonia nitrogen,nitrate nitrogen and total nitrogen was faster in the aeration phase after changing the mode of operation.Changing the operation mode is more conducive to nitrification and denitrification.Meanwhile,the nitrogen removal effect will be better.?2?Study on the effect of sponge iron and iron salt on coupling treatment?1?The effluent concentration of 2#,3#,4# is lower than that of 1#.Generally speaking,Fe⁰,Fe²⁺ and Fe³⁺ enhance the removal effect of COD in the wastewater.When adding sponge iron,removal effect of COD is the best.Namely,the removal rate of effluent COD is 66 mg/L,the average removal rate is 76.3%.When adding Fe²⁺ in 2# reactor,the removal rate of COD is 73.4% and when Fe³⁺ in 4# reactor,the COD removal rate of the reactor was 74.1%.After comparing,the COD removal rate of the 2#,3# and 4# reactors was 4.4%,1.5% and 2.2%,which are higher than those of 1#.?2?Each reactor has a strong removal effect on ammonia nitrogen and the effluent ammonia nitrogen was below 1.4 mg/L,the removal rate above 95%.The removal rate of ammonia nitrogen was the best,the average removal rate was 98.2%,1.4% higher than that of the control group.The average removal rate of ammonia nitrogen in the 3# and 4# reactor with iron salt was 96.1%,95.4% respectively,compared with the control group was 0.7%,1.4%.?3?The conversion of nitrite nitrogen in each reactor is very thorough.Also,the concentration of nitrite in effluent is only 0.1 mg/L.The accumulation of nitrate nitrogen in the reactor with sponge iron and iron salt was less than that in the control group?1#?.The cumulative accumulation of nitrate nitrogen in the 2# reactor with sponge iron was 4.7 mg/L,and the accumulation of nitrate nitrogen in the 3# and 4# reactor was 15.3 mg/L,12.7 mg/L.Compared with the control group?1#?,the accumulation of nitrate in 2 #,3 # and 4# reactors was 15 mg / L,4.4 mg/L and 7 mg/L respectively.?4?The addition of sponge iron and iron salts on the removal of total nitrogen have a certain strengthening effect.Among them,the removal efficiency of total nitrogen in the 2# is the highest---the effluent concentration is 12.6 mg/L and the removal rate was 66.5%.While the the total nitrogen concentrations of 3# and 4# are 25.7 mg/L and 21 mg/L respectively,and the removal rates are 31.6% and 44.1%,respectively.The removal rate of total nitrogen in the 2#,3# and 4# reactors by adding the sponge iron and iron salt are 46.8%,11.9% and 24.4%,higher than those of the control group?1#?respectively.?3?Treatment of Acrylic Fiber Wastewater by Different Processes?1?The removal rate of COD,ammonia nitrogen and total nitrogen is the highest when the HRT is 41 h under the condition of A/O biofilm,and the effluent concentration is 321 mg/L,50.9 mg/L and 88.5 mg/L respectively.When the HRT is 41 h and the reflux ration of nitrification liquid is 300%,the results show that the effluent COD,ammonia nitrogen and total nitrogen concentration were the lowest at 313 mg/L,39.4 mg/L and 68.7 mg/L,respectively.?2?the HRT is 50.7 h in the A/O/A/O biofilm process,the effluent COD,ammonia nitrogen and total nitrogen concentration are the lowest,respectively,314 mg/L,101.3 mg/L,and 122.3 mg/L.The results showed that the effluent COD,ammonia nitrogen and total nitrogen concentration were relatively lowest when the HRT was 50.7 h,and the reflux ratio of nitrification liquid is 300%.Namely,they are 311 mg/L,98.3 mg/L,119.7 mg/L respectively.