Comparison Of Pretreatment Efficiency Of Flourescent Whitening Agent APC Wastewater By Fenton And Iron-carbon Micro-electrolysis Process

Fluorescent whitening agents wastewater is one of the hard-to-degrade industrial wastewaters.Due to its complex composition of water quality and poor biodegradability,conventional treatment processes usually use advanced oxidation and biological treatment combined processes to achieve removal of pollutants,but for advanced oxidation The selection of the treatment process and the matching of subsequent biological treatment processes are not sufficiently advanced and require further research.This research is based on iron-carbon micro-electrolysis process and Fenton process,and investigated the effect on the effluent after treatment of these two processes on the subsequent biological treatment process operation and iron-carbon microelectrolysis-EGSB-from two factors:treatment efficiency and running cost.The overall operational efficiency of SBR and Fenton-EGSB-SBR combined processes.The advanced oxidation treatment section adopts iron-carbon micro-electrolysis technology and Fenton technology.The iron-carbon filler used in the iron-carbon micro-electrolysis process has always been a research hotspot of this technology and has been researched and matured.This experiment selects two kind of iron carbide stones that have been put into practical use.A simulation was conducted and it was found that the iron carbide filler with high iron-carbon ratio was better treated in the actual treatment process,and it was found that with the extension of the reaction time,the COD removal efficiency gradually increased,and the reaction reached about 7 hours.To the greatest extent,the COD removal rate reached 27%,and the B/C ratio of the treated effluent was 4.65 times higher than that of raw water.The Fenton process was optimized for reaction time,H₂O₂ dosage,and H₂O₂/FeSO₄dosing ratio during the experiment.It was found that the reaction time was 1 h,the H2O2 dosage was 0.25 mol/L,and H₂O₂/FeSO₄ was added.When the ratio is 20:1,the treatment effect can achieve the best treatment effect.The COD removal rate can reach about 58%and the APC removal efficiency can reach 90%.The reaction surface was optimized for the obtained data.The fitting result showed that the reaction time was 78.7min,H₂O₂dosage was 0.27mol/L,Fe²⁺dosage was 0.01mol/L,and the best COD removal effect was achieved and the rate reaches 62%.According to the results of the response surface experiment,the actual COD effect removal efficiency can reach almost 60%,and the effluent B/C ratio can be increased from 0.043 to 0.329,which is 7.65 times higher than the original water.The effluent from the advanced oxidation unit enters the EGSB anaerobic reactor.At the beginning of the reactor,the glucose is used to simulate the high COD wastewater and then the wastewater influent ratio of the advanced oxidation pretreatment is gradually increased,so that the microorganisms in the reactor can adapt to the water quality,and the iron carbon microelectrolysis The effluent COD removal rate of the EGSB reactor connected to the effluent reached 14%,the TOC removal rate reached 24.3%,and the ammonia nitrogen content increased 35 mg/L on average.When the hydraulic retention time was extended from 2 days to 4 days,the COD removal rate reached 15.2%.The effluent COD removal rate of the EGSB reactor connected to Fenton effluent reached30.3%,the TOC removal rate reached 31.9%,and the ammonia nitrogen content increased 38 mg/L on average.When the hydraulic retention time was extended from 2days to 4 days,the COD removal rate did not change significantly.EGSB anaerobic treatment reactor effluent into the SBR reactor for aerobic biological treatment,SBR cycle is set to 12 hours,after a period of 11.5 hours aeration,precipitation for 20 min then change the water,the experimental results show that iron carbon microelectrolysis After the effluent of the EGSB combined process was treated by the SBR reactor,the COD removal rate of the SBR reactor reached 30%,the TOC removal rate reached 26.9%,and the ammonia nitrogen removal rate reached 40%.After the effluent of the Fenton-EGSB combined process was treated by the SBR reactor,the effluent COD removal rate reached 33.3%,the TOC removal rate reached 32.2%,and the ammonia nitrogen removal rate reached 24%.Through the economic analysis of two advanced oxidation processes,the cost of actual infrastructure costs and equipment purchase costs are eliminated in actual projects.The cost per ton of fluorescent whitening agent APC wastewater treated with iron-carbon microelectrolysis-EGSB-SBR process is 9.98 yuan/ton.The cost of each ton of fluorescent whitening agent APC wastewater using the Fenton-EGSB-SBR process was calculated to be 44.87 yuan/ton from the point of view of optimizing the treatment effect.If the cost is calculated from the economic point of view,the cost is 16.1 yuan/ton.