The application of iron–carbon(Fe–C)micro-electrolysis to wastewater treatment is limited by the passivation potential of the Fe–C packing.In order to address this problem,high-gravity intensified Fe–C micro-elect...The application of iron–carbon(Fe–C)micro-electrolysis to wastewater treatment is limited by the passivation potential of the Fe–C packing.In order to address this problem,high-gravity intensified Fe–C micro-electrolysis was proposed in this study for degradation of dinitrotoluene wastewater in a rotating packed bed(RPB)using commercial Fe–C particles as the packing.The effects of reaction time,high-gravity factor,liquid flow rate and initial solution pH were investigated.The degradation intermediates were determined by gas chromatography-mass spectrometry,and the possible degradation pathways of nitro compounds by Fe–C micro-electrolysis in RPB were also proposed.It is found that under optimal conditions,the removal rate of nitro compounds reaches 68.4%at 100 min.The removal rate is maintained at approximately 68%after 4 cycles in RPB,but it is decreased substantially from 57.9%to 36.8%in a stirred tank reactor.This is because RPB can increase the specific surface area and the renewal of the liquid–solid interface,and as a result the degradation efficiency of Fe–C micro-electrolysis is improved and the active sites on the Fe–C surface can be regenerated for continuous use.In conclusion,high-gravity intensified Fe–C micro-electrolysis can weaken the passivation of Fe–C particles and extend their service life.展开更多
The pulp and paper industry produces a large amount of colored effluent in the pulping,bleaching,and papermaking processes.The wastewater from the pulp washing and bleaching stages is also known as mid-stage pulping e...The pulp and paper industry produces a large amount of colored effluent in the pulping,bleaching,and papermaking processes.The wastewater from the pulp washing and bleaching stages is also known as mid-stage pulping effluent,which is difficult to treat due to its toxicity and dark dolor.This paper reports a novel Fe/C micro-electrolysis process for the treatment of the mid-stage pulping effluent.Results show that this process is effective in removing the color under optimal reaction conditions.Scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FTIR)analyses indicate that the colored pollutants were removed from the wastewater in the Fe/C micro-electrolysis by adsorption,collection and filtration mechanisms.The Fe2+ions produced in the micro-electrolysis process functioned as Fenton’s reagents with H2O2 in the follow-up oxidation stage,which enhanced the removal of chemical oxygen demand(COD)and color.展开更多
基金This work was supported by the Fund for Shanxi"1331Project"(Grant No.nuc2021-006),Scientific Activities of Selected Returned Overseas Professionals in Shanxi Province(Grant No.20200004)Shanxi Scholarship Council of China(Grant No.2019032).
文摘The application of iron–carbon(Fe–C)micro-electrolysis to wastewater treatment is limited by the passivation potential of the Fe–C packing.In order to address this problem,high-gravity intensified Fe–C micro-electrolysis was proposed in this study for degradation of dinitrotoluene wastewater in a rotating packed bed(RPB)using commercial Fe–C particles as the packing.The effects of reaction time,high-gravity factor,liquid flow rate and initial solution pH were investigated.The degradation intermediates were determined by gas chromatography-mass spectrometry,and the possible degradation pathways of nitro compounds by Fe–C micro-electrolysis in RPB were also proposed.It is found that under optimal conditions,the removal rate of nitro compounds reaches 68.4%at 100 min.The removal rate is maintained at approximately 68%after 4 cycles in RPB,but it is decreased substantially from 57.9%to 36.8%in a stirred tank reactor.This is because RPB can increase the specific surface area and the renewal of the liquid–solid interface,and as a result the degradation efficiency of Fe–C micro-electrolysis is improved and the active sites on the Fe–C surface can be regenerated for continuous use.In conclusion,high-gravity intensified Fe–C micro-electrolysis can weaken the passivation of Fe–C particles and extend their service life.
文摘The pulp and paper industry produces a large amount of colored effluent in the pulping,bleaching,and papermaking processes.The wastewater from the pulp washing and bleaching stages is also known as mid-stage pulping effluent,which is difficult to treat due to its toxicity and dark dolor.This paper reports a novel Fe/C micro-electrolysis process for the treatment of the mid-stage pulping effluent.Results show that this process is effective in removing the color under optimal reaction conditions.Scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FTIR)analyses indicate that the colored pollutants were removed from the wastewater in the Fe/C micro-electrolysis by adsorption,collection and filtration mechanisms.The Fe2+ions produced in the micro-electrolysis process functioned as Fenton’s reagents with H2O2 in the follow-up oxidation stage,which enhanced the removal of chemical oxygen demand(COD)and color.
