Degradation Of Bisphenol A In High Temperature Wastewater By Nano Metal Catalyst Activated Periodate

Bisphenol A(BPA)is an endocrine disrupting hormone.At present,the abuse of its chemicals leads to great harm to organisms and the environment,which has attracted extensive attention of researchers.According to previous studies,advanced oxidation process(AOPs)is a process of highly oxidizing and efficient degradation of pollutants by active free radicals(such as · OH).In recent years,advanced oxidation process based on periodate(PI)has attracted some attention of scholars,but compared with other oxidants(such as persulfate),periodate is difficult to be activated.In recent years,a cutting-edge technology applied to environmental remediation has emerged,that is,the combination of nanotechnology and AOPs.At present,the activation mode of periodate is relatively single,while the activation research of nano metal composites applied to PI is few,and the exploration of internal deep mechanism is obviously insufficient,which is difficult to provide effective theoretical guidance for its practical application.In addition,the research on high-quality nano metal catalytic materials is lack,so it is necessary to study it.Firstly,based on the liquid-phase reduction method,the innovative nano metal composite S-(n Fe0-Ni)/BC was prepared in the laboratory,and the composite was characterized by means of XRD、 XPS、 SEM-EDS and FTIR.Secondly,the comparative experimental results of pollutant degradation system show that when the initial BPA concentration is 20μm,the initial PI dosage is 1mm,catalyst dosage of 0.2g/L,temperature: 65℃,initial p H: 4.0,after 120 min,the BPA degradation efficiency of BC/PI/BPA、PI/BPA、{S-(n Fe0-Ni)/BC}/BPA、 only high temperature/BPA system is 13.8%、 10.1%、 < 1%、 < 1% respectively,while the degradation rate of {S-(n Fe0-Ni)/BC}/PI/BPA system is as high as 86.4%.S-(n Fe0-Ni)/BC has excellent performance of activating PI to degrade pollutants.The pseudo first-order kinetic fitting of the degradation of the standard system showed that there was an obvious segmentation phenomenon.The effects of different reaction conditions(initial BPA concentration,initial PI dosage,initial p H,reaction temperature,catalyst dosage,inorganic anion)on the degradation efficiency of BPA in high temperature wastewater by {S-(n Fe0-Ni)/BC}/PI system were also studied.After that,the results of radical quenching showed that O21 and IO3·,· OH are the main free radical of the system,and the importance: IO3·> O21>· OH.In order to deeply study the degradation mechanism of the first stage(0-5min),through the concentration gradient experiment of three main free radical quenchers(TBA,L-HIS and Phenol)and nonlinear kinetic fitting,the results show that O21 and IO3·,· OH still exist in the first stage competitive degradation of pollutants.The competitive dynamics is in line with the Exp Assoc model,and the further prediction results of the model are consistent with the reality.The concentration gradient can be divided into two quenching stages,which can be confirmed by the experiment of Phenol,it is confirmed from the front that phenol can be quenched IO3·,· OH,providing theoretical support for follow-up research.The second stage conforms to the pseudo first-order degradation kinetics,Using the pseudofirst-order kinetic constant fitting difference method,the contribution rates of IO3·、 ·OH、 O21 and other active species were calculated to be 50.76%、 12.7%、 20.09% and 16.45%,respectively.Simultaneously studied the second-stage free radical contribution law from both qualitative and quantitative perspectives.Finally,the results of homogeneous ion experiments show that the {S-(n Fe0-Ni)/BC}/PI system is a heterogeneous synergistic catalytic effect mainly on the surface of the S-(n Fe0-Ni)/BC material,and the homogeneous catalytic degradation effect is very high Limited.