| Printing and dyeing wastewater has the characteristics of complex water quality and large emissions.The existing printing and dyeing wastewater treatment technology still has many limitations,and it is not possible to achieve emission requirements with low energy consumption and no pollution.Among them,Pulsed Corona Discharge Plasma?PCDP?is a printing and dyeing wastewater treatment technology that combines physical and chemical effects such as ultraviolet light,ultrasonic wave and OH,but the ultraviolet light generated by pulse discharge is not fully utilized.,causing waste of energy.Based on this,this study combines PCDP and PS,fully utilizes the ultraviolet light generated by pulsed discharge plasma to activate PS to produce SO4-·for the treatment of typical dye orange II?AO7?.The degradation effect and energy utilization efficiency of PCDP activated PS system on AO7 were studied.The effects of PS addition,initial concentration of AO7 and peak pulse voltage on the degradation of AO7 were investigated.The effects of·OH and SO4-·in the reaction process and the degradation mechanism of AO7 were analyzed.The following conclusions were obtained:?1?By comparing the removal effect and energy efficiency of AO7 by PCDP discharge system,PS system alone and PCDP activated PS system.The results showed that PCDP could effectively activate PS,and the degradation rate of AO7 increased with the increase of PS additive.When the molar ratio of PS to AO7 was 90:1,the first-order reaction kinetic constant and synergy of PCDP-PS system degradation of AO7the strength and energy efficiency reached the maximum,0.140 min-1,7.8 and0.294×10-3 g·kW-1h-1,respectively.?2?The degradation characteristics of AO7 by PCDP activated PS system were studied by investigating the solution properties and electrical parameters of PCDP activated PS system.The results showed that the lower the initial concentration of AO7,the higher the removal rate of AO7.When the initial concentration of AO7 was 20 mg/L,the removal rate of AO7 in PCDP-PS system was as high as 100%.In addition,the PCDP-PS system has the strongest removal effect on AO7 under acidic conditions and the weakest under alkaline conditions;As the pulse peak voltage rises from 19.4 kV to22 kV,the removal rate of AO7 is significantly increased from 43%to 84%;When the air flow rate increased from 5 min·L-1 to 9 min·L-1,the removal rate of AO7 increased from 60%to 94%,indicating that the removal rate of AO7 increased with the increase of air flow in a certain range.?3?By analyzing the changes of active substances in PSPS activated by PCDP and the degradation products of AO7,it is found that:·OH and SO4-·are the main active substances for degrading AO7 in PCDP-PS system,and with the increase of treatment time,the more the effect of SO4-·obvious.The active substance produced by the PCDP activated PS system first attacks the azo double bond of AO7,and then decomposes the benzene series into small fractions of carboxylic acid,alcohol and alkane,and finally mineralizes into CO2 and H2O. |
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