Study On The Degradation Of Sulfonic Acid Wastewater By Microelectrolysis Combined With Double Anode Electrochemical Method

Sulfonic acid compounds exist in large quantities in the production wastewater of petroleum,dyestuffs,pharmaceuticals,electroplating,pesticides,textiles,metal scavengers and other fields.This type of wastewater is usually characterized by high concentration,high volume,high acidity,difficult biodegradation and potential toxicity.This paper deals with sulfonic acid wastewater as metal detergent production wastewater.The use of conventional water treatment technology is difficult to effectively remove pollutants,low treatment efficiency and other problems.The main research contents are the influence of micro-electrolysis and double-anode electrochemical method on wastewater treatment effect and the optimization of experimental design analysis,the preliminary analysis of degradation kinetics of micro-electrolysis and double-anode electrochemical method for wastewater treatment,and the preliminary discussion of their coupling experiments and degradation mechanism.The single-factor experiments on the degradation of sulfonic acid wastewater by microelectrolysis yielded a COD removal rate of 42.72%under the optimal parameters of influent COD concentration of 15275 mg/L,aeration rate of 15 mg/L,reaction time of 60 min,and initial pH of 3.A quadratic polynomial model was obtained using a three-factor,three-level response surface optimization experimental design with a correlation coefficient of R²=0.974.The best parameter condition for COD removal was pH 1.3,reaction time 80min,aeration17L/min,and COD removal rate reached 46.499%,the COD removal rate of 45.24%was verified experimentally.The preliminary analysis of the degradation kinetics showed that the COD degradation of this actual sulfonic acid wastewater treated by microelectrolysis process was basically in accordance with the secondary reaction kinetics with the correlation coefficient R²=0.986,which was obtained by fitting the secondary decay equation _tC=114488.55 1+0.0012t with the phase coefficient R²=0.995.The microelectrolysis effluent was used as the feed water in the study of sulfonic acid wastewater degradation by double-anode electrochemical method.Single-factor experiments showed that the COD removal rate of wastewater could reach 35.12%under the optimal parameters:titanium-based lead dioxide and iron,pH 3 of feed water,60 min of electrolysis time,2 cm of plate spacing,and 50 m A/cm² of current density.In the study of the effect of anode materials on the degradation of wastewater,the addition of iron anodes significantly improved the degradation of wastewater by electrocatalytic oxidation.A three-factor,three-level response surface optimization experimental design was used to obtain a quadratic polynomial model with a correlation coefficient of R²=0.998.The best parameter conditions for COD removal were pH 3,electrolysis time 60min,current density 55m A/cm²,and COD removal rate reached 36.026%,the COD removal rate of 35.77%was verified experimentally.The analysis of the current density of the electrolysis unit yielded a current density J of 550A/m²,the analysis of the current efficiency CE calculation of the double-anode electrochemical method yielded a CE value of 2.62,and the calculation of the energy consumption yielded a consumption of 6.56 k Wh of electrical energy per kg of COD removed from the wastewater.The kinetic analysis of degradation yielded that the kinetics of dual-anode electrochemical method for degradation of wastewater was between zero and one level,and a polynomial fit was performed to obtain the COD removal rate as a trinomial relationship with electrolysis time:y=1254.6+20.66071x+0.13321x²with a correlation coefficient R² of 0.991.microelectrolysis-double-anode electrochemical method for The total removal rate of sulfonic acid wastewater was 64.82%.The coupled microelectrolysis process and double-anode electrochemical process degraded the sulfonic acid wastewater to obtain a wastewater COD removal rate of 61.2%and a pH value of 5.28 in the effluent.The coupling process greatly reduces wastewater treatment time and improves wastewater degradation efficiency.The UV and IR spectra of the wastewater before and after degradation were scanned and the main degraded substances in the wastewater were salicylic acid,methanol,long-chainα-olefins and other pollutants.The new absorption peak at 524 nm in the wastewater after microelectrolysis degradation indicates that microelectrolysis can convert the above pollutants into pigmented small molecule organic substances,which can be converted into H₂O and CO₂ by double-anode electrochemical degradation.In contrast,substances such as methanesulfonic acid and alkylbenzenesulfonic acid with sulfonic acid groups were degraded only to a certain extent due to the stability of the sulfonic acid groups.