Study On The Treatment Of Methyl Orange Dye Wastewater By UV Synergistic Biochar Activated Persulfate

Due to the dye industry’s recent rapid growth,the discharge of dye effluent has seriously polluted the water environment.Dye wastewater presents a challenge for industrial wastewater treatment due to its high organic content,challenging natural degradation,and poor biochemical characteristics.Conventional biological and physical therapeutic methods are overly expensive and inefficient.Contrarily,peroxynitrate oxidation technology has the power to decompose complicated and challenging dye wastewater effectively,producing sulfate radicals（SO₄^-·）with strong oxidizing power,and the treated products are tiny molecules that do not result in secondary pollution to the environment.Quick production of SO₄^-·is made possible by activating persulfate with UV light,although different chemicals in the wastewater will absorb the light and reduce the rate of breakdown.The numerous functional groups on the surface of biochar could act as activators for the electron transfer medium,which would then cause the persulfate to break down and release SO₄^-·and other organic radicals.Based on this,this dissertation employs biochar and UV light to activate persulfate in order to remediate wastewater from the methyl orange（MO）imitation dye.Persulfate can be activated with UV light to produce sulfate radicals more quickly.Biochar also improves activation efficiency and uses less photoenergy.To treat MO dye wastewater using UV-activated persulfate alone,an internal UV-emitting device was built.To find the best conditions for the reaction,the impacts of various experimental parameters on the degradation of MO wastewater were examined.To create a UV synergistic biochar activated persulfate system for treating MO dye wastewater,biochar was then added.Based on the ideal reaction conditions of UV activated persulfate,the optimal amount of biochar for the optimal treatment effect of MO was investigated,the degradation effect of inorganic anions and printing and dyeing auxiliaries on MO was investigated,and the mechanism of UV synergistic BC activated PS was initially explored.The main conclusions obtained from the above study are as follows:（1）Wastewater from MO simulated dye production can be efficiently treated using UV-activated persulfate oxidation technology（UV/PS system）.The UV/PS system degrades MO effectively,and in terms of scale,UV/PS system degrades MO more effectively than UV alone and PS alone.The following are the ideal circumstances for the UV/PS system to treat wastewater containing MO dye:the initial MO concentration is under ideal circumstances,the MO degradation rate reached 86%after 12 minutes,and the kinetic study revealed that the MO dye wastewater degradation process by UV/PS system was consistent with the kinetics of a quasi primary reaction.（2）In comparison to the UV/PS system,the UV/BC/PS system treated the MO simulated dye wastewater with a quicker reaction time and better degradation of the MO dye wastewater.The experimental results indicated that the system best degraded MO at the level of 0.2 g of added biochar.This was accomplished by adding various amounts of biochar to the reaction system.At the ideal reaction circumstances,the UV/BC/PS system had a better degradation rate for MO dye wastewater than the UV/PS system,at 98.7%,and the rate of degradation of MO rose by 12.7%in 12minutes when compared to that of the UV/PS system.The kinetic analysis concluded that the degradation of MO dye wastewater by UV/BC/PS system was in accordance with the quasi primary reaction kinetics.（3）Inorganic anions（HCO₃^-and Cl^-）and printing and dyeing auxiliaries（sodium citrate and sodium dodecylbenzene sulfonate）in water have certain effects on the combined system to treat MO.HCO₃^-slightly inhibits the degradation of MO in UV/BC/PS system and then promotes the degradation of MO,while Cl^-on the contrary,slightly promotes the degradation of MO and then increases with the concentration of Cl^-on the degradation of MO.The degradation of MO is slightly promoted by Cl^-,and then inhibited by increasing Cl^-concentration.Sodium citrate and sodium dodecylbenzene sulfonate inhibited the degradation of MO in UV/BC/PS system.Although inorganic anions and printing and dyeing auxiliaries showed inhibitory effects on the system,the degradation rate of MO was still high,indicating that the UV/BC/PS system has some resistance to the influence of anions and printing and dyeing auxiliaries.（4）The reactive radicals that are most important in the UV/BC/PS system are sulfate radicals SO₄^-·,and UV activation of PS in free form in solution contributes more radicals to the degradation of MO than does BC activation of PS on the surface and in the periphery.UV and BC also work in concert to activate PS.Consequently,methyl orange dye effluent can be quickly and effectively treated using UV light in conjunction with biochar activated persulfate.