Experimental Study On The Degradation Of Procion Blue MX-R By Manganese Oxide With Different Compounds

Manganese oxide is ubiquitous in the environment and participates in many organic redox cycles in nature.Because of its strong oxidizing property,it is an important way to degrade organic matter in water.Based on the previous research group,it was found that hydroxylamine hydrochloride has a strengthening effect on the degradation of Procion MX-R by natural manganese oxide ore,and it can be combined with other substances reported in the literature to promote different advanced oxidation processes.In this paper,the response of natural manganese ore and commercial MnO₂ to hydroxylamine hydrochloride?HA?,citric acid,pyropHospHate and ethylenediaminetetraacetic acid?EDTA?addition under different conditions was studied by sequential batch experiments.The effects of hydroxylamine hydrochloride?HA?,citric acid,pyropHospHate and ethylenediaminetetraacetic acid?EDTA?on the time-varying of reactants and products in different manganese oxides degradation dye systems were studied.The corresponding relations between different pH,probe additives and Mn?II?/Mn?IV?conversion and target degradation were analyzed.the results show that:?1?HA promotes the dye degradation of manganese oxide ore.The dye concentration is 200mg/L,the manganese oxide ore is 20g/L,and the HA dosage is150mmol/l.At this time,45%dye degradation rate can be obtained.The dye degradation process is a process of consuming dissolved oxygen and consuming H⁺,accompanied by the formation of H₂O₂;the pH of the system is affected by the addition of HA;the dissolved oxygen consumption and H₂O₂ production increase with the increase of HA dosage.For different initial pH systems,the pH of the system rises rapidly and the dissolved oxygen decreases rapidly during the reaction.Then the pH and dissolved oxygen reach their respective stable values.The concentration of H₂O₂ in the system increases with the increase of HA dosage.?2?Citric acid,pyropHospHoric acid and EDTA can promote the dye degradation of manganese oxide ore,but the promotion range is smaller and smaller with the increase of its dosage.When dye concentration is 200 mg/L,manganese oxide ore dosage is 20g/L,for citric acid dosage is 12 mM,46%dye degradation rate can be obtained;for pyropHospHate dosage is 10 mM,42%dye degradation rate can be obtained;for EDTA dosage is 1.36mM,51%dye degradation rate can be obtained.The dye degradation process involves both H⁺consumption and H⁺formation.The pH of each system is stabilized quickly during the reaction process.The acidic environment can promote dye degradation.The lower pH level system corresponds to the higher dye degradation rate system and higher Mn?II?concentration levels.Compared with the systems without citric acid,pyropHospHate and EDTA,the additive system has higher Mn?II?concentration.The degradation of dyes by manganese oxide ores involving citric acid,pyropHospHate and EDTA did not cause significant changes in dissolved oxygen in the system.There was no oxygen consumption and no oxygen generation in the degradation process of dyes.?3?Similar to the manganese oxide ore system,HA has the best value for the dye degradation of MnO₂.When the dye concentration is 200mg/L,the MnO₂ dosage is 5g/L,and the HA dosage is 150mmol/l,dye degradation rate is 97%.The dye degradation process is a process that consumes dissolved oxygen and H⁺,accompanied by the formation of H₂O₂;dissolved oxygen,trivalent manganese,and solution pH are also affected by the addition of HA;H₂O₂ production increases with the increase of HA dosage.The initial pH has the best effect on dye degradation.With the increase of initial pH,the system pH rises rapidly and dissolved oxygen decreases rapidly.Then the pH and dissolved oxygen reach their respective stable values.The concentration of hydrogen peroxide increases with the increase of HA dosage.?4?Similar to the manganese oxide ore system,citric acid,pyropHospHoric acid and EDTA promoted the degradation of dyes of MnO₂,but this increase is smaller with the increase of the dosage.When the dye concentration is 200mg/L,the MnO₂ dosage of0.2g/L,for citric acid dosage is 12 mM,dye degradation rate is 69%;for pyropHospHate dosage is 10 mM,dye degradation rate is 64%;for EDTA dosage is 1.36mM,dye degradation rate is 51%.The process of dye degradation involves not only H⁺consumption but also H⁺formation.The pH of each system in the process of reaction is stable very quickly.The acidic environment can promote the degradation of dyes.The system with lower pH level corresponds to the system with higher dye degradation rate.Compared with the systems without citric acid,pyropHospHate and EDTA,the additive system has a higher concentration of Mn?III?.By complexing with the additives,Mn?III?reduces the consumption of Mn?III?caused by disproportionation,increases the selectivity of Mn?III?for dye degradation,and strengthens the process of dye degradation.The degradation of dyes by manganese dioxide with citric acid,pyropHospHate and EDTA did not cause significant changes in dissolved oxygen in the system.There was no oxygen consumption and no oxygen generation in the degradation process of dyes.Sodium citrate and sodium pyropHospHate could not provide the H⁺,which was necessary for dye degradation,and showed strong inhibition on dye degradation?5?Fe²⁺and Fe³⁺promoted the degradation of dyes,but Fe³⁺promoted the degradation of dyes.Fe²⁺had the best effect on dye degradation.When the dye concentration was 200mg/L,the MnO₂ dosage was 0.2g/L and the FeSO₄ dosage is1mmol/l,dye degradation rate is 86%.When the dye concentration is 200 mg/L,the MnO₂dosage is 0.2 g/L,and the FeCl₃ dosage is 1mmol/l,dye degradation rate is 95%.?6?Manganese dioxide plays an important role in the oxidation of Procion blue MX-R.When HA is added,a large amount of Mn?III?is formed in the system,and the ultraviolet absorption peaks of anthraquinone group,benzene ring,sulfonate group and triazine group decrease to a great extent.?7?Degradation of dyes in various systems can be described by first or second order kinetic equations.The background effects of HA,citric acid,pyropHospHate and EDTA in the receptor system,such as the specific form of the kinetic equation and the kinetic characteristic parameters,are different with the background changes.?8?The orbital electron binding energies of the same elements on each sample surface are different,and the orbital electron binding energies are affected by the chemical environment on each sample.The surface Mn:O atomic ratios of Sample 1,Sample 2,and Sample 3 were 1:2,1:2,and 1:4.8,respectively.In the reaction system without HA,the MnO and MnO₂ components on the surface of MnO₂ decreased after the reaction,while the Mn₂O₃ component increased.In the reaction system with HA,the MnO and Mn₂O₃components on the surface of MnO₂ increased significantly after the reaction,while the MnO₂ component is greatly reduced.