Study On The Intermediates Of Phenol Wastewater With The Process Of Potassium Ferrate Degradation

Over the past four decades of reform and opening up,the traditional chemical industry as a basic industry,has brought about serious problems of organic pollution while it is rapidly developing.Among the organic pollution,the pollution of phenolic organics has become increasingly prominent.The characteristics of phenolic organics are high toxicity,hard to degrade,and easy accumulation.Phenolic organics have become an important factor which created surface water pollution.With the improvement of China's environmental regulatory requirements and governance,the treatment of organic wastewater not only needs to take into account about the economic factors,the discharge of organic pollutants,but also should consider the regulation of p H value in the discharged solution and the demanding increasingly stringent of intermediate products which may caused secondary pollution.Due to the moderate pH value,no harmful product in the filtrate can reduce secondary pollution,and the water body can be reused again.Therefore,the control of the PH value in the treated wastewater and the study of intermediate products have become the research hotspots in the current water treatment field.In this paper,potassium ferrate with the dual properties of oxidation-flocculation was selected as the water treatment agent,and theresearch object was the organic pollutant-phenolic compound in industrial wastewater.The change rule of phenolic substances under the action of potassium ferrate was analyzed to find a green,safe,and efficient method for the treatment of phenolic organics which can effectively avoids secondary pollution and allows the wastewater to be recycled to meet the standards of landscape water use.The purpose of this paper is:(1)Analyze and understand the influence factors of different experimental conditions on the phenol intermediates that after the phenol treated with potassium ferrate,the process,and the distribution of intermediates;(2)Analyze the harm to the environment caused by the content,characteristics and toxicity of different intermediates in the final filtrate,and assess the potassium ferrate treatment capacity as a water treatment agent;(3)The apparent kinetics of the degradation for phenol by potassium ferrate was used to investigate the rapid acidity and thoroughness of the whole oxidation process.(4)In order to achieve a safe discharge standard for the treated solution,the standards are examined from the remaining contaminants of the treatment solution,the contents of the intermediates,and the pH values of the solutions in each stage so that the discharged water can be recycled and used without harm to the aquatic organisms;(5)The treatment agent often appears inactive after being dissolved in water,and the degradation efficiency of pollutants is reduced.In order to reduce the dosage,the agent can maintain the activity in water,and improvements were made in the dosing manner.This article refers to the GB 8978-1996 Integrated Wastewater Discharge Standard-Class III standard.Simulated polluted waste water was configured to have a pH of 8 to 10 and a phenol concentration of 15 mg/L ofraw water,treated with potassium ferrate.The inspection indexes are: the amount of phenol residue and final intermediates produced after the degradation of phenol wastewater;The experimental variables were as follows: single factor and orthogonal experiment were used to combine the factors such as the dosage of potassium ferrate,the pH of the raw water,the oxidation time,the stirring speed of the oxidation stage,the flocculation time,the stirring speed of the flocculation stage,after the oxidation reaction and flocculation reaction,the pH value and iron valence change in the final filtrate,and finally the change of low iron content in the filtrate,the production mechanism and change mechanism of the production intermediates of potassium ferrate for phenol wastewater treatment were studied,and the optimal reaction conditions were selected.At the same time,the kinetic analysis of the degradation of phenol and the formation of intermediate-oxalic acid under the action with potassium ferrate were carried out.The micromechanism of wastewater treatment for phenol with potassium ferrate was studied and used as the theoretical basis of this study.Research indicates:1.Intermediates exist in the oxidation stage: phenol-hydroquinone-benzoquinone-maleic acid-succinic acid-oxalic acid;Intermediates exist in the flocculation stage: maleic acid-succinic acid-oxalic acid;2.The final intermediate was oxalic acid,the filtrate had no harmful intermediates and was weakly alkaline.The remaining phenol is 0.0975 mg/L?0.1 mg/L,which conforms to China's surface water quality standards and can be used as landscape water;3.After improved the dosage method,potassium ferrate added the dosage of alkaline was 1.3 g/100 mL,inactivating agent added the dosage of alkaline was 1.2 g/100 mL,the dosage of inactivating agent was 6mL,thephenol removal rate was 99.35 %,and the yield of oxalic acid was 36.16 mg/L.Compared with the removal effect of the oxalic acid(phenol removal rate was74.19 % and oxalic acid production was 31.66 mg/L),the oxidation of potassium ferrate was significantly enhanced and the removal effect of the intermediates was significantly increased;4.According to the analysis of apparent kinetics,the reaction order of phenol degradation was 2.33,and the reaction order of oxalic acid production was 1.54,indicating that potassium ferrate can rapidly oxidize phenol to produce oxalic acid.