Study On Treament Of Emulsion Wastewater In Mechanical Processing Industry

The emulsified wastewater has the characteristics of high COD concentration,complex composition,good stability,and difficulty in biodegradation.In this paper,the method of combining acid precipitation and salting out is used to demulsify.The effect of the dosage of concentrated sulfuric acid,the mass ratio of concentrated sulfuric acid and NaCl,and the temperature of the heated emulsion on the demulsification of the emulsion was investigated.Fenton oxidation treatment was performed on the wastewater after demulsification.The characteristics and rules of the effects of pH,H₂O₂dosage,Fe²⁺dosage,reaction time,and number of additions on Fenton oxidation treatment were investigated.The results showed that under the conditions of 0.75 mL 98%H₂SO₄/100 mL emulsion,H₂SO₄ and NaCl mass ratio of 1:1,temperature of 70?,and time of 150 min,demulsifying effect is good.The removal rate of turbidity reached 93.73%,and COD removal rate is 56.95%.In the Fenton oxidation treatment for demulsification wastewater,the single factor optimal reaction conditions were as follows:the initial pH was controlled at 3,the H₂O₂dosage was 250 mL/L,the FeSO₄·7H₂O dosage was 10 g/L,H₂O₂ was added at one time,the oxidation reaction was 1.5h;the COD removal rate was 65.7%,COD concentration can be reduced to 14413 mg/L.In addition,orthogonal test analysis shows that the molar ratio of H₂O₂/Fe²⁺has the greatest effect on the effect of Fenton oxidation treatment,followed by the dosage of H₂O₂.The initial pH value has the least influence on the COD removal rate.Orthogonal tests also confirmed that the amount of H₂O₂ added was 250mL/L,the molar ratio of H₂O₂/Fe²⁺was 50,the initial pH was 6,the oxidation reaction was 1.5 h,and the COD removal rate was 64.5%.