Research On The Treantment Of Emulsified Oil Wastewater By Inorganic Salt-electro Fenton

Emulsified oil wastewater has a very wide range of sources in industrial production,large production,hard biodegradation and complex composition.It will have a significant impact on the human life and ecological environment if direct emissions or not disposed of properly.Demulsification is the key of oil removal and COD reduction of the treatment of emulsion wastewater.This paper takes emulsion wastewater of engine production plant of Chongqing motorcycle manufacturers on as the object research,adopts the method of inorganic salt-electro Fenton.This paper mainly studies the effect of demulsification performance of defferent kinds of inorganic salts in different factors,and chooses the right inorganic salt and condition.The effect characteristics and laws of related factors on removal efficiency were studied in electro-Fenton.Through the experiment,we can get the following conclusions:The study of demulsification showed that: the inorganic salt dosage hadgreat influence on the COD removal,too high or too low dosage will reduce demulsification effect.And the coagulation function of cation is K⁺< Mg²⁺ <Fe²⁺ <Al³⁺ < Fe³⁺ at the same anion and its concentration.The p H had great influence on the demulsification,the coagulation effect of Fe₂?SO₄?₃ and Al₂?SO₄?₃ reached the maximum in the pH is 6.The COD removal was higher as the extension of slow mixing time,Fe₂?SO₄?₃ and Al₂?SO₄?₃ remove COD is favorable in 13 min,but continue to extend the time,removal efficiency was lower.The demulsification removal was higher as the extension of separation time,Fe₂?SO₄?₃ and Al₂?SO₄?₃ were maximum in the time is 23 min and 26 min,and up to 91.2%,90.0% respectively.The electro Fenton test showed that COD and oil removal was favorable in the higher current density and time.The final treatment effect was increase with the increase of pH and H₂O₂ dosing quantities within a certain range.COD and oil removal showed an increasing trend with the increase of H₂O₂ dosing frequency,and the increased rate slow down after quickly.COD and oil was slightly removed by electrocoagulation,removal was less than 20% respectively.This paper studies the change process of Fe²⁺ and ·OH through treatment of oil wastewater by electro-Fenton.The test showed that Fe²⁺ concentration show the trend of increase with the extension of time by electrocoagulation treat ultrapure water.Electro-Fenton treated ultrapure water,Fe²⁺ concentration was less and ·OH concentration was increasing with time.Electro-Fenton treated oil wastewater,the concentration of ·OH almost to zero,·OH concentration increased gradually as the reaction progresses,Fe²⁺ concentration was a little higher than dealing with ultrapure water.Orthogonal experiment studied the effect of pH,current density,H₂O₂ dosing frequency and dosing quantities.This test howed that when p H=3.5,current density = 13.7mA/cm²,adding H₂O₂ = 1.05mmol/L,H₂O₂ dosing frequency =9,the COD removal was maximum and up to 92.6%.When p H=3,current density = 11.5mA/cm²,adding H₂O₂ = 1.15mmol/L,H₂O₂ dosing frequency =9,the oil removal was maximum and up to 91.8%.