Study On Wastewater Treatment Process Of Waste Metal Cutting Fluid

Cooling, lubrication, cleaning and antirust cutting fluid is the main effect. In recent years, with the development of the country, the development of industrial enterprises is also faster, so the amount of cutting fluid is increasing, the amount of industrial wastewater generated by cutting fluid is increasing. Because of the high content of COD,the composition of the waste cutting fluid is very complex, and the waste cutting fluid is a difficult problem in recent years.Treatment of waste cutting fluid at home and abroad is also varies, Basic it using a single processing method, it is difficult to meet the national discharge standard.This article uses the demulsification- coagulation- oxidation- adsorption method,two experiments were carried out.water content and removal rate of COD.Experiment is a waste cutting fluid after KOH and n-butanol extraction distillation to oil-water separation,oil recycling, water further processing, and the suitable coagulation conditions were determined:Under the condition of pH of 7, PFS addition amount of 11 g/L, for the amount of PAM is 500 mg/L;At the same time the best oxidation conditions were determined: pH value in 3, the best dosage of H2O2 is 350 ml/L, the quality of FeSO4·7H2O is 4 g/L;The best dosage of activated carbon was 15g/L, the effluent COD was 27489mg/L, the removal rate was 80.6%.Due to the high initial COD, not satisfied with the treatment effect, so it has carried on the experiment 2.Experiment 2 is to deal with the original waste cutting fluid,with concentrated sulfuric acid demulsification,Suitable adding amount to 5 ml of concentrated sulfuric acid; Coagulation conditions as follows:When the pH value of 7, join the polymeric ferric sulfate(PFS) 1.8 g/L, cationic polyacrylamide(PAM) 50 mg/L;After coagulation oxidation, the appropriate oxidation conditions were determined:pH value of 3,7 g/L join FeSO4·7H2O, 20 min after add 30% H2O270ml/L;Oxidation and then dispatch the pH is alkaline, make the price of 3 iron ion Fe(OH) 3 in the form of precipitation,oxidation effect is best;After using activated carbon adsorption process, the amount of activated carbon for 20 g/L, COD removal rate was 92.2%, the effect is satisfactory.