Evaluation of the Metalwork Cutting Fluid Treatment performance Using Fenton Oxidation Process in Comparison with Coagulation-Flocculation

Metal cutting/metal working fluids (MCFs/MWFs) are used as a coolant/lubricant fluid in different metal working operations and machining industries. Treatment and disposal of this kind of wastewater imposes an excessive cost on metalworking industries because of its high COD concentration and non-biodegradability. High COD and low BOD/COD ratio of cutting fluid, cause the conventional treatment processes to be ineffective in this industry. In this paper, the effectiveness of Fenton Oxidation process was evaluated in comparison with coagulation as a treatment method for MWCFs wastewater. The study was conducted in laboratory scale and the main measured parameters were indicated COD removal efficiency and sludge production rate. The results of study showed that Fenton Oxidation Process indicated maximum COD removal efficiency of 88.31% and minimum sludge production rate of 230 (ml/l) with dosages of H2O2 50(g/l) and FeSO4 10(g/l). Results of the Chemical Coagulation Process showed that the maximum COD removal efficiency of 88.36% obtained at a FeCl3 dosage of 40 (g/l) with a higher sludge production rate of 616 (ml/l). In addition, it could be seen that with a 50 (g/l) dosage of H2O2 oxidant, the Iron salt dosage could be decreased by 0.25 and sludge production rate would be decreased to nearly 0.37, respectively. The results showed that the Fenton Oxidation could be considered as a competitive process in MWCFs wastewater treatment.