Identification of Optimum Conditions for Desalination of Produced Water by Electrodialysis

Produced water is one of the major drawbacks of petroleum production. Desalination is the most important step in controlling the produced water. Capability of electrodialysis in desalination of produced water was demonstrated by a sample containing a TDS of 4393 ppm using a flow rate of 0.3 L/min in an electrodialysis stack for 360 minutes. Desalination of %62 implied that this method was viable to produce required water for livestocks and agricultural uses from relatively thin produced water. To figure out the influences of feed flow rate, applied voltage, and duration of the process on the performance of electrodialysis, L9 array of Taguchi method was used to design the experiments. After conducting all designed experiments, it was concluded that the duration of the process and the applied voltage had direct relationships with the amount of separation, while there was an inverse relationship between the feed flow rate and the desalination of electrodialysis. Among the process variables, the period of the process had the most noticeable influence on the separation, while the feed flow rate had the least effect on desalination. In the vicinity of implied operating conditions the voltage of 7 V, flow rate of 0.3 L/min, and time duration of 200 min were obtained as the optimum conditions for desalination of produced water.