Abstract:
This research was carried out to treat wastewater from pulp and paper mill wastewater by chemical and electrochemical techniques in anionic membrane electrochemical reactor in laboratory scale at ambient temperature. By using the sulfuric acid, it was found that this process can be reduced the level of BOD, COD and color of around 80, 42 and 94%, respectively at the initial pH of 2. However, the properties of the treated wastewater were still higher than the acceptable values of the government standard. By using the electrochemical technique, the optimum condition was found at the dilution times of 50 times, circulating flow rate of 3.46 l/min, current density of 2.53 mA/cm² and the concentration of NaCl of 0.0428 M. At this condition, greater than 90-100% of BOD, COD and color were respectively removed. With respect to the continuous treatment process by electrochemical technique, it was found that the system reached the steady state condition within 7 h after start up. The color of the treated wastewater from this process was almost clear and not objectionable, the level of COD and TSS were in the range of the government standard but the level of BOD and TDS were still higher than the acceptable values of approximately 3.2 and 3.1-fold respectively. According to the operating cost of the treatment system, it can be said that the operating cost per unit COD by electrochemical technique was lower than that of the chemical treatment process.