A study of electrochemical oxidation treatment on

• Main Authors: Ching-Song Wang, 王清松
• Other Authors: Jiunn-Ming Chen
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/68170310187348501017

碩士 === 國立中興大學 === 生物產業機電工程所 === 91 === The main purpose of this research is to adopt electrochemical oxidation in aquaculture seawater directly and indirectly. By oxidation ammonium and nitrite and sterilization, the goal of the effective and rapid water purifying could be achieved. The basic tests in real aquaculture seawater were first conducted. The test results showed that the better operational parameters were the graphite material of 1 piece in the anode and 1 piece in the cathode, the direct current of 7.5 A and the seawater flow rate of 7 L/min .The man-made simulated aquaculture seawater was then used to perform the basic test repeatedly. The material of the pole-plate and the partition-plate was graphite and the salinity of the simulated seawater was fixed at 25 ppt. The results of the repeated basic tests indicated that the optimum operational conditions were 6 cm of the gap between pole-plates ( partition-plates ), 9 of the pH value, 10 A of the direct current and 38.5 mA/cm2 of the pole-plate current density. When the flow rate of the simulated seawater was 7 L/min with the hydraulic retention time ( HRT ) 3.11 min, the average removal rates of ammonium and nitrite were 0.65 and 0.51 mg/L．min, 0.80 and 0.49 mg/L．min and 0.99 and 0.66 mg/L．min as both of the initial concentrations of ammonium and nitrite were 1 mg/L, 5 mg/L, 10 mg/L, respectively. It also demonstrated that the removal speed of ammonium was much faster than nitrite and the higher of the concentration of ammonium, the larger of the removal rate obtained. The commercialized electro-coagulation machine was also used to perform the ammonium and nitrite removal in this research. Poor performance was obtained due to low current density 3.4 mA/cm2 and a large gap between pole-plates. But, the sterilization efficiency achieved 94％ as the direct current was 30 A.