Improvement of biological total phosphorus release and uptake by low electrical current application in lab-scale...

The overall process enhancement by different electrical current application on the biological phosphorus release and uptake have been investigated. Five reactors were constructed for three experiments and activated sludge was used as inoculums. In Exp.1 by comparing the control and the bio-electrochemical reactors, it was found that the overall phosphorus removal efficiency could be enhanced at lower electrical current applications of 5mA and 10mA, but were restrained at higher than 20mA, although 20mA could be a sensitive turning point. Moreover, the electrochemical effects of the cathodic and the anodic reactions on the phosphorus release and uptake, respectively, have been further evaluated separately under an electrical current application of 10mA in Exp.2 and Exp.3, respectively. As observed, both of the biological release and uptake were improved by the cathodic reactions in the cathode reactor, but not by the anodic reactions in the anode reactor, and thus indicated that the cathodic reactions play an important role in the improvement of the biological phosphorus release and uptake.