Experimental Research On The Electro-catalytic Oxidation Treatment For DDNP Production Wastewater Using BDD Film Electrode

In this paper, BDD film electrode is applied to treat DDNP production wastewater. The study mainly investigateds the effects of operating factors such as cell voltage, interelectrode distance, initial concentration and additive NaCl and so on, and determining the best reaction condition. Then kinetic analysises are applied to the main factors of affecting wastewater degradation.The experimental results show that: cell voltage is the critical factor for the degradation of DDNP production wastewater. CODcr removal is increased as increasing the cell voltage. The smaller the electrode distance is, the better CODcr removal is, but too small electrode distance affects CODcr removal. The initial concentration of wastewater is significant for the degradation of DDNP production wastewater. The higher initial concentration is, the worse CODcr removal is. There is a optimal dosage value of electrolyte in the experiment. When additive NaCl is 1g/L, CODcr removal is best. The best reaction condition is: cell voltage is 12 V, electrode distance is 2.5cm, initial concentration of the wastewater is 900mg/L, additive NaCl is 1g/L and electrolysis duration is 210min. Under the condition, CODcr removal can reach 43% and energy consumption is 19.1 kW·h/kg CODcr. The kinetics study of DDNP production wastewater electro-catalytic oxidation indicates that the reaction accords with the apparent first-order kinetics law. The reaction rate constant has linear relationship with the 1.4th power of cell voltage and negative the 0.24th power of initial concentration.