Treatment Of Simulated Dye Wastewater By Combination Of High Voltage Pulsed Discharge And Ozonation

The application of advanced oxidation technologies has played an important role in wastewater treatment all over the world due to its fast reaction velocity, high removal efficiency, harmlessness, extensive application and so on. More research and development was being done recently.In this paper, a new wastewater treatment technology, which combines high-voltage pulsed discharge with ozone oxidization, is put forward. To carry out the experiments, a low-energy pulsed power supply instrument was manufactured, and a whole set of experimental facilities were constructed. Satisfying experiment results have been obtained.Reactive red was chosen to be experimental object. Influencing factors, such as discharge voltage, capacitor content, distance between discharge electrodes and pH etc, were investigated thoroughly. According to the experimental results and practical conditions, experimental parameters were selected. Under four different conditions, which were high voltage pulsed discharge, ozonation, combination of discharge with O₂ and combination of discharge with ozonation respectively, the decoloration and COD removal experiments of 200mg/L reactive red K-2BP wastewater were investigated and compared. Besides, the influence of radical scavenger (Na₂CO₃) and inorganic salt (NaCl and Na₂SO₄) on wastewater treatment efficiency was also investigated and discussed.Under conditions of high-voltage pulsed discharge combined with ozonation, three kinds of similar-structural azo dyes, acid yellow 17, acid yellow Bis and acid yellow 11, were used as experimental objects to investigate the decoloration and COD removal efficiency of this technology to dyes of same type and similar structure. Experimental results show that:(1) Compared with single high-voltage pulsed discharge, the combination of it with O₂ can increase 1.3% of decoloration efficiency and 3% of COD removal efficiency. Compared with single ozonation, the combination of it with high-voltage pulsed discharge can increase 10% of decoloration efficiency and 15.2% of COD removal efficiency. The addition of radical scavenger Na₂CO₃ greatly decreases the COD removal efficiency, but the decoloration efficiency remains unchanged. Under single ozonation conditions, COD removal increases with the addition of Na₂SO₄ but decreases with the addition of NaCl. Under high voltage pulsed discharge combined with ozonation conditions, COD removal decreases with the increase of conductivity.