|
With the development of the petrochemical industry, oil waste pollution of the environment is getting worse. Oily waste water density, its small difference, high organic content, and poor biodegradability characteristics become more difficult to degradation of wastewater. Existing physical treatment, chemical treatment, biological treatment, and methods such as DC solution for oily wastewater treatment has its own drawbacks, it is difficult actual promotion. Explore efficient, simple and no secondary pollution run a new method, environmental work is still one of the important research content. In this paper, oily wastewater was treated, change DC power supply for the pulse intermittent power supply, has used titanium electrodes, graphite electrodes and aluminum electrodes pulse electrolysis to remove petroleum contaminants study examines the electrolysis conditions change impact on oil removal, after ten months of laboratory experiments, a total of more than 1050 experimental data obtained are discussed pulsed electrolysis to remove petroleum contaminants influencing factors and mechanism, and further use of coagulation principle, to carry out pulse electrolysis - coagulation combined oily wastewater treatment technology exploration. The following results were obtained: (1) pulse electrolysis oily wastewater treatment process different from its optimum electrolytic electrode materials with different parameters: a) with titanium plate as electrode, electrolysis voltage of 7V, frequency of 4000Hz, duty cycle 60%; 2) with graphite as electrode, electrolysis voltage of 10V, frequency of 3750Hz, the duty cycle to 50%; 3) with aluminum as electrode, electrolysis voltage 7V, frequency 4000Hz, duty cycle 70%. (2) on the lower salinity of oily wastewater, graphite electrodes electrolysis treatment is better than titanium electrode and the aluminum electrode; while high salinity wastewater, aluminum electrode electrolysis treatment is better than graphite electrode and titanium electrode . (3) respectively, titanium, graphite and aluminum as electrode, electrolytic Northern certain oilfield wastewater, 15min after oil removal rates were 54%, 56% and 84%. (4) to make aluminum electrode pulsed electrolysis - coagulation combined treatment process, simulated water electrolysis only 15min, oil removal rate was 82%, and then again in wastewater dosing PAM 50mg / L, the removal rate increased 94%. Under the same conditions, on a northern oilfield wastewater removal efficiency of 93%. Method has the characteristics of efficient operation. (5) proposed pulse electrolysis - coagulation combined treatment process, study its mechanism of action, not only electrolytic oxidation of aluminum electrode degreasing effect, while the dissolution Al 3 to form aluminum hydroxide precipitate, with flocculation , the dosage of PAM further play a role in coagulation, formation of electrolytic oxidation of aluminum hydroxide flocculation, PAM coagulant three ways to act simultaneously efficient removal mode, the pulse electrolysis - coagulation combined method effectively oily wastewater treatment provide a theoretical basis.
|