Test Research On The Treatment Of Bathing Wastewater By Electrocoagulation-flotation

Bath industry needs to consume the massive water resources, but the bathing wastewater it produced actually is an ideal reclamation source for its large discharge amount, simple pollutant composition and low pollutant concentration, which would play an important role in the urban water economization.Electrocoagulation-flotation is one of the electrochemical techniques. It suits bathing wastewater Reuse Project in following perspectives: small floor area,low flocculation, reaction time which can be shortened, and reaction reactor capacity which can be reduced. For the public bathhouses, hotels, bath center and other water-consuming and wastewater- easy- collecting place, the implication of Electrocoagulation-flotation for wastewater treatment has a good future.The objectives of this study lie in two aspects: one is to study the mechanism of how the Electrocoagulation-flotation treatment remove the pollutants in wastewater, and the principle of electrode deactivation and the measures for against deactivated. The other objectives is to study the effect that using Electrocoagulation-flotation to treat bathing wastewater through experiments. Screening of water quality parameter, the anionic surfactant (LAS) is selected as the main controlling factor in experiment and the influence of current density, electrolyte dosage,pH and time on removal efficiency of LAS are analyzed. Carrying on the orthogonal test based on single factor analysis, determine the optimal parameters: pH=4; The NaCl density is 0.35g/L; current density is 13.3 mA/cm2; time= 15 minutes. Under the optical conditions the LAS removal efficiency amounts to 83.43%; the COD removal efficiency amounts to 89.28%;the turbidity removal efficiency amounts to 98.79%; the NH3-N removal efficiency amounts to 98.79%;and the relationship between the 1/C(LAS) and the time was described by a macro-kinetics model during the positive correlation between time and the removal efficiency of LAS.The factors which affect the current and voltage were analyzed. The mathematical model of relationship between voltage, current density, conductivity and plate distance was established based on the former research results. The thesis analyses the relation between the energy consumption of Electrocoagulation-flotation and various factors based on the theoretical derivation, and the energy-saving measures has been put forward, which has practical significance to reduce the cost of Electrocoagulation- flotation.The mathematical model of electrolytic bubble size was established based on the Bubble Nucleation Theory. Compared with the former experimental result, the model has been verified. It shows that: (1) In the low current, the Simulation and experimental values agree with each other well. That the bubble size simulated by the mathematical model is reasonable;(2) In the large current, the bubbles separate from the electrode under the influence of momentum. Bubbles'size reduces caused by a lower gas momentum.