Mechanism Of Micro-bubble Air Flotation In Water Treatment Process And Flotation Experiment

With the increasing demand for the natural resources, more and more waste is discharged into the natural environment. The natural water body is polluted more and more serious by industry and domestic wastewater. Then, the discharge requirement of the industrial and domestic wastewater is improved, also, presented a challenge to potable water purification. As an efficient and rapid water purification method, flotation plays an important role in sewage treatment, water recycling and potable water purification.The foreign and domestic history of research and development of water purification by flotation was elaborated in this paper. Several common flotation method and their working principles, advantages and disadvantages were described. The study objection of this paper was Dianchi water, and dealt with it by self-sucking shear-flow micropore micro-bubble generator and self-made electrocoagulation-flotation device.In the experimental study of dealing with Dianchi water by self-sucking shear-flow micropore micro-bubble generator, through single factor experiment and orthogonal experiments, the influences of flow velocity, load pressure, liquid level height and water treatment time on removal efficiency of CODMn and are studied. The orthogonal experiments show that, each factor is not the same degree of impact of the removal efficiency of CODMn-Test and analysis show that flow velocity and load pressure are the major factors to influence the experimental results. The optimal combination of all factors has been found through the test. When flow velocity is equal to0.35m/s, load pressure is equal to0.15MPa, liquid level height is equal to2m and water treatment time is equal to20min, the CODMn removal rates of Dianchi water reached46.23%.In the experimental study of dealing with Dianchi water by self-made electrocoagulation-flotation device, The orthogonal experiments show that, each factor is not the same degree of impact of the removal efficiency of CODMn-Test and analysis show that current density and electrolysis time are the major factors to influence the effect of electrocoagulation-flotation. The optimal combination of current density and electrolysis time without changing the initial pH and without adding electrolyte case has been found through the test. When current density is equal to1mA/cm2, electrolysis time is equal to15min, the CODMn removal rates of Dianchi water reached54.24%.Compared with the result of dealing Dianchi water by self-sucking shear-flow micropore micro-bubble generator, the result of dealing Dianchi water by self-made electrocoagulation-flotation device is better. The bigger bubbles made by micro-bubble generator are suitable for removing large algae and don’t work for small algae. But self-made electrocoagulation-flotation device consumes more energy.