| 摘要 |
A method for treating waste water involves mixing the waste water with an active slurry and water saturated with air under excess pressure. Following pressure reduction, air bubbles separate out from the liquid supersaturated with gas, and biological oxidation of impurities by means of the active slurry together with floatation are carried out at the same time in a single reaction chamber. A part of the treated water is saturated with air and is returned to the head end of the process. Excess active slurry is drawn off together with part of the non-oxidized, floated impurites. A method for separating suspended matter not requiring biological oxidation of impurities also includes separation by floatation and recirculation of part of the liquid phase, with intermediate saturation of the latter with air under pressure. The process for saturating a liquid with gas, used in one of the stages of both biological treatment of waste water and separation of suspended matter, can be used as an independent process in various industries. A saturator is used for saturation purposes and consists of a pipe network made up of at least two loops having a common portion. The pipe network is vertical or almost vertical, has downward and upward stream portions, and two ejectors mounted in series on the upper portion of the pipe carrying the downward stream. The downward-flowing stream divides into two streams directed to each of the ejectors, thereby providing common recirculation of liquid and of still undissolved gas, whereby the liquid is totally saturated with gas. Excess undissolved gas is drawn off together with the gas-saturated liquid. The latter is drawn off at the top portion of the pipe carrying the upward-flowing stream. |
