| 摘要 |
<p>A multi-step method is provided for the purification of waste water, especially pulp mill effluents. It comprises a number of steps carried out in a specific sequence. The first step involves passing an oxygen-containing gas through the waste water while the waste water is in intimate contact with a finely divided activated carbonaceous material, preferably including, as a preliminary step, the addition of the finely divided activated carbonaceous material to the waste water. The second step involves adding a clarification agent selected from one or more of a coagulant, a flocculant, and a polyelectrolyte to the treated waste water provided by the first step. The third step involves recovering a solids-free effluent by known means, e.g. by a clarification step carried out by gravitational, flotational or centrifugal means to provide the waste water free of the suspended material originally contained therein and a sludge including the suspended material originally contained in the waste water, the added carbon and the added clarifying agent. Optionally, it includes the fourth step of regenerating the carbonaceous material from the sludge, and/or the fifth step of regenerating the clarification agent from the sludge.</p> |
