| 摘要 |
<p>A method for treating wastewater by circulating wastewater around a system comprising a downcomer (1) and a riser (2) which communicate directly at their lower ends, the level of the wastewater in the downcomer (1) being maintained above the level of the wastewater in the riser (2) to provide a hydrostatic pressure head which causes circulation of the wastewater around the system, supplying a gas containing oxygen to the wastewater as it passes through the downcomer (1), pumping at (9) the wastewater from the top of the riser (2) back into the top of the downcomer (1) and removing treated wastewater from the riser (2) at the same rate as wastewater is introduced at (4) into the system; the height of the hydrostatic pressure head is controlled by adjusting the height at which treated wastewater is removed from the riser (2) and the lever of the wastewater in the riser (2). It is also provided an apparatus for putting the method into practice.</p> |
