| 摘要 |
<p>A polluted water treatment system 10 operated to reduce impurities in sewerage polluted water to an acceptable level for dumping. The system includes a horizontal subsurface filter (HSF) 12 having an inlet zone 18 through which the inflow of polluted water is permitted to pass, a treatment zone 20 which permits the polluted water to undergo treatment by removal of at least some of the impurities of the polluted water and an outlet zone 22 from which the treated polluted water flows from the HSF 12. The impurities may include, for example, organic materials (BOD and COD) and oxidization processes within the HSF may reduce the quantity of the nitrites that are dumped from the outflow zone 22. The outlet zone 22 also includes a collection well 28 having a pump 30 located therein to recycle the treated effluent back to either the inlet zone 18 of the HSF 12 or to a secondary vertical filter 40. A level switch 26 located in the inlet zone 18 of the HSF 12 controls the level of water in the inlet zone to a set level 15 by regulating the amount of recycle water returned to the HSF 12 or indirectly via the vertical filter 40. The vertical filter 40 may be used to pre-treat any polluted water before it enters the HSF 12 and furthermore, it may also be used to remove phosphates from the polluted water.</p> |
