sewage treatment plant onboard ship - biological sewage treatment plant in ship — Transcript

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1. 0:04[Music]
2. 0:07the biological sewage treatment plant
3. 0:09consists of four interconnected
4. 0:11compartments raw sewage or effluent
5. 0:13passes through a bar screen which breaks
6. 0:15it up into smaller particles from where
7. 0:17it passes into the primary compartment
8. 0:23when the level in this compartment rises
9. 0:25sufficiently overflow of the liquid
10. 0:27takes place into the aeration
11. 0:29compartment
12. 0:33this compartment contains bacteria which
13. 0:35require oxygen and a nutrient to
14. 0:37propagate
15. 0:41the nutrient is solid waste material and
16. 0:44oxygen is supplied by bubbling
17. 0:45compressed air through the broken waste
18. 0:50the sewage is broken down here by
19. 0:52aerobic activation
20. 0:56the liquid from the aeration compartment
21. 0:59passes to a settlement compartment where
22. 1:01the activated sludge as it is known
23. 1:04settles and leaves a clear effluent
24. 1:09as there is no oxygen in this
25. 1:11compartment the sludge is continuously
26. 1:13recycled to the aeration compartment
27. 1:16where it mixes with the incoming waste
28. 1:18to assist in the treatment process
29. 1:23the clear effluent discharged from a
30. 1:25settlement compartment must be
31. 1:27disinfected
32. 1:30this infection is achieved by treating
33. 1:32the clear effluent with the solution or
34. 1:34tablets of sodium hypochlorite in the
35. 1:37chlorination compartment
36. 1:42the discharge pump lowers the level in
37. 1:44the chlorination tank automatically by
38. 1:46pumping overboard
39. 1:50automation is carried out by means of
40. 1:52high or low level floats the discharge
41. 1:55pump cuts in at high levels and cuts out
42. 1:58at low level
43. 2:01[Music]
44. 2:09you