- When the dissolved oxygen (DO) was at least 2 mg/L in the sludge activation tank, removals of COD and SS were at the highest level, while a DO of 5 mg/L was required to for effective removal of NH3-N; DO had no effect on phosphate removal.
- The construction and layout of the activating tank, consumption of sodium hydroxide and its comparison, dissolution of zinc and the factors concerned, and control of zinc concentration, etc.
- He is siphoning out petrol from a tank.
- I need a funnel to pour petrol into the tank.
- Please run off the water from the tank.
- He has filled up the tank with petrol.