()are used to digest the sewage to produce innocuous sludge in a biological sewage treatment plant.
The basic process of biological sewage treatment consists of the liquor either by bubbling air through it or by agitating the surface()
A number of biological sewage treatment plants are in use at sea but nearly all work on what is called the extended aeration processBasically the consists of oxygenating the liquor by bubbling air through itAccording to the above two sentences, the word "this" means ().
The International Sewage Pollution Prevention Certificate shall be issued for a period specified by the Administration, which shall not exceed from the date of issue()
Disinfector in the sewage biological treatment plant usually is ()
“Sewage”as defined in MARPOL Annex IV means:()
The basic process of biological sewage treatment consists of the liquor either by bubbling air through it or by agitating the surface()
When anaerobic bacteria convert the sewage to an inert sludge,()
A number of biological sewage treatments plants are in use at sea but nearly all work on the principle called ()
Most marine biological sewage treatment plants consist of all the following statements except ().