In which of the following method chemicals are used to treat wastewater?
a) Chemical method
b) physical method
c) both a & b
d) none of these
Biogas as a Source of Energy (بائیو گیس بطور وسیلہ توانائی):
Which of the following is used as energy source for sewage?
a) energy
b) biogas
c) physical gas
d) chemical gas
The digestion which is done in the absence of oxygen called?
a) aerobic
b) anaerobic
c) both a & b
d) none of these
Which of the following gas is the main cause of global warming?
a) chlorofluorocarbons
b) methane gas
c) both a & b
d) none of these
Water Purification Method(پانی صاف کرنے کے طریقے):
