GATE Questions & Answers of Primary, Secondary and tertiary treatment of wastewater

What is the Weightage of Primary, Secondary and tertiary treatment of wastewater in GATE Exam?

Total 3 Questions have been asked from Primary, Secondary and tertiary treatment of wastewater topic of Water and Waste Water subject in previous GATE papers. Average marks 1.67.

The spherical grit particles , having a radius of 0.01 mm and specific garvity of 3.0, need to be separated in a settling chamber. It is given that

$\bullet$ g = 9.81 m/s2

$\bullet$ the density of the liquid in the settling chamber - 1000 kg/m3

$\bullet$ the kinematic viscosity of the liquid in the settling chamber = 10-6m2/s

Assuming laminar condition , the settling velocity (in mm/s, up to one decimal place) is ___________

The wastewater having an organic concentration of 54 mg/l is flowing at a stady rate of 0.8m3/day through a deteniton tank of dimensions 2 m × 4 m × 2 m. If the contents of the tank are well mixed and the decay constant is 0.1 per day, the outlet concentration (in mg/l, up to one decimal place) is ___________

The most important type of species involved in the degradation of organic mater in the case of activated sludge process is