Environmental Engineering Booster Quiz-4

A mixed liquor with 2500 mg/l of suspended solids has the settled volume of 225 ml from a liter of this mixed liquor. Its sludge volume index is

What is the maximum permissible limit of fluoride in drinking water?

For a grit channel, if the recommended flow velocity is 0.25 m/s and the detention period is 1 minute, then length of the tank is:

The following data pertain to a waste water sample

Initial Dissolved oxygen = 10 mg/l

Final Dissolved oxygen = 3 mg/l

Dilution = 2 %

The Biochemical oxygen demand of the given wastewater sample is:

A drain carrying sewage of BOD = 200 mg/l and flow rate of 50 m³/s joins a river whose upstream BOD is 10 mg/l and flow rate is 500 m³/s. Assume immediate and complete mixing of drain with the river. What is the estimated downstream BOD of the river flow?

Raw water is entering a treatment plant and contains 250 mg/l suspended solids. If 55% of these solids are removed in sedimentation then find the solids removed in sedimentation as sludge?

A grit chamber of dimension 15 m x 2 m x 0.8 m liquid depth flow of 800 m³/hr. Its detention time is

Biochemical oxygen demand is quoted at what temperature?