Environmental E...

If a ground water containing irons treated manganese, calcium and magnesium is treated in its sequential order in a nearby water treatment plant before distributing it into the distribution mains, Identify the correct order of the treatment suitable for the given sample of water.

The chlorine demand of a water sample was found to be 0.2 mg/l. The amount of bleaching powder containing 30% available chlorine to be added to treat 1000 liter of such a water sample is

The indicator used in the Starch Iodide Test for the determination of residual chlorine is

A wastewater treatment plant must process average flow wastewater produced in a city of population 200000. Design criteria for surface overflow rates have been set by the municipal corporation at a maximum of 40 m/day. The primary sedimentation tank is designed to be 50 m long, 5 m wide and liquid depth of 2.5 m. If the length of the weir is 40 m then the weir loading rate (in m³/day/m) is______

The number of slow sand filters required for a population of 40000 having an average water supply of 150 lpcd considering the area of 1 filter unit is 500 m² and the rate of filtration is 150 l/hr/m² (Consider 1 unit is on standby) is _____

Determine the amount of lime (kg/day) and soda (kg/day) required for treatment per million liters of water, if the raw water contains 200 mg/l of total hardness and 150 mg/l of total alkalinity.

An effluent at a flow rate of 2760 m³/day from a sewage treatment plant is to be disinfected when a chlorine dose of 15 mg/ℓ is used following the disinfection model of N_t = N₀ e^{-0.15 t}

where, N_t = No. of microorganisms surviving at any time ‘t’ (in min)

N₀ initial No. of microorganisms present.

If the volume of the tank is 50 m³, the % removal of microorganisms in the tank

A water sample having the particle velocity distribution as shown below:

If the total suspended solids is 1000 gm and the overflow rate is 0.3 m/s, the efficiency of the sedimentation tank is

A rapid sand filter with area of filter 200 m² is used to process the water for a town with a population of 10 million. The rate of filtration of the filter is 25 m³/m²/hour. The porosity of the bed and specific gravity of the material used in the bed are 0.42 and 2.72 respectively. If the bed is expanded to 0.75 m from its original undisturbed depth of 0.675 m, then the head loss in (mm) due to expanded bed will be ________.