What change in velocity would be necessary if the bed was to extend by 18%?(Giving Date: Sand media size: 3 mm, operating bed depth of 0.5 m and Minimum fluidization Velocity for sand filter used in wastewater treatmen= 4 m/s, density of sand media: 2000 kg/m3  and its porosity = 0.3)

1. The following information is provided for an activated sludge system design: Parameter Symbol Value Units Flow rate Q 10000 m³/d Influent BOD So 150 mg/L Effluent BOD S 2 mg/L Hydraulic residence time Ꮎ 4 hr Mean cell residence time Oc 6 d Maximum specific growth rate μm 3 1/d Half saturation constant Ks 40 mg/L Yield coefficient Y 0.5 Endogenous decay coefficient b 0.08 1/d Death rate coefficient γ 0.04 1/d Determine: a) The aeration tank biomass concentration (X) in mg/L b) The aeration tank oxygen requirement in kg/d c) The rate of biomass wasting in kg/d

Gave wrong values earlier. These are the correct values A settling tank having a depth of 3.5 m and surface area of 1000 m2 is used to remove particles of size 0.01 mm and specific gravity of 2.6. Calculate the removal percentage of the tank for the discharge of 7000 m3/d. Take viscosity of water as 1.1x10-3 kg/m.s.

Please design a rapid sand filter that will effectively remove 65% of thesuspended solids in a flow of 10 cubic meters per minute. The suspendedmaterial consists of particles that are perfectly spherical with a diameter of 10microns. Please use sand with an effective size of 1 mm and a porosity of 0.5.You should limit your clean bed head loss to 0.5 meters per meter. (Pease use an attachment efficiency, α of 0.75)Viscosity of water =1.0087x10-3 Ns/m2Density of water =998.23 kg/m3What are the dimensions of this filter (Depth and Surface Area)?

What is the largest size of a spherical sand grain that the Stokes’ Law can be used to calculate its settling velocity. What is the terminal settling velocity for the sand in quiescent water? If you want to use a settling basin (with 3 m in depth) to achieve 100% removal for all sand grains of this size in the water, what are the required size (area and volume) of the basin for treating Q=10000 m3/hr. Assuming water temperature is at ~20 0C and the density of sand is 2650 kg/m3.