How large an area should a sedimentation tank cover if it is sized to treat 0.2 m3/s with an ofr of 20 m/d? if the influent tss concentration is 30 mg/l, the tss removal efficiency is 90%, and the sludge flowrate is 3% of the inflow, what is the steady state sludge concentration? (hint: assume the density of the sludge is not significantly different from water.)

The higher the astm grain-size number, the coarser the grain is. a)-true b)-false

Awall of 0.5m thickness is to be constructed from a material which has average thermal conductivity of 1.4 w/mk. the wall is to be insulated with a material having an average thermal conductivity of 0.35 w/mk so that heat loss per square meter shall not exceed 1450 w. assume inner wall surface temperature of 1200°c and outer surface temperature of the insulation to be 15°c. calculate the thickness of insulation required.

For a process taking place in a closed system containing gas, the volume and pressure relationship is pvi-constant. -1.5 bar, the process starts with initial conditions, pi = =0.03 m3 and ends with final volume, v2-0.05 m3 determine the work done by the gas.