Two sedimentation tanks operate in parallel. The combined flow of the tanks is 0.2 m³/s. The depth of each tank is 3 m and each has a detention time of 2 hrs. During the operation, the operator decided to remove particles that having settling velocity of 0.1 mm/s, 0.4 mm/s and 1 mm/s. What is the percentage of removal that should be expected for each particle in an ideal sedimentation tanks.

Determine overall removal obtained for a sedimentation tank having following data: 32.6 m/day Surface overall rate 1 G 1.2 dyanic viscosity 1.027 centipoise Pw 0.997 g/cm³ Particle size 0.1 mm 0.08. m 0.07 mm 0.06 0.04 0.02 0.01 Weight fraction 10% 15% 40% 70% 93% 99% 100% greater in size Use Stoke's law to find out the settling velocity.

A detention pond is designed to achieve 100% removal of 0.1 mm fine sand particles at the design flow rate Q. If the pond is receiving a flow rate double of the design flow rate (i.e., =2Q), what is its removal rate for the same 0.1 mm fine sand particle?

Sedimentation is the process of allowing particles in suspension in water to settle out of the suspension under the effect of gravity. A water treatment plant has four clarifiers treating 1.5 MGD of water. Each clarifier is 4.88 m wide, 24.4 m long, and 4.57 m deep. Determine the following: (i) The detention time (ii) The overflow rate marks (iii) The horizontal velocity (iv) The weir loading rate assuming the weir length is 2.5 times the basin width.

A slurry flowing at a rate of 8000 m3 /d is fed to a rectangular sedimentation tank to separate the sand particles (SG=2.65) from water (ρ=1000 kg/m3 , µ=1 cP). The critical settling velocity was chosen to be that of a particle with a diameter of 0.02 mm. Calculate the minimum detention time required (in h) and the dimensions of the tank (in m). Assume that the depth is 3.5 m and the L:W is 3:1.

A batch test on the sedimentation of slurry containing 200kg / m (C.) is carried out experimentally where the initial height of sediment zone is 900mm (h.). The following data are assumed as follows: Underflow concentration- 1200kg / m Feed flow rate-3m / min The relation between setting velocity (u) and height of sediment zone (h.) Can be represented by the following equation: u (mm / min) -0.0178 * h - 3.22 Where the h have taken the values: 700,300,260,200 and 180 mm. Graphically, find the critical rate of sedimentation then the cross section area of ​​tank.

Problem No. 3 A sedimentation tank with 600 m surface area is designed to treat 1100 m'/day of water with influent suspended solid of 150 mg/l. Determine the effluent suspended solids, Due to population increase, the quantity of water increased to 2500 m'/day and it is intended to install another sedimentation tank in parallel with the existing one, determine the surface area of the second tank. The mass fraction remains and corresponding settling velocities of water sample is illustrated in the following table: percent 100 70 50 30 15 Vx 10 m/min 3.0 2.0 1.5 1.0 0.5

Question: A rectangular primary sedimentation basin is to be designed for an activated sludge treatment plant serving a municipality. The regulatory agency criteria for primary sedimentation basins used for activated sludge system are as follows: peak overflow rate (S) = 80 m3/d-m2, average overflow rate (S) = 40 m3/d-m2, peak solids loading = 50 kg/d-m2, peak weir loading = 372 m3/m-d. The average flow to the basin is 12 000 m3/d.   Calculate the tank surface area in m2. Calculate the peak flow rate in m3/d. Calculate the total suspended solids concentration in the incoming flow to the basin (mg/L) Calculate the total weir length (m)

A rectangular sedimentation basin with a length twice the width and 3 m deep, receives a flow of 2400 m/day with a normal concentration of suspended solids of 120 mg/l Determine: 1. The surface over flow rate (SOR) when the detention time is 6 hours. 2 The water entering velocity to the basin (cm/min) 3. The efficiency of the basin when the total mass of sludge produced per day is 216 kg.

A primary clarifier is to be designed to treat a municipal wastewater. The influent to the clarifier has a flow rate of 7570 m³/d and a total suspended solids concentration of 320 mg/L. A laboratory settling test was performed with the following results: Suspended Solids Concentration (mg/L) at Given Depths Sampling Depth (m) Time (min) 0.61 1.22 246 2.44 272 243 1.83 3.05 10 230 262 282 20 157 195 230 253 30 115 160 211 221 230 45 90 134 163 179 195 60 48 102 131 154 170 90 29 58 86 115 141 (a) Determine the design overflow rate and detention time assuming 65% of the suspended solids are to be removed. Use typical scaling/safety factors as appropriate. (b) Determine the required diameter (to the nearest 0.1 m) and the required depth (to the nearest 0.01 m) for the clarifier.