Question

A water treatment plant is to be designed to supply a daily flow of 35000 m/d. The raw water is taken from a local river that has a turbid water. The main treatment units of this treatment plant are as illustrated in Figure 1: Screen River Water > Sedimentation Coagulation Flocculation Filtration Adsorption Adsor prion > Disinfection Storage Distribution Figure 1: Water treatment plant main unit The design criteria of each treatment unit is as follows: 1. Coagulation tanks (Rapid mixers): Design Criteria Value Total average flow 35000 m/d Number of tanks 2 Detention time 30 seconds Velocity Gradient 900 S Dynamic viscosity S 1 .518 x 10-5 N.m/s- at 5°C Size the tanks. Draw a plan, and a vertical cross section of the tank showing the ground level line. Select a mixer based on the required power. Assume any missing data.

Answer 1

Given Q = 35000 mild No.of tankex -2 Detention time = 30800 Velocity gradient Dynamic viscosity = 1518x105 N-m/s2 Volume of Fluculator : QxDT - 35000 x 30 Zux60x60 = 12.15 m3 Assume depth = 2.5m & No.of tanks = 2 .; Volume of each tank = 12:15: 6.07m' teret dhe letio orterado stezdtem Let the tank be Circular - I xD?x 21.5= 6:07 D = 0.44m CS$canned with CamScanner

GLS on Wastewater 2:5m ut andre :Tato 4 Vertical cross section -0.uum planview @ xo.uum se chodtoon Velocity gradient Guide 900 - P j V 12:1581.518x1ös PE 149.39 W = 130w . :: Power required for miner - 150w CS$canned with CamScanner