Automatic Backwashing Research Paper

B. SHUTDOWN PROCEDURES:

1. Turn water supply pump selector switch to "off". The Heli-mixer will be running and should be left running. The chemical feed pump turns off automatically the moment the pump switch is turned off.

2. Refill chemical supply tanks.

3. Check chemical stock and order if necessary.

4. Check to make sure plant is secured before leaving the premise.

3-2.2 BACKWASH SYSTEM

Backwashing of the filter consists of up flow water wash followed by a rinse cycle. Backwashing is normally run automatically by setting the timer at predetermined interval to activate backwash cycle. The filter can also be manually backwashed. Backwashing of the filter is initiated when any of the following conditions occurs:

1. When filter effluent turbidity

Daily, midway after shutdown and before start-up time. This is done by setting the backwash timer for automatic backwashing. For example, if the plant operates from 1800 hours to 1000 hours the following day, the timer is set to initiate backwash cycle at 1400.

3. If any of the above events are close and the operator wants to backwash at a time convenience.

A. AUTOMATIC BACKWASH PROCEDURE

1. Activate Microflex timer.

2. Set timer at desired number of hours when automatic backwashing starts, usually at 24-hour interval.

B. MANUAL BACKWASH PROCEDURE

1. Push the red button on the backwash timer to start backwashing. This overrides the timer and starts the backwash cycle. Whenever manual cycle is initiated, timer resets itself and starts timing from that moment to preset time. Both manual and automatic backwashing and rinsing cycles operates at preset times. After the cycles are completed, a 20-minute settling period is initiated. The backwash controller automatically returns to the service position and the plant is ready to run after completing the cycles.

4. Secondary Treatment Plant

4-1 PROCESS DESCRIPTION

4-1.1

Each sample may be drawn from the beginning and end of the tube.

4-1.3 GRANULAR ACTIVATED CARBON (GAC) FILTRATION SYSTEM

A. DESCRIPTION

GAC Filtration System consists of 2 Evoqua PV series absorbers that filled with 34 ft3 of GAC. GAC commonly used to treat natural organics, taste and odor, and synthetic organic chemicals in drinking water.

Each unit has a dimension of 48” in diameter and 5’7” in height. During operation, it is designed to operate at 50 GPM (max) which weight around 4300 lbs. B. OPERATION

During operation, untreated water flows according to the valves set-up. Depend operation procedure, it can either split into each vessel or flow into one vessel and then the next. The water enters from the top inlet and flows downward through the filter media to the bottom outlet.

C. BACKWASHING SYSTEM

Backwashing is usually unnecessary, unless excessive biological growth occurs. This operation will carry out manually. When backwashing, the water comes from the effluent water line and goes through the filter from the bottom. The water continues to flow upward through the media. Backwash water then goes through the upper distribution pipe and flow to “Backwash Out”