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Aeration of water in activated sludge treatment processes is a requirement. The microbes that decompose organic wastes require oxygen to live. Aeration introduces oxygen from the atmosphere. It serves the additional purpose of mixing the return activated sludge (RAS)
into the wastewater. There are several techniques for aerating activated sludge.
The most popular technique in large, municipal water plants is dissolved air floatation. Air is blown into a tank from a system of pipes, known as headers. They are equipped with diffusers at the bottom of the tank. Large centrifugal blowers provide the air source.
The diffused air flotation process requires sensors to monitor air flow and pressure from the blower. Automation Product Group, Inc., offers pressure sensors and gauges to monitor air pressure into the tank. Pressure and flow can be used to monitor fouling of the diffusers.
In some treatment plants, level of the activated sludge process is also monitored. This is especially important in plants in wet climates that receive a large infiltration from storm sewers or leaks in sanitary sewers. The level sensor is used to monitor infiltration into
the plant. |
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| Amplified Output Pressure Transmitters |
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Available ranges from vacuum
up to 500 psi and 0 up to
10,000 psi |
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Standard outputs: 4-20 mA,
0-5 VDC, 0-10 VDC, 1-5 VDC,
and 1-6 VDC |
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High overpressure capability |
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Single piece stainless steel process fitting and sensor |
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Zero and span adjustments |
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1/4-18 NPTM fitting standard |
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True 0-5 or 0-10 VDC, can transistion from vacuum to positive pressure |
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±0.25% accuracy of full scale
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