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14 Cards in this Set
- Front
- Back
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Sludge production |
1. primary settling 2. dissolved air floatation 3. biological processes |
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Sludge volume |
water percentage determines the volume - thickening and de-watering used to reduce the water percentage. |
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Thickening |
picket fence and dissolved air floatation used to compress sludge at surface |
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Dewatering |
centrifuge and belt press used to dewater it |
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Sludge drying beds |
-porous beds where liquid drains out and the sludge is drained off
-better suited to drier climates |
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Aerobic sludge treatment |
composting- heat produced kills pathogens |
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Anaerobic sludge treatment |
digestion |
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Sludge disposal |
1. applied to land 2. incinerate 3. disposed to landfill |
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landfill design life |
minimum of 10 years |
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landfill liners |
prevents landfill gas and leacheate loss Two types 1. Impermeable soil (clay) 2. synthetic membrane (occupy less volume) |
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Gas control |
1. due to odours 2. recovery for energy production 3. CO2 is asphyxiant 4. can be flammable |
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Methods of collecting gas |
1. passive control- relies on natural gas movement 2. active control- use a blower to suck gas out |
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leachate production |
Rainwater and moisture from waste absorb and collect contaminants and forms highly concentrated leachate |
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Leachate treatment |
- treated as industrial type effluent - recycle through mature section of landfill to allow VFA to be consumed by methanogens - reduce COD which increases PH and enhances metal precipitation |
