Skimmers and remediation pumps - Surechem · Skimmers and remediation pumps. 2 ... What is a skimmer • A skimmer skims oil from water. • There are two methods: – With a floating

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Skimmers and remediation pumps

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� Skimmers and remediation pumps are meant to remove liquid pollution from groundwater

Remediation pumps

Tapa EstlandVillager literally sees water burning. Kerosine from a nearby old military airfieldis floating on the groundwater

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� The “liquid” can be either

• The polluted groundwater itself and / or

• An oil-like liquid or solvent “floating” on the groundwater

– Also called Light Non-Aqeous Phase Liquid or LNAPL

• A solvent at the lowest level in a groundwater filled borehole

– Also called Dense Non-Aqeous Phase Liquid or DNAPL

Remediation pumps

LNAPL

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� Groundwater pollution; DNAPL and LNAPL

Remediation pumps

Leakage from anoil drum resulting in pure LNAPL ongroundwater

Pure DNAPL solvent onimpermeable layer

Pollutedgroundwater

Polluted soilgas

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� What is a skimmer

• A skimmer skims oil from water.

• There are two methods:

– With a floating filter

– With a float

Skimmer

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� Float or filter

• Float or filter can move up and down to follow fluctuations of the water table with range 0,5 m (or 1 m)

• Float is used for maximum flow but leaves an oil layer of 2.5 cm

• Filter is used to clean the last oil down to 0.25 mm

Skimmer

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� Float or filter

• Float floats ON water but is submerged in oil. Result: Oil is collected only

Skimmer

water

LNAPL

Oil outletto pump

Oil inlet

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� Hydrophobic filter

• Filter floats in water with hydrophobic sieve section in the oil layer. Only oil is collected

• Works down to 0.25 mm LNAPL layer

Skimmer

water

LNAPL

Oil outletto pump

Hydrophobicoil inlet

Weightedsection

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� Connections

• Quick connect coupling allows connection with above ground suction pump or with in-well suction pump

Skimmer

Quickconnectcoupling

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Skimmer

� Above ground suction pump possible with liquid levels <3-4 m

• Pump should be explosion proof and LNAPL resistant

To diaphragmpump

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Skimmer

� In all other cases mount a suction pump directly on the skimmer

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Suction-pressure pump

� 2” suction pressure pump; perfect for skimmers. Main features• Automatic incorporated regulator

• Pneumatic: Safe and explosion proof

• Does not need to be submerged

• Inert; can pump “all” solvents

• Can operate mounted on a skimmer

• Can also operate stand alone

• Factory tested automatic operation

• Factory pre-set can be customized

• Fitted with a non-return valve

• Limited flow

• For 2” wells

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Suction-pressure pump

� Suction-pressure pump stand alone operation�LNAPL or DNAPL above groundwater table

• Pump will produce an oil/water mix Remediation of LNAPL

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Suction-pressure pump

� Suction-pressure pump stand alone operation

• Pump should stay submerged in polluted water,

• Slow pumping needed if there is an LNAPL

Remediation of polluted

groundwater only

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Suction-pressure pump

� Suction-pressure pump with skimmer

• Pump will only collect oil; not water

• Only input: Air pressure

Remediationof LNAPL

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Suction-pressure pump

� Suction-pressure pump working principle: A pneumatic pressure powered piston pump.

• Suction is created by the spring

Remediationof LNAPL

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Air power

� All pumps are air-powered

� Air should be pre-treated to prevent long term problems

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Large capacity pressure pump

� Main features

• Must be submerged

• Very high capacity < 55 l/min

• Float regulated; no piston

• Automatic incorporated pneumatic operation

• Inert materials, will pump all solvents

• For polluted groundwater and DNAPL

• Considerable air consumption

• For 4”wells, (3” type optional)

• Top filling or bottom filling types available

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Large capacity pressure pump

� Main pumping applications

• Landfill leachate

• Landfill gas condensate

• Hydrocarbon recovery

• Total fluids

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Large capacity pressure pump

� Working principle

Filling cycle:Water enters bycheck valve, pushes up floatthat switches air vent to air entrance

Empty cycle:Water enters bycheck valve, pushes up floatthat switches air vent to air entrance

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Large capacity pressure pump

� Top filling or bottom filling

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Large capacity pressure pump

� Some field pictures

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Remediation pumps

� Also see the manuals