Dehydris Lime - Produce quality sludge and generate savings with pre-liming
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Transcript of Dehydris Lime - Produce quality sludge and generate savings with pre-liming
PRODUCE QUALITY SLUDGE AND GENERATE
SAVINGS WITH PRE-LIMING
BIOSOLIDS
Dehydris™Lime
ADVANCED DEWATERING OF SLUDGE BY PRE-
LIMING BEFORE CENTRIFUGATION
P-PPT-B-005-EN-1107
BIOSOLIDS
2
CONTENTS
Dehydris™
Lime � Dehydris™ Lime on the dryness scale
� Dehydris™ Lime Workshop
� Uses and post treatments
� Operation Description
� The plus of Dehydris™ Lime
� References
� Case Study: Calais (62), FRANCE
BIOSOLIDS
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Dehydris Lime DRYNESS SCALE COMPARISON
Dehydris™
Lime
0.4 %Dryness
4 – 6 %20 – 45 %
60 – 90 %
Process Thickening Dehydration Drying
Sludge volume /
Extracted water volume
Range Name Drainis™ Dehydris™ Evaporis™
Process Name Drainis™ Turbo
Dehydris™ Osmo
Dehydris™ Lime
Dehydris™ Twist
Evaporis™ LT
Evaporis™ LE
BIOSOLIDS
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Dehydris Lime PROCESS (1/2)
Dehydris™
Lime
BIOSOLIDS
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Dehydris Lime PROCESS (2/2)
Dehydris™
Lime
6
Landfill Agriculture re-use
Dehydris Lime
• Reduced volume of cake• Calcium intake • Heap holds its shape• Biological stability
• Reduced volume of cake • Dryness: 30%
• No recycling (dryers STC, BDS)• Improved drying kinetic
Thermal Drying
Dehydris Lime – USES AND POST TREATMENTS
Post treatments
UsesUses
BIOSOLIDS
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Area of application:
• Physical-chemical and biological UWW sludge, whether or not digested
Used limes:
• Quicklime thermicity delayed
• Quick lime thermicity delayed or fine quick lime
• Liquid lime solution ready for use
Polymers:
• High pH stable polymers
• Standard polymer is used for digested sludge
OPERATION DESCRIPTION
Dehydris™
Lime
tem
péra
ture
time
60°°°° C
Quicklime thermicity delayed
� Maintaining the rate of reaction� Delayed activation as sharp
as for classic quicklime
Classic quicklime
Reactivitydelay
BIOSOLIDS
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Dehydris Lime ADVANTAGES
• Intimate mixing of lime in sludge – stability sustainable organic
• Identical dryness to that obtained with post-liming
– up to 50% gain compared to dewatering with centrifuge only
• Granular structure– heap holds its shape
• Reduced phosphate content in the centrates returned to the plant inlet
• Simple implementation• Easy-to-run unit • Enhanced security
– No mechanical blade mixer
– No dust
Dehydris™
Lime
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Contract CapacityStart-up Date
Type of sludge
Sludge-end use
Calais (62), France 120,000 PE 2007 Activated sludge Agricultural spreading
Île d’Arrault (45), France 100,000 PE 2011 BRM (Ultrafor™) Agricultural spreading
Basse Wavre, Belgique 200,000 PE 2010 Anaerobic digestion Agricultural spreading
Château-Thierry (02), France 40,000 PE 2012 Activated sludge Agricultural spreading
AMONG Dehydris Lime REFERENCES
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A CASE STUDY: CALAIS « JACQUES MONOD » (62), FRANCE
CONTEXT:
• A 120 000 p.e. UWW treatment plant (prolonged aeration)
• Replaces post-liming (mixer out of use) by pre-liming prior to centrifugation (a Degrémont Services achievement)
• Pre-liming commissioned in 2007
DESIGN:
• The sludge treatment line:– Floatation, pre-liming, centrifugation
• Treatment capacity : 800 Kg DS/hour
• Delayed temperature increase quick lime, lime treatment rate: 30% CaO/DS
• Centrate dephosphatation efficiency >75%
• Final dry solids content: 28%
• Sludge end use:agricultural spreading