Water treatment by ballasted flocs and degreasing

• US 7,244,362 B2
• Filed: 02/08/2002
• Issued: 07/17/2007
• Est. Priority Date: 02/09/2001
• Status: Expired due to Fees

• Current Assignee: Veolia Water Solutions & Technologies Support
• Original Assignee: OTV S.A.
• Inventors: Binot, Patrick
• Primary Examiner(s): Hruskoci; Peter A.
• Application Number:
  US10/467,134
• Publication Number:
  US 20040129642A1
• Time in Patent Office: 1,985 Days
• Field of Search: 210/710, 210/711, 210/713, 210/714, 210/708, 210/724, 210/725, 210/727, 210/738, 210/787, 210/788
• US Class Current: 210/714
• CPC Class Codes: B01D 17/0202 by ab- or adsorption
• CPC Class Codes: B01D 17/0211 with baffles
• CPC Class Codes: B01D 17/041 with moving devices
• CPC Class Codes: B01D 17/047 with separation aids
• CPC Class Codes: B01D 21/0018 provided with a pump mounted in or on a settling tank
• CPC Class Codes: B01D 21/0045 Plurality of essentially parallel plates
• CPC Class Codes: B01D 21/08 provided with flocculating compartments
• CPC Class Codes: B01D 21/2488 bringing about a partial recirculation of the liquid, e.g. for introducing chemical aids
• CPC Class Codes: B01D 21/26 Separation of sediment aided by centrifugal force or centripetal forcecentrifuges B04B; cyclones B04C
• CPC Class Codes: C02F 1/38 by centrifugal separation
• CPC Class Codes: C02F 1/40 Devices for separating or removing fatty or oily substances or similar floating material cleaning or keeping clear the surface of open water from oil or like materials E02B15/04; devices in sewers for separating liquid or solid substances from sewage E03F5/14, e.g. for use in drains leading to the sewer E03F5/16
• CPC Class Codes: C02F 1/5281 Installations for water purification using chemical agents
• CPC Class Codes: C02F 11/12 by de-watering, drying or thickening
• CPC Class Codes: C02F 2305/12 Inert solids used as ballast for improving sedimentation C02F3/1226 takes precedence

Abstract

The invention concerns the use of a coagulation-flocculation-decantation device for water treatment to degrease water inside the device itself so as to eliminate therefrom more than 20% of hexane-extractable matter without resorting to separate degreasing means by flotation. The invention also concerns a plant comprising a coagulation-flocculation-decantation device by ballasted flocs having a coagulation zone (1), means supplying (4) a granular material denser than water (4), a flocculation (6), a decantation zone (8) and means for recycling (15) granular material including at least a hydrocyclone (17). The characterised in that it does nut comprise degreasing means provided upstream of the coagulation-flocculation-decantation device, the grease being removed from the water inside the coagulation-flocculation-decantation device itself without means for injecting air or an equivalent gas.

Claims

1. A method of degreasing water or wastewater in the course of treating water or wastewater, comprising:

subjecting the water or wastewater to treatment by flocs ballasted by granular material and directing the water or wastewater through coagulation, flocculation and sediment devices, and degreasing the water or wastewater within the coagulation, flocculation and sediment devices and eliminating at least 20% of hexane extractable material from the water or wastewater without subjecting the water or wastewater to flotation degreasing means.

2. The method of claim 1 including eliminating more than 50% of hexane extractable materials from the water or wastewater.

3. The method of claim 1 including at least partially removing grit from the water or wastewater.

4. The method of claim 3 including utilizing a coarse grit removal device upstream from the coagulation, flocculation and sediment devices and operating the coarse grit removal device at a settling speed of more than 15 m/h.

5. The method of claim 4 including operating the coarse grit removal device at a settling speed between 80 and 200 m/h.