Classifications

• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
  • C02F1/469—Treatment of water, waste water, or sewage by electrochemical methods by electrochemical separation, e.g. by electro-osmosis, electrodialysis, electrophoresis
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
  • B09C—RECLAMATION OF CONTAMINATED SOIL
  • B09C1/00—Reclamation of contaminated soil
  • B09C1/08—Reclamation of contaminated soil chemically
  • B09C1/085—Reclamation of contaminated soil chemically electrochemically, e.g. by electrokinetics
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2201/00—Apparatus for treatment of water, waste water or sewage
  • C02F2201/46—Apparatus for electrochemical processes
  • C02F2201/461—Electrolysis apparatus
  • C02F2201/46105—Details relating to the electrolytic devices
  • C02F2201/4611—Fluid flow
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2201/00—Apparatus for treatment of water, waste water or sewage
  • C02F2201/46—Apparatus for electrochemical processes
  • C02F2201/461—Electrolysis apparatus
  • C02F2201/46105—Details relating to the electrolytic devices
  • C02F2201/46115—Electrolytic cell with membranes or diaphragms

Definitions

• the invention concerns an apparatus for the electro inetic removal of metals and other charged elements from soil, sludge, slag etc., said apparatus having a built-in positive or negative electrode which is surrounded by a first circulation system demarcated with a charge-selective membrane which transfers ions with the same charge as the electrode, said first circulation system being separated from a second circulation system with a charge-selective membrane arranged for accumulation, and which in turn is demarcated by yet a further charge-selective membrane which transfers ions with a charge opposite to that of the electrode.
• anion-exchange membranes and cation-exchange membranes which principally can only trans- fer anions (negatively-charged ions) and cations (positively-charged ions) respectively.
• the principle is that of making a sandwich of chambers separated alternately by anion-exchange membranes and cation-exchange membranes, and applying a potential to this stack. Every second chamber is connected together, and thus there is formed a concentration chamber and a demineralisation chamber alternately.
• anions can pass the anion-exchange membrane, which must lie up against the anode, into a concentration chamber, while cations can go through the cation-exchange membrane, which lies up against the cathode, into the next concentration chamber.
• cations can go through the cation-exchange membrane, which lies up against the cathode, into the next concentration chamber.
• This known apparatus is not suitable for use in soil be ⁇ cause the apparatus is cylindrical in configuration, in that the disadvantage here is that it is only with diffi ⁇ culty that it can be removed or serviced without actually digging it up from the medium. Moreover, the cylindrical configuration does not ensure a good contact surface be ⁇ tween the earth in which the apparatus is placed and the sides of the apparatus. Furhermore, the known apparatus is not sufficiently robust to withstand the pressure from the surrounding earth.
• an apparatus which according to the invention is characteristic in that the apparatus is a spear which is built up around a pressure-stable core of plastic and contributes towards the distribution of cir- culation liquids, and in that the spear tapers down towards that end which faces downwards in the medium.
• At least two units must be used, but preferably more, and be configured with at least one anode and at least one cathode whereby a potential can be applied to the medium. Since the migration of ions in the earth is very slow, the use of many units will be preferred.
• the medium is separated from the apparatus' second circulation system arranged for collection by an ion-exchange membrane which is arranged to prevent the passage of ions with the same charge as the electrode, in that positive electrodes are mounted with anion-exchange membranes and negative electrodes are mounted with cation-exchange membranes.
• the electrode for protection against precipitation layers is disposed in the first circulation system, and separated from the second circulation system by an ion-exchange membrane in such a manner that ions with an opposite charge to the electrode are prevented from gaining direct access to the electrode, in that a positive electrode is mounted with a cation-exchange membrane for the separation of the two circulation systems, whereas a negative electrode is mounted with an anion-exchange membrane.
• a net is mounted around the outermost membrane in such a manner that a liquid phase is formed between the sur ⁇ rounding medium and the outermost membrane.
• the advantage herewith is that the web distributes the moistness from the medium over a large area, whereby the surface loss due to holes or cavities which are formed by projecting stones can be compensated for. In practice there is thus achieved a contact surface close to 100%, even though there are places where there is no contact between the medium and the web. Moreover, further compensation is achieved for irregularities in the contact surface.
• fig. 2 shows the construction, positioning and configu ⁇ ration in principle of membranes, seals and plastic net respectively in the apparatus shown in fig. 1.
• Fig. 1 shows in principle the construction of a charge- selective apparatus according to the invention.
• the charge-selective apparatus 16 consists of a core 9 tapered towards the bottom, and in which a series of through-going holes is provided in the top and the bottom.
• Most of the outer side of the downwardly-tapered core, which is made of plastic, is covered by a perforated metal plate or a metal web 2 which has contact with the top through an electrical ⁇ ly-conducting connection 1 and a hole 19.
• the outermost membrane 13 On the outside of the outermost membrane 13 there is placed a downwardly-tapered, flexible textile, plastic or mineral web 11, this being built up in or consisting of an water absorbent, similarly flexible and ion-conveying material.
• a top ring 14 and a bottom ring 5 In order to ensure the sealing of the inner membrane at the top and the bottom, it is provided with a top ring 14 and a bottom ring 5.
• the outer membrane 13 is provided with a top ring 15 and a bottom ring 7.
• Fig. 2 shows in principle the construction, positioning and configuration of electrically-connected metal plates/webs, membranes, seals and plastic net respectively. All of the parts which are provided on the outside of the downwardly- tapered plastic spear 16 and 9, i.e. the downwardly-tapered metal plate/web 2, the two downwardly-tapered plastic nets 3 and 4 and the outermost, flexible ion-conveying layer 11 can, because of the special construction and sealing at the top and bottom and the described tapering towards the bottom, be assembled and disassembled part by part, which hereby enables the individual components to be replaced.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Life Sciences & Earth Sciences (AREA)
• Environmental & Geological Engineering (AREA)
• Engineering & Computer Science (AREA)
• Health & Medical Sciences (AREA)
• Soil Sciences (AREA)
• Analytical Chemistry (AREA)
• Molecular Biology (AREA)
• Electrochemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Hydrology & Water Resources (AREA)
• Water Supply & Treatment (AREA)
• Organic Chemistry (AREA)
• Separation Using Semi-Permeable Membranes (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=8090245

Family Applications (1)

Country Status (5)

Families Citing this family (1)

Family Cites Families (3)

• 1996
  • 1996-02-12 DK DK14296A patent/DK14296A/da not_active Application Discontinuation
• 1997
  • 1997-02-12 WO PCT/DK1997/000064 patent/WO1997029865A1/da not_active Ceased
  • 1997-02-12 EP EP97904345A patent/EP0969936A1/en not_active Withdrawn
  • 1997-02-12 AU AU17191/97A patent/AU1719197A/en not_active Abandoned
• 1998
  • 1998-07-30 NO NO983516A patent/NO983516L/no unknown

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events