PATENT ABSTRACTS 433

impurities from the carbon dioxide bottom stream in a separate purification column, to recover a high-quality, liquid, carbon dioxide stream.

adjacent or intervening injection wells or pipes for the purpose of creating a denitrification zone at a distance sufficiently far from the extraction well or extraction pipe.

4681685

M E T H O D A N D A P P A R A T U S F O R C O N C E N T R A T I N G

B I O P A R T I C L E S

Paul Sutton, Joseph Peplinski assigned to Dorr- Oliver lnc

A method and apparatus for controlling bio- mass growth in a fluidized bed reactor during anaerobic or aerobic treating of a waste feed. In particular, means is provided for concentrating a portion of bioparticles, the bioparticles being media with biomass adhered thereto and the concentrating means being integral to the fluid bed reactor, so that bioparticles delivered to a separator means for separating the biomass from the media are of high concentration requiring lit- tle downstream processing of the biomass separated thereby.

4683064

P R O C E S S F O R D E C R E A S I N G T H E N I T R A T E C O N T E N T I N W A T E R

Rolf O Hallberg, Rudolf H Martinell, S 13500 Tyres Sweded

The invention relates to a process for decreasing the content of nitrate in ground water, artificial ground water, that is infiltrated surface water, or surface water flowing through an aquifer or through a basin or a filter containing naturally occurring filter material. Water containing denitrification organisms and/or substrate there- fore is introduced intermittently through a num- ber of injection wells or injection pipes arranged around one or more extraction wells or extrac- tion pipes for purified water. During each in- troduction of water containing denitrification organisms and/or substrate therefore said water is fed to only some of said injection wells or pipes and simultaneously water is drawn from nearby,

4632429

M E T H O D O F R E N D E R I N G D O C U M E N T S R E S I S T A N T T O P H O T O C O P Y I N G A N D A N T I - C O P Y I N G P A P E R T H E R E F O R

Norman A Gardner, Michael P Voticky, Mon- treal. Canada assigned to Nocoi Inc

A document has information appearing thereon, with at least a portion of the information being located on a front face of a portion of the docu- ment. The front face portion has a color with a sufficiently low reflection spectral response to render the document portion substantially in- capable of being photocopied in an information. readable manner. The document portion is capable of transmitting visible light from the rear face to the front face to cause sufficient contrast between the relatively non-translucent informa- tion and the transmitted light to enable the in- formation to be read by a human eye viewing the front face of the document when visible light is transmitted through the document from the rear face to the front face.

8704424

T R E A T M E N T S Y S T E M F O R L A N D F I L L L E A C H A T E

Ronald L LAVIGNE, Ronald L LAVIGNE

A biological living-filter system (3) for treatment of sanitary landfill leachate which comprises a treatment basin (8) which is lined with a water impervious material and filled with an or- ganically enriched treatment medium (5) which is conducive to maintaining a population of micro-organisms. The system also includes leachate tolerant plants (30) growing in the treat- ment medium (5) and flow control means (2) for the leachate.

434 PATEKT ABSTRACTS

For information about PATSEARCH”

Pergamon InfoLine Inc. 1340 Old Chain Bridge Road

McLean. Virgmla 22 101 USA

Telephone (703) 442-0900 Telex: 90- I8 I I

Pergamon InfoLme LImIted I2 Vandv Street

London Eti?A 2DE England

Telephone (01) 377-4650 Telex: 8814614

Pergamon Orbit InfoLine Inc. 8000 Westpark Dnve McLean, VA 22102

USA Telephone (703) 442-0900

T&x: 90-1811

Pergamon OrbIt InfoLme Ltd I? Vandy Street

London EC?A 2DE UK

Telephone (01) 377.4650 Telex: 8814614

SECTION C SUMMARIES OF SPECIAL REPORTS