EXHIBIT 10.51



$150,000.00                                                    November 13, 2000

                             SECURED PROMISSORY NOTE

================================================================================

         This Note has not been registered  under the Securities Act of 1933, as
amended,  or  any  state  securities  laws,  and  no  sale,  transfer  or  other
disposition of any interest herein or therein may be made unless, in the written
opinion  of counsel  to the  Corporation,  such  transfer  would not  violate or
require registration under any such statute.

================================================================================

         1. Background.  This Note is issued pursuant to the Securities Purchase
Agreement  dated November 10, 2000 (the "Purchase  Agreement")  among  Commodore
Environmental Services, Inc. (the "COES"), Commodore Applied Technologies,  Inc.
("CXI" or the  "Borrower"),  the Holder (as  defined  below) and  certain  other
purchasers of notes of similar tenor,  issued from time to time pursuant to such
agreement (collectively, the "Notes").

         2. Payment. The Borrower, for value received, hereby promises to pay to
the order of Mathers  Associates  (the  "Holder"),  the principal  amount of ONE
HUNDRED  FIFTY  THOUSAND  DOLLARS  ($150,000.00),  together with interest on the
outstanding  principal  balance  hereunder  on the  earliest to occur of (i) the
prepayment of the Notes out of one hundred  percent (100%) of the first proceeds
received by CXI as a cash  distribution  (whether in the form of an intercompany
dividend, bonus, loan or otherwise) from Dispute Resolution Management,  Inc., a
Utah  corporation   ("DRM")  an  81%  owned  subsidiary  of  CXI,  or  (ii)  the
consummation of a contemplated Two Million Dollars  ($2,000,000)  debt financing
with BHC Funding,  Inc. or (iii) on February 12, 2001 (the "Maturity Date"). All
payments of principal and/or interest shall be paid as set forth below, and each
such payment  shall be made in lawful  money of the United  States of America by
wire  transfer  of  immediately  available  funds  of the  Borrower  payable  to
Greenberg  Traurig,  LLP, as attorneys for the benefit of the CXI investors,  as
follows:

                                TO: Citibank N.A.
                        153 East 53rd Street - 20th Floor
                               New York, NY 10043
                                 ABA # 021000089
                              Attn: Adrianna Arroyo

                        FOR CREDIT TO: Greenberg Traurig
                          Escrow Account No.: 37092076
                     REFERENCE: Name: CXI Investors Account
                            File Number: 20440.010700
                         Attorney Name: Stephen A. Weiss



<PAGE>


         or at such other address as the Holder shall from time to time indicate
by written notice to Borrower.

         The  outstanding  principal  balance of this Note  shall  bear  simple,
non-cumulative  interest from the date hereof until paid in full, at an interest
rate of twelve percent (12%) per annum.  Accrued  interest on this Note shall be
payable on the Maturity Date.

         By  acceptance  of this Note,  the Holder  agrees that it will promptly
deliver and surrender this Note to the Borrower upon full payment  thereof,  and
that it will promptly  notify the Borrower of any disposition of the Note and of
the name and address of the  transferee of this Note. For purposes of this Note,
the  Borrower  may assume  that the  registered  Holder is the holder  hereunder
unless notified to the contrary in the manner provided in Section 4.

         This Note may be prepaid, in whole or in part, at any time, on five (5)
business days prior notice, without penalty.

         3. Events of Default.  Any of the following  events which occur and are
continuing shall constitute an "Event of Default":  (a) if the Borrower defaults
in the payment of any principal or interest  under this Note when the same shall
become  due and  payable,  either by the terms  hereof  or  otherwise  as herein
provided,  and such  default  is not cured  within  five (5) days of the date of
notice of such  default;  (b) if a receiver,  trustee or other such  official is
appointed for the Borrower,  or if any  proceedings  are commenced by or against
the Borrower  under any  bankruptcy,  reorganization,  arrangement,  insolvency,
readjustment  of debt,  dissolution or liquidation law or statute of the federal
government  or any state  government  and, if such  proceedings  are  instituted
against the Borrower, the Borrower by any action or failure to act indicates his
approval of, consent to or  acquiescence  therein,  or an order shall be entered
approving the petition in such proceeding and, within forty-five (45) days after
the entry thereof, such appointment or order is not vacated, or stayed on appeal
or otherwise, or shall not otherwise have ceased to continue in effect or (c) if
the Borrower  breaches any material  covenants  set forth in any of the Purchase
Agreement or any  Ancillary  Agreement  (as such term is defined in the Purchase
Agreement)  and such  breach  is not  cured  within  thirty  (30) days of notice
thereof.  Upon the  occurrence  of an Event of  Default,  the  entire  principal
balance and all unpaid  accrued  interest of this Note  shall,  at the  Holder's
option,  become  immediately  due and payable upon written notice thereof to the
Borrower.

         4.  Communications  and  Notices.   Except  as  otherwise  specifically
provided herein,  all communications and notices provided for in this Note shall
be sent by first  class  mail,  facsimile  or  telegram to the Holder at Mathers
Associates,  230 Mathers Road, Ambler,  Pennsylvania 19002,  attention:  Norbert
Zeelander,  Fax:  (215)  643-7091 or the Borrower at 150 East 58th  Street,  New
York, New York 10155, attention:  James DeAngelis, Chief Financial Officer, Fax:
(212) 753-0731.  Any first-class mail notice provided pursuant to this Section 4

                                       2
<PAGE>


shall be deemed given three days after being sent by first-class  mail.  Notices
sent by  telegram or  facsimile  shall be deemed  received  upon  delivery.  The
Borrower and the Holder may from time to time change their respective addresses,
for  purposes  of this  Section  4, by  written  notice  to the  other  parties;
provided,  however,  that notice of such  change  shall be  effective  only upon
receipt.

         5.  Governing  Law;  Jurisdiction.  This  Note  shall be  construed  in
accordance  with and  governed  by the laws of the  State of New  York.  For the
purposes of any suit, action or proceeding involving this Note, the Borrower and
the Holder  hereby  expressly  submit  itself to the  jurisdiction  of the state
courts of the State of New York and to the  jurisdiction  of the  United  States
District Court for the State of New York,  and consent that any order,  process,
notice of motion or other application to or by any such court or a judge thereof
may be served within or without such court's  jurisdiction  by certified mail or
by personal service,  provided that a reasonable time for appearance is allowed,
and the  Borrower  and the Holder  agree that such  court  shall have  exclusive
jurisdiction  over any such suit,  action or  proceeding  commenced by either or
both of said parties.  The Borrower and the Holder hereby  irrevocably waive any
objection  that it may now or hereafter have to the laying of venue of any suit,
action or  proceeding  arising out of or  relating  to this Note  brought in the
state courts of the State of New York or in the United States District Court for
the State of New York and hereby  further  irrevocably  waive any claim that any
such suit, action or proceeding brought in any such court has been brought in an
inconvenient forum.

         6.  Assignment.  This Note shall  bind and inure to the  benefit of the
respective successors and assigns of the parties hereto;  provided that Borrower
shall not be permitted to assign its obligations hereunder.

         7.  Security.  This Note shall be secured  by a  security  interest  in
certain assets of the  Corporation as set forth in the Security  Agreement dated
the date hereof by and among the Corporation and the Holders.

         8.  Waiver.  No waiver of a right in any  instance  shall  constitute a
continuing waiver of successive rights, and any one waiver shall govern only the
particular  matters  waived.  The  Borrower  expressly  waives any  presentment,
demand, protest, notice of protest, or notice of any kind.

         9. Collection Costs. In the event that the Holder shall place this Note
in the hands of an attorney for collection  during the  continuance of any Event
of Default, the Borrower shall further be liable to the Holder for all costs and
expenses  (including  reasonable  attorneys'  fees) which may be incurred by the
Holder in enforcing  this Note,  which amounts may, at the Holder's  option,  be
added to the principal hereof.

         10. Waiver of Jury Trial.  THE BORROWER  EXPRESSLY  WAIVES ANY RIGHT TO
TRIAL BY JURY OF ANY CLAIM, DEMAND,  ACTION OR CAUSE OF ACTION (A) ARISING UNDER
THIS NOTE OR ANY OTHER INSTRUMENT,  DOCUMENT OR AGREEMENT  EXECUTED OR DELIVERED
IN  CONNECTION  HEREWITH,  OR  (B) IN ANY  WAY  CONNECTED  WITH  OR  RELATED  OR
INCIDENTAL TO THE DEALINGS OF THE PARTIES  HERETO OR ANY OF THEM WITH RESPECT TO
THIS NOTE OR ANY OTHER INSTRUMENT,  DOCUMENT OR AGREEMENT  EXECUTED OR DELIVERED
IN CONNECTION  HEREWITH,  OR THE TRANSACTIONS  RELATED HERETO OR THERETO IN EACH


                                       3
<PAGE>

CASE WHETHER NOW EXISTING OR HEREAFTER ARISING, AND WHETHER SOUNDING IN CONTRACT
OR TORT OR OTHERWISE;  AND THE BORROWER HEREBY AGREES AND CONSENTS THAT ANY SUCH
CLAIM, DEMAND, ACTION OR CAUSE OF ACTION SHALL BE DECIDED BY COURT TRIAL WITHOUT
A JURY,  AND THAT ANY PARTY MAY FILE AN ORIGINAL  COUNTERPART  OR A COPY OF THIS
SECTION WITH ANY COURT AS WRITTEN  EVIDENCE OF THIS WAIVER OF THE RIGHT TO TRIAL
BY JURY.

         IN WITNESS  WHEREOF,  the Borrower  has executed  this Note on the date
first above written.


                                    COMMODORE APPLIED TECHNOLOGIES, INC.



                                    By:   /s/ Paul E. Hannesson
                                    -------------------------------------------
                                    Paul E. Hannesson, Chairman, Chief Executive
                                    Officer and President



                                       4
<PAGE>