EXHIBIT 10.22


                                REVOLVING CREDIT
                                 PROMISSORY NOTE

$2,000,000.00                                                      March 9, 2000
                                                          Minneapolis, Minnesota


         FOR VALUE RECEIVED, the undersigned, MERCURY WASTE SOLUTIONS, INC.,
Minnesota corporation ("Maker") promises to pay to the order of BANKERS AMERICAN
CAPITAL CORPORATION ("Lender") at its office at 302 N. Riverfront Drive,
Mankato, MN 56001, or any other place subsequently designated in writing by the
holder hereof, the principal sum of up to TWO MILLION AND No/100 Dollars
($2,000,000), or if less, the aggregate unpaid principal outstanding hereon,
together with interest at a variable rate equal to the Prime Rate plus six
percent (6%) per annum. Interest shall be computed on the actual days elapsed in
a year of 360 days. For purposes of this Note, "Prime Rate" shall mean the rate
of interest published from time to time in the Money Rates Column of the Money &
Investing Section of the WALL STREET JOURNAL as the "Prime Rate", as the same
may change from time to time.

         Interest accruing on this Note shall be payable monthly, commencing
April 1, 2000, and on the first day of each month thereafter until the Maturity
Date (as defined in the Loan Agreement), at which time the entire principal
balance outstanding plus all unpaid accrued interest shall be due and payable in
full.

         Maker may borrow and repay and reborrow against this Note, up to the
maximum principal amount outstanding at any one time of $2,000,000 to fund
Maker's working capital needs.

         Both principal and interest are payable in lawful money of the United
States of America to Lender at the office of Lender at the location described
above.

         This Note may be prepaid in whole or in part at any time without
penalty or premium.

         This Note is issued pursuant to the terms of that certain Loan
Agreement by and between Maker and Lender dated May 8, 1998, as amended by First
Amendment to Loan Agreement dated May 7, 1999, as further amended by Second
Amendment to Loan Agreement dated September 30, 1999, as further amended by
Third Amendment to Loan Agreement dated March 9, 2000, as the same may be
amended from time to time (the "Loan Agreement") to which reference is made for
the terms and conditions under which this Note was issued and the events upon
the occurrence of which the Lender may declare all sums outstanding hereon due
and payable in full immediately. This Note is secured by the assets of the Maker
pursuant to that certain Security Agreement dated May 8, 1998 executed by Maker
in favor of Lender, as the same may be amended from time to time (the "Security
Agreement"), and the other collateral, as set forth in the Loan Agreement, and
is guaranteed by MWS New York, Inc., a wholly owned subsidiary of Maker,
pursuant to the terms of a certain Guaranty dated May 8, 1998 in favor of Lender
(the "Guaranty").

         Maker hereby waives demand, presentment for payment, notice of
nonpayment, protest and notice of protest hereon, agrees that when or at any
time after this Note becomes due, the holder hereof

<PAGE>


$2,000,000                                                         March 9, 2000
                                                          Minneapolis, Minnesota

may, without notice, offset or charge this Note against any Lender account or
other account when maintained by Maker with the holders hereof, and agrees to
pay, upon the occurrence of an Event of Default (as defined in the Loan
Agreement) all costs of collection, including, but not limited to, reasonable
attorneys' fees, whether or not suit is commenced.

         This Note shall be governed by, interpreted and construed in accordance
with the internal laws of the State of Minnesota. The undersigned hereby
consents to the personal jurisdiction of the state and federal courts located in
the State of Minnesota in connection with any controversy related to this Note,
waives any argument that venue in such forums is not convenient and agrees that
any litigation instigated by the undersigned against the Lender in connection
with this Note, or any document or instrument securing payment of this Note
shall be venued in either the District Court of Hennepin County, Minnesota or
the United States District Court for the District of Minnesota, Fourth Division.





                                       MERCURY WASTE SOLUTIONS, INC.,
                                       A MINNESOTA CORPORATION

                                       BY s/ Todd Anderson
                                          --------------------------------------

                                          ITS Chief Financial Officer
                                             -----------------------------------


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