Abstract:
An injection vessel for injecting liquid amendment into contaminated subsurface sediment in ecologically sensitive areas such as shallow water salt marshes, tidal flats, or fresh water wetlands is disclosed. The injection vessel described herein includes a shallow-draft floating platform that has an injection system mounted thereon. The injection system includes an injection grid containing a plurality of injection syringes that receive liquid amendment from a metering pump. The injection grid is lowered such that the output of the injection syringes is within the contaminated sediment. The metering pump provides the liquid amendment to the injection syringes and a fluid path is established that injects the liquid amendment into the contaminated sediment. A propulsion system mounted on the floating platform provides for locomotive and maneuvering power. A control system allows the operation of the system either in a semi-autonomous mode in which an on-board controller is programmed to provide the command signals, or in a remote control mode with an operator providing real time command signals through either a wireless or wired controller. The control system provides propulsion commands to the propulsion system and injection commands to the injection system. The propulsion commands include both locomotive commands and maneuvering commands. The injection commands include the lowering and raising of the injection gird and the operation of the metering pump to dispense the predetermined amount of liquid amendment.

Description:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   The work leading to this invention was carried out with United States Government support provided under a grant from the NOAA, Grants No. NA16RG1035, and NA070R0351. Therefore, the U.S. Government has certain rights in this invention. 

   CROSS REFERENCE TO RELATED APPLICATIONS 
   BACKGROUND OF THE INVENTION 
   This invention relates to injection vessels capable of injecting liquid amendment into contaminated sediment, and in particular to injection vessels capable of operating in shallow salt water and fresh water systems with little environmental impact. 
   Remediation of contaminated sediment in shallow salt water marshes, tidal flats, or fresh water wetlands, after ecological harm has occurred, should be performed in a manner to minimize the intrusion of the remediation equipment in these ecologically sensitive areas. Sediment remediation techniques that are currently used typically involve dredging, tilling, installing horizontal wells, and manually injecting liquid amendment into the contaminated subsurface sediment. The various types of equipment that are currently used to perform these operations are usually large, bulky, noisy, and polluting, hence the anthropogenic impact of these methods and the equipment used to carry out these methods can be substantial. 
   Therefore, it would be advantageous to provide an injection vessel that is capable of delivering liquid amendment into the sediment without adversely impacting the ecologically sensitive environment in which it operates. 
   BRIEF SUMMARY OF THE INVENTION 
   An injection vessel for injecting liquid amendment into contaminated subsurface sediment in ecologically sensitive areas such as shallow water salt marshes, tidal flats, or fresh water wetlands is disclosed. The injection vessel described herein includes a shallow-draft floating platform that has an injection system mounted thereon. The injection system includes an injection grid containing a plurality of injection syringes that receive liquid amendment from a metering pump. The injection grid is lowered such that the output of the injection syringes is within the contaminated sediment. The metering pump provides the liquid amendment to the injection syringes and a fluid path is established that injects the liquid amendment into the contaminated sediment. A propulsion system mounted on the floating platform provides for locomotive and maneuvering power. 
   A control system allows the operation of the system either in a semi-autonomous mode in which an on-board controller is programmed to provide the command signals, or in a remote control mode with an operator providing real time command signals through either a wireless or wired controller. The control system provides propulsion commands to the propulsion system and injection commands to the injection system. The propulsion commands include both locomotive commands and maneuvering commands. The injection commands include the lowering and raising of the injection grid and the operation of the metering pump to dispense the predetermined amount of liquid amendment. 
   In one aspect, the propulsion system of the injection vessel includes a pair of paddle wheels that are mounted on the floating platform and are powered by a pair of electric motors coupled to the controller. In one embodiment, the propulsion commands can be forward or reverse and on and off for each motor. 
   In another aspect, the controller includes an on-board computer/controller that receives commands from an off-vessel user having a field computer, wherein the field computer and the on-board computer/controller are coupled via a wireless connection, which can be a radio frequency or optical link. The commands can be generated by a user using the field computer via a keyboard, keypad, or controller such as a joystick. In another aspect the on-board computer/controller receives commands from a hardwired controller operated by a user, and wherein the controller can be a joystick. In another aspect, the on-board computer/controller can receive commands programmed and stored in a programmable memory coupled to the on-board computer/controller, or the programmable memory can be coupled to the field computer and transmitted over the wireless link. 
   Other features, functions, and aspects of the invention will be evident from the Detailed Description of the Invention that follows. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     The invention will be more fully understood with reference to the following Detailed Description of the Invention in conjunction with the drawings of which: 
       FIG. 1  is an isometric view of an embodiment of the injection vessel; 
       FIG. 2  is an isometric view of an embodiment of the propulsion system suitable for use with the injection vessel depicted in  FIG. 1 ; 
       FIG. 3  is an isometric view of an embodiment of a floating platform suitable for use with the injection vessel depicted in  FIG. 1 ; 
       FIG. 4  is an isometric view of an embodiment of an injection frame assembly suitable for use with the injection vessel depicted in  FIG. 1 ; 
       FIG. 5  is an exploded view of an embodiment of an injector assembly suitable for use with the injection vessel depicted in  FIG. 1 ; 
       FIG. 6  is a block diagram of an embodiment of a control system suitable for use with the injection vessel depicted in  FIG. 1 ; 
       FIG. 7  is a display of a page of data from one the control system depicted in  FIG. 6 ; and 
       FIG. 8  is a display of a page of data from the injection controller depicted in  FIG. 6 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  depicts an embodiment of the present injection vessel. In particular, the injection vessel  100  includes a floating platform  102  that is powered by propulsion system  104  that includes electric motors  124   a  and  124   b , where motor  124   b  is not visible in  FIG. 1 . The injection vessel  100  also includes an injection assembly  106  that includes an injection frame assembly  108  securely mounted to the floating platform  102  and an injection manifold  110  that is securely mounted to the injection frame assembly  108 . The injection assembly  106  further includes a moveable injection grid assembly  112  that is positioned within the injection frame assembly and that includes a plurality of openings  113  at least one of which has an injector assembly  114  securely affixed therewithin. The injector assembly  114  is fluidly coupled to the injection manifold  110  via flexible tubing  120 . A reservoir  116  containing the liquid amendment is securely mounted on the floating platform  102  and is fluidly coupled to a metering pump  117 . The metering pump  117  provides a predetermined amount of the liquid amendment to the injection manifold  110  via a pipe  118 . A raising/lowering mechanism  122  is securely mounted on the injection frame assembly  108  and is mechanically coupled to the injection grid assembly  112  in order to raise and lower it. The injection grid assembly  112  is guided in its movements on the vessel through a series of stabilizer stanchions  128 . A control system  126  is coupled to the electric motors  124   a  and  124   b , to the raising/lowering mechanism  122 , and to the metering pump  117  to provide the various control signals needed to operate the injection vessel  100 . In the preferred embodiment, the raising/lowering mechanism  122  is a winch that is coupled via cables to the injection grid assembly  112 . Furthermore, in the preferred embodiment the injection manifold  110  is a 6″ diameter PVC pipe with outlets provided evenly spaced about one-half the exterior. Preferably there are 6 outlets spaced 30 degrees apart with the pattern repeated as needed and dependent upon the maximum number of injector assemblies that are to be used. In addition, in the preferred embodiment, the injection grid assembly  112  is preferably Duragrate® molded fiberglass grating. 
   In operation, the control system  126  navigates the injection vessel  100  to a predetermined location via control signals sent to the electric motors  124   a  and  124   b . The control system  126  then instructs the raising/lowering mechanism  122  to lower the injection grid assembly  112  containing the injector assembly  114  such that a portion of the injector assembly  114  is inserted into the contaminated subsurface sediment. The metering pump  117  is then signaled to provide the liquid amendment to the injector assembly  114  to inject the liquid amendment into the contaminated subsurface sediment. The raising/lowering mechanism  122  is signaled to raise the injector grid  112 , thus raising the injector assembly  114  out of the sediment. The control system  126  then selects the next location to be remediated, and provides control signals to the electric motors  124   a  and  124   b  to move the injection vessel  100  to the next selected location. 
     FIG. 2  depicts an embodiment of the propulsion system  104  of the injection vessel  100  depicted in  FIG. 1 . The propulsion system  104  includes a pair of paddle wheels  202   a  and  202   b  that are independently powered by electric motors  124   a  and  124   b  via drive belts  210   a  and  210   b  respectively. The two paddle wheels are mounted between a pair of rigid paddle swing arms  204   a  and  204   b  such that each paddle wheel  202   a  and  202   b  can rotate independently of the other. The paddle wheel swing arms  204   a  and  204   b  are mounted to the floating platform  102  by pivot bearings  206   a  and  206   b  respectively. The two pivot bearings are securely attached to the floating platform  102  and are configured and arranged to allow the two paddle wheels  202   a  and  202   b  to be raised and lowered into and out of the water as needed. A pair of shaft supports  208   a  and  208   b  are inserted into the swing arms  204   a  and  204   b  to provide for added support and rigidity. The electric motors  124   a  and  124   b  can be securely mounted to the swing arms  204   a  and  204   b  respectively or may be securely mounted on the floating platform  102 . 
   In the preferred embodiment, the two electric motors are 24 volt DC motors, that are capable of providing rotation in either direction such that the individual paddle wheels can be counter rotated with respect to one another to allow the injection vessel to turn and maneuver. In this embodiment, the swing arms are constructed out of anodized aluminum and the paddle wheels are constructed from fiberglass reinforced plastic. 
     FIG. 3  depicts an embodiment of the floating platform  102  of the injection vessel  100  depicted in  FIG. 1 . In particular, the floating platform  102  includes a pair of pontoons  302   a  and  302   b  on which a frame  304  is constructed and securely attached thereto. The frame includes a pair of openings. The first opening, the injector well  306  is sized and configured to allow the injection grid assembly  112  to pass therethrough. The second opening, the paddle wheel well  308  is sized and configured to allow the pair of paddle wheels  202   a  and  202   b  to operate. 
   In the preferred embodiment, the floating platform  102  is a pontoon boat using a plurality of ¼″ thick pontoons held together by anodized aluminum “z-bars” and stainless steel fasteners. A suitable pontoon boat is manufactured by Rettey Corporation, Colchester, Ill. 
     FIG. 4  depicts an embodiment of the injection frame assembly  108  of the injection vessel  100  depicted in  FIG. 1 . In particular, the injection frame assembly  108  includes eight corner brackets  402  and twelve frame members  404  that are connected as depicted using a suitable fastening method such as a screw/washer/locknut assembly or riveting. In the preferred embodiment, the eight corner brackets  402  and twelve frame members are formed from 11 gauge stainless steel. 
   As depicted in  FIG. 1 , the injection assembly  106  includes a plurality of injector assemblies  114  receiving liquid amendment via flexible tubing  120  from the injection manifold  110 .  FIG. 5  depicts an embodiment of an injector assembly  114  of the injection vessel  100  depicted in  FIG. 1 . In particular, the injector assembly  114  includes a fluid input  501  in which the flexible tubing  120  is pressed onto a barbed hose nipple  502 . The barbed hose nipple  502  is coupled to an injector barrel  508  via a bushing  504  and a bushing plate  506 . The bushing  504  and bushing plate  506  are sized and configured to fit into, but not pass through, one of the plurality of openings  113  in the injection grid assembly  112 . The injector barrel  508  is slidably received in the bushing  504  and bushing plate  506  but the bushing  504  and bushing plate  506  are unable to pass through. Thus, the injector barrel  508  is able to slide within the bushings such that the needle  514  can be responsive to the contours of the sediment or obstacles within the sediment by sliding within the bushing  504 . The injector barrel  508  is coupled to a needle  514  having a fluid output  516  via a check valve  510  and a male luer lock  512  that is sized and configured to accept the check valve at a first end and the needle  514  at a second end. 
     FIG. 6  depicts an embodiment of the control system  126  of the injection vessel  100  depicted in  FIG. 1 . The control system includes an on-board computer/controller  610  that receives commands from one or more inputs, e.g., an off-vessel operator via a wireless link, an on-board or off-vessel operator using a hard-wired joystick or other form of controller, or an on-board memory that has been preprogrammed with instructions and provides one or more output control/command signals. As will be discussed in more detail below, the control system  126  also includes an injection controller  618 . 
   In particular, in response to movement commands, the on-board controller provides first and second motor control signals  612  and  614  respectively to the first and second electric motors,  124   a  and  124   b , respectively. In the preferred embodiment, the movement commands control forward and reverse operation of each of the pair of paddle wheels,  202   a  and  202   b . In this embodiment, the on-board computer/controller  610  provides forward-reverse and on-off commands to the motors and their associated control electronics to provide for movement and maneuvering of the injection vessel. In another embodiment, the computer/controller  610  can provide fractional power commands to control the speed and direction of each paddle wheel  202   a  and  202   b.    
   The on-board computer/controller  610  also provides an injection initiation signal  616  to an injection controller  618 . The injection controller provides the necessary injection commands  622  to the injection system via line  620  and provides monitoring data to the on-board computer/controller. The injection controller  618  provides the injection commands  622  to the raising/lowering mechanism  122  to lower the injection grid  112 , to the metering pump  117  to dispense the predetermined amount of liquid amendment, to the system as a whole to wait a predetermined amount of time for the injected liquid amendment to settle into the sediment, and to the raising/lowering mechanism  122  to raise the injection grid  112 . 
   The control system  126  includes a variety of operational command modes. In one embodiment, an off-vessel operator using a field computer  602  communicates via a wireless connection  607  between a wireless modem  606  coupled to the field computer  602  and a second wireless modem  608  coupled to the on-board computer  610 . The off-vessel operator receives data from the on-board computer  610  and provides instructions and commands to the on-board computer  610 . In this embodiment, the off-vessel operator interfaces to the field computer  602  via a HyperTerminal that allows direct control over the on-board computer  610 . In the preferred embodiment, the wireless connection  607  is a 900 MHz spread spectrum radio signal and the wireless modems are Ewave Super Screamer multi-protocol wireless modems available from Ewave, Inc. of Dallas Tex. Advantageously, by not having an operator onboard the injection vessel, the vessel will draw less water, enabling the injection vessel to have potentially more access to contaminated areas while minimizing the environmental impact on the area. In another embodiment, the wireless connection can be an optical connection, such as using infrared radiation. 
   In this preferred embodiment, as depicted in  FIG. 7 , the off-vessel operator has a window display  702  that can display a menu of operational commands, data from the on-board computer/controller  610 , data from the injection controller  618  or other data that is needed by the operator for the operation of the injection vessel. Thus, the movement of the injection vessel is controlled via keypad strokes  704  on keyboard  604 . In the illustrated embodiment, other keypad or keyboard strokes may be used to provide commands to the system. Alternatively, a controller such as a joy-stick  628  may be provided as an input to the field computer  602  to provide movement commands and to initiate the injection process by using the controller trigger button.  FIG. 8  depicts an embodiment of a window  802  displaying the injection controller data for the operator. 
   In another embodiment, a joystick or other controller  628  is hardwired into the on-board computer/controller  610  to provide a direct input from the user to the on-board computer/controller  610 . In this embodiment, the user may be located on the injection vessel itself or may be off-vessel and tethered to the on-board computer/controller  610  via a cable of sufficient length. Movement commands are based on the position of the joy-stick and the initiation of the injection process is provided by depressing the trigger button of the joystick. 
   In another embodiment, the movement and injection process initiation commands to the on-board computer/controller  610  can be pre-programmed into a memory  624  and executed autonomously by the on-board computer/controller  610 . Navigation, movement and maneuvering, and injection control can be pre-programmed. If an optional global positioning receiver is used, as discussed in more detail below, the injection vessel can be nearly autonomous since the on-board computer/controller will have all the information necessary to carry out a pre-programmed mission. The data can include for example, the starting position of the injection vessel, preselected locations to inject the liquid amendment, the amount of liquid amendment, and the final location. The controller can be programmed with navigation and route selecting algorithms to aid in this process. In this embodiment, it may be desirable for an operator to monitor the injection vessel and to be able to manually override the injection vessel on-board computer/controller  610  in the event of a failure or an emergency. Accordingly, the wireless system described above could be used. In another embodiment, the programmable memory can be coupled to the field computer and commands and data transmitted via the wireless connection between the field computer and the on-board computer/controller. 
   The on-board computer/controller  610  can also include an on-board global positioning system (GPS) receiver  626  to provide location and velocity data. The GPS receiver  626  can incorporate a differential GPS receiver so that sub-meter positioning can be achieved during injections. The differential GPS receiver can be configured to work with the US Coast Guard correction signal for marine purposes as well as the Wide Angle Augmentation System (WAAS) supported by the Federal Aviation Administration (FAA) such that corrections inland may be achieved as well. In addition, the GPS receiver  626  can be configured to support third-party corrections such as the satellite system by Omni-Star for corrections world wide. A suitable GPS receiver is available from Trimble Navigation Ltd., Sunnyvale, Calif. 
   In the preferred embodiment, the field computer  602  is a suitable lap-top computer that can be interfaced to a network such as an Ether Net and provide the necessary processing and graphics for the user. A suitable on-board computer/controller is the TEMPERATURE SENSING-2800 SBC DOS based computer/controller available from Technologic Systems, Fountain Hills, Ariz. This computer/controller was selected since it is a completely self contained module and includes a DOS ROM based operating system with full TCP/IP support, 2 PC/AT RS232 serial ports, 8 Mbytes of RAM, 1 Mbyte of FLASH RAM, 24 I/O ports, self-contained time clocks, a lithium battery and battery backed CMOS memory. In the preferred embodiment, the injection controller  618  is a programmable logic controller that is powered using 12 volts and accepts 8 DC inputs and has 6 outputs. Relays or electronic switches then provide the appropriate current to the raising/lowering mechanism  122 , which as provided above is preferably a winch and cable system. The interface between the on-board computer/controller  610  and the injection controller  618  is preferably via an Ethernet. 
   It should be appreciated that other variations to and modifications of the above-described injection vessel may be made without departing from the inventive concepts described herein. Accordingly, the invention should not be viewed as limited except by the scope and spirit of the appended claims.