Remediation injection vessel for marshes, tidal flats, and wetlands

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.

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.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1depicts an embodiment of the present injection vessel. In particular, the injection vessel100includes a floating platform102that is powered by propulsion system104that includes electric motors124aand124b, where motor124bis not visible inFIG. 1. The injection vessel100also includes an injection assembly106that includes an injection frame assembly108securely mounted to the floating platform102and an injection manifold110that is securely mounted to the injection frame assembly108. The injection assembly106further includes a moveable injection grid assembly112that is positioned within the injection frame assembly and that includes a plurality of openings113at least one of which has an injector assembly114securely affixed therewithin. The injector assembly114is fluidly coupled to the injection manifold110via flexible tubing120. A reservoir116containing the liquid amendment is securely mounted on the floating platform102and is fluidly coupled to a metering pump117. The metering pump117provides a predetermined amount of the liquid amendment to the injection manifold110via a pipe118. A raising/lowering mechanism122is securely mounted on the injection frame assembly108and is mechanically coupled to the injection grid assembly112in order to raise and lower it. The injection grid assembly112is guided in its movements on the vessel through a series of stabilizer stanchions128. A control system126is coupled to the electric motors124aand124b, to the raising/lowering mechanism122, and to the metering pump117to provide the various control signals needed to operate the injection vessel100. In the preferred embodiment, the raising/lowering mechanism122is a winch that is coupled via cables to the injection grid assembly112. Furthermore, in the preferred embodiment the injection manifold110is 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 assembly112is preferably Duragrate® molded fiberglass grating.

In operation, the control system126navigates the injection vessel100to a predetermined location via control signals sent to the electric motors124aand124b. The control system126then instructs the raising/lowering mechanism122to lower the injection grid assembly112containing the injector assembly114such that a portion of the injector assembly114is inserted into the contaminated subsurface sediment. The metering pump117is then signaled to provide the liquid amendment to the injector assembly114to inject the liquid amendment into the contaminated subsurface sediment. The raising/lowering mechanism122is signaled to raise the injector grid112, thus raising the injector assembly114out of the sediment. The control system126then selects the next location to be remediated, and provides control signals to the electric motors124aand124bto move the injection vessel100to the next selected location.

FIG. 2depicts an embodiment of the propulsion system104of the injection vessel100depicted inFIG. 1. The propulsion system104includes a pair of paddle wheels202aand202bthat are independently powered by electric motors124aand124bvia drive belts210aand210brespectively. The two paddle wheels are mounted between a pair of rigid paddle swing arms204aand204bsuch that each paddle wheel202aand202bcan rotate independently of the other. The paddle wheel swing arms204aand204bare mounted to the floating platform102by pivot bearings206aand206brespectively. The two pivot bearings are securely attached to the floating platform102and are configured and arranged to allow the two paddle wheels202aand202bto be raised and lowered into and out of the water as needed. A pair of shaft supports208aand208bare inserted into the swing arms204aand204bto provide for added support and rigidity. The electric motors124aand124bcan be securely mounted to the swing arms204aand204brespectively or may be securely mounted on the floating platform102.

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. 3depicts an embodiment of the floating platform102of the injection vessel100depicted inFIG. 1. In particular, the floating platform102includes a pair of pontoons302aand302bon which a frame304is constructed and securely attached thereto. The frame includes a pair of openings. The first opening, the injector well306is sized and configured to allow the injection grid assembly112to pass therethrough. The second opening, the paddle wheel well308is sized and configured to allow the pair of paddle wheels202aand202bto operate.

In the preferred embodiment, the floating platform102is 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. 4depicts an embodiment of the injection frame assembly108of the injection vessel100depicted inFIG. 1. In particular, the injection frame assembly108includes eight corner brackets402and twelve frame members404that 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 brackets402and twelve frame members are formed from 11 gauge stainless steel.

As depicted inFIG. 1, the injection assembly106includes a plurality of injector assemblies114receiving liquid amendment via flexible tubing120from the injection manifold110.FIG. 5depicts an embodiment of an injector assembly114of the injection vessel100depicted inFIG. 1. In particular, the injector assembly114includes a fluid input501in which the flexible tubing120is pressed onto a barbed hose nipple502. The barbed hose nipple502is coupled to an injector barrel508via a bushing504and a bushing plate506. The bushing504and bushing plate506are sized and configured to fit into, but not pass through, one of the plurality of openings113in the injection grid assembly112. The injector barrel508is slidably received in the bushing504and bushing plate506but the bushing504and bushing plate506are unable to pass through. Thus, the injector barrel508is able to slide within the bushings such that the needle514can be responsive to the contours of the sediment or obstacles within the sediment by sliding within the bushing504. The injector barrel508is coupled to a needle514having a fluid output516via a check valve510and a male luer lock512that is sized and configured to accept the check valve at a first end and the needle514at a second end.

FIG. 6depicts an embodiment of the control system126of the injection vessel100depicted inFIG. 1. The control system includes an on-board computer/controller610that 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 system126also includes an injection controller618.

In particular, in response to movement commands, the on-board controller provides first and second motor control signals612and614respectively to the first and second electric motors,124aand124b, respectively. In the preferred embodiment, the movement commands control forward and reverse operation of each of the pair of paddle wheels,202aand202b. In this embodiment, the on-board computer/controller610provides 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/controller610can provide fractional power commands to control the speed and direction of each paddle wheel202aand202b.

The on-board computer/controller610also provides an injection initiation signal616to an injection controller618. The injection controller provides the necessary injection commands622to the injection system via line620and provides monitoring data to the on-board computer/controller. The injection controller618provides the injection commands622to the raising/lowering mechanism122to lower the injection grid112, to the metering pump117to 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 mechanism122to raise the injection grid112.

The control system126includes a variety of operational command modes. In one embodiment, an off-vessel operator using a field computer602communicates via a wireless connection607between a wireless modem606coupled to the field computer602and a second wireless modem608coupled to the on-board computer610. The off-vessel operator receives data from the on-board computer610and provides instructions and commands to the on-board computer610. In this embodiment, the off-vessel operator interfaces to the field computer602via a HyperTerminal that allows direct control over the on-board computer610. In the preferred embodiment, the wireless connection607is 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 inFIG. 7, the off-vessel operator has a window display702that can display a menu of operational commands, data from the on-board computer/controller610, data from the injection controller618or 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 strokes704on keyboard604. 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-stick628may be provided as an input to the field computer602to provide movement commands and to initiate the injection process by using the controller trigger button.FIG. 8depicts an embodiment of a window802displaying the injection controller data for the operator.

In another embodiment, a joystick or other controller628is hardwired into the on-board computer/controller610to provide a direct input from the user to the on-board computer/controller610. 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/controller610via 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/controller610can be pre-programmed into a memory624and executed autonomously by the on-board computer/controller610. 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/controller610in 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/controller610can also include an on-board global positioning system (GPS) receiver626to provide location and velocity data. The GPS receiver626can 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 receiver626can 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 computer602is 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 controller618is 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 mechanism122, which as provided above is preferably a winch and cable system. The interface between the on-board computer/controller610and the injection controller618is 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.