Patent Application
20150233884
1. Field of Invention
The field of environmental monitoring has many chemical parameters and environmental contaminants to be measured for the purposes of environmental compliance. The environmental contaminants to be monitored will vary based on the industry or site to be assessed. The cost of developing monitoring systems tar each type of industry or contaminated site is prohibitive, therefore, an automated monitoring system that can be configured using a series of independent chambers with analytical sensors and calibration modules combined into a package that will measure many of the important parameters of a facility would have the ability to attract a significant share of the environmental monitoring market.
This invention relates generally to the art of the automated sampling and analysis of environmental contaminants in water or atmospheres at unattended locations. Unattended locations include municipal water treatment facilities and/or groundwater investigations. The invention describes a monitoring system with multiple independent chambers with the ability of measuring the volume of the sample introduced into each of the chambers. Analytical sensors are exposed to the samples contained in the interior of each of the chambers. The monitoring system is capable of calibrating each of the sensors located in the multiple chambers with independent calibration modules. The system allows for the design of a “plug and play” monitoring system. This flexibility allows a user to design a customized monitoring system for the environmental contaminants of interest at their facility.
2. Background-Prior Art
The following is a tabulation of some prior an that is relevant
3. Discussion of Prior Art
The field of automated monitoring systems is mature with a history of prior art spanning over 30 years and many commercialized versions readily available on the current market. The advent of automated instrumentation was made possible by the availability of affordable microprocessors in the early 1980s. The prior art describing monitoring methods supporting multiple sensors include:
U.S. Pat. No. 7,247,278 describes a monitoring system to transfer groundwater samples from a well to an analytical sensor located at the surface, and methods for calibrating the sensor at the surface. There is no disclosure of multiple analytical chambers, multiple calibration systems or deployment of alternative sensors.
U.S. Pat. No. 5,646,863 describes a monitoring system that has a series of flow-through measuring cells for measuring multiple analytes, however, the invention does not describe interchangeable chambers, interchangeable calibration modules, or the measurement of the sample volumes delivered to the chambers. The sampling system flows the sample through the sample chamber for analysis by the analytical sensors. The description limits the capability of the number of analytical methods that may be performed by the system. The system does not allow for the expansion of the system for additional future sensors.
U.S. Pat. No. 6,021,664 describes a flow-through system that has one sample cell with several sensors (temperature, conductance, dissolved oxygen, pH and ammonia). No reference is made for measuring the volume in the sample cell, or to an interchangeable cell for other contaminants. Most of the disclosure is associated with purging groundwater wells. The sampling system flows the sample through the sample chamber for analysis by the analytical sensors.
U.S. Pat. No. 6,936,156 describes a flow-through system with the capability of recirculating through the sample cells. The system does not describe multiple sample chambers each capable of measuring the volumes delivered to the chamber. Additionally, the invention does not describe a method for incorporating additional sample chambers or cells, or the calibration of the sensors in the additional cells. The sampling system flows the sample through the sample chamber, or re-circulates the sample for analysis through the sample chamber.
Most of the commercial instruments (Hach) describe flow-through cells with the ability to calibrate the system by the injection of standards into the flow-through systems.
The invention described in this disclosure is a monitoring system composed of separate sample chambers with associated analytical sensors capable of determining the concentrations of important environmental contaminants in the environment. The system described has the ability to measure the volume of the sample, standards or reagents injected into the sample chambers. The environmental contaminants include biological, dissolved metals, anions, volatile and semi-volatile organics and radiologicals. Many of the prior art citations and current commercialized instruments use rigid flow-through systems that are not readily suited for many environmental analyses.
The deployment of analytical sensors (pH, ORP, conductivity, colorimetric, radiometric, etc.) at remote locations requires the sensors to be housed in an environmentally controlled space, provide power, control, and communication capabilities to operate the sensors, and transmit the data to remote users. A method of sampling must be provided to expose the sensors to the media being monitored such as natural waters, process water, or atmospheres. An important aspect of any analytical protocol is the ability to interrogate the sensors at frequent intervals using standards. The interrogation may be accomplished by using multiple calibration standards to create a calibration curve, or by using one standard to calculate a calibration factor.
This invention consists of a central sampling/analytical platform with the ability to connect additional analytical boards, various analytical sensors, alternative sample chambers and the accompanying calibration components as “plug and play” modules. This design recognizes that most analytical protocols, regardless of the sensor being employed, share similar tasks such as sample introduction, temperature control, communications, control, and cleaning. Therefore, the design of the sampling/analytical platform unifies all the operational components that are constant regardless of the type of analytical sensor being deployed. These common features include sampling, components, cleaning, communication, environmental controls, and power control. The basic design of the analytical platform does not include any specific sample chamber, analytical sensor, or method of sensor interrogation (introduction of standards). All three of these sensor-specific features are plug-in modules to the basic sampling/analytical platform. This relative freedom of the sampling/analytical platform from any specific analytical sensor allows the system to quickly be configured for many types of analytical sensors. This type of analytical platform design is independent of any specific type of sensor allowing the analytical platform to accommodate new sensor technologies as they become available.
In this disclosure, the analytical sensor and its accompanying analytical components (sample chamber and interrogation module) are all plug-in modules that are connected to the sampling/analytical platform when the specific analytical sensor is required. This concept is illustrated on
An example would be a pH electrode, accompanying sample chamber, and interrogation module. The electrical leads of the pH electrode are fabricated into a plug, or other type of connector, that connects to the electronics of the sampling/analytical platform, and the pH electrode is inserted into a sample chamber compatible with the analytical sensor and the platform. The interrogation module has its electronic components fabricated into a second plug, or other type of connector, that connects to the electronics of the sampling/analytical platform. The tubing for the delivery of the standard(s) is inserted into the same sample chamber housing the pH electrode. The operation of the sampling, calibration, and analysis using the pH probe is controlled by the microprocessor incorporated in the main board.
Once the three components (analytical sensor, sample chamber and interrogation module) are connected, the operation of the sampling/analytical platform allows for a complete analysis of water samples using the pH sensor including sampling, interrogation, quality control checks and cleaning.
It is possible that several sensors may use the same sample chamber. An example would be a single sample chamber accommodating a pH, ORP and conductivity sensors.
Sample chambers are designed to allow for the volumetric measurement of the different solutions introduced into the sample chamber for the purpose of diluting standards and/or reagents to aid in the analysis of the target analyte. The volume may be measured within a sample chamber using optical sensors, conductivity sensors or other methods to determine the volume of water in the sample chamber. The sample chambers may be fitted with stirring motors, or other methods for agitating the solution. Additionally the sample chamber may be fitted with methods of heating the chamber to establish a constant temperature during the analysis.
The addition of alternative analytical sensor modules with accompanying interrogation modules allows monitoring of additional parameters such as conductivity, ORP, etc. The design of this sampling/analytical platform is a flexible design that allows analytical sensors to be added (or incorporated) as they are developed without the costly requirement to redesign the platform to house the new analytical sensors.
The sample chamber is an important component of the sampling/analytical platform. This is not a flow-through chamber, but a chamber where the volumes of reagents (and/or standards) and temperature may be controlled by the program of the sampling/analytical platform. The design and volume of the sample chamber may be optimized to house a particular analytical sensor, or multiple sensors. The ability to control the volumes of solutions introduced into the sample chamber allows for the creation of headspace above the solutions. The creation of a headspace allows analytical sensors to be exposed to atmospheres above the solution for the detection of volatile organic and inorganic compounds, therefore, the analytical platform may accommodate multiple sensors, multiple interrogation components, and multiple sample chambers, depending upon the analytical sensor deployed.
In addition to the “plug and play” analytical sensors and calibration component, the analytical platform is designed to accept a wide variety of sampling methods including, liquid sampling, pumps (peristaltic, diaphragm and centrifugal) and air sampling pumps (
A unique feature of this system is its ability to inject chemicals into the environment. This feature allows the system to inject tracers into the groundwater to measure aquifer parameters, or to measure reagents for site remediation (
The “plug and play” sampling/analytical system may be housed in a variety of structures (trailers, sheds) for environmental protection. The sampling analytical system has the ability to operate with a variety of power sources including line power (120 volts), solar cells, and wind turbine.
The communication between the remote user and the monitoring, system may be accomplished with radio telemetry, cellular or satellite communications (
The invention disclosed does not use flow-through cells, but interchangeable sample chambers where volumes of reagents, standards, and samples may be precisely introduced into the sample chambers to perform the required analysis. Water level sensors are employed in each sample chamber to deliver a precise volume of sample, reagent or standard. The analyses or calibrations are performed in isolation after all the solutions are injected into the sample chamber. The sample chamber may be stirred, and temperature adjusted by heating or cooling, after being introduced in the sample chamber.
This separation of the sensors, sample chambers, and calibration modules from the sampling/analytical platform is not described in the prior art or literature. The prior art and literature describe elaborate systems containing all the sample chambers, sensors, sampling components, and methods of calibration formed into a single unit. The prior art systems do not describe the ability to quickly exchange a sensor with the accompanying sample chamber and calibration modules within the framework of the sampling/analytical platform. If an alternative sensor is to be deployed with the systems described in the prior art, and the alternative sensor technology is incompatible with the fabricated sample chamber, there does not appear to be an adequate method of quickly adapting the platform to the requirements of the new sensor.
The disclosed monitoring system has the flexibility to assemble multiple chambers, analytical sensors, calibration modules, and sampling methods to match the requirements of a monitoring program. The system does not have any preferred, embodiment except for the method of interconnecting the various boards into a sampling and analytical system. The rigid design documented in the prior art is quite separate from the flexible design presented in this disclosure.
The sampling methods supported by the board 14 include peristaltic pumps and submersible pumps that are directly inserted into monitoring wells 36, 37, 38. The board 14 is connected to multiple pumps 17, 18, 19 located within the multiple monitoring wells 36, 37, 38 by multiple cables 20, 21, 22. The pumps 17, 18, 19 located within the multiple monitoring wells 36, 37, 38 may include electrical turbine and gas-operated diaphragm pumps. The multiple cables 20, 21, 22 are used to conduct electrical signals, electrical power or compressed air depending on the sampling method. Multiple water tubes 23, 24, 25 transport water samples from each of the multiple pumps 17, 18, 19 to the inlets of the multiple selection valves 26, 27, 28 located on the board 14. The outlets of the multiple selection valves 26, 27, 28 are connected into a single sample delivery tube 29. The terminal end of the tube 29 is connected to the inlets of chamber selection valves 125, 126 located on auxiliary board 124. The valves 125, 126 are three-way valves. The common port of the valve 125 is connected to sample chamber 47 with chamber tube 127. The common port of the valve 126 is connected to sample chamber 48 with chamber tube 128. The terminal ends of the tubes 127, 128 are extended to the bottom of the sample chambers 47, 48. The normally-open ports of valves 125, 126 are connected to the waste tube 129.
The multiple sample chambers 47, 48 have multiple volume probes 49, 50, 150 for determining the volume of the sample introduced into the multiple sample chambers 47, 48.
Multiple water level sensors 30, 31, 32 are located in the multiple wells 36, 37, 38. The multiple sensors 30, 31, 32 are connected by multiple electrical cables 33, 34, 35 to the board 14. The multiple sensors 30, 31, 32 are used to measure the water levels in the monitoring wells 36, 37, 38.
An optional power control board 39 is connected with a power control cable 40 to the board 10. The board 39 incorporates a microprocessor 41. The primary function of the power control board is to provide power to the monitoring system when line power (110-volts) is not available. The board 39 is capable of measuring and regulating power from solar panels 42, and/or wind turbine 44 to a battery 120. The board 39 is connected to the solar panels 42 with an electrical cable 43. The board 39 is connected to the wind turbine 44 with an electrical cable 45. The battery 120 is connected to the board 39 with a battery cable 121.
An optional weather station 46 is connected to the board 10 to determine the climatic conditions for the purposes of when to collect water samples.
Referring to
The multiple analytical sensors 59, 60, 61 are connected to the multiple chambers 47, 48 using, multiple sensor ports 57, 58.
The calibration of the analytical sensors 59, 60, 61 located within the multiple chambers 47, 48 is performed using multiple calibration boards 71, 80, 89. It is typical that one calibration board is dedicated for each analytical sensor incorporated in the monitoring system. Multiple standard selection valves 72, 73 are connected to the calibration board 71. Multiple standard bottles 74, 75 contain low and high standards in
The boards 71, 80, 89 are connected to the board 10 using electrical cables with connectors 79, 88, 96.
The number of the boards 71, 80, 89 used in any monitoring system is dependent on the number of the sensors 59, 60, 61 employed in the system.
Referring to the
The use of multiple main control boards is presented on the
Referring to
The design allows for the control and operation of the chemical monitoring system to be coordinated with the sampling system to allow for tracer tests. A tracer injection pump 101 is connected to a tracer bottle 103 with a tracer inlet tube 102. The outlet of the pump 101 is connected to a tracer outlet tube 104. The tube 104 injects the tracer through its terminal end 105 into the interior of the monitoring well 34. The pump 17 is located in the adjacent monitoring well 36. The tube 23 connects the pump 17 with the valve 26. The tube 29 connects the outlet of the valve 26 with the interior of the chamber 47. The board 14 connects with the board 10 with cable 15. The pump 101 is electrically connected to the board 14 with a cable 100.
Referring to
The monitoring system is reconfigured for performing aquifer tests. The control board 10 connects to the pump control board 14 with the cable 15. The board 14 connects to the multiple pumps 17, 18, 19 with the multiple cables 20, 21, 22. The pumps 17, 18, 19 are located within the interiors of the multiple wells 36, 37, 38. The multiple pumps 17, 18, 19 connect to the multiple tubes 23, 24, 25 to a flow meter 107. The flow meter connects to the board 14 with an electrical cable 108. The multiple sensors 30, 31, 32 connects with the multiple cables 33, 34, 35 to the board 14.
Referring to the drawing
The monitoring system collects a sample by the main control board 10 sending a command to the pump control board 14 to select a monitoring well. The pump control board 14 activates the selected pump. The microprocessor 16 controls the pump control board pump 14 and is capable of operating several types of pumps including peristaltic, turbine and diaphragm pumps. If the sampling program selects pump 17 in well 36 then the program of the microprocessor 16 on the board 14 sends the appropriate electrical power, signals or air pressure to operate the selected pump. The activated pump 17 conducts a water sample through an activated valve 26 through the water tube 29. The tube 29 connects to the multiple chamber selection valves 125, 126 located on the auxiliary board 124. The program on board 10 activates the appropriate valve 125, 126 and the water sample transferred into the sample chamber 47, 48. The sample flows into the selected sample chamber 47, 48 until the corresponding water level sensor 49, 50 located within the chambers is satisfied. The program terminates the operation of the pump 17, the valve 26, and valves 125, 126. This action terminates the basic sampling program.
The pump control board 14 collects water level data from the multiple water levels sensors 30, 31, 32 located in each of the monitoring wells 36, 37, 38 during the sampling episode.
The multiple water level sensors 30, 31, 32 are used to measure the water levels in the monitoring wells 36, 37, 38 to determine groundwater flow direction and changes of water level over time. The combination of multiple water level sensors 30, 31, 32 measuring water levels in monitoring wells 36, 37, 38 with the ability to evacuate the wells with the pumps 17, 18, 19 allows for automatically performing low-flow purging of the wells, slug tests and aquifer tests. Automatic low-flow purging is performed by automatically sampling a well without a significant change in the static water level in a monitoring well. The monitoring system automatically collects water level data during the sampling episode. If the sampling rate of the pump causes a decrease in the elevation of the monitoring well, the program decreases the pumping rate until the sampling rate does not disturb the static water level.
An optional power control board 39 and the program contained in the microprocessor 41 monitors the currents and voltages of the solar cells 42, wind turbine 44 and battery 120. The board 39 is used to determine which power source can be used to charge the battery and disconnect the battery to prevent damage from overcharging the battery 120.
An optional weather station 46 is connected to the main control board 10 to determine the climatic conditions for the purposes of when to collect water samples.
Referring to drawing
The standardization of the analytical sensors located, in the sample chambers can be performed using several types of techniques including:
Calibration curve uses the calibration boards 71, 80, 89 to introduce multiple standards in the sample chambers. An example would be the calibration of an analytical sensor located in sample chamber 47 with calibration board 71. The first standard calibration solution is added by the activation of the selection valve 72 to conduct the first standard through the tube 78 into the sample chamber 47. The standard is added until the water sensor 49 is satisfied. The standard is analyzed and then evacuated from the chamber 47. The second calibration solution is added by the activation of the selection valve 73 to conduct the second standard through the tube 78 into the sample chamber 47. The standard is added until the water sensor 49 is satisfied. The standard is analyzed and then evacuated from the chamber 47.
Standardization of the sensor may be performed by the analysis and calculation of a calibration factor. The calibration factor may be calculated from the analysis of sample and spiked sample. The program introduces a sample into the sample chamber and analyzes the sample then evacuates the sample then introduces a sample and adds a known volume and concentration of a standard to the sample. This requires that the volume of the sample and the standard are known to great precision. An example of this type of standardization would be the introduction of a sample from well 36 to sample chamber 47 (
It is typical for radiometric analysis detecting trace activities of radioactive isotopes to require several hours to complete the analysis, therefore, it is important if a sample and a spiked sample are to be analyzed, that both samples are collected at the sample time. A second sample chamber is therefore, required to store the sample for later analysis.
The operation of the system illustrated on
The monitoring system on
The board 14 is designed to operate a variety of pumps for the collection of samples from the wells and the injection of tracers and chemicals into the well. The pump 101 is used to inject tracers from the bottle 103 into the monitoring well 34. The tracers flow front the injection well to the adjacent wells. The pump 17 collects water samples in the well 36. A water sample passes through the activated valve 26 through tube 29 and into the sample chamber 47. The sample is analyzed and the concentration of the tracer determined.
A slug test is performed b instantaneous removal of a column of water from a monitoring well, and measuring the recharge of the well from the surrounding aquifer. An aquifer test is performed by the removal of water from a central well and the measurement of the response in water levels of the adjacent wells. The monitoring system is configured for an aquifer test in
Reference is made to our Provisional Application No. 61/766745 filed Feb. 20, 2013 entitled “Sampling and Analytical Platform for Remote Deployment of Sensors” by the present inventors.
