DETECTION OF HYDROCARBONS IN AQUEOUS ENVIRONMENTS

• US 20140011285A1
• Filed: 07/03/2013
• Published: 01/09/2014
• Est. Priority Date: 07/03/2012
• Status: Active Grant

• Current Assignee: Marquette University
• Original Assignee: Chevron USA Incorporated (Chevron Corp.)
• Inventors: Ricco, Antonio J., Josse, Fabien J., Bender, Florian, Mohler, Rachel, Kelmser, Urmas, Synowiec, Karen, Lorenz, Robert Michael
• Granted Patent: US 9,244,051 B2
• Time in Patent Office: Days
• US Class Current: 436/139
• CPC Class Codes: G01N 1/405 by adsorption or absorption
• CPC Class Codes: G01N 2291/0255 (Bio)chemical reactions, e.g. on biosensors
• CPC Class Codes: G01N 2291/0256 Adsorption, desorption, surface mass change, e.g. on biosensors
• CPC Class Codes: G01N 2291/02809 Concentration of a compound, e.g. measured by a surface mass change
• CPC Class Codes: G01N 2291/0422 Shear waves, transverse waves, horizontally polarised waves
• CPC Class Codes: G01N 2291/0423 Surface waves, e.g. Rayleigh waves, Love waves
• CPC Class Codes: G01N 2291/106 one or more transducer arrays
• CPC Class Codes: G01N 29/022 Fluid sensors based on microsensors, e.g. quartz crystal-microbalance [QCM], surface acoustic wave [SAW] devices, tuning forks, cantilevers, flexural plate wave [FPW] devices microdevices per se B81B
• CPC Class Codes: G01N 33/1826 organic contamination in water
• CPC Class Codes: Y10T 436/21 Hydrocarbon
• CPC Class Codes: Y10T 436/255 including use of a solid sorbent, semipermeable membrane, or liquid extraction

Abstract

A process for a pre-concentration unit including: a sorbent material coated passage-way having an entrance for receiving a hydrocarbon-containing groundwater sample and for pre-concentrating the hydrocarbons in a hydrocarbon-containing groundwater sample by successive sorption/desorption cycles, and having an exit for discharging the pre-concentrated hydrocarbons; a heating unit for heating the sorbent material coated passage-way; and; an array of shear horizontal-surface acoustic wave sensors with coatings adapted for detecting and quantifying the pre-concentrated hydrocarbons, disposed at the exit of the sorbent material coated passage-way; and a housing for enclosing the pre-concentration unit and the array of shear horizontal-surface acoustic wave sensors, adapted for continuous use at a body of hydrocarbon-containing groundwater, and coupled to mathematical methods for generating concentrations of specific analytes from both transient and steady-state signals.

Claims

1. A system for in situ monitoring of groundwater, comprising:

a. a pre-concentration unit comprising;

a sorbent material coated passage-way having an entrance for receiving a sample of the groundwater containing a hydrocarbon and for pre-concentrating the hydrocarbon contained in the sample by successive sorption/desorption cycles, and having an exit for discharging the pre-concentrated hydrocarbon; and

a heating unit for heating the sorbent material coated passage-way;

b. an array of shear horizontal-surface acoustic wave sensors with coatings adapted for detecting and quantifying the pre-concentrated hydrocarbon, disposed at the exit of the sorbent material coated passage-way of the pre-concentration unit; and

c. a housing for enclosing the pre-concentration unit and the array of shear horizontal-surface acoustic wave sensors.

2. The system according to claim 1, wherein the housing is adapted for continuous use at a body of hydrocarbon-containing groundwater.

3. The system according to claim 1, wherein the output of the device indicates the species and concentrations of one or more hydrocarbons in the groundwater sample.

4. The system according to claim 1, further comprising a computer processor in communication with the acoustic wave sensors, the processor configured to receive signals for the acoustic wave sensors and to execute a computer executable code responsive to the signals, the computer executable code comprising code for calculating an equilibrium concentration corresponding to a specific analyte.

5. The system according to claim 1, further comprising a controller in communication with the heating unit for controlling the heating of the sorbent material coated passage-way.

6. The system according to claim 1, wherein the pre-concentration unit is a cylindrical pre-concentration unit.

7. The system according to claim 1, wherein the pre-concentration unit is a planar pre-concentration unit.

8. The system according to claim 1, wherein the planar pre-concentration unit comprises a serpentine passage-way.

9. The system according to claim 1, wherein the planar pre-concentration unit comprises a bifurcated passage-way.

10. A method for in situ monitoring of groundwater, comprising passing sample of the groundwater containing a hydrocarbon to a device comprising a pre-concentration unit comprising a sorbent material coated passage-way having an entrance for receiving the and for pre-concentrating the hydrocarbon by successive sorption/desorption cycles, and having an exit for discharging the pre-concentrated hydrocarbon;

and a heating unit for heating the sorbent material coated passage-way; and

an array of shear horizontal-surface acoustic wave sensors with coatings adapted for detecting and quantifying the pre-concentrated hydrocarbon, disposed at the exit of the sorbent material coated passage-way; and

a housing for enclosing the pre-concentration unit and the array of shear horizontal-surface acoustic wave sensors; and

wherein the output of the device indicates the species and concentration of hydrocarbons in the hydrocarbon-containing groundwater sample.

11. A method for quantification of hydrocarbons using estimation theory that allows the equilibrium concentrations to be calculated for specific analytes from the initial stages of the transient response.

12. A pre-concentration device, comprising:

a. an inlet for accepting an aqueous sample containing a hydrocarbon compound to be detected;

b. a plurality of conduits, each comprising a respective sorbent material and heater element, arranged serially so as to pre-concentrate the hydrocarbon contained in the sample by successive sorption/desorption cycles.

13. The device according to claim 12, comprising an outlet for discharging the pre-concentrated hydrocarbon.

14. The device according to claim 12, wherein at least one of the conduits is cylindrical.

15. The device according to claim 12, wherein at least one of the conduits is planar.

16. The device according to claim 12, wherein the planar pre-concentration unit includes a serpentine conduit.

17. The device according to claim 12, wherein the planar pre-concentration unit includes a bifurcated conduit.