Detection of hydrocarbons in aqueous environments

• US 9,244,051 B2
• Filed: 07/03/2013
• Issued: 01/26/2016
• Est. Priority Date: 07/03/2012
• Status: Active Grant

• Current Assignee: Marquette University
• Original Assignee: Chevron USA Incorporated (Chevron Corp.)
• Inventors: Josse, Fabien J., Bender, Florian, Ricco, Antonio J., Mohler, Rachel, Kelmser, Urmas, Synowiec, Karen, Lorenz, Robert Michael
• Primary Examiner(s): Wallenhorst, Maureen
• Application Number:
  US13/934,347
• Publication Number:
  US 20140011285A1
• Time in Patent Office: 937 Days
• Field of Search: 436/25, 436/28, 436/60, 436139-142, 436/147, 436/157, 436/174, 436/177, 436/178, 436/180, 422/68.1, 422/69, 422/82.12, 422/527, 210/679
• US Class Current: 1/1
• 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 configured for receiving a sample of groundwater containing a hydrocarbon and for pre-concentrating the hydrocarbon contained in the sample by successive sorption/desorption cycles, and having an exit configured for discharging a pre-concentrated hydrocarbon-containing aqueous sample; and

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

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

c. a housing 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 configured for continuous use in at a body of hydrocarbon-containing groundwater.

3. The system according to claim 1, wherein output of the system 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 7, wherein the planar pre-concentration unit comprises a serpentine passage-way.

9. The system according to claim 7, wherein the planar pre-concentration unit comprises a bifurcated passage-way.

10. The system of claim 1, wherein the sorbent material coated passage-way comprises a continuous coating of the sorbent material from the entrance to the exit.

11. The system of claim 1, wherein the pre-concentration unit comprises a second sorbent material coated passage-way having an entrance for receiving the pre-concentrated hydrocarbon-containing aqueous sample and for further pre-concentrating the hydrocarbon contained in the sample by successive sorption/desorption cycles;

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

12. A method for in situ monitoring of groundwater, comprising

passing groundwater containing a hydrocarbon to a device comprising a pre-concentration unit comprising a sorbent material coated passage-way and a heating unit for heating the sorbent material coated passage-way, pre-concentrating the hydrocarbon in the groundwater by successive sorption/desorption cycles in the sorbent material coated passage-way,

discharging a pre-concentrated hydrocarbon-containing aqueous sample from the pre-concentration unit by heating the sorbent material coated passage-way;

and

detecting the pre-concentrated hydrocarbon-containing aqueous sample in an array of shear horizontal-surface acoustic wave sensors with coatings for detecting the aqueous pre-concentrated hydrocarbon sample

wherein an output of the device indicates the species of hydrocarbons in the hydrocarbon-containing groundwater.

13. The method of claim 12, wherein the heating of the sorbent material coated passage-way warms the hydrocarbon-containing groundwater in the passageway without boiling or causing a gas phase to develop.

14. The method of claim 13, wherein the successive sorption/desorption cycles comprise exposing the hydrocarbon-containing groundwater to the sorbent material coated passage-way and in multi-steps heating successive zones of the coated passage-way to promote the release of sorbed analytes.

15. The method of claim 13, wherein the successive sorption/desorption cycles comprise exposing the hydrocarbon-containing groundwater to the sorbent material coated passage-way and passing a heated zone through the pre-concentration unit with the same velocity as the hydrocarbon-containing groundwater to promote the release of sorbed analytes.