Methods and controller for determining hydrogen sulfide treatment dosage

Patent metadata

Field	Value
Publication number	US-2025115493-A1
Application number	US-202318377587-A
Country	US
Kind code	A1
Filing date	Oct 6, 2023
Priority date	Oct 6, 2023
Publication date	Apr 10, 2025
Grant date	—

Abstract

A method for controlling a hydrogen sulfide concentration of a wastewater stream, the method including measuring a hydrogen sulfide concentration in one phase of the wastewater stream. At least one additional parameter of the wastewater stream is measured, and a hydrogen sulfide concentration of the other phase of the wastewater stream is calculated with a mathematical model that characterizes the hydrogen sulfide concentration in the other phase based on a set of variables that includes the measured hydrogen sulfide concentration in the one phase and the measured at least one additional parameter. Based on the calculated hydrogen sulfide concentration of the other phase, a treatment dosage of a treatment agent that reduces the hydrogen sulfide concentration of the wastewater stream is determined and applied to the wastewater stream.

First claim

What is claimed is:

1 . A method for controlling a hydrogen sulfide concentration of a wastewater stream, the method comprising:
measuring, with a sensor, a hydrogen sulfide concentration in one phase of the wastewater stream, including either (i) a liquid phase concentration of hydrogen sulfide of the wastewater stream; or (ii) a gas phase concentration of hydrogen sulfide of the wastewater stream; measuring, with a sensor, at least one additional parameter of the wastewater stream; calculating a hydrogen sulfide concentration of the other phase of the wastewater stream with a mathematical model that characterizes the hydrogen sulfide concentration in the other phase based on a set of variables that includes (i) the measured hydrogen sulfide concentration in the one phase; and (ii) the measured at least one additional parameter; based on the calculated hydrogen sulfide concentration of the other phase, determining a treatment dosage of a treatment agent that reduces the hydrogen sulfide concentration of the wastewater stream; and applying the determined treatment dosage of the treatment agent to the wastewater stream.

2 . The method of claim 1 , wherein the mathematical model includes a deterministic model that is based on (i) a theoretical relationship between the measured at least one additional parameter and the hydrogen sulfide concentration of the other phase; and (ii) a theoretical relationship between the hydrogen sulfide concentration in the one phase and the hydrogen sulfide concentration of the other phase.

3 . The method of claim 1 , wherein the mathematical model includes an empirical model that is based on correlations of (i) empirical data of the measured at least one additional parameter and the hydrogen sulfide concentration of the other phase; and (ii) empirical data of the hydrogen sulfide concentration in the one phase and the hydrogen sulfide concentration of the other phase.

4 . The method of claim 2 , wherein the deterministic model is also based on correlations of empirical data of the measured at least one additional parameter and the hydrogen sulfide concentration of the other phase.

5 . The method of claim 2 , wherein the deterministic model is also based on correlations of empirical data of the hydrogen sulfide concentration in the one phase and the hydrogen sulfide concentration of the other phase.

6 . The method of claim 1 , wherein the step of determining the treatment dosage includes comparing the calculated hydrogen sulfide concentration of the other phase to a predetermined threshold value of hydrogen sulfide concentration.

7 . The method of claim 1 , wherein the measured at least one additional parameter of the wastewater stream includes from 2 to 8 measured parameters of the wastewater stream.

8 . The method of claim 1 , wherein the measured at least one additional parameter of the wastewater stream includes from 3 to 5 measured parameters of the wastewater stream.

9 . The method of claim 7 , wherein the measured at least one additional parameter of the wastewater stream includes at least two of: (i) a temperature of the wastewater; (ii) a pH of the wastewater; (iii) biochemical oxygen demand of the wastewater; (iii) a concentration of a hydrogen sulfide treatment agent in the wastewater; (iv) an oxygen concentration in the wastewater; and (v) a sulfate concentration in the wastewater.

10 . The method of claim 9 , wherein the measured at least one additional parameter of the wastewater stream further includes at least one of: (vi) a flow rate of the wastewater; (vii) a turbidity of the wastewater; (viii) a total organic carbon content of the wastewater; (ix) an ultraviolet adsorption of the wastewater; (x) a total suspended solids content of the wastewater; (xi) a zeta potential of the wastewater; (xii) a conductivity of the wastewater; (xiii) a hardness of the wastewater; and (xiv) an oxidation-reduction potential of the wastewater.

11 . The method of claim 1 , wherein the set of variables further includes at least one known parameter of the wastewater stream.

12 . The method of claim 11 , wherein the at least one known parameter of the wastewater stream includes at least one of (i) a slope of the wastewater stream; (ii) a mean velocity of the wastewater stream; and (iii) a hydraulic depth of the wastewater stream.

13 . A method for controlling a hydrogen sulfide concentration of a wastewater stream, the method comprising:
measuring, with a sensor, a hydrogen sulfide concentration in one phase of the wastewater stream, including either (i) a liquid phase concentration of hydrogen sulfide of the wastewater stream; or (ii) a gas phase concentration of hydrogen sulfide of the wastewater stream; measuring, with a sensor, at least one additional parameter of the wastewater stream; calculating a hydrogen sulfide concentration of the other phase of the wastewater stream with a mathematical model that characterizes the hydrogen sulfide concentration in the other phase based on a set of variables that includes (i) the measured hydrogen sulfide concentration in the one phase; and (ii) the measured at least one additional parameter; and based on the calculated hydrogen sulfide concentration, taking at least one corrective action on a hydrogen sulfide gas scrubber that is configured to remove hydrogen sulfide from the wastewater stream.

14 . The method of claim 13 , wherein the at least one corrective action includes changing a downtime schedule or a maintenance schedule of the hydrogen sulfide gas scrubber.

15 . A controller for controlling a hydrogen sulfide concentration of a wastewater stream, the controller including at least one processor that is configured to:
(i) receive signals indicative of a measured hydrogen sulfide concentration in one phase of the wastewater stream, including either (i) a liquid phase concentration of hydrogen sulfide of the wastewater stream; or (ii) a gas phase concentration of hydrogen sulfide of the wastewater stream; (ii) receive signals indicative of at least one additional measured parameter of the wastewater stream; and (iii) calculate a hydrogen sulfide concentration of the other phase of the wastewater stream with a mathematical model that characterizes the hydrogen sulfide concentration in the other phase based on a set of variables that includes (i) the measured hydrogen sulfide concentration in the one phase and (ii) the measured at least one additional parameter.

16 . The controller of claim 15 , wherein the at least one processor is further configured to:
(iv) based on the calculated hydrogen sulfide concentration of the other phase, determine a treatment dosage of a treatment agent that reduces the hydrogen sulfide concentration of the wastewater stream; and (v) output at least one signal that is indicative of the treatment dosage.

17 . The controller of claim 16 , wherein the output signal is configured to control a supply pump that administers the determined treatment dosage.

18 . The controller of claim 15 , wherein the controller is further configured to:
(iv) determine, based on the calculated hydrogen sulfide concentration, a downtime schedule or a maintenance schedule of a hydrogen sulfide gas scrubber that is configured to remove hydrogen sulfide from the wastewater stream.

Assignees

• Hach Co

Inventors

• Rajasekharan Vishnu
• Gray Matthew
• Young Russell

Classifications

• C02F2303/02

  Odour removal or prevention of malodour · CPC title

• C02F2209/005

  Processes using a programmable logic controller [PLC] · CPC title

• C02F2209/001

  Upstream control, i.e. monitoring for predictive control · CPC title

• C02F2209/40

  Liquid flow rate · CPC title

• C02F2209/06

  pH · CPC title