Regulating water treatment agent dosage based on operational system stresses

• US 5,411,889 A
• Filed: 02/14/1994
• Issued: 05/02/1995
• Est. Priority Date: 02/14/1994
• Status: Expired due to Term

• Current Assignee: Ecolab USA Incorporated (Ecolab, Inc.)
• Original Assignee: Nalco Chemical Company (Ecolab, Inc.)
• Inventors: Godfrey, Martin R., Hoots, John E.
• Primary Examiner(s): Snay, Jeffrey R.
• Application Number:
  US08/194,679
• Time in Patent Office: 442 Days
• Field of Search: 436/52, 436/56, 436/6, 436/84, 436/166, 436/164, 436/172, 436/800, 436/79, 436/80, 436/163, 422/62
• US Class Current: 436/6
• CPC Class Codes: C02F 1/008 Control or steering systems not provided for elsewhere in subclass C02F
• CPC Class Codes: G01N 21/643 non-biological material
• CPC Class Codes: G01N 33/18 Water
• CPC Class Codes: Y10T 436/117497 with a continuously flowing sample or carrier stream

Abstract

A target-specie responsive regulation of water treatment agent feed is achieved by the monitoring of a subject target-specie indicator. A target specie in a sample taken from the system is selected as the subject target-specie indicator, or instead an incipient reagent is added to the system sample to form a subject target-specie indicator. Such a formed subject target-specie indicator comprises a combination of the incipient reagent and a target specie. The subject target-specie indicator might then monitored by fluorescence analysis of the sample to determine at least one fluorescence emission value that can be correlated to the in-system concentration of the target specie. In combination with an inert tracer, the system consumption for the target specie can be determined. A responsive adjustment of the in-system concentration of a water treatment agent can be made.

Claims

1. A method of regulating the in-system concentration of a water treatment agent in an industrial fluid system comprising:

adding an inert tracer to an industrial fluid system, the inert tracer being added in known proportion to a target specie also being added to said industrial fluid system, wherein the system consumption of the target specie is effected by the water treatment agent;

drawing a sample of fluid from said industrial fluid system;

monitoring the target-specie by analysis of said sample to determine at least one characteristic that can be correlated to an in-system concentration of said target-specie;

monitoring said inert tracer by analysis of said sample to determine the in-system concentration of said inert tracer;

determining the system consumption of the target specie from the measured in-system concentration of the target specie and the inert tracer; and

regulating the in-system concentration of the water treatment agent in the fluid system based on the system consumption of the target specie.

2. A method of regulating the in-system concentration of a water treatment agent in an industrial fluid system comprising:

adding an inert tracer to an industrial fluid system, the inert tracer being added in known proportion to a target specie also being added to said industrial fluid system, wherein the system consumption of the target specie is effected by the water treatment agent;

drawing a sample of fluid from said industrial fluid system;

adding to the sample an incipient reagent in an amount effective to convert the target specie to a subject target specie indicator;

monitoring the subject target-specie indicator by analysis of said sample to determine at least one characteristic that can be correlated to an in-system concentration of said target-specie;

monitoring said inert tracer by analysis of said sample to determine the in-system concentration of said inert tracer;

determining the system consumption of the target specie from the measured in-system concentration of the target specie and the inert tracer; and

regulating the in-system concentration of the water treatment agent in the fluid system based on the system consumption of the target specie.

3. The method of claim 2 wherein said monitoring of said subject target-specie indicator is performed by fluorescence analysis of said sample to determine at least one fluorescence emission value that can be correlated to said in-system concentration of said target specie indicator.

4. The method of claim 2 wherein said subject target-specie indicator comprises a combination of said incipient reagent and a substantially nonfluorescent target specie, and wherein said correlation of said fluorescence emission value to said in-system concentration of said subject target-specie indicator is established by at least one difference between at least one fluorescence characteristic of said incipient reagent and one fluorescence characteristic of said subject target-specie indicator.

5. The method of claim 2 wherein said monitoring of said subject target-specie indicator is conducted at the site of said industrial system on a substantially continuous basis.

6. The method of claim 2 wherein at least one adjustment of said in-system concentration of said water treatment agent is made based on said system consumption for said target specie.

7. The method of claim 2 wherein said incipient reagent is substantially nonfluorescent and said subject target-specie indicator is fluorescent.

8. The method of claim 2 wherein said incipient reagent is fluorescent and said subject target-specie indicator is substantially nonfluorescent.

9. The method of claim 2 wherein both said incipient reagent and subject target-specie indicator are fluorescent, and wherein said fluorescence analysis is performed using a fluorescence analysis technique that at least minimizes interference between fluorescence emission of any residual incipient reagent and fluorescence emissions of said subject target-specie indicator.

10. The method of claim 2 further including feeding said water treatment agent to said fluid system together with a second inert tracer and monitoring the in-system concentration of said second inert tracer.

11. The method of claim 2 further including feeding said water treatment agent to said fluid system and monitoring the zero-consumption concentration of said water treatment agent and said target specie by fluorescence analysis by:

(1) feeding said water treatment agent through a feed line to said fluid system as a component of a treatment product which contains a second inert tracer in known proportion to said water treatment agent; and

(2) determining the concentration of said inert tracer and said second inert tracer within said fluid system.

12. The method of claim 2 wherein said target specie is sulfide, calcium, iron, carbonate, copper (bi)carbonate, alkalinity, copper, sulfate, fluoride, magnesium, and phosphate.

13. The method of claim 2 wherein said target specie is sulfide, calcium, iron, carbonate, copper and phosphate.

14. A method of target-specie responsive regulation of water treatment agent in-system concentration in an industrial fluid system comprising:

drawing a sample of fluid from an industrial fluid system containing at least one target specie, wherein said system consumption of the target specie is affected by at least one water treatment agent;

adding to said sample an incipient reagent in an amount effective to convert said target specie to a target-specie indicator which comprises a combination of said incipient reagent and said target specie;

monitoring said target-specie indicator by fluorescence analysis of said sample to determine at least one fluorescence characteristic of said target-specie indicator that can be correlated to the in-system concentration of said target-specie indicator;

correlating said in-system concentration of said target-specie indicator to an in-system concentration of said target specie;

adding an inert tracer to said industrial fluid system in known proportion to the feed of said target specie to said industrial fluid system;

monitoring said inert tracer by analysis of said sample to determine the in-system concentration of said inert tracer;

correlating said in-system concentration of said inert tracer to a zero-consumption concentration of said target specie;

determining the system consumption value for said target specie by subtracting said in-system concentration of said target specie from said zero-consumption concentration of said target specie; and

regulating the in-system concentration of a water treatment agent in said fluid system based on said system consumption of the target specie.

15. The method of claim 14 wherein said target-specie is calcium.

16. The method of claim 14 wherein said target-specie indicator is a complex formed between calcium and 1,2-bis(o-aminophenoxy) ethane-N,N,N'"'"',N'"'"'-tetraacetic acid.