Selenium removal using aluminum salt at conditioning and reaction stages to activate zero-valent iron (zvi) in pironox process

Patent metadata

Field	Value
Publication number	US-2017129792-A1
Application number	US-201615355927-A
Country	US
Kind code	A1
Filing date	Nov 18, 2016
Priority date	Sep 18, 2009
Publication date	May 11, 2017
Grant date	—

Abstract

A system containing a reactor vessel including zero valent iron media, a source of a conditioning additive, a source of a reaction additive, and a process control subsystem is disclosed. A method for reducing a concentration of one or more contaminants in contaminated water including contacting zero valent iron media with a conditioning additive, contacting contaminated water with conditioned zero valent iron media, and introducing a reaction additive is also disclosed. The conditioning additive and reaction additive may each contain an aluminum salt.

First claim

1 . A system comprising:
a reactor vessel comprising at least one inlet, an outlet, and a side wall; zero valent iron media at least partially coated with one or more iron oxide compounds disposed within the reactor vessel; the reactor vessel being configured to receive a conditioning additive comprising a soluble aluminum salt through the at least one inlet, and contact the zero valent iron media with the conditioning additive to produce a conditioned zero valent iron media, the reactor vessel being configured to receive a contaminated water and a reaction additive comprising a soluble aluminum salt through the at least one inlet and contact the conditioned zero valent iron media with the contaminated water and the reaction additive; and a process control subsystem comprising a control module configured to maintain a predetermined concentration of aluminum ions in a solution within the reactor vessel.

2 . The system of claim 1 , wherein the process control subsystem further comprises:
a first sensor system configured to measure at least one of a flowrate of a solution being received in the reactor vessel through the at least one inlet and a concentration of one or both of the conditioning additive and the reaction additive; and a second sensor system configured to measure a concentration of one or both of the conditioning additive and the reaction additive in the solution within the reactor vessel, the control module being in electrical communication with the first and second sensor systems and configured to receive information from the first and second sensor systems.

3 . The system of claim 2 , wherein the control module is configured to maintain the predetermined concentration of aluminum ions in the solution within the reactor vessel by adjusting a flowrate of the reaction additive responsive to a result of an analysis of the information from the first and second sensor systems.

4 . The system of claim 1 , wherein at least one of the conditioning additive and the reaction additive comprises aluminum chloride.

5 - 10 . (canceled)

11 . The system of claim 2 , wherein the process control subsystem further comprises a third sensor system in electrical communication with the control module and configured to measure at least one of a concentration of aluminum ions in a solution exiting the reactor vessel through the outlet and a flowrate of the solution exiting the reactor vessel through the outlet.

12 . A method for reducing a concentration of one or more contaminants in a contaminated water having a first concentration of contaminants, the method comprising:
providing zero valent iron media, at least partially coated with an iron oxide compound, in a reactor vessel; contacting the zero valent iron media with a conditioning additive comprising a soluble aluminum salt to produce a conditioned zero valent iron media; contacting the contaminated water with the conditioned zero valent iron media in the reactor vessel to produce a product water having a second concentration of contaminants lower than the first concentration of contaminants; introducing a reaction additive comprising a soluble aluminum salt into the reactor vessel; and maintaining a concentration of aluminum ions within the reactor vessel within a predetermined range by monitoring and adjusting a flowrate of the reaction additive.

13 . The method of claim 12 , wherein contacting the zero valent iron media with the conditioning additive comprises contacting the zero valent iron media with aluminum chloride.

14 . The method of claim 13 , wherein contacting the zero valent iron media with the conditioning additive comprises contacting the zero valent iron media with aluminum chloride and sodium nitrate.

15 . The method of claim 12 , wherein introducing the reaction additive comprises introducing aluminum chloride.

16 . The method of claim 12 , wherein producing the product water having the second concentration of contaminants comprises reducing a concentration of one or more contaminants selected from the group consisting of selenium, arsenic, cadmium, chromium III, chromium VI, cobalt, copper, lead, mercury, antimony, molybdenum, nickel, titanium, tungsten, vanadium, and zinc in the contaminated water.

17 . The method of claim 12 , wherein providing zero valent iron media in the reactor vessel comprises providing zero valent iron media in one of a packed bed, a fluidized bed, and a mixed bed.

18 . The method of claim 12 , wherein introducing the contaminated water comprises introducing contaminated water originating from a source selected from the group consisting of flue-gas desulfurization waste water, petroleum refining process waste water, mining operations waste water, surface water, and ground water.

19 . The method of claim 12 , further comprising introducing an oxidizing agent into the reactor vessel and contacting the oxidizing agent with the contaminated water, the conditioned zero valent iron media, and the reaction additive.

20 . The method of claim 12 , further comprising maintaining the conditioned zero valent iron media in a fluidized state within the reactor vessel.

21 . The method of claim 12 , wherein contacting the zero valent iron media with the conditioning additive comprises contacting the zero valent iron media with about 20 mM of the soluble aluminum salt.

22 . The method of claim 12 , further comprising maintaining a concentration of aluminum ions within the reactor vessel between about 0.25 mM and about 2.0 mM.

23 . The method of claim 12 , further comprising maintaining anaerobic conditions within the reactor vessel.

24 . A system comprising:
a reactor vessel including zero valent iron media at least partially coated with an iron oxide compound disposed within the reactor vessel; a source of a conditioning additive comprising a soluble aluminum salt in fluid communication with the reactor vessel and configured to introduce the conditioning additive into the reactor vessel to contact the zero valent iron media and produce a conditioned zero valent iron media; a source of contaminated water fluidly connectable to the reactor vessel and configured to introduce the contaminated water into the reactor vessel to contact the conditioned zero valent iron media; a source of a reaction additive comprising a soluble aluminum salt in fluid communication with the reactor vessel and configured to introduce the reaction additive into the reactor vessel to contact the contaminated water and conditioned zero valent iron media; and a process control subsystem configured to maintain a concentration of aluminum ions within the reactor vessel within a predetermined range.

25 - 29 . (canceled)

30 . A method for reducing a concentration of one or more contaminants in a contaminated water having a first concentration of contaminants, the method comprising:
providing zero valent iron media, at least partially coated with an iron oxide compound, in a reactor vessel; contacting the zero valent iron media with a conditioning additive comprising a soluble aluminum salt to produce a conditioned zero valent iron media; and contacting the contaminated water with the conditioned zero valent iron media in the reactor vessel to produce a product water having a second concentration of contaminants lower than the first concentration of contaminants.

31 - 40 . (canceled)

41 . A method for selectively reducing the concentration of selenate in a contaminated water ha

Assignees

• Texas A & M Univ Sys
• Evoqua Water Tech Llc

Inventors

• Huang Yongheng
• Wismer Michael
• Reyes Lew Andrew
• Qiao Xiangyi
• Dukes Simon
• Sassaman Frank
• Berger David

Classifications

• B01J20/0229

  Compounds of Fe · CPC title

• C02F2103/365

  from petrochemical industry (e.g. refineries) · CPC title

• C02F2101/20

  Heavy metals or heavy metal compounds · CPC title

• C02F2103/06

  Contaminated groundwater or leachate · CPC title

• B01J20/0225

  Compounds of Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt · CPC title