Systems and methods for water treatment
View Patent ↗Electrochemical devices and methods for water treatment are disclosed. An electrodeionization device ( 100 ) may include one or more compartments ( 110 ) containing an ionselective media, such as boron-selective resin ( 170 ). Cyclic adsorption of target ions and regeneration of the media in-situ is used to treat process water, and may be driven by the promotion of various pH conditions within the electrochemical device.
1. A method of treating seawater, comprising:
introducing seawater comprising chloride ions and boron-containing compounds to a first compartment and an adjacent second compartment of an electrically driven separation device, each of the first and second compartments both-comprising a resin bed and an outlet, the resin bed comprising a blend of an anion exchange resin and a boron selective resin;
applying electric current to the electrically driven separation device in a polarity direction to promote transport of the chloride ions in the seawater from the first compartment to the second compartment and to promote ionization of at least a portion of the boron-containing compounds in the seawater in the first compartment;
adsorbing at least a portion of the ionized boron-containing compounds on the resin bed in the first compartment; and
recovering treated water at the outlet of the first compartment.
2. The method of claim 1 , wherein the blend is about 50/50 by volume of the anion exchange resin and the boron selective resin.
3. The method of claim 2 , further comprising reversing the polarity direction of the electric current applied through the electrically driven separation device thereby to adsorb ionized boron-containing compounds on the resin bed in the second compartment and regenerate the resin bed in the first compartment by releasing boron-containing compounds from the resin bed.
4. The method of claim 3 , further comprising releasing at least a portion of boron-containing compounds bound in the resin bed in the second compartment.
5. The method of claim 4 , further comprising recovering a boron-containing stream at the outlet of the second compartment.
6. The method of claim 5 , further comprising adjusting a pH level of the treated water.
7. The method of claim 6 , further comprising monitoring a concentration of boron in the treated water.
8. The method of claim 7 , wherein the step of reversing the polarity direction occurs in response to detecting a concentration of boron in the treated water that is above a predetermined level.
9. The method of claim 8 , wherein the predetermined level is about 1 ppm.
10. The method of claim 3 , further comprising directing treated water to a third compartment of the electrically driven separation device to further treat the treated water.
11. The method of claim 3 , further comprising monitoring a pH level of the treated water and wherein the step of reversing the polarity direction occurs in response to detecting a pH level of the treated water that is above a predetermined level.