# The Director of the United States Patent and Trad e mark Office Has received an application for apatent for a new and usef ul invention. The title and description of the invention are enclosed. The requirements of law have been com plied with, and it 

# has been determined that a patent on the i n

vention shall be granted under the law. Therefore , this 

# U nited States Patent Grants to the person(s) having title to this patent the right to exclude others from mak

ing, using, offeringfor sale, or selling the invention throughout the United States of America or importin g the i nvention into the United States of America , and 

# if t h

e inven

tion i s a process, of t he right t o exclude oth

ers fro m usin g, offe ringfor sa l e or selling throughout the Un ited States of America, or i m

po r ting into the United States of America, products made by that process, fo r the term set forth in 35 US. C. 

# 154(a)(2) or (c)(l), subject to the payment of mainte

nancefees as provided by 3 5 US. C. 

# 41 (b). See the Ma i ntenance Fee Notice on the inside of the cover.

Deputy Director of rite United Stares Parent and Trademark Office

# c•2> 

# United States Patent Sawyer et al. (54) M E THOD FOR CO NTAMINANT REMOVAL FROM AQUEOUS SOLUTION (75) l nvemors: John Sa wye r , Char l eston, WV (US); Geofl'rey PapeUer
. Dunbar, WV (US); Marty L

. W eirick
. South Char leston , WV (US ) (73) Assignee: Liberty H ydro , In c.. South C harl eston , WV (US) ( • ) Notice: Subject to any disclaime r. the term of thi s patent i s extended or adj usted under 35 U.S.C. 154(b) by 670 days
. (2 1 ) Appl. No.: 12/762,501 Apr. 19 , 2010 (22) Filed : (65) Pri o r Publicatio n Data US 201010307978 AI 

### Dec. 

### 9. 2010 Rel ated U.S. AppUcati o n Data (60) Provis ional a ppli cation No. 6112 14 ,566, filed on Apr. 25, 2009. provisional appli ca ti o n No
. 6 1 /236.424. liled on Aug. 24, 2009. (5 1) Int. C l
. BOlD 15/00 (2006
. 01 ) (52) U.S. C l
. USPC
..... . 21CW679 ; 2 1 01694; 2 101747
. 1 :2 101 502. 1 (58) Field 

## or Classification Search USPC
.......... .................. 2 101679.694.747.1.502.1 See application fi le for co mplete search hi story.


### 100 

# \. 

# I I II I

**II II**  **~** 

# lllll l lll l ll ll ll ll l l ll lll l l l l llll l lllll ll l US00866883 1 82
( 1

O) 

## Patent No.: 

# US 8,668 , 831 B2 Mar
. 11 , 2014 (45) 

## Date of Patent: (56) References C ited U.S. PATENT DOCUMENTS 4.800. 190 A • .1/1989 Smolik
......................... 5021416 5.869.32 1 A • 211999 Frank l in .................. _ 4351253.6 5,87 1 , 569 A • 2/1999 OehiCf"etal .....•..••...•...... 961 153 • cited by examiner 

### Primary Examiner

- Chester 

### B arry (74) 

### Auomey, Age nt

, or Finn

- M ende l so hn , Ducker & Dunleavy , P .C. (57) ABSTRACT l n e prescm inve nti o n provides for a permeable reactive bar

rier and an e ffective method of re m ov ing contaminants f rom wat er us ing adsorbent powders. suc h 

### as 1..ero valent iron particles. adhered throughout a retic ul ated foam struct ure . Thi s s tructure p rovid<!S improved mass trans f er. higher reaction rates and red u ced residence times
. The barri er includes a reticu l ated f oam s u bstrate wi th high permeability, an adherent coa t ing and a reactive adsorbe nt arranged in a reticulated f oam s tru cture. The substrate can be selected fr o m various mat erials including polyu rethane and po l yes t er. Th e adherent may be se l ect ed fro m a wide range of materials inclu di ng polyu rethanes. acrylic s. s ili cones. si li conized acrylics, latex e rnul 

### ions. and Olher inherently tac ky materials that cu re to a wa1er res istant coati ng. 1be reac t ive adsorbe nt 

### can be se l

ected from various adsorbents including a powdered zero- '-alent iron (ZVI). 

### 8 C1aiJm, 

### 1 Drawing Sheet



### Coat ing reticulated foam substra t e with an 110 ad herent coating on the subs trate. 

## -

Coa tin g foam s ub strate with a n excess of a reactive adsorbent. 

# - 120

Subjecting the s ubstrate to move ment , suc h as vibration. s haking or s pinning, t o force ,_ 

### 1 30

**th ~**  

### adsorbent to migrate therethrough coa ting th e en ti re sub s tra te



### , .

# U . S . Patent Mar.ll,2014 

## US 8,668,831 B2

100 

# "'- Coating reticulated foam substrate with an f- 

### adherent coating on th e substrate. 

## 1 10

Coating foam s ubstrat e with an excess of a I-- 

## 120 react i ve adsorbent.


## ' Subjecting the substrate to movement, such as vibration, s haking or

**pinnin~** 

### to

**for~e** 

# ,__ 130 the adsorbent to migrate therethrough coating the entire substrate

### US 8,668,831 B2 1 METHOD FOR CONTAMINANT REMOVAL FROM AQUEOUS SOLUTION REFERENCE TO PENDlNG APPLICATIONS This ap pli cation claims the benefit o f U.S. Provisional Pat ent Application Ser. No. 611214,566 filed o n Apr. 25,2009 and entitled Contaminant Removal form Aqueous So luti o n s and of U.S. Prov i sional Pat ent Applicat i o n Ser. No. 611236, 424 111 ed o n Aug. 24, 2009 e ntitled Permeable R eactive Bar

rier. REFERENCE TO MlCROA C HE APPEND IX 

## 2 Various aspectS of the substrate include any known or foreseeably known substrate material such as polyurethane and polyester. The adherent may be selected from a wide range of materials including polyurethanes. acrylics. sili

5 cones, silicon ized acrylics. latex emulsions. and other inherently tacky materials tbat 

### cure to a water resistant coating. The reactive ad sorbent can be selected from various adsorbents including, but not l imited to, powdered

**ze~vale nt**  iron (ZVl), activated carbo n , carbon, copper, zinc. o r zeo lites. or 10 any combinations thereof.

This application is not referenced in any microfiche appen- IS dix. Upon reading the above description •. various alternative e mbodiments will become obvious to those slt illed in the art. These embodiments 

### are to be considered within the scope and spirit of the s ub ject invention, which is only to be limited by the claims which follow and their equivalents.
BACKGROUND OF THE INVENTI ON I. Field of the Invention Th e present invention i s ge nerally directed toward a foam and met hod to re move contaminants from aqueous so lution s, more specifica ll y toward a method utilizing reticulated foam BRfEF DESCRIPTION OF THE DRAWINGS FIG
. 1 is a flow chart show ing a n embod ime nt 1 00 o f the 20 method of the p resent invention
. DESCRIPTION OF THE INVENTI ON used in fluid t reatment and the method to make same. The present invention is general ly directed toward a foam

2. Background 25 and method to remove contaminants from aqueous solutions. There 

### are several contaminants in surface waters that 

### are of more specifically toward a reticul ated foam used in flui d considerable concern due to their effects o n wildlife as well as treatment and the method to make same. humans. These conta minan ts can include, but 

### are not limited It is to be understood that the invention is not limited in its to: selenium. perchl orate. chromates, halogenated organ i c application to the detai l s of the construction and arrangement compounds, aluminu m , lead, copper, techneti um and arsenic. 30 of pans illustrated in the accompanying drawings. The invenThe prior an discloses that these contaminants can be Lion is capable of other cmbod
. iments and of being practiced removed or neutralized by reaction with cenain adsorbents or carried out in a variety of ways. It is to be understood that such as; but n o t limited to , activated carbon, diat omaceou s the phraseo l ogy and terminology employed herein 

### are for the earth, alumina, o r zero valent iron ( F e 0

, or ZV I ). p u rpo se of description and not of Jimitation. H

owever, the prior art usc of these adsorbents have been 35 The present invention provides the effective re m ova l of s hown to have economic and physical constraints with their contaminants in ground water. B y using a reticulated foam use. For in stance, while ZV I is we ll known as an adsorbent, structure with the active species on the surface of the foam , drawbacks in actual application have been identified. To many of the sho n com in gs o f prior art permeable reactive maximize surface area. ZV1 has been used as a powder. barriers can be overcome . Examples of applications include Unfonunate l y. the powder quickJy agglomerates, reducing 40 removal of chlori n ated organic compounds from groundwa

both the available surface area and the ability of water to flow ter o r reducing hexavalent chromi um species to the less toxic through the ZV I parti cles. Ribbons of ZV I have been used, trivalent chromi um species using zero valent iron ( ZV I ) parsuc h as iron wool, but the surface area is not maximi1.ed, and tides. By incorporating the zero valent iron particles in to a the flow path is quickly diminished. Thus, there is a need for reticulated foam structure , the high permeability can be mainan improvement to the removal or ne utrali za ti o n o f contami- 45 tained over the course of the lif etime of the ZV I as it reac t s nants in surface water. with impuriti es a nd decontaminates the water. Thi s s tru c tur e BRIEF SU MMARY OF THE I NVENTI ON The present invention satisfies tbe needs discussed above. Th e present invention is generally directed toward a foam and a meth od to remove contaminants fro m aqueous sol utions. more specifical l y toward a method utilizing reticulated foam used in flui d treat ment and the method to make same.

I t i s to be understood that the inventio n is not limited in its application to the details of the construction and arrangement of p arts illu strated in the accompanyin g drawings. The invention i s capable of ot he r e mbodiments and of being practiced or carried ou t in a variety of ways. It i s to be understood that the phraseology a nd terminology e mpl oyed herein are for the purpose of description and not of limit ation. provides improved m ass transfer. hi gher reaction rates, and reduced reactive adsorbent vo lume .

One embodiment of the reticulated foam substrate of the 

## so present i nve nti on i s constructed fro m preferably polyure

thane or polyether and ha ving an appropriate size with approximately 4to 60 pores pe r inch. This substrate is coated and moistened with an adherent to give a uniform light coating over all of the surfaces of the foam. The moist co:ued 55 substra t e is then covered with powdered

**ze~vale nt**  iron (ZV I ), which becomes stuck in the adherent on the surface of the su bs trate. An excess of the powder is applied to one or more s urfaces of the s ub s trat e. M ovement of the substrale. s u c h as vibration, s haking o r spinni ng . allows or forces the 60 powder to migrate therethrough. As the i ron powder strikes a wet s urf ace. it adheres until the entire subslrale is coated with iron particles
. The amount of iron adhered 10 the substrale i dependent o n the particle size of tbe iron powder and the One aspect of the present invention p rovides f or a permeable reactive barrier which is easily manuf actured and i ts size easily controlled t o remove contam inants in gro und water. Th e barrier includes a reticu lat ed foam substra te h av ing a 65 high permeabi lit y. an adherent coati n g and a reactive adsorbent arra nged in a reticu lat ed foam structure . available surface area of the substrale_ ZVI particle sizes from I 10 3 50

**microns~** accepcable sizes. with the smaller particle 

### sizes resulting in a lower total amount ofZV I in the resulting subsuale.llle larger pore sizes

### US 8,668,831 B2 

## 3 of the substrate resu lt in reduced surface 

### area. and a lower amount ofZVI. Th e pore size and ZV I particle size 

### are chose n depending on the requirements of a particu l ar application, but s mall er pore sizes ge n

erally require smaller particle s i 7-es. Further, when the 

### substra t e i s placed in-ground, the 

### pore size 5 

### i s chosen such th at the 

### reti c ul a t ed foam substrate acts as a protective barrierto prevent migration of t he surrou n ding soil into the reticu l ated struct u re, and th e resu lting bloc kage and flow restriction. 

### 4 residence time req uired t o completely react the contaminants. the flow rate o f the 

### ground water. and the 

### specific si t e conditions.

There 

### are several benefits from the present invention. One of the 

### m ajor ben e fi ts i s the foam substrate has a greatly increased pore area. 

### allowing for a longer li fe o f the media. 

### Iron u ndergoes an expans io n as t he oxidation process proceeds. opening up new surface area 10 

### the liquid and 

### providing co ntinued area for reactions t o occur. As th e natural It 

### i s n ot necessary that the adherent be ab le to withstand permanent w ater contact, as the ZV I powder will form a three dimensional interlinked structure in a short tim e, giving some st

ru c tu ra . l integrity to the coating indepe nde nt of th e adherent Th e purpose of the adherent i s to h old the ZV I in pla ce until th i s bonding o f the ZV I panicles occ urs . The n e t resu lt o f th e ZV I panicle bonding is a mi c r oporou s r e ti c ulated ZV I f oa m. 10 

### expansion of th e iro n closes ofT the flow path of the fluid, il 

### prevents further flow through the remediation unit. 'The 

### present i n vention provides a l arge r volume to absorb this expans ion, and thus a lo n ger useful lif e. w ith a greate r proportion of the ir o n being used to re m ove co nt a minan ts, mainIS 

### tai n ing a low flu id fl ow press u re drop t h roug h out th e life of the media. Th e sta t e of th e surface of th e Z V I i s cri tical t o t

h

e s uccessful r eacti o n with the ox idi :t.ed se l eni um , o r ot h er contami

nants, in the wat e r

. As s uc h, the surf ace ox id es m us t be 20 rem oved fr om the iro n surfa ce by dissolution. Said d i ssolu

tion may be accomplished with an acid spec ie s where th e a ni on is so luble as an ir o n sa lt or. in cases where the 

### wate r has the proper chem i stry. simpl y by con tac t with fl owi n g water. Once a surface of truly 7-ero valent iron i s establ is hed , th e 25 

### normal che m ical reactions p roceed. The reactive adsorbent may i nc lude m ore t ha n jus t ZV I. For in stan ce, an act ivated carbon may be incl u ded t o ass i s t in the removal of certai n contaminants. either before or after reduction by ZV I. In so m e cases the act ivated carbon alone 30 m

ay be 

### sufficie nt t o comple t e ly remove t h e co n taminants. One embodi m ent of the use of a permeable reactive barrier to act as a filter for grou nd water having contam i nants therein is disclosed. Thi s permeab l e react ive barrier is easily manu factured and its size easily cont ro ll ed t o remove contaminants 35 in g r ou n d water. The barrier incl udes a retic ul ated foam substra t e having a h ig h permeab ility , an adhere nt co ating and a reactive adsorbent arranged in a re ti c ul a t ed foam st ructure
. Variou s aspects o f the s ub s trate include any known or foreseeably know n sub s t rate materia l suc h as polyureth ane 40 

### and polyeste r . The adhe r e nt may be se l ected from a w ide range o f m a t e rial s incl uding polyurethanes, ac ryli cs, sili

cones, s ili coni zed acrylic s, latex e mul s io ns, and 

### other inher

e ntl y tacky material s that c ure t o a water res i stant coating
. Th e r eac tive adsorbe nt can be select ed from various adsor- 45 

### ben ts including , but not limited to
. powdered zero-va l e nt iron (ZVI), 

### act ivated carbon , carbo n, copper. zi nc, or zeoli tes. or any combin atio ns thereof.

The present inventi on provides the 

### effective re m oval of con taminants in ground water. B y us ing a reticulated foam 

### so struc ture with the ac ti ve spec ies on t he s urf ace of t he foam
. many of the shortco min gs of prior an permea ble react ive barriers can be 

### overcome. Examples of appli ca t io n s i nc lude re m oval of chlorinated organic compounds from groundwater o r reduc ing hexavalent chrom iu m species 10 

### the less toxic 

### ss trivale n t chrom ium species using zero valent iron (ZV I ) particles. B y incorporating the 1-ero vale nt iron particles into a reticulated foam structure, the h i gh permeability can be 

### maintai n ed over th e course of t he lifet ime of the ZV I as it reacts with i mpurities and decontaminates the water. This struc tu re 60 

### provides improved mass transfer. hi gher reaction rates. and reduced reactive adsorbent vo lume
.

In o n e use, th e reactive re t icu lated foa m i s placed in th e g r

ound so as t o intercept th e groundwa t er containing co nt a minant s. As the wa t e r fl ows through the reactive foam, th e 65 

### con taminants arc reduced, destroying th e m . or re ndering the m n o n- t o xi c. The amount o f foam req ui red depe n ds o n the Ano th er be n e fit of the p resent inven t ion is th e surface area o f th e ir o n is grea tl y increased from o th er designs. resu lting in a larger surf ace o f soli d co nta ct ing the liq u id. leading to a highe r reaction rate with t h

e contam inant s per unit vo lume. Thi s hi g her reac ti o n rate means a much s m a ll er unit ca n be used. savi n g space and cost. 'The 

### a m ou nt of iro n used in reducing contaminan ts is increased, resu ltin g in a decreased volume of iron left at the end for disposal/recycle. result ing in a fu rther reduction in costs.

A further benefi t of the 

### present invention i s that low resistance t o fl ow leads t o a lowered p ress u re drop. and decreased by pass around the reactive f oam. In most cases the flow rate throug h the reactive foam will be greater th an th ro ug h the s urroundin g soil , decreasing the amount of bypass over other d

es ig n s. As illustrated in 

### AG
. I. 

### an e mbodiment 

### tOO of the method 10 

### create the 

### reticu l ated f oam u sed in the present invention is disclosed
. A reticulat ed foam substrate is coated with an adherent coating the 

### adherent. as s h own in s t e p 110, 

### a nd then with an excess of a reactive adsorbent, as show n in s t e p 120
. 

### These adsorbe n ts can be se lect ed fro m va ri o us adsorbents includin g. but not li mited t o, powdered zero-vale nt iron (ZVl ). activated carbon , carbon, co pper , zi n c, or 7-Colites, o r any combination s thereo f. The s u bstrate i s then su bjected t o m

ovement , suc h as vi brati o n, s hakin g or spin n ing. forc es th e adsorbe nt to migrat e therethr o ug h , coa tin g the e nti re s ubstrate. 

### as s hown in step 130.



### Examples o f use include : Example I T

en di sks of t hree inch diameter by one inch t h ick reticul ated polyuret hane f oam with nominal I 

### 0 pores per inch were coated with a urethane paint to give approx i ma t ely 1
. 1 g/cubic inch of u rethane coating. The disks were then placed one at a time in a pl astic contai n er and 

### 60 g of M al l incrockt Baker zero valent ir on powder was added. The containe r was sealed and 

### tumbled to give a uniform coating of t h

e ZVI over the 

### e ntire volume of the 

### f oam dis k
. 'The 

### disks were removed from the 

### co ntainer and allowed to dry in air. Afte r drying the disks contai n ed 45-50 g o f ZV I. or 6 glcubic inch
. Example 2 A six inch diameter by one inch thi ck di sk s of reticulated polyurethane foam with n o minal I 

### 0 pores pe r inch was coa t ed with an aq u eo us silieo n ized acry li c s lurry to g ive a coa ting of approximately 1.1 

### g/c u bic in c h of ad h ere n t. The disks were th e n p l aced one at a lime in a plastic co n ta ine r and 60 g of M

a llinc r ock t Baker zero val e nt iron powder was added. The



### , . container" the ZV I ov were remo1

The dis k of seleni uo dence lime resuJts shm to fi rst ordc halflifeof1 give the des 

### desired red! outle t.

Te

n d i sk retic ul ated 1 wcrecoa t cx g/cubic in one at a ti m valent iron tumb led to vol u me o f I con tainer a contained a

T

en disli reticu la t ed] were

**coat~** 

### mately I g were then p g of H CA-1 tainerwass

### U S 8,668,83 I B2 

## 5 co ntaine r was sealed and tumbled to g ive a uniform coat ing of th e ZV I over th e entire volume of th e foam di sk
. The disks w

e re rem oved from the container and allowed to dry in air. Example 3 The d! s ks from examp l e 2 were tested by passing a stream of selemum laden water through them with a variable residence time. The results 

### are given in tab l e I be low. These results s ho w the ZV1 foam disks remove se l e n

iu m according to first o rd er kinetics in the selenium concen tration. with a half life of about 12 minutes
. Thu s, the flow rate i s ad j us t ed to g ive the d esired residence time in the ZV I foam bed to give the desired redu cti o n o f th e inlet concentration o f se l e nium in the o utl e t. TABLE I

sel

e nium reduction by con tac t with the ZV I foam R

esidence TOUII Time in Selenium. minutes ppb Inlet (0
. 0) 2 4
. 6 2.7 2 1. 7 14.2 10
. 8 21.5 7
. 36 Example4 T

e n di s ks o f 67 millimeter diameter by o ne inch thick reticulated polyurethane foam with no minal I 0 p o re s per in c h w

ere coa ted with a silicone adhesive to g ive approximately 1 glcubic inch of s ili co ne coating. The di s k s w ere th e n placed o n

e at a time in a plastic co nt ai n e r and 100 go fH CA- 1 50zcro va l e nt iron powder was added. Th e co ntainer was sealed and tumbl ed to give a uniform coa ting of the ZV I over the e nti re volume of th e foam disk. Th e disks were removed from th e con tai n er an d a ll owed to dry in air
. Afte r drying the disks co ntain ed a n average o f 7.3 g o f ZV I , o r 1 .3 glc ubi c inch. Example 

### 5 

## 6 ZVI O \ e r the e nure \oiUJDe of lbe fa.u 111te -ce remo\ed from the craainer and slowed 10 

### dn - WiL A!:la drying the di oont.ained

**3D~** 

### d 1- 'f.dZ\1. :1 g/cubic m ch

- Whil e the tmentioo 

### bas beell 

### described a 

### cr:r. degree

**o~ pan.icul~ty.**  it is maoifestlha

**m:~~~y ~**  • be made 1n the detail o f constructioo 

### and the

**~mall** 

### d components without departing from the 

### spmt liDd sccpe of this disclosure
. It i understood thai !he im-=ooo i DOl • 10 ited to the embodiments set forth herrin for 

### purposes d exe m pli fication
. The invention claimed i s: l
. A m e thod to re m ove con taminants f rom an 

### aquc:ou.s soluti on co mpri s in g the s t eps of: 15 (a) placing a permeable reactive barrier in an aqu eous

20 stream co nt ai ning contaminants. sa id permeable barrier co mpri si n g: a reticulated foam substrate; an adh ere nt coating said reticulated f oam s ub s trate ; and reac tive adsorbent coating sai d adherent: and (b) running s aid aqueous s tream throug h said pe rm ea bl e reac ti ve barrier. 2
. The method of claim 1. wh erei n said reticulated foam s ub stra t e i s cons tru cted fr o m a material se l ec t ed from ceram25 ics. m e tal s. polye t h ers. polyurethane and po l yes t er. 3
. The method of c laim I. wherein said adherent is se l ected from the group co n s i s ting of polyurethanes. acrylics, s ili

co n es. s il iconi zc d acryli cs. latex e mul s io ns. and ot h er inhere ntly tac ky material s th a t c ure to a wa t er-resi s tant coati ng. 3 0 4
. The m e thod o f claim I. wher e in sa id reactive adsorbent i s selected from the group consisting o f powdered zc r o va l ent iro n, ac ti va ted carbon, carbo n. co pper. z inc. 7£0 iites. and any co mbinati o ns th ereof.

5
. The m e thod of cla im 1 , wherein said retic ul ated foam 35 substra t e h as 4 to 60 pores per inch
. 6
. The m e thod of claim 1
. wherein said pemu:able reactive barrier is made by a m ethod compri si ng the s tep s of: (a) coating a reticulated foam substrate with an adhere nt

(1 10); 40 (b ) coa tin g said adherent of step (a) with a reactive adsorbent ( 120 ): and

Ten di s ks of 67 millim e ter diameter by on e in ch thick reticulated polyu r e th a n e f

oam with no minal I 0 pore s per in c h 45 were coa t ed with a po lyurethane adh es ive to give approximately I glc ubi c inch of polyurethane coa ting
. The di s ks were then placed o n e at a time in a pl as ti c containe r a n d 100 (c) m ov ing sa id re liculated foam s ub s trnl c to force said reactive adsorbent to migrate throu g h sa id reticulated f oam s ub s tmte e ff ect ively coa tin g s ub stantia lly all of said reticulated foam s ub stra t e ( 130). 7
. Th e method of claim 6 , where in th e re t iculated foam s ub s trate is reti c u l ated polyethy lene foam
. 8
. The method of claim 6
. wherein sai d reti culated foam sub trat e i s reticu l ated polyether foam
. g of I I CA-15C zero val e nt iron powder was added. The container was sca l ed a nd tumbl ed to give a unif o rm coa tin g of the 

# • • •••



# . .