p. 1



# OAR Box 1313
Prepped by LaTeia Shed



### Document

Number: 

# 52 ) ll-B-2 6
Docket Number: 

# A-88-0 2

Printed 6/12/20089:03:29AM

Sheet 52 of 99

# ® 7 7X 5 .Q

h ''•! ! 

### .••-. JA N I 8199 1 ll'i i P. 2



## A-88-0 2 MIDWES T RESEARC H INSTITUT E Suite 350 40 1 Harriso n Oak

s Boulevar

a Cary , Nort h Carolin a 2751 3 Telephon e (919 ) 467-521 5 Facsimil e (919 ) 467-8060



## i r 

## 5C"5}5 DOCKE T Date : Ma y

15 , 198 7 <-_-.--- — *~— ~ (Finalize dDecembe r 8 , 1987 ) Subject : Engineerin g Analysis—Reliabl e Platin g & Polishin g Company

Chromium Electroplatin g NESHA P EP A Contrac t 68-02-3817 ; ESE D Projec t 85/02 a MR I Projec t 7717- K From : Robi nBarke r r & 

### To : A l Vervaer t

ESED/ISB/SS S (MD-13 ) U . S . Environmenta l Protectio nAgenc y Researc hTriangl e Park , N C 2771 1

I . Purpos e O n.Apri l 1 , 1987 , testin g wa s conducte do na scrubbe r use dt o contro l chromi c aci demission s fro m on e anodizin g tan k a t Reliabl e Platin g and Polishin g Company , Inc . (Reliable ) i nBridgeport , Connecticut , t o estimat e th e amoun t o f uncontrolle dchromium emission s fro

m th e process . Th e purpos e o f thi s memorandu m i s t o (1 ) presen t th e result s o f thes e tests , (2 ) compar e th e estimate dchromium emission s fro

m Reliabl e t o chromium emissio nresult s fro

m anemissio ntes t a t anothe r anodizin g facility ; an d (3 ) compar e th e estimate demission s fro m Reliabl e t o emissio ntes t dat a fo r har dan ddecorativ e chromiu m electroplatin g facilities . II . Backgroun d Reliabl e i s a smal l jobsho ptha t perform s chromi c aci danodizin g o f aircraf t an delectroni c parts . Th e anodizin g tank a t Reliabl e i s equippe d wit ha Niehau s fume scrubber . Th e scrubbe r system doe s no t contai na recirculatio nunit . Th e once-throug hscrubbe r wate r i s combine dwit h othe r effluen t stream s an di s treate di n a wastewate r treatmen t system . Durin g a visi t t o th e plant , chromi c aci dwa s visibl e acros s th e surfac e o f th e solutio nonl y durin g th e firs t 5 t o 1 0 minute s o f th e anodizin g cycle , whe nth e voltag e wa s steppe dupt o 4 0 volts . Steppin g th e voltag e cause s a

n initia l curren t surg e tha t generate s hydroge nand oxyge nga s tha t break s throug hth e surfac e o f th e solutio nentrainin g chromi c aci dwhic hresult s i nth e misting . Thereafter , the voltag e i s maintaine da t 4 0 volts , an dth e amperag e drop s of f significantly ; n o mistin g wa s observe dacros s th e surfac e o f th e solutio nfo r th e remainde r o f th e anodizin g cycle . A tri prepor t documentin g the detail s o f th e anodizin g proces s an

dit s associate dai r pollutio ncontro l equipmen t i s presente di nAttachmen t 1 .

/P. 3

III . Samplin g Procedure s Th e testin g consiste do f obtainin g composit e sample s representativ e o f th e scrubbe r influent , scrubbe r effluent , an danodizin g solutionfo r eac ho f fou r l-hou r anodizin g cycles . Eac hsampl e consiste do f fou r gra b sample s tha t wer e collecte dapproximatel y 15 , 30 , 45 , an

d6 0 minute s int o eac hanodizin g cycle . Th e samplin g location s ar e show ninFigur e 1 an

d ar e designate da s letter s A , B , an dC . Th e composit e sample s obtaine d during th e test s wer e analyze dfo r bot hhexavalen t an dtota l chromium . Th e scrubbe r wate r flo w rat e als o wa s measure dperiodicall y b y placin g a n18.9-lite r (5-gallon ) containe r i nth e outle t strea m an d recordin g th e amoun t o f time require dt o fil l th e container . The tempera ture , operatin g voltage , an doperatin g curren t o f th e anodizin g solution ; th e numbe r andtype s o f part s anodize ddurin g eac hanodizin g cycle ; an d th e outle t wate r flow rat e o f th e scrubbe r wer e recorde ddurin g eac h anodizin g cycle . Thes e dat a ar e presente di nAttachmen t 2 . IV . Result s o f Mas s Balanc e Th e result s o f th e sampl e analyse s wer e use dt o perform a chromiu

m mas s balanc e aroun dth e scrubbe r t o estimat e uncontrolle dchromiu m emissions . Th e analytica l result s fo r eac hcomposit e sampl e ar e presente d i nTabl e 1 . Th e analytica l result s show tha t al l o f th e chromiu m i nth e outle t scrubbe r wate r wa s i nth e hexavalen t state . Th e followin g equatio nwa s use dt o solv e fo r th e uncontrolle d chromiu m mas s emissio nrate : M = [(Qw)(Cw)]/ E (1 ) where , M

= uncontrolle dchromiu m mas s emissio nrate , kg/ h(lb/h) ; Qw = outle t wate r flow rat e o f scrubber , a/ h(gal/h); . C w = chromium

concentratio no f outle t wate r stream , kg/ a (lb/gal) ; an d E = efficienc y o f th e scrubber , 9 0 percent . Th e derivatio no f th e abov e equatio ni s presente dinAttachmen t 3 . Th e uncontrolle dchromiu m emissio nrat e wa s calculate dusing a scrubbe r efficienc y

o f 9 0 percent . Previou s sourc e test s a t chromiu m electroplatin g facilitie s showe dtha t th e efficienc y o f packed-be d scrubber s range dfro m 9 3 t o 9 9 percent . Th e vendo r o f th e Niehau s fum e scrubbe r state s tha t i t ca nachiev e a nefficienc y

o f 9 5 t o 9 9 percent . However , th e conservativ e estimat e o f 9 0 percen t efficienc y wa s usedi n thes e analyse s becaus e i t i s expecte dtha t th e fum e scrubbe r i s les s efficien t tha na packed-be dscrubber . A nexampl e calculatio no f the uncontrolle dchromiu m emissio nrat e i s als o presente di nAttachmen t 3 . Th e estimate duncontrolledchromiu m emissio nresult s an dworkloa d description s fo r eac htes t runar e presente di nTabl e 2 . The uncontrolle d

5LDRAI N

VENTILATIO N HOOD S -** > LEGEN D AIRFLO W

_ > -^
.

-5 -*r y

ANODIZIN G c TAN K

COMPOSIT E SAMPL E LOCATION S
A = WATE RSTREA

M INLE T B = WATE RSTREA

M OUTLE T C = ANODIZINGSOLUTION AI RSTREA M OUTLE T

• * i I WATE RSTFlEA

M OUTLE T g . l

_

AI R STREA M INLE T SCRUBBE R

—A
^ WATE R STREA M INLE T

Figur e 1 . Schemati c o f chromi c aci danodizin g tan k an d Niehau s fume scrubbe r a t Reliabl e Platin g Company

i n Bridgeport , Connecticut .



## 0 >P. 5

TABL E 1

. ANALYTICA L RESULT S O F COMPOSIT E SAMPLE S TAKE N DURIN G

EACH TES T RU N AT RELIABL E PLATIN G AN D POLISHIN G COMPAN Y I N BRIDGEPORT , CONNECTICU T

Sampl e descriptio n Ru nNo . Sampl e concentration , ug/m a (oz/gal ) Hexavalen t Tota l chromiu m chromiu m
Outle t scrubbe r wate r

Inle t scrubbe r water 3

Anodizin g bat h 1 2 3 4 AVERAG E 1 2 3 4 AVERAG E 1 2 3 4 AVERAG E 3. 9 (5.2x107 )

0. 8 (1.1x10, ) 0. 3 (4.0xl0~* ) 5. 1 (6.8xl0 ~ ) 2. 5 (3.3x10"" ) <0. 1 (0 ) <0. 1 (0 ) <0. 1 (0 ) <0. 1 (0 ) <0. 1 (0 ) 50,30 0 (6.72 ) 50,50 0 (6.74 ) 50,70 0 (6.77 ) 50,30 0 (6.72 ) 50,45 0 (6.74 ) 3. 9 (5.2xlO" J

0. 8 (1.1x10', ) 0. 3 (4.0x10, ) 5. 1 (6.8x1 0 ) 2. 5 (3.3xl0 _lf ) <0. 1 (0 ) <0. 1 (0 ) <0. 1 (0 ) <0. 1 (0 ) <0. 1 (0 ) 52,00 0 (6.94 ) 51,90 0 (6.93 ) 51,10 0 (6.82 ) 50,30 0 (6.72 ) 51,32 5 (6.85 )

a Th e amoun t o f chromiu m in th e inle t wate r strea m wa s below

th e detectabl e limi t o f th e analytica l procedur e (0. 1 ug/ma ) an d wa s assume d t o be equa l t o zero .



# fP. 6

TABL E 2 . UNCONTROLLE D CHROMIU M MAS S EMISSIO N

RATE S BASE D O

N HEXAVALEN T ANO TOTA L CHROMIU

M CONCENTRATIO N

O F OUTLE T SCRUBBE RWATE R

RunNo . 

### 1
2
3
4

Averag e Uncontrolle d chromiu m emissio nrat e a t scrubbe r efficienc y

o f 9 0 percent , kg/ h(lb/h) a

0.001 9 (0.0042 ) 0.0003 9 (0.00086 ) 0.0001 5 (0.00033 ) 0.002 5 (0.0055 )
0.001 2 (0.0026 ) No . o f part s o r rack s anodize d
1 4 rack s

2 2 part s

1 6 part s

1 7 rack s Typ e o f par t anodize d
Smal l aircraf t an

d electroni c part s Aircraf t part s
Aircraf t part s

Smal l aircraf t an

d electroni c part s

a Tota l an

d hexavalen t chromiu m concentration s inscrubbe r wate r wer e equal .

m ^P. 7

chromiu m emissio nrate 3 range dfro m 1.5x10 " kg/ h(3.3xl0~ 4 lb/h ) t o 2.5x10 " kg/ h(5.5x10 " lb/h) . Th e variatio ni nth e estimate d uncontrolle dchromium emissio nrate s i s directl y relate dt o th e tota l surfac e are a an

dconfiguratio no f th e part s anodize ddurin g eac htes t run . Th e sam e typ e o f aircraf t part s wa s anodize ddurin g ru nNos . 2 an

d3 wit h2 2 part s anodize ddurin g ru nNo . 2 and1 6 part s anodize ddurin g ru n No . 3 . Th e workloa ddecrease d2 7 percen t fro m ru nNo . 2 t o ru

nNo . 3 wit h a subsequen t decreas e o f 6 1 percen t i nth e uncontrolle demissio nrate . Th e type s o f part s anodize ddurin g bot hru nNos . 1 an d4 wer e simila r an

d consiste do f rack s o f smal l aircraf t an delectroni c part s wit h1 4 rack s o f part s anodize ddurin g ru nNo . 1 an d1 7 rack s o f part s anodize ddurin g run No . 4 . Th e workloa dincrease d1 8 percen t fro m ru nNo . 1 t o runNo . 4 wit h a subsequen t increas e o f 2 4 percen t i nth e uncontrolle dchromiu m emissio n rate . Th § averag e uncontrolle demissio nrat e fo r runNos . 2 an d3 i s 2.7x10 " kg/ h(5.9x10 " lb/h) , an dth e average 3 uncontrolle demissio nrat e fo r ru nNos . 1 an

d4 i s 2.2x10 " kg/ h(4.9x10 " lb/h) . Th e averag e o f run Nos . 2 an

d3 i s onl y

1 2 percen t o f th e averag e o f runNos . 1 an d4 , whic h suggest s tha t bot htota l surfac e are a an dconfiguratio no f the part s substantiall y

affec t th e amoun t o f uncontrolle demissions . Th e averag e uncontrolle dchromiu m emissio nrat e fo r al l fou r run s wa s 1.2x10 " kg/ h(2.6x10 " lb/h) . Eve nthoug hth e dat a show a wid e rang e o f uncontrolle demissio nrate s du e t o th e differen t workload s durin g eac h run , i t i s reasonabl e t o averag e the estimate demission s becaus e workloa d variation s ar e commo nfo r th e industry . V . Discussio n Th e estimate duncontrolle dchromiu m emissio nrate s fo r Reliabl e wer e compare dt o tes t dat a obtaine dfro m Dougla s Aircraf t Compan y (Dougla s Aircraft) , i nTorrance , California , t o determin e i f th e estimate demissio n rate s fo r Reliabl e wer e simila r t o thos e obtaine dfro m anothe r anodizin g operation . Thre e emissio ntes t run s wer e conducte da t Dougla s Aircraf t a t th e inle t andoutle t o f a scrubbe r controllin g chromi c aci demission s fro m on e larg e anodizin g tank . Standar dEPA Metho d5 sampling train s wer e useda t eac htes t location . Th e anodizin g tan k a t Dougla s Aircraf t wa s operatin g a t a ful l workloa ddurin g onl y th e thir demissio ntes t run , an dsampling wa s conducte donl y

whe npart s wer e inth e tank . Therefore , the estimate d emissio nrate s fo r Reliabl e wer e compare donl y t o the emissio nrate s obtaine ddurin g th e thir demissio ntes t ru na t Dougla s Aircraft . Tabl e 3 present s th e tes t result s an dproces s parameter s fo r Reliabl e an dDougla s Aircraft . Th e uncontrolle dhexavalen t chromium emissio nrat e at Dougla s Aircraf t wa s 2.8x10 " kg/ h(6.2x10 " lb/h) . Th e hexavalen t chromiu m emissio nrat e i s simila r t o th e highes t estimate dchromiu m emissio nrat e (2.5x1 0 kg/ ho r 5.5x10 " lb/h ) obtaine da t Reliable . Th e uncontrolle dchromiu m emissio nrate s from Reliabl e wer e als o compare dt o controlle demissio nrate s fro m har dan

ddecorativ e chromiu mP. 8

TABL E 3 . COMPARISO N OF TES T RESULT S AN

D PROCES S PARAMETER S BETWEE N RELIABL E AN

D OOUGLA S AIRCRAF T

Reliabl e Dougla s Aircraf t
Uncontrolle demissio nrate , kg/ h(lb/h ) Hig hvalu e

Lo w valu e
Averag e

Workloa d descriptio n Type s o f part s Capacit y Tan k parameter s Numbe r o f tank s Dimension s (1 , w , d) , m (ft )

2 2 Surfac e area , m

(f t ) Capacity , a (gal )
Operating voltage , stepwis e (v ) 0.002 5 (0.0055 ) 0.0001 5 (0.00033 ) 0.001 2 (0.0026 )

Aircraf t an

d electroni c Ful l

1 3.5 , 0.61 , 0.9 1 (11.5 , 2.0 , 3.0 )

2.1 4 (23.0 ) 1,89 3 (500 ) 4 0 0.002 8

(0.0062 )

Aircraf t

Ful l

1 9.4 , 1.1 , 2. 2 (31.0 , 3.7 , 7.3 )

10.5 9 (114 ) 17,55 7 (4,638 ) 2 0

/P. 9

8 platin g tank s whe neithe r fum e suppressants , mis t eliminators , o r packed be dscrubber s wer e use da s th e primar y contro l techniqu e t o contro l chromi c aci dmisting . Th e averag e controlle dtota l chromiu m emissio n rate s wer e 2.2x10 " kg/ h(4.8x10 " lb/h ) fo r fum e suppressants , 2.5x10 " 3 kg/ h(5.5x10 " lb/h ) fo r mis t eljminators, an d1.23x10 " kg/ h (2.7x10 " lb/h ) fo r packed-be dscrubbers . Tabl e 4 present s th e compariso no f uncontrolle demission s fro m Reliabl e t o controlle demission s fro m electroplatin g operations . Th e averag e o f th e tw

o lowes t uncontrolle d chromiy m emissio nrate s (ru

nNos . 2 an d3 ) a t Reliabl e wa s 2.7x10 " kg/ h(5.9x10 ' lb/h) , whic hi s 1 9 percen t highe r tha nth e controlle dchromium emissio nrat e fo r decorativ e chromiu m electroplater s wit ha fume suppressan t a s th e primar y contro l technique . Th e highes t uncontrolle dchromium'emissio nrate , 2.5x10 " kg/ h (5.5x10 " lb/h) , obtaine da t Reliabl e durin g ru nNo . 4 , i s equa l t o th e averag e controlle d chromiu m emissio nrat e fro

m hardchromiu

m electro plater s wit hmis t eliminator s a s th e primar y contro l device . Th e averag e uncontrolle dchromiu m emissio nrat e a t Reliable , 1.2x10 " kg/ h(2.6x10 " lb/h) , i s approximatel y equa l t o th e averag e controlle dchromiu m emissio n rat e fro

m hardchromiu

m electroplater s wit hpacked-be dscrubber s a s th e primar y contro l device .



# 1P.1 0



### TABL E 4 . COMPARISO

N O F UNCONTROLLE D EMISSION RATE S A T RELIABL E T O CONTROLLE D EMISSIO

N RATE S FROM

ELECTROPLATINGOPERATION S

Emissio nrates , kg/ h(Ib/h ) Reliabl e Decorativ e chromiu m platin g Fum e suppressan t wit hestimate d contro l efficienc y o f 90* a Har d chromium pla t I n Mis t eliminator s wit hcontro l efficiencie s o f 87-98* ° ked- b

scrubber s wit hcontro l efficiencie s o f 93-99* c Hig hvalu e

Lo w valu e
Averag e o f al I run s 0.002 5 (0.0055 ) 0.000t 5 (0.00033 ) 0.001 2 (0.0026 ) 0.00021 9

(0.000484 ) 0.003 8 (0.0084 ) 0.001 2 (0.0026 ) 0.002 5 (0.0055 ) 0.0016 7 (0.0037 ) 0.00071 9 (0.0016 ) 0.0012 3 (0.0027 ) Averag e o f run Nos . 2 and 3 a t Re l iable* * 0.0002 7 (0.00059 )
j*Dat a obtaine d fro

m on e emissio ntes t conducte d a t a decorativ e chromiu m platin g operation . Dat a obtaine d fro

m averag e o f tw o emissio ntest s conducte d a t har d chromium platin g operations . *:Dat a obtaine d fro

m averag e o f thre e test s conducte d a t har d chromiu m platin g operations . Oat a use d fo r comparisono f uncontrolle d emissio nrate s fro m Reliabl e t o controlle d emissio n rate s fro

m decorativ e chromiu m platin g operatio nwit ha fume suppressan t use d a s th e primar y contro l technique .p.1 1

1 0 VI . Reference s 1 . Chromiu

m Electroplater s Tes t Report : McDonnel l Dougla s Aircraf t Company , Torrance , California . Engineering-Science , Pasadena , California . Sourc e Emissio nTestin g o f Tan k 19 3 an d Tan k 19 5 a t Dougla s Aircraf t Company , Torrance , California . Octobe r 1-3 , 1986 . Novembe r 12 , 1986 . p . 5 . 2 . Backgroun d Informatio nDocument , Chromiu m Electroplatin g NESHAP , Draf t Chapte r 4 . U . S . Environmenta l Protectio nAgency . Researc hTriangl e Park , Nort hCarolina , p . 4-56 . 3 Attachment s



## /OP.1 2



### Attachmen t

I

& MIDWES T RESEARC H INSTIT L •"50 5 Creeamoc r fi Raieign

. N. C 2'. Teleonon e (919 ) 781- '

Date : Marc h16 , 198 7

(Finalize dApri l 2 , 1987 ) Subject : Sit e Visit—Reliabl e Platin g Company

Chromiu m Electroplatin g NESHA P EP A Contrac t 68-02-3817 ; ESE D Projec t 85/02 a MR I Projec t 7717- K From : Robi nBarke r To : A l Vervaer t

ESED/ISB/SSS (MD-13 ) U
. S
. Environmenta l Protectio n Agenc y Researc h Triangl e Park , N.C
. 2771 1 I
. Purpos

e Th e purpos e o f thi s sit e visi t wa s t o gathe r backgroun dinformatio n abou t th e chromi c ad d anodizin g operatio na t thi s plan t an d t o asses s visuall y th e amoun t o f mistin g fro m th e chromi c aci danodizin g tank . II . Plac e an

d Dat e Reliabl e Platin g an

d Polishin g Company , Inc . Pos t Offic e Bo

x421 7 8 0 Bisho pAvenu e Bridgeport , Connecticu t 0660 7 (203 ) 366-526 1 Decembe r 18 , 198 6
III . Attendee s Reliabl e Platin g Company BobMorris , Plan t Maintenanc e Auggi e Dattolo , Proces s Enginee r U . S . Environmenta l Protectio nAqenc y (EPA )
A l Vervaert , IS B Midwes t Researc hInstitut e Robi nBarke r

/(P.1 3

IV . Discussio n Th e plan t visi t bega nwit ha discussio nabou t th e chromi c aci d anodizin g operation . Th e discussio nwa s followe d b y a tou r o f th e facility . A . Genera l Reliabl e Platin g Compan y i s a jo

bsho p engage d primaril y i nchromi c a d d anodizin g o f aircraf t and miscellaneou s parts . Decorativ e chromiu m platin g an

d othe r platin g operation s ar e als o performe d a t thi s plant . Reliabl e Platin g Compan y i s a certifie d Unite d State s militar y contractor . Th e platin g sho p 1 s operate d 8 hour s pe r day , 5 day s pe r week . B . Proces s Descriptio n Th e on e chromi c ad d anodizin g tan k a t thi s facilit y

1 s configure d a s show ni nFigur e 1 . Th e chromi c aci d anodizin g proces s consist s o f th e followin g steps : alkalin e cleaning , col d wate r rinse , nitri c aci d dip , col d wate r rinse , anodizing , an d nicke l acetat e sealin g and/o r ho t wate r sealing . Th e aluminu m frequentl y

1 s dye d afte r sealing . Th e anodizin g H n e 1 s equippe dwit ha nautomati c hois t t o transfe r part s Int o an d ou t o f th e proces s tanks . Th e anodizin g solutio ncontain s chromi c aci d 1 na concentratio no f approximatel y

6 0 t o 7 5 gram s pe r Ute r ( 8 t o 1 0 ounce s pe r gallon ) o f water . Th e operatin g temperatur e range s fro m 35 ° t o 38° C (95 ° t o 100°F) . Th e anodizin g tan k 1 s 3. 5 meter s (m ) (11. 5 fee t (ftl ) long , 0.6 1 m (2. 0 ft ) wide , an

d 0.9 1 m

(3. 0 ft ) dee p an

d ha s a capacit y

o f approxi matel y 1,89 3 liter s (50 0 gallons ) o f anodizin g solution . Th e tan k 1 s equippe d wit ha 4,000-amper e rectifier . The voltag e i s applie dstep-wis e unti l a leve l o f 4 0 volt s i s reached . Thi s leve l i s applie dfo r th e remainde r o f the anodizin g time . Th e curren t typicall y range s fro

m 20 0 t o 30 0 amperes , an

dth e anodizin g time i s approximatel y 1 hour . C . Emissio nContro l Th e anodizin g tan k i s equippe d wit ha double-side d draf t hood t o captur e th e chromi c ad d mist . Th e ventilatio nhood i s ducte d t o a we t scrubbe r manufacture db y Neihau s Brothers , Inc . Th e scrubbe r i s locate d adjacen t t o th e anodizin g tank . Th e Niehau s scrubbe r i s a fum e exhaus t an

d separatin g uni t develope d primaril y

fo r the electroplatin g an d chemica l industries . Th e scrubbin g actio ni s achieve d b

y a combinatio no f wate r absorptio nan dcentrifuga l separation . Figur e 2 1 s a schemati c o f th e Niehau s scrubber . It s operatio ni s describe db y Niehau s a s follows :



## / £DRAI N

- > ->*> • LEGEN D AIRFLO W

VENTILATIO N HOOD S AI RSTREA M OUTLE T

EA M

AI RSTREA M INLE T SCRIBBI. K

Figur e 1 . Schemati c o f chromi c aci danodizin g tank .



## 1 5P.1 5

WATE R INLE T

. INTAK E STAC K SPRA Y CHAMBE R

SEPARATIN G CHAMBE R

BLOWE R

DRAI N OUTLE T

Figur e 2 . Centrifugal-flo w scrubbe r man u facture db y Niehau s Brothers , Inc .

/ /P.1 6



### ".. . contaminate dai r 1 s draw ninthroug hth e intak e duc t int o whfc hspray s o f wate r ar e introduced . Thes e sprays , upo nimpinging o nth e highspee dblowe r whee l ar e reduce dt o fo g whic hintimatel y mi xwit hth e contaminate dair , dissolvin g th e contaminants . Th e blowe r whee l bein g axiall y locate dwithi nth e separatin g chambe r als o act s a s th e impelle r o f a centrifuge , thereby separatin g the wate r entraine dcontaminant s whic har e draine da t th e botto m o f the unit . Th e cleane dai r spiral s ou t th e discharg e locate da t th e top. " The desig nga s flo w

rat e o f th e scrubbe r i s 8 5 cubi c meter s pe r minut e (3,00 0 cubi c fee t pe r minute) . Th e desig nwate r flo w rat e range s fro

m 7. 6 t o 11. 4 liter s pe r minut e ( 2 t o 3 gallon s pe r minute) . Th e scrubbe r wate r 1 s no t recycle dandth e scrubbe r 1 s continuousl y spraye dwit hfres h water . Th e scrubbe r wastewate r 1 s combine dwit hothe r wast e stream s an d1 s draine dt o a wastewate r treatmen t system . Sulfu r dioxid e 1 s usedt o pretrea t th e wastewate r t o reduc e th e hexavalen t chromiu m t o trivalen t chromium . Afte r pretreatment , th e wastewate r 1 s pumpe dt o a clarifle r wher e a polyme r 1 s adde dcausin g the heav y metal s t o precipitat e a s sludg e an dsettl e t o th e bottom o f th e tank . Clea nwate r 1 s the ndraw nof f th e top . Th e sludg e 1 s pumpe dt o a pres s wher e i t 1 s compresse dInt o a cake . V . Observation s A smal l amoun t o f gassin g occurre da t th e side s o f th e tan k (cathode ) andaroun dth e workpiec e (anode ) whil e th e tank wa s 1n operation . However , th e ga s di dno t appea r t o b e breakin g throughth e plating solutio nsurface . Ther e wa s no chromi c aci dvisibl e ona piec e o f clea nwhit e pape r tha t wa s hel dove r th e bat hfo r a shor t periodo f time . VI . Conclusion s Th e Reliabl e Platin g Compan y plan t i nBridgeport , Connecticut , 1 s representativ e o f a smal l jobsho ptha t perform s chromi c ad danodizin g o f aircraf t an

dmiscellaneou s parts . T o determin e th e desirabilit y o f performin g emission s testing , i t 1 s recommende dtha t a chromiu m mas s balanc e b e performe do nth e chromi c aci danodizin g operatio nb y collectin g sample s o f th e once-throug hscrubbe r wate r t o determin e i f the quantit y o f chromi c ad dtake nu pi nth e scrubbe r wate r indicate s whethe r emission s appea r t o b e significant . I f th e result s o f th e mas s balanc e sho w tha t chromi c ad demission s fro m anodizing tank s ar e negligible , n o furthe r testing woul db e performed . However , i f th e result s o f th e mas s balanc e Indicat e tha t chromi c aci demission s may b e significant , emission s testin g o nth e anodizin g bat hwil l be recommended . VII . Referenc e 1 . Niehau s Brothers , Inc. , Nelhau s Fum e Separators , Indianapolis , Indiana . 1986 .


# / rP.1 7



### Attachmen t 2

SOURC E SAMPLINGPROCES S DATA SHEET S Place : Reliabl e Platin g & Polishin g Compan y Bridgeport , Connecticu t Tes t ru n No

. 1 Tes t star t time : Tes t sto p time :

Time , 24- h cloc k 09:3 5 09:4 5 09:5 0 09:5 5 10:0 5
10:1 5 10:2 0 10:2 5 10:3 5 10:4 0 Operatin g

voltage , volt s 3 5 3 5 3 5 35 3 5
3 5 3 5 3 5 3 5 3 5 09 10 :

1 :3 5 4 0
Tan k

parameter s Operatin g current , amperes 10 0 8 0 8 0 8 0 8 0
8 0 8 0 8 0 8 0 8 0 Temp. ,

* C CF ) 35 3 5 35 3 5 3 5
35 35 35 3 5 3 5 (95 ) (95 ) (95 ) (95 ) (95 ) (95 ) (95 ) (95 ) (95 ) (95 ) Date :

Gra b sample s take n a t

—
— 9:5 0

- - 10:0 5

— 10:2 0

— 10:3 5 Apri l 1 , 1987

Scrubbe r parameter s wate r f t o

w rate , 2,/mi n (gal/min ) 7.5 7 (2.0 )
— ~ ~
—

—
—
— 7.3 4 (1.94 )

- - Gra b

samples take n a t

—
— 09:5 0
— 09:5 0

_ _ 10:2 0
— 10:3 5
—



### /£>P.1 8



### SOURC E SAMPLINGPROCES S DATA SHEET S Place : Reliabl e Plating & Polishin g Company Bridgeport , Connecticu t Tes t ru nNo . 2 Tes t star t time : 11:0 0 Tes t sto ptime : 12:0 5 Date : Apri l 1 , 198 7

Time , 24- h cloc k 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 12 . 0 5 .1 5 2 5 3 0 3 5 4 5 5 5 0 0 0 5 Operatin

g voltage , volt s 3 5 3 6 3 6 3 6 3 6 3 7 3 6 3 6 3 6 Tan

k parameter s Operatin

g current , ampere s 4 0 4 0 3 0 3 0 2 0 2 0 2 0 2 0 2 0 Temp. ,

* C CF ) 3 5 (95 ) 3 5 (95 ) 3 5 (95 ) 3 5 (95 ) 3 5 (95 ) 3 5 (95 ) 3 5 (95 ) 3 5 (95 ) 3 5 (95 ) Gra

b sample s take n a t

— 11:1 5
~ 11:3 0

— 1 1 :4 5

— 12:0 0

— Scrubbe r parameter s

Wate r f1o

w rate , i/mI n (gal/min ) 7.3 4 (1.94 )
~
— ~
—
—
—
— 7.0 0 (1.85 ) Gra b

sample s take na t

— 11:1 5 « 11:3 0

— 1 1 :4 5
~ 12:0 0

—



# nP.1 9



### SOURC E SAMPLINGPROCES S DAT A SHEET S Place : Reliabl e Platin g & Polishin g Compan y Bridgeport , Connecticu t Tes t ru nNo . 3 Date : Apri l 1 , 198 7 Tes t Tes t

Time , 24- h cloc k 12:1 5 12:2 5 12:3 5 12:4 0 12:4 5 12:5 5 13:0 5 13:1 0 13:1 5 star t time : sto p time :
Operatin g voltage , volt s 3 7 3 7 37 3 7 3 7 3 7 3 7 3 7 3 7 12:0 8 13:1 5

i Tan k

parameter s Operatin g current , amperes 2 0 2 0 2 0 2 0 2 0 2 0 2 0 2 0 2 0 Temp. ,

* C CF ) 35 (95 ) 3 5 (95 ) 35 (95 ) 3 5 (95 ) 3 5 (95 ) 3 5 (95 ) 35 (95 ) 35 (95 ) 3 5 (95 ) Gra b

sample s take n a t

— 12:2 5

— 12:4 0

~ 12:5 5

— 13:1 0

TM ~ Scrubbe r

wa+e r t 1ow rate , 8,/mi n (gal/min )

- -
— ~
— — ~ ~
— parameter s

7.3 4 (1.94 ) Gra b

sample s take n a t

— 12:2 5 « 12:4 0
— 12:5 5
~ 13:0 0
""" "

/ /P.2 0



### SOURC E SAMPLINGPROCES S DAT A SHEET S Place : Reliabl e Platin g Tes t ru nNo . 4 Tes t star t time : 13:2 5 Tes t stoptime : 14:3 0 Date : Apri l 1 , 198 7

Time , 24- h cloc k 13:3 0 13:4 0 13:5 0 13:5 5 14:0 0 14:1 0 14:2 0 14:2 5 14:3 0 Tan k Opera t in

g voltage , volt s 3 6 3 6 3 6 3 6 3 6 3 6 3 6 3 6 3 6 parameter s

Operatin

g current , ampere s 10 0 10 0 10 0 10 0 10 0 10 0 10 0 10 0 10 0 Temp. ,

* C CF ) 3 4 (94 ) 3 4 (94 ) 3 4 (94 ) 3 5 (95 ) 3 5 (95 ) 3 5 (95 ) 3 5 (95 ) 3 5 (95 ) 3 5 (95 ) Scrubbe r

Gra b sample s taken a t

— 13:4 0
~ 13:5 5 « 14:1 0

— 14:2 5

— parameter s

water flo

w rate , i/mi n (gal/min )

~

- -

- -
— —
—
— ~ 7.4 2 (1.96 ) Gra b sample s take n a t

— 13:4 0
— 13:5 5
~ 14:1 0
~ 14:2 5

—



# / ?P.2 1



### Attachmen t 3

DERIVATIO N O F MAS S BALANC E Assumptions : (1 ) No chromiu

m impinge s o nth e interna l surface s o f th e ductwor ko r scrubber . (2 ) Captur e efficienc y

o f ventilatio nsystem

i s 10 0 percent . (3 ) N o chromiu m enter s throug hth e inle t wate r stream o f th e scrubber . Chromiu m Mas s Balance : (1 ) M = Mg+M w where , M = chromium

mas s rat e ininle t ga s stream , kg/h ; M g = chromium

mas s rat e inoutle t ga s stream , kg/h ; an d M w = chromium

mas s rat e i noutle t wate r stream , kg/h . Equatio n1 ca nb e rewritte nas : (2 ) M = (Qg)(Cg)+(Qw)(Cw ) where , Q g = flo w

rat e o f outle t ga s stream , m /h ; C g = concentratio no f chromiu m i noutle t ga s stream , kg/ m ; Qw = flo w rat e o f outle t wate r stream , a,/h ; an d C w = concentratio no f chromiu m i noutle t wate r stream , kg/ a Alternatively , M g = M(l-E ) where , E = scrubbe r efficiency , percen t Restructuring , M 

### - TST T Substitutin g fo r Mg , (3 ) M=^2 l
o r M w = (E)(M ) Restructuring , Substituting fo r Mwo , (4 ) M 

## . IMlCw i



## <aoP.2 2



### EXAMPL E CALCULATION

OF CHROMIU

M UNCONTROLLE D EMISSIO

N RAT E Given : Q

w = 7.3 4 n/mi no r 440. 4 i/ h E = 9 0 percen t C w = 3. 9 yg/m l o r 3.9x10 " kg/ a Uncontrolle dchromiu

m emissio nrat e

M = (44( M 

### * /h) 

### feo X l 

### ° ~ 6 kq/< 0 

### = 0.001 9 kg/ h



## *t