# REGULATORY AND TECHNOLOGICAL DEVELOPMENTS IN THE TREATMENT OF OILY BILGE WATER

Presented at the International Conference on Marine Engineering Systems ICMES 2003 Finland May 2003 Author: Hal Alper

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- 1INTERNATIONAL COOPERATION ON M A RINE ENGINEERING SYSTEM S Paper presented at the 9 TH I n ter n ational Confer ence on M a r i ne E ngineer ing Sy stem s at the Helsinki Universityof Technology(HUT ) Ship Laboratoryand on board MS SILJA SERENADE 19- 21 M a y2003 

### REGULATORY AND TECHNOLOGICAL DEVELOPMENTS IN THE TREATMENT OF OILY BILGE WATER

Author : 

### Hal Alper, MYCELX Technologies Corpor ation, Gainesville, Georgia, U.S.A.

1. INTRODUCTION

Of th e o il releasedb y v e ssels, 2 5 % is rep o r ted to co m e fro m sp ills an d7 5 % fro m o p e ratio n a l d i sch a rg es. Oily bi l g e di scharge i s second onl y t o oi l y bal l a st t a nk d i sch a rg e in its co n t rib u tio n
. Histo r ically, o ily b ilg e water has been treated using Oil/W ater Separator technology (OW S ) or di scharged wi th m i ni m a l t r eat m e nt

. OW S t echnol ogy al one i s not capabl e of m eet i ng current oi l y bilge water discharge standards in m a ny cases. There has b een m u ch wo rk in th e p a st in reg a rdto d e term in in g wh at t h e di scharge st andard shoul d be for oi l y bi l g e wat e r and how best t o det ect and m oni t o r t h e di scharge. The resul t ap p ears to b e th at 1 5 p p m will b e th e stan d a rdo f discharge for oily bilge wa ter, although within localities

m o re strin g e n t lim its ex ist. A variety of technologies have arisen to fill the gap b e tween OW S Cap ab ility an dd i sch a rg e stan d a rd s. Am ong th ese are sy st em s based on gravi t y separat i on, si ze separat i on, chem i cal affi ni t y separat i on and flocculation. There has al so been a gap between regul at i on and enforcem ent

. Unregul at ed di scharges have been problem atic. There have been significant advances in th e ab ility to d e tect su ch d i sch a rg es in th e p a st few years; th e m o st sig n i fican t is Syn t h e tic Ap ertu re Rad a r (SAR). Th is p a p e r will rev i ew d e v e lo p m en ts in d e tectio n t echnol ogy and oi l y bi l g e wat e r tr eat m e nt

. 2. Regul a tory Devel o pments 2.a. Regul a ti ons

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In the past decade the regul atory horizon in regard to t r eat m e nt and di sposal of oi l y bi l g e wat e r has changed g r eatly. Th e IMO (In tern atio n a l Maritim e Org a n i zatio n ) has been t h e l eader i n devel opm ent of regul at i ons. The Int e rnat i onal C onvent i on for Prevent i on of Pol l u t i on from Shi p s (M AR POL 73/ 78) set s th e st andard i n regard t o bi l g e wat e r and other form s of ship-generated p o llu tio n
. Th e Act to p r ev en t p o llu tio n fro m sh ip s (33.U.S.C

. # 1901 et seq.) i s th e US l e gi sl at i on i m pl em ent i ng cert a i n provi si ons of M A R P OL. C o ast guard regul at i ons (33 C F R # 151,153 and 155) as

am ended by Oi l pol l u t i on act (OPA) and C l ean wat e r act requi re oi l y wast es di scharged wi t h i n 12 naut i cal m i l e s of shore have an oi l cont ent fewer th an 15 ppm
. Vari ouslo calities h a v e m o re strin g e n t req u i rem e n t s an d so m e restri ct any di scharge and requi re onshore tr eat m e nt

.

The Nat i onal Defense Aut hori zat i on Act of 1996

am ended Sect i on 312 of t h e Federal W a t e r Pol l u t i on C ont rol Act (al s o known as t h e C l ean W a t e r Act (C W A ) to require that the Secretary of Defense and the Adm i ni strat o r of th e Envi ronm ent a l Prot ect i on Agency (EPA) develop UNDS (Unifo rm National Discharge St andards) for vessel s of th e arm e d forces. (Sect i on 312 (n) (1)). 40 CFR Part 9 and Chapter 7 (EPA), 40 CFR Chapter 7 (Departm ent of De fen s e) co m p letes th e first phase of the three phases to set UNDS for arm e d forces vessel s . The phase 1 rul e det e rm i n es t h e t ype of vessel di scharges t h at requi re cont rol by M P C D ’s (M ari n e Pollution Control Devices), which includes surface bilge water an do il water sep a rato r d i sch a rg e. Th is ru le creates a new 40 CFR part 1700 est abl i s hi ng UNDS th at appl y t o di scharges. Thi s regul at i on i s prom ul gat e d under t h e aut hori ty of sect i on 312 and 502 of th e C l ean W a t e r Act (333 U.S.C

. 1322 and 1362). Any new devi ce m u st conform t o M E PC .60(33) (M ari n e Envi ronm ent a l Prot ect i on C o mm i t t ee) as prom ul gat e d by M A R P OL i n which the standards of perform ance are set for oil filterin g eq u i p m en t. 2.b. Enforcement Enforcem ent of regul at i ons has tr adi t i onal l y been p r o b l em atic in reg a rdto b ilg e water d i sch a rg es. Satellite

m oni t o ri ng dat a i ndi cat es t h at t h e hi ghest concent r at i on of bi l g e wat e r di scharge i s ri ght before sunri s e, i ndi cat i ng t h at m o st of th e di scharges occur at ni ght . Technol ogi cal developm ents in the last two decades have m a de d e tectio n o f illeg a l d i sch a rg es m o re feasib le. Th e technologies currently utilized for this purpose are as fo llo ws: 2 . b.1 . Techno lo g i es/Senso rs fo r Oil spill Surv e illa nce

• Detectio n o f th e p o t en tial p r esen ce o f o il: Ai rborne SLAR , Satellite SAR

. • Id en tifyin g o il sp ills: Airb o rn e LFS (Laser Fl uoro Sensor).

• Determ in atio n o f Oil sp ill th ick n e ss: Airb o rn e IR/UV Li ne Scanner, MWR (M icrowave R a di om et er).

• Detect potential presen ce o f a lik ely p o llu tio n
cu lp rit: Airb o rn e SLAR, Satellite SAR.

• Id en tificatio n o f th e lik ely p o llu tio n cu lp rit: Ai rborne FLIR (Forward-Looki ng InfraR e d).

2.b.2. SAR Devel o pment

• E a rl y Imagi ng Radar – SL AR The fi rst i m agi ng radars were Si de-Looki ng Ai rborne R a dars (SLAR ’ s) devel oped for reconnai ssance purposes. SLAR is known as “Real Aperture Radar” because its al ong-t r ack resol u t i on i s det e rm i n ed by t h e si ze of t h e phy si cal ant e nna foot pri n t

. These radars at wavelengths of 2 cm , can im age the Earth’s surface under day/ni ght conditions. The track resol u t i on of SLAR i s l i m i t e d by ant e nna l e ngth.

The devel opm ent of SAR (Sy n th et i c Apert u re R a dar)

overcom es t h i s probl em by i n corporat i on of a pul sed coherent radar i n conjunct i on wi th a sy nthet i c apert u re whi c h i s not l i m i t e d by t h e fi xed foot pri n t of t h e radar dish. The size of an apertu re in a SAR system is proport i onal t o th e l e ngth of th e arc descri bed by th e satellite du r in g sig n a l co llectio n
. Th is resu lts in th e curi ous property of SAR sy st em s havi ng hi gher resolution at greater distances . SAR system s can be used at longer wavelengths than SL AR. Oil spills can often be detected in SAR im agery b ecause the oil changes the back- scatter characteristics of the ocean. Radar backscatter from the ocean resu lts prim arily from capillary

waves th rough B r agg scat t e ri ng. The presence of oi l
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- 3d a m p en s th e cap illary wav e s, th ereb y d ecreasin g rad a r b ack -scatter. Th u s , o il slick s ap p ear d a rk in SAR im ag es relative to oil-free areas (Figure 1).

Fig.1 The SAR Wide Swath image above was acqu ired over t h e Galician coast in Spain on 1 7 No v e mbe r 2002, i . e . fe w days afte r the P r e s ti ge t a n k er st art t o spill m a ssive am ou n t of oil.

• Seasat SAR The first space based im aging radar to be used for im aging of the earth was the L-band SAR on Seasat, l aunched i n 1978. Seasat SAR was a si ngl e param e t e r i n st rum e nt usi ng a fi xed wavel e ngt h, pol ari zat i on and i n ci dence angl e and hence produced severe geom et ri c l a y over di st ort i ons.

• Shuttle imaging radars (SIR) SIR-A, SIR-B space based SA R’s followed Seasat SAR wi t h art i c ul at i ng ant e nnas provi di ng vari abl e i n ci dence angl es (15-60 degrees). Thi s dem onstr at ed pot ent i a l for usi ng i n ci dence angl e back-scat t e r si gnat u res whi c h l a t e r l e d t o t h e second generat i on SIR

- C / X-SAR ’ s incorporating m u lti-frequenc y, m u lti-polarization,

v a riab le in cid e n ce an g l e. Th e m u lti-p a ram e ter cap ab ility of th e SIR

- C / X-SAR , coupl ed wi t h th e i n t r oduct i on of rout i n e sensor cal i b rat i on, opened a new regi m e i n SAR

b a sedscien tific ap p licatio n s . Oil sp ills are d e tectab le an d th e m u lti-p a ram e ter cap ab ility p e rm its o il typ e an do ilsu rfactan t d i fferen tiatio n to b e d e term in ed

.

Fo r o il sp ill d e tectio n , lo w reso lu tio n (LRI) SAR im ag es wi th a spat i a l resol u t i on of 100m *100m have been found to b e su itab l e.

• ERS-1 , ERS-2 Based upon the Seasat experience, the European space agency (ESA) em barked on the developm ent of the ERS1 , ERS-2 satellites wh ich in co rp o r ateda C-b a n dSAR wi th a si ngl e frequency , si ngl e pol ari zat i on and fi xed i n ci dence angl e-23 degrees. The ER S-1 and ER S-2 are bei ng fl own i n t a ndem m ode (fl y i ng one aft e r th e other al ong th e sam e t r ack) t o al l o w i n t e r-ferom e tr i c processi ng of im ages from both spacecrafts. The SAR onboard the ERS satellites are th e m o st su itab l e sin g l e in stru m e n t s fo r oil spill detection onboard present and near-future satellites.

Th e o il sp ill d e tectio n cap ab ilities o f d i fferen t rad a r satellites:

• ERS-1 , ERS-2 : Ad eq u a te fo r o il sp ill d e tectio n at

l o w and m oderat e wi nds (2-8m / s).

• RADARSAT-1 (Can ad ian Rad a r Satellite): acceptable for oil spills when operating in Narrow-Scan SAR-Near-Range M ode.

• ENVISAT : The wi de Swat h m ode of t h i s uni t i s
u s efu l in o il sp ill m o n ito rin g
.

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NOAA is exploring the possibilityof participation in the M a rine SAR Analy s is and Interpretation sy stem (MARSIAS) effo rt. Th is is a m u ltin atio n a l p r o j ect sponsored by t h e European Uni on wi th t h e goal of producing a com p rehensive coastal ocean oil spill det ect i on and m oni t o ri ng sy st em usi ng SAR and ot herrem o t e sensi ng dat a
.

2.b.3. IMO Mandated Black Box In tern atio n a l Maritim e Org a n i zatio n (IMO) h a s b een stu d y in g th e p o ssib ility o f eq u i p p i n g sh ip s with Vo yag e Data Reco rd ers (VDR) an dAu to m a tic Id en tificatio n Sy st em s (AIS). The ai m of i s t o suppl em ent t h i s t ype of equi pm ent wi th “envi ronm ent a l i ndi cat ors.” The

m a n d a to ry reg u l atio n s fo r certain sh ip s to carry VDR an d AIS (M SC 73/ 21a2.doc R e gul at i on 20 Annex 7) cam e i n t o force on Jul y 1, 2002. Utilization of the above should m a ke it possible for the first tim e to b e ab le to d e tect illeg a l d i sch a rg es an d track the discharge back to its specific vessel.

3 . REVIEW OF CHEMISTRY OF BILGE WATER AND ESTABLISH ED TREATMENT TECHNOLOGIES

3.a. Nature and properties of bilge water Bilg e water is a ch em ically co m p lex m i x t u r e o f so lv en ts, surface active agents (surfactan ts, i.e. soap), m e tal salts such as greases and lubricants and tram p oils (i.e.

com p ressor condensat e). Som e of th e above are bi oaccum u lative persistent organic pollutants (POP’s) such

as pol y a rom a t i c hy drocarbons and chl o ri nat e d arom at i c hy drocarbons. Others such as arom at i c hy drocarbons (B TEX) and oi l , copper, i r on, m e rcury , zi nc and ni ckel , o r g a n i c m e tal salts in ad d itio n to d e terg en ts an d so lv en ts are aquat i c t oxi ns General l y speaki ng organi c non-pol ar com pounds (oi l s )

are n o t so lu b l e in water. Ho wev e r if so lid s, so lv en ts o r
su rfactan ts are p r esen t, o ils will ten dto em u l sify in water. The degree of em ul si fi cat i on i s i nversel y proport i onal t o t h e buoy ancy of t h e m i cel l e s. If suffi ci ent em ul si fi cat i on occurs t o achi e ve neut ral or cl osed t o neut ral buoy ancy g r av ity sep a ratio n d e v i ces lo se th eir effectiv en ess in separat i ng th e organi c com pounds from wat e r. One way to g au g e th e relativ e so lu b ility o f a su rfactan t an dth ereb y th e typ e an dstab ility o f th e em u l sio n is th e HLB (Hy d rophi l e – Li pophi l e B a l a nce) m e t hod. In t h i s
m e t hod a num ber bet w een 1 and 40 i s assi gned t o m a ny
co mm e rcial em u l sifyin g ag en ts, wh ich is in d i cativ e o f th e balance of hydrophilic to lipophilic portions of the

m o lecule. The higher the HLB, the m o re water-soluble th e m a t e r i a l

. T h e water so lu b ility o f an em u l sio n o r a surfact ant can be used t o m a ke an approxi m a t i on of i t s H L B wh ich is in d i cativ e o f th e stab ility o f th e em u l sio n
.
B e havi or i n Water HL B Range No Disp ersab ility 1

- 4 Poor Di spersi on 3-6 Milk y Disp ersio n After Ag itatio n 6-8

St abl e M i l k y Di spersi on 8-10 Translucent To Clear 10-13 C l ear Sol u t i on 13+

The average approxim a ted HLB is one criteria which can b e u s edto ev alu a te th e o p tim al b ilg e water treatm e n t system for a particular vessel.

3.b. Review of principles of OWS (Oil Water Separator technol ogy) Oil water sep a rato rs are Grav ity Sep a ratio n d e v i ces which utilize a difference in buoyancy of two imm i scible l i qui ds t o achi e ve separat i on. There are vari ety of

co n f ig u r atio n s wh ich are u tilizedin clu d i n g b u t n o t l i m i t e d t o underfl ow wei r s, paral l e l pl at e coal escers and centrifugation devices. OW S are very effective when two discrete phases are present. W h en em ul si fi cat i on or sol v at i on occurs buoy ancy di fferences are t oo sm al l t o be exploited utilizing existing OW S technology. In this case upst r eam or downstr eam t echnol ogy m u st be em pl oy ed i n
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. The presence of neutral buoy ancy part i c ul at e m a t t e r t e nds t o further com p licate the waste stream and the treatm e nt technology. W e will review som e em erging technologies in reg a rdto o ily b ilg e water treatm e n t wh ich are eith er upst r eam or downst r eam of t h e OW S (as gravi ty separat i on i s opt i m al as a fi rst st ep for bul k rem oval of non-aqueous phase com ponent s).

4 . EMERGING TECHNOLOGIES IN THE TREATMENT OF OI LY BILGE WATER

4.a. B i ol ogi cal oxi dati on o f OW S-treatedo ily b ilg e wat e r i n a support m e di um i n whi c h hy drocarbon degradi ng bact eri aare bound by a bi ol ogi cal gl ue (secreted by the bacteria). Oil an drelatedco n t am in an ts are degraded in this bio-laye r as the bacteria oxidize the hy drocarbons. One of th e U.S.C

. G and I.M

. O approved B i ol ogi cal Oxi d at i on sy st em s i s t h e Pet r oLi m i n at or100. W h i l e bi ol ogi cal sy st em s can m eet t h e proposed B OD di scharge l i m i t s of 26 ppm , th e effl uent of th e bi ol ogi cal process cont ai ns a hi gh concent r at i on of nonbi odegradabl e organi cs whi c h do not consi s t e nt l y m eet t h e proposed l i m i t s for C OD(C h em i cal Oxy g en Dem a nd) and TOC (Tot al Organi c C a rbon) when exposed t o hi ghstren g t h o ily b ilg e water. Th is n ecessitates p o s t b i o oxi dat i on t r eat m e nt s l i k e Advanced C h em i cal Oxi d at i on. 4.b. Chemica l Ox ida t io n : Oxi d at i on processes
u tilizin g ch em ical o x i d i zers su ch as p e ro x i d e s esp ecially i n t h e presence of ul t r avi o l e t l i ght i s a wel l

- known technology utilized in th e production of high purity i ndust r i a l wat e r. Al t hough t h ese sy st em s can be very effective, especially at lo wer i n fl uent concent r at i ons, foul i ng and m a i n t e nance can resul t i n hi gher th an expect ed cost s. Addi t i onal l y peroxi des are dangerous

com pounds whi c h can becom e unst abl e and even expl osi v e when not properl y st abi l i zed. 4.c. Vapor Phase E x tracti on : Vapor phase extr act i on of oi l y and greasy com ponent s from oi l y bi l g e wat e r usi ng supercri t i cal C O 2 or st eam can be very effect i v e but cost s t e nd t o be hi gh due t o th e hi gh cost of heating and cooling. Studies are still being done on the ext e nt of recovery of carbon di oxi de from bi l g e wat e r and other econom i c concerns on th e process i n cl ude th e
recom p ression costs on the CO2 system

. 4.d. Surface Modified Filtration Devices: Granul ar
su b s trates an dab so rb en ts o r cartrid g e filters can b e
m odi fi ed wi th “curabl e pol y m eric surfactants” (referred to as “MYCELX”) which have affinity for em ulsified dropl et s (Fi gure 2). These devi ces are general l y used post

- OW S t o rem ove hi ghl y em ul si fi ed m a t e ri al s (Fi gures 3-6) and t o bri ng th e effl uent concentr at i on t o bel o w 1 ppm . These uni t s have affi ni t y for organi c
com pounds and do not devel op additional differential pressure i n t h e presence of very th i c k oi l s or under hi gh l o adi ng condi t i ons. Another advant age of th ese uni t s i s th e tim e in v a rian ce o f th e affin ity reactio n , resu ltin g in a fi xed foot pri n t

. A fi xed si ze uni t can handl e i n fl uent concentr at i ons over 2000 ppm and at fl ow rat e s from 5- 150 gpm wi t hout affect i ng t h e effl uent concent r at i on wh ich will rem a in co n s tan t at well b e lo w 5 p p m . Th e sp en t filters can b e u s edas an altern ativ e fu el if feasib le. Th e d i sad v a n t ag e o f th is u n it is th at th e sp en t filters cannot be di scarded i n t o th e sl udge t a nk wi thout shreddi ng.
Fig . 2 : Pa rtia lly Sa tura te d vs. Unsaturated Filter

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Fi g.4

Fi g. 3 and Fi g. 4 MYCE L X fi l t ers empl oyed i n treatment of Naval bi l g e w a ter at 300 gpm (Photos by Kirk Abbott). Fi g. 5

Fi g.6

Fi g. 5 and Fi g. 6: MYCE L X fi l t ers cl eani ng emulsified o il o n o il drilling rig . Clea n wa ter being discharged directly overboard

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. Membrane Filtration (Ultrafiltration): It is d e term in edth at Ultrafiltratio n is a v i ab le sep a ratio n process for the treatm e nt of b ilg e water fo r co m p lian ce wi t h overboard di scharge. C o mm e rci a l tr eat m e nt s of bi l g e wat e r usi ng m e m b ranes i n cl ude t hose wi th noncellulosic and ceram ic substrates. Non-cellulosic

m e m b ranes are abl e t o capt u re m o st organi c com pounds over 1000 (Dal t ons) M o l ecul a r W e i ght , and are

co n s eq u e n tly su scep tib le to irrev e rsib le m e m b ran e foul i ng. C e ram i c m e m b ranes have been t e st ed and used in n a v a l sh ip s fo r treatm e n t o f o ily b ilg e water with general l y good resul t s . They requi re peri odi c cl eani ng and m a intenance and are overwhelm ed by concentrated sl ugs of i n fl uent . C o m b i n ed C e nt ri fugal sep a rato r/Mem b ran e Ultrafiltratio n system s an d Ultrafiltratio n / Mem b ran e Distillatio n system s h a v e also been i nvest i g at ed for t r eat m e nt of l a rge vol um es of bi l g e wat e r th at cont ai n hi gh concent r at i ons of em ul si fi ed and free-phase oil, as well as suspended solids.

4.f. Fl occul a ti on: Flo ccu latio n u n its are u tilizedin conjunct i on wi t h hi gh perform ance gravi t y separat i on devi ces (general l y cent r i f uge) t o good effect . Effl uent concent r at i ons bel o w 15 ppm are obt ai nabl e wi t h t h ese sy st em s. C e ntri fuge sy st em s t e nd t o be capi t a l and

m a in ten a n ce in ten s iv e ren d e rin g th em co stly to o p e rate, however they are able to ach i e ve si gni fi cant reduct i on i n
o il co n cen tratio n s ev en with som e what em ulsified waste stream s. It is n ecessary to g e t th e in flu e n t to fairly lo w
co n cen tratio n s in o r d e r fo r th e flo ccu latio n system to

wo rk o p tim ally. Flo ccu latio n system s can b e overwhel m ed by hi gh l o adi ng resul t i ng i n gel l i k e fl occul a nt whi c h i s di ffi cul t t o handl e and requi res shut down and m a i n t e nance. Oft e n secondary t r eat m e nt wi th carbon, cl ay or ot her absorbent i s requi red.

5. DISCUSSION The t echnol ogi es for det ect i on, i d ent i f i cat i on and

en fo rcem en t o f o ily b ilg e water d i sch a rg es n o t in

com p liance with local and IMO regulations exist and are
v i ab le. Th e will to im p l em en t an den fo rce th ese regul at i ons appears t o be t h e l i m i t i ng fact or i n reduci ng illeg a l o ily b ilg e water d i sch a rg es.

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- 8 It i s not possi bl e t o sel ect a si ngl e bi l g e wat e r tr eat m e nt t echnol ogy as th e best for al l cases. Sel ect i on of an optim um design will depend on throughput, loading, degree of em ul si fi cat i on and t h e condi t i ons under whi c h t h e uni t s m u st operat e , or robust n ess t h e uni t m u st exhi bi t

. C e rt ai nl y convent i onal OW S i s wel l est abl i s hed and i s t h e si ngl e best t echnol ogy for m a ki ng th e fi rst prim ary cut. OW S are fully capable of achieving num bers bel o w 15 ppm i n t h e presence of di scret e i mm i sci b l e phases. B i ol ogi cal uni t s funct i on very wel l under condi t i ons of m oderat e t h roughput wi t h cont rol l e d l o adi ng. Loadi ng spi k es can overwhel m and shut down bi ol ogi cal uni t s
. C a pi t a l cost s t e nd t o be hi gh and t h e uni t can becom e tr oubl esom e i f proper m a i n t e nance i s not perform ed. M e m b rane separat i on t echnol ogi es such as
u ltrafiltratio n are d e sirab l e in circu m stan ces wh ere loading is fairly low and uniform . These system s can becom e overwhel m ed due t o foul i ng or overl oadi ng of t h e m e m b ranes i n whi c h case shut down and cl eani ng and

or m e m b rane replacem ent m u st take place. Additionally

m e m b rane uni t s do not have fi xed foot pri n t s and requi re
m o re room or dwel l t i m e i n cases of hi gher l o adi ng or higher throughput. Initial capital outlay is high. Surface

m o d i fiedfiltratio n d e v i ces ex h i b it h i g h p e rfo rm an ce an d t h e hi ghest degree of robust n ess i n regard t o l o adi ng and throughput. These devices will not shutdown in the

co n d itio n o f h i g h lo ad in g an dwill m a in tain a co n s isten tefflu e n t co n cen tratio n an dlo w o p e ratin g p r essu re. In itial capital costs are low, but repl acem ent filters are required,

an dth e sp en t filters m u st b e u s edfo r fu el o r sto r ed

. C e nt ri fugat i on / Fl occul a t i on uni t s exhi bi t very good overal l perform ance but th e centr i f uges requi re hi gh d e g r ee o f m a in ten a n ce an din itial cap ital o u tlay is h i g h

. Flocculation units involve ch em ical addition and can be overwhel m ed i f centr i f uges are not worki ng properl y and i n fl uent concent r at i ons ri se t oo m u ch above 200 ppm , dependi ng on th e th roughput

. At t h i s t i m e evaporat i on, supercri t i cal C O 2 and ot her chem i cal separat i on technologies do not seem to be utilized in the field very
m

u ch. Addi t i onal l y operat i ng cost s for t h ese t ypes of devi ces are hi gh. C o st t o operat e can range from 2$/ 1000gal l ons or m o re t o l e ss t h an 50 cent s / 1000gal l ons dependi ng on t h e si ze of t h e sy st em , t h e l o adi ng and degree of em ul si fi cat i on and t h e uni t em pl oy ed. 5. CONCLUSION The t echnol ogy for det ect i ng and regul at i ng bi l g e wat e r di scharge now exi s t s . Enforcem ent of such regul at i ons i s
everm o re present, and the potential for significant fines cont i nue t o m ount for m a jor vi ol at ors. There are a num ber of opt i ons i n regard t o t echnol ogy for t h e t r eat m e nt of oi l y bi l g e wat e r. The aut hor does not bel i e ve any si ngl e t ype of uni t i s opt i m al in all circu m stan ces. Th e selectio n o f th e ap p r o p r iate u n it will d e p e n do n th e typ e o f sh ip (i.e. steam sh ip v s
. g a s t u rbi n e), t h e am ount of l o adi ng, t h e degree of

em ul si fi cat i on, th e th roughput and th e robustn ess requi red of t h e uni t , i n addi t i on t o capi t a l and operat i onal expenses. Eval uat i on of average bi l g e wat e r com posi t i on and degree of em ulsification should be taken into account in selectio n o f o ily b ilg e water treatm e n t eq u i p m en t. Peri odi c spi k es i n i n fl uent concentr at i ons shoul d al so be t a ken i n t o consi d erat i on. The tr eat m e nt uni t shoul d be abl e t o operat e wi t hout shut down when chal l e nged wi t h isolated slugs ten tim es the average loading or higher. Acknowledgements:
The author woul d l i k e t o acknowl e dge Kirk Abbott (Director of Engineering, MYCELX Technologies Corporation, USA) for his work and effort on this paper and correspondi ng present a t i on at IC M E S 2003.

Primary References : 1.C l ean W a t e r Act Sect i on 312 (as am ended by Sect i on 325 of FY96 Nat i onal Defense Authori zat i on Act )

. 2. Nature of Discharge Report for Surface Vessel Bilgewater/Oil-W a ter Separator Discharge as am ended by UNDS.
3.Int e rnat i onal C onvent i on for th e Prevent i on of Pol l u t i on from Shi p s, 1973, as m odi fi ed by t h e Prot ocol of 1978 rel a t i ng th eret o (M AR POL 73/ 78). The 2001 am endm ent - Adopt i on: 27 Apri l 2001; Entry i n t o force - 1 Sept em ber 2002. 4. EPA 40CFR Part 9 Chapter VIII
5.“R em oval of organi c pol l u t a nt s and warfare agent s utilizing surface m odified filtra tion devices”, presented at NDIA 2003 – Hal Al per, M Y C ELX Technol ogi es C o rporat i on. ( S

econdary Ref e rences avai labl e upon request )

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