Note: Descriptions are shown in the official language in which they were submitted.
`:
~3~66
8ackgrount o~ th~ Snventlon
Th~s al~closure ?ert~ln~ to organic waste ~roce~sl~q.
Moro particularly, ~hl~ dlsclo3ure p~rtain~ to n ~ethod and
app~ratus for processing hiodogr~t~ble org~nio wasta in an
~qu~ou~ ~ediu~. The disclosure al~o pert~ins to fi~ appara-
tus ~nd proces6 ~or deterslning the ~iochemical ox~gen
~em~nd ~OD) of ~n organlc waste ~n ~n aqu~ou~ mediu~.
A vsriety o~ wethods ~or ~he di3rosal oi org~nic
w~e, ~lther industrl 1 or agricultural. Are av~l~a~le.
Some of the~e ~etho~s, such as buri~ d-flll, ~uwplng at
se~, and the lik~, h~Ye 3 n~gatlve ~nvi~Dn~en~al ~pa~t ~nd
ar~ 30t deslr~ble. On the other h~nt, ~e~ho~s ase ~vail~ble
or convertinS orgrnic w~t- to a:30urc~ o~ en~rgy and/o~ a
usnbl- produ~t and lnclude, ~ong othe:s, biologio~l a~robic
ferment~tion, biological ~naero3:ie ~erment~tion, thcr~ophilie
aor~7ic ~iS1gl:~tlon, dest:u ti~ dlsit1llhtio~, (inolu~ing hy~_o-
carboni2ntlon ~1 pyroly~ n elr.er~t~on. ~. J. J~well
et al., "Methar.e Gen~r~tlon ~ m Ag:rieultusal W~t~s~QVi~W
o~ Concept and ~utu~ ppl:Lestlon~, P~p~r . ~74-107,
pr~ n:e~ A'C t~- 1974 ~orth~e~t ~gional ~-et.~ng o~
,
B ~ :
.
:
,~^..,..1 .
. - ~ 6fi
.
American Society of Agricultural Engineers, West Virginia
University, Morgantown, West Virginia, August 18-21, 1974.
Of this latter group, biological anaerobic fermentation
appears to be the most promising and has received consider-
able attention in recent years.
Current interest Ln blological anaerobic fermentation
appears to be due, at least in part, to the development of
the anaerobic ilter. See, for example, J. C. Young et al.,
Jour. Water Poll. Control Fed., 41, R160 (19691; P. L.
~cCarty, "Anaerobic Processes", a paper presented at the
3irmingham Short Course on Design Aspects of siological
Treatment, International Associatlon of Water Pollution
Research, 3irmingham, England, September 18, 1974; and J. C.
Jennett et al., ~our. Water Poll. Control Fed., 47, 104 (1975).
The anaerobic filter basically is a rock-filled bed similar
to an aerobic trickling filter. In the anaerobic filter,
however, the waste is distributed across the bottom or the
. filter. The flow of waste is upward through the bed of rocks
so that the bed is completely submerged. Anaerobic micro-
organisms accumulate in the void spaces between the rocks and
provide a large, active biological mass. The effluent
typically is essentially free of biological solids. See
J. C. Young et al., supra at R160.
The anaerobic filter, however, is best suited for the
treatment of water-soluble organic waste. J. C. Young et
al., supra at R160 and R171. Furthermore, verv long reten-
tion times of the waste in the filter are required in arder
to achieve hlgh reductions in the chemical oxygen demand
(COD) of the waste to be treated. That is, depending upon
the COD of the waste stream, reductions in such COD oi' from
36.7 percent to 93.4 ercent requircd retention times of
-2-
.
, ~,
.~,:.. . ~
: ~;
.
. ~34~i6
.
, from 4.5 hours to 72 hours. J. C~ Young at al., supra at
R167. In addition, such results were achieved tith optimized
synthetic wastes which were balanced in carbon, nitrogen, and
phosphorus content and which had carefully adjusted pH values
Accordingly, there remains a great need for a waste pro-
! cessing method which can tolerate the presence of solids in
the waste stream and which can more rapidly process the waste
on an "as is" basis,
Summary of the Invention
In accordance with the prssent invention, there is pro-
vided a method for processing biodegradable organic waste in
an aqueous medium which comprises serially passir.g an organic
waste-containing aqueous medium through a first immobilized
microbe bioreactor and a second immobilized microbe bioreactor,
in which:
A. the first bioreactor is a hydrolytic redox bio-
. re~ctor containing a porous inorganic support which is suit-
able for the accumulation of a biomass, and
~. the second bioreactor is an anaerobic bioreactor
containing a porous inorganic support ~hich is suitable for
the accumulation of a biomass.
If desired, however, the second bioreactor can be an
anaerobic bioreactor comprising a controlled-pore, hydro
phobic inorganic membrane which contains a parous inorganic
support which is suitab}e for the accumulatian of a biomass.
Also in accordance with the present invention, there is
provided an apparatus for processing biodegradable organic
waste in an aqueous medium which comprises a first immobilized
microbe bioreactor sexially connected to a second immobilized
microbe bloreactor, in which:
-3-
:;
: ~ ~:
'~
t ;~ , ~
~L139L~
A the first bioreactor i~ a hydrolytic redox blo-
re~ctor containing a porous inorganic 3upport whlch is suit-
able for th~ accumulation of a biom~ss, Rnd
~ the ~econd bior~acto~ is an an~ero~lc kioreactor
co~taining a porous inorglmic support which ls s~itdble for
the accw~ulation of ~ biol~ss
Again, if de3ired, the ~econd bior~actor can be an
an~erobic bioreactor comprlsing ~ controlled-pore, hydro-
phobic inoryanic ~embrane which contain3 a porous inorganic
~upport whlch 18 suitable ~or the accumulntion of a biomass
Thc present invention al~o provldes an apparatus for
the det-rmination o~ the biochemical oxygen d~mand o~ an
organic waste in an ~queous medlum which csmpri~es a sampling
and/or sensing means serially connected to an immobilized
mi~robe bioraactor which ln ~urn is serlally connected to a
s~mpling and/or sens~ng means, ln which the bioreac~or is an
~ero~ic ~ioreactor containlng a porous inorganic support which
iQ ~uita~le for th~ ~ccu~ulatlon of a ~io~a e,
The present i~vcntlon ~urther provides ~ method for the
determination of the biochemical oxygen demand of an organic
wnste in ~n asu~ous medium whLch comprises s~-ially passing
a~ organic waste-containing aqueous ~edlu~ through a fi~st
~ampling ~nd/or s~nsin~ means, an immobiliz2d mlcrobe bio-
ra~ctor, ~nd a second 3a~plins L~djor ~en~ing m~ans, in
which the bioroactor is n aeroblc bior~acto; cont~ininS a
porou- inorganic ~upport which ~3 ~uitable ~or the accumu-
l tion of a biom ~3.
3rief DescrlPtion o~ the Drawings
: . The drawings :(Fig. 1 & Fig. 2) illustrate two embodi- :
: ments of the present invention as described by Examples
1 and 2, and E~amples
: - 4 -
,
1`:'-- "'`
I ` ~ 3L3~6~
.
4-7, respectively, which embodiments comprise treating
sewage or other waste to give an effluent having a signi-
ficantly reduced oxygen demand and methane as a gaseous pro-
duct.
Detailed Description of the Invention
As used herein, the term "biodegradable" meang only that
at least some of tha organlc waste to be treated must be
capable of being degraded by microorganisms. As a practical
matter, at least about 50 percent by weight of the organic
waste usually will be biodegradable. It may be necessary or
desirable, however, to utiliza in the processinq method of
the present invention waste having substantially lowsr
levels of biodegradable organic matter.
Thus, the organic waste or the aqueous medium containing
such waste can contain non-biodegradable organic matter and
inorganic materials, provided that the organic waste and
.aqueous medium are essentially free of compounds having signi-
ficant toxicity toward the microbes present in aither reactor.
In general, the nature of the aqueous medium is not cri-
tical. In most instances, water will constitute at least about50 percent by weight of the medium. Preferably, water will
constitute ~rom about 80 to about 98 percent by weight of
the aqueous medium.
Frequently, the waste stream to be treated by the ~ro-
cessing method of the present lnvention can be used without
any pretreatment. Occaslonally, i' may be desirable or
necessarv to dilute the waste stream with water, to separate
;~ ~from the waste stre~m excessive amounts of solids or excessivaly
coarse sollds which might interfere with the pumplng equlpment
necessary to move ~- a~ueous medlum through the processlng
.~ _5_
: .,
; ~ , : .
~: ~''
: ~.
:
. . ~.3~ ;6
apparatus of the present Lnvention, or to increase the pH of
the a~ueous medium by, for example, the additlon of an
inorganic or organic base, such as potassium carbonate,
sodium hydroxide, triethylamine, and the like. Alternativel~,
801id or es3entially nonaqueous organic waste can ba diluted
! with water as desired.
The term "bioreactor'', as used herein, is a contraction
of "biochemical reactor" and, thersfore, means that the
chemical transformations or conversions taking placa therein
are carried out by living organisms. ~he term "immobilized
microbe bioreactor" is used to identify such living organlsms
as microbes which are in an immobilized state ~as that term
is used by those having ordinary s~ill in the art).
As already indicated, both the first and second bio-
reactors of the processing method and apparatus of the pre-
sent invention contain a porous inorganic support which is
suitable for the accumulation of a biomass. In the case o~
. the second bioreactor, the inorganic support optionally is
contained within a controlled-pore, hydrophobic inorganic
membrans.
As a matter of conveniencaj ths lnorganic support in
the two bioreactors will be of the same ty2e, although such
is not required. Preferably, the inorganic support in each
bioreactor is a porous, high surface area inorganic support
which is suitable for the accumulation of a high biomass sur-
face within a relatively 3mall volume. More preferably, at
least 70 percent of the pores of the inorganic support will
have diameters at least as large as the smallest major dimen-
sion, but less than about five times the largest major dimen-
~ion, of the microbes present in the bioreactor. Most
-6-
. :.
:
~ . ~ '
: .
` :: ` .:, , :: . . ~:, ": ;, - ' ` . ` , , ' : ' ! . . :
~L3~66
pre~erably, the average dlameter ot the pores of the inorganic
support is Ln the range of ~rom about 0.3 to about 220~.
As used herein, the expression "high sur~ace area inor-
ganic support" means an inorganic support having a surface
area greater than about 0.01 m2 per gram of support. In gen-
eral, surface aroa is determined by lnert gas adsorption or
the 8.E.T. method; see, e.g., S.J. Gregg and K.S.W. Sing,
"Adsorption, Surface Area, and Porosity", Academic Pre5s, Inc.,
New York, 1967. Pore diameter~, on the other hand, are most
readily determined by mercury intrusion porosimetr~l; see, e.g.,
N.M. Winslow and J.J. Shapiro, "An ~nstrument for the Measure-
ment of Pore-Size Distribution by Mercury Penetration'', ASTM
Bulletin NQ. 236, Feb. 1959.
The inorganic support in general can be either sLliceous
or nonsiliceous metal oxides and can be either amorphous or
crystalline. Examples of siliceous materials include, among
others, glass, silica, halloysite, ~aolinite, cordierite,
wollastonite, bentonite, and the like. Examples of nonsili-
ceous metal oxides include, among others, alumina, spinel,
apatite, nickel oxide, titania, and the like. The inorganic
support also can be composed of a mixture o~ siliceous and
nonsiliceous materials, such as alumina-cordierite. Cordierite
and clay (i,e., halloysite and/or kaolinite) materials such
as those employed in the examples are preferred.
For a more complete description of the inorganic support,
see application Serial No. 833,278, filed September 14,
1977, in the names of Ralph A. Messing and Robert A. Oppermann,
now U.S. Patent No. 4,153,510.
As already indicated, the inorganic support in each bio-
reactor provides a locus for the acoumulation of microbes.~ha ~orQu9 n~ure o~ :ha support not only permits the
.
, ~ ! - . . , ' ' , . . ~ :' ::: . : , . , ,: ,
:', ' ',. '' :` : : . ' , ., :.,: .-:' , ' '.. .,. ' I
'~13~6
accumulation o~ a relatively high biomass per unit volume of
bioreactor but also aids ln the retention of the biomass
within each bioreactor.
As used herein, the term "nticrobe" (and derivatlons
thereof) Ls meant to include any microorganism which degrades
organic materials, e.g., utilizes organic materials as nutri-
ents. This ~erminology, then, also lncludes microorgani9ms
which utilize as nutrients one or more metabolites of one or
more other microorganisms. Thus, the term "microbe", by way
of illustration only, includes algae, bacteria, molds, and
yeasts. The preferred microbes are bacteria, molds, and
yeasts, with bacteria being most preferred.
In general, the nature of the microbes present in each
bioreactor is not critical. It is only necessary that the
biomass in each bioreactor be selected to achieve the desired
results. Thus, such biomass can consist of a single microbe
species or several species, which species can be known or
unknown (unidentified). Furthermore, the biomass in each bio-
reactor need not be strictly aerobic or strictly anaerobic,
provided that the primary functions of the two bioreactors are
consistent with their designations as hydrolytic redox and
anaerobic bioreactors, respectively. The term "primary func-
tion" as used herein means that at least 50 percent of the
- biomass in each bioreactor functions in accordance with the
reactor designation.
Stated differen-tly, the demarcation line or zone between
a hydrolytic redox function and an anaerobio function is not
critical and need not always lie between the two reactors.
In practice, such demarcation line or zone can vary from the
midpoint of the first bioreactor to the midpoint of the second
bioreactor and to some extent can be controlled by regulating
the amount of oxygen dissolved in the waste stream.
As used herein, the term "hydrolytlc redox'' refers to
the function of the first bloreactor which i9 to break down
any macromolecules present lnto smaller units, e.g. monomers
and oligomers, by hydrolysis and oxldation-reduction reactions.
In so doing, the first bioreaator also serves to deplete the
aqueous medium of dissolved oxyqen.
It should be apparent, therefore, that the first bio-
reactor is not an aerobic bioreactor as the term "aerobic"is used in the prior art. The aqueous medium is no-t aerated
continuously or even saturated with air or oxygen. 3ecause
residual oxygen in the medium i9 depleted, however, at least
some oxidation-reduction occurs aerobically.
Examples of microbes ~hich can be employed in the hydro-
lytic redox bioreactor include, among others, strict aerobic
bacteria such as Pseudomonas Eluorescens, Acinetobacter
-
calcoaceticus, and the like; facultative anaerobic bacteria
such as Escherichia coli, Bacillus subtilis, Stre~tococcus
faecalis, Staphylococcus aureus, Salmonella typhimurium,
Klebsiella pneumoniae, Enterobacter cloacae, Proteus vulqaris,
and the like; anaerobic bacteria such as Clo~t~idium
butyricum, Bacteroides fra2ilis, Fusobacterium necroohorum,
Leptotrichia buccalis, Veillonella parvula, Methanobacterium
_ _ ,
formicicum, ethanococcus mazei, ?Nethanosarcina bar~eri,
Peptococcus anaerobi~s, Sarcina ventriculi, and the like;
molds such as Trichoderma viride, .~s~irqillus niger, and the
liXe; and yeasts suoh as SaccharomYces cerevisiae, Saccharomyces
ellipsoideus, and the like. Obviously, the hydrolytic redox
bioreactor should not contain either strict aerobes or
strict anaerobes only.
~4i~
Examples of mlcrobe3 which can be utilized in the
anaerobic bioreactor lnclude, among others, ~acultatLve
anaerobic bacteria, anaeroblc bacteria, and yeasts such aq
those listed above. Of course, the anaerobic bioreactor
should not contain strict aerobes only, although the presence
of such microbes usually is not harmful.
As already pointed out, the microbes employed ln each
bioreactor are selected on the basis of the results desired.
I~ a particular product is not recuired, the choice of
microbes can be made on the basis o~ wa9te converqion e~iciency,
operatlng parameters such as temperature, flow rate, and the
like, microbe availability, microbe stablllty, or the like.
I~, on the other hand, a particular produot i9 desired, the
microbes typically are selected to maximize production ol
that product. By way of illustration only, the table below
indicates some suitable combinations oi miorobes whioh will
yield the indicated produot.
~.
::
~3~
~ a ~ ~ ~ nl c c c c c c ~ O O ,~
O ,~ ,~ C' V ~ '~ ~CJ ~; .C .~C ~ ~ ,C O ~ ~
~ ~ ~ æ ~ x ~
U ''
~ rl ~
,~ iq v ~ ~ Ul ~ .i
C rl ~ ~ ~ . ~ aJ ~ V
~ O O ~ ~ I U .,~ ,. ~ ~ ~ ~
c ~ e ~ ~ ~ ~ ~n o u 0~ i~
O O O . ~ R ~1 ,C X I C (~ ~ .~ O 5-1 O
U q . N ~ ~ ~1 U A ~ C ~3 h I ~1 0 C 3
~0 Ll h~J O U h C ~: i~ V
V:ll U UUo U U vu h U Uo U ~U O U if ~!l i
~U S~ A 8 ~ A ~ .. J IrJ 8 8 A~ eO ~ ~ ' I .
Ao ~ C C C C C a C C C i'J 11 h . . I
a~ ~v S S S S S Sv S Sv S a u u o o
æ ~ ~ æ æ ~ æ æ æ æ ~ tn ~ U U ul
-'1
ol
R I a~ I rl I U ~ I
R ~ 3 1 ~ I h 1~
ol ~J¦ h¦ o~ 31 ~1 ~1 ul a)1 ~ h¦ .11
l ul~ $1 ol 81 3J ~I cl u~l nl cl ~1 81
U ~ h ¦ o ~ 5
$1 ~1 ol ~ ^col ol ~ Su
81 ~1 81 ~1 01 ~U ¦ 3 1 U ¦
:
o
1~34~66
In general, the microbes are Lntroduced lnto each bio-
reactor in accordance wlth aonventional procedures. For
exampla, the bioreactor can be seeded with the desired microbes,
typically by circulating an aqueous microbial suspension through
the bioreactor. Alternatively, the microbes can be added to the
waste stream at any desired point. }n cases where the waste
stream already contains the approprlate types of mlcrobes, the
passage of such waste through the t~/o bioreactors will in due
course establish the requisite microbe colonies therein. Of
course, the bioreactors can be a~sembled using inorganic
support having microbes immobllized thereon.
~ he second bioreaator optionally contains a controlled-
pore, hydrophobic inorganic membrane. As used herein, the term
"membrane" refers to a continuous, formed article, the shape and
dimensions of which are adapted to process requirements. Thus,
the membrane can be a flat or curved sheet, a three-dimensional
article such as a rectangular or cylindrical tube, ox a complex
monolith having alternating channels for gas and aqueous medium.
A9 a practical matter, the membrane most often will consist of
a cylinder, open at both ends to provide passage of aqueous
mediu~ through its length. Wall thiakness is not critical,
but must be suf~icient to permit the membrane to withstand
process conditions without deformation or breakage. In gen-
eral, a wall thickness of at least about 1.0 mm is desired.
The membrane can be either siliceous or nonsiliceous
metal oxides. Examples of siliceous~materlals include, among
others, glass, silica, wollastonite, bentonite, and the like.
Examples of nonsiliceous metal oxides include, among others,
alumina, spinel, apatite, nickel oxide, titania, and the like.
Siliceous materials are preferred, with glass and silica being
,.
12-
. .
~ ' : '
~ll.a3~6~:;
most preferred. Of the nonslliceous metal oxides, alumlna is
preferred.
The membrane mu9t ha~e a controlled poro91ty such that
at least about 90 percent of the pores have diameters of from
about 1O0A to about 10,000A. Preferably, the pore diameter
range will be from about 900A to about 9,000A, and most pre-
ferably from about 1,500 to about 6,000R.
Methods of preparing inorganic membranes having controlled
porosity as described above are well known to those ha~ing
ordinary skill in the art and neèd not bs discu8sed in detail
here. See, e.g., U.S. Patent Nos. 2,106,764, 3,485,687,
3,549,524, 3,673,144, 3,782,982, 3,827,893, 3,850,849, and
4,001,144, British Patent Specification No. 1,392,220, and
Canadian Patent No. 952,289. In addition, variou3 porous
inorganic materials are commercially available which can be
formed into shaped articles by known methods. Among suppliers
of such porous inorganic materials are the following:
Alcoa, Catalytic Chemical Co. Ltd., Coors, Corning Glass
Works, Davison Chemical, Fuji Davison Co. Ltd., ~arriscns &
Crosfield (Paci~ic) Inc., Xaiser Chemicals, Mizusawa Kagaku
Co. Ltd., (Chemical Division), and Shokubai Xasei Co. Ltd.
As a second recuirement, in addition to controlled 2or
sity, the inorganic membrane must be hydrophobic. Since the
inorganic materials of which the membrane usually is composed
are not inherently hydrophobic, the property of hydrophobicity
normally must be imparted to the membrane by treating it
either before or after the membrane is shaped or formed. As
a ~ractical matter, such treatment Will be a post-formation
treatment. The nature~o.^ the treatment is not critical, and
essentially any treatment can be employed which will render
the membrane hydrophobic. The property of hydrophobicity,
~-13-
- '
' ~
,
.
~3~66
however, must be imparted throughout the entire void volume
o~ the membrane, and not just to the external surface areas.
~ydrophoboclty i3 most conveniently lmparted to the
shaped or ~ormed membrane by immersing the membrane in an
organic solvent which oontains dissolved therein a suitable
hydrophobic reagent, removing the membrane from the solvent,
and allowing it to air dry. Although the concentration o~ the
reagent is not critical, an especially useful concentration
range has been found to be from about 3 to about 25 percent,
weight per volume of solvent. A most convenient concentration
is 10 percent. Essentially any solvent in which the hydro-
phobio reagent is soluble can be employed. Examples of suit-
able solvents inolude, among others, hexane, cyclohexane,
diethyl ether, acetone, methyl ethyl ketone, benzene, toluene,
the xylenes, nitrobenzene, chlorobenzena, bromobenzene, chloro-
form, carbon tetrachloride, and the like. Examples of suitable
hydrophobic reagents include, among others, natural waxes such
as spermaceti, beeswax, Chinese wax, carnauba wax, and the
like; synthetic waxes such as cetyl palmitate, cerotic acld,
myricyl palmitate, ceryl cerotate, and the liXe; aliphatic
hydrocarbons such as octadecane, eicosane, docosane, tetraco-
sane, hexacosane, octacosane, triacontane, pentatriacontane,
and the like; polycyclio aromatic hydrocarbons such as
naphthalene, anthracene, phenanthrene, chrysene, pyrene, and
the like; polybasic acids such as Empol Dimer Acid and Empol
~rimer Acid (Emery Industries, Inc.); polyamide resins such
as the Emerex Polyamide Resins ~Emery Industries, Inc.);
water-insoluble polymeric isocyanates such as poly(methylene-
phenylisocyanate) which is commercially available as PAPI
(Upjohn Company); alkylhalosilanes such as octadecylt~ichloro- `
silane, di(dodecyl)difluorosilane, and the like; and similar
-14- ~
' ~ :
1~34~
materials. The alkyhalosilanes are preferred, with octadecyl-
trichlorosilane being most preferred.
~ rom the foregoing, it should be apparent to one having
ordinary skill in the art that essentially any hydrophobLc
reagent which wlll adhere to the inorganic membrane with a
reasonable degree of permanence can be employed. Such
adherence can be by purely physical means, such as van der
Waalq attraction, by chemical means, such as ionic or covalent
bonding, or by a combination of physical and chemical means.
It also should be apparent to one having ordinary skill
in the art that the configurati.ons of the two bioreactors
are not critical to either the processing method or the
apparatus of the present invention. Thus, the present
invention comprehends any confLguration which i9 not lnconsistent
with the instant disclosure. ~ost often, each bioreaator will
be a conventional cylindrical or tubular plug flow-type reactor,
such as those described in the examples. ~ccordingly, each
bioreactor typically comprises a cylinder or tube open at both
ends which contains the inorganic support. Typically, such
cylinder is composed of any suitable material which is imper-
vious to both gases and liquids. Suitable materials include,
among others, glass, stainless steel, glass-coated steel,
poly(tetrafluoroethylene), and the like. Each bioreactor
optionally is jacketed. The jacket, if present, can be con-
structed from any of the usual materials, such as those listed
for the bioreactcrs.
It will be appreciated by thcse having ordinary skill in
the art that when evolved gaseous products are tc be contained
or otherwise handled, the configuration of the second bLo-
reactor must be appropriately designed. Such design require-
ments, however, are well ~md~r~tood by those having ordinary
.
skill in the art ---
` ~ -15-
,
~3~
In the ca9e o~ the 3econd bloreactor, the bloreactor
or cylinder optionally compri3es the controlled-pore, hydro-
phobic inorganic membrane. The bioreactor still can be, and
pre~erably is, jacketed, especially when it ls either neces-
3ary or desirable to contain, lsolate, analyze, utilize, or
otherwise handle gaseous products evolved during the processing
method of the present invention.
In more general terms, each bioreactor normally will be
shaped in such a manner as to provide one or more channels
for the passage of a fluid. Where multiple channel3 are pro-
vided, such channels can provid~ independent flow of the fluid
through such channels or they can be serially connected. The
aqueous medium can flow through such channels or around such
channels. Thus, the inorganic support can be contained in
such channels or located around such channels. For example,
given the cylindrical bioreactor already described, the inor-
ganic support can be contained within the cylinder or tube.
Alternatively, the cylinder or tube can be jacketed and the
inorganic support can be located between the ~acket and the
cylinder or tube. Hence, the aqueous medium can flow
either through or around the cylinder or tube.
When the inorganic membrane i9 used in the second bio-
reactor, gaseous products will pass from or into the cylin-
drical membrane, depending upon whether the aqueous medium
passes through or around the cylindrical memorane. When the
inorganic membrane i9 not used, gaseous products simply pass
from the bioreaotor liquid phase to a vapor or gas phase.
Gaseous product removal, of course, i9 readily achieved
by the various means ~nown to those having ordinary skill in
; 30 the art. Typically, the gaseous products are simply pumped
away from the second bioreactor. Th:t isj the gas space of
-16-
, . ,. . ,. i, . , . . . ;. .:, .: .: . : : -~ . : - ; .~ ; :
:. " ' :, ' : ~; ~ ' ' .''. :, , ';'' ' j.'. ' ,:,. :., ': ' "': '
~L134$~;6
the second reactor i9 connected to a gas collection means
via a means for maintaining the gas collectlon maans at a
pressure which i~ les9 than that of the second reactor gas
space. Alternatively, when the inorganic membrane is
employed-in the 3econd bloreactor, a liquid 301vent having
a high affinity for the gaseous products (i.e., in which the
gaseous product3 have a high degree of solubility) can be
circulated about or through the membrane in what normally
would be the gag side of the membrane. Sultable solvent3
for many gase3 include silicone~ and fluorocarbon~, among
others. The use of such a gas solvent usually ls neither
nece33ary nor desired and, therefore, i9 not preferred.
Since the proce33ing method and apparatu3 of the pre3ent
invention are well-suited for the production of u3able
gase3, it is preferred that the second bioreactor have a gas
removal means attached thereto. When an inorganlc membrane
i3 employed, it i3 pre~erred that the second bioreactor is
sealably enclosed within a ~acket having a gas removal means
attached thereto.
While proces3 temperatures are critical only to the
extent that the microbe3 present in each reactor remain
viable, as a practical matter the proces3 of the present
invention will be carried out at a temperature of from about
10C. to about 60C. Under normal circumstances when the
inorganio membrane is used in the second reactor, both
reactors are maintained at ambient temperature. '~hen the
inorganic membrane is not employed, the first reactor pre-
ferably is maintained at an elevated temperature, i.e., a
temperature above ambient temp-rature. The prsferred tem-
perature range for the first reaotor under such circumstance3
is irom about 30C. to about 40C.
: :
-17-
' ~ '
1~34~66
As already indicat~d, the waste stream to be treated by
the processing method of the present invention ~requently
can be used without any pretreatment. Whether or not pretreat-
ment i9 required is determined largely by the results expected.
3y way of illustration only, various of the examples describe
the treatment of sewage or other waste to give an affluent
having a significantly reduced chemical oxygen demand and
methane as a principal product. Because the methane thus
produced can be employed as a euel, Lt is desLred to minimize
the production of non-euel gaseous by-product~, such as
carbon dioxide. Accordingly, no pretreatment of, e.g., sew-
age is necessary when the anaerobic bioreactor utilizes an
inorganic me~rane. ~hat is, the use of the membrane ~re-
quently results in the production of methane with less than
five percent carbon dioxide content. In order to keep car-
bon dioxide in the methane at acceptably low levels when the
membrane is not used, however, it is necassary to ad~ust the
pH of the sewage to about 8 or above. ~his pH ad~ustment
serves primarily to keep the carbon dioxide, produced by
the microbes, in solution. ~hus, various of the examples
illustrate two preferred embodiments of the process of the
present invention, one cf which utilizes an inorganic membrane
in the anaerobic bioreactor, and the other of which does not.
~he present invention also provides an apparatus eor the
determination of the biochemical oxygen demand (BOD) of a bio-
degradable organic waste in an aqueous medium. Such apparatus
comprises a sampling and/or sensing means serially connected to
an aerobic bioreactor, which bioreactor in turn is serially
connected to a sampling and/or sensing means.
As used hereln, the term "sampling and/or sensing means"
is meant to include a sampling means, a sensing means, and a
sampling and sensing means.
-18-
: :
1~34~66
Accordingly, the sampllng and/or 3ensing means can be
nothing more than a port, fitted wlth, for example, a stopcock
or rubber septum, to provide a means for the manual withdrawal
of a sample from the waste stream. Alternatively, such 3ampl-
ing means can be an automated sampling device which automatic-
ally removes samples o~ a precise si~e at predetermined inter-
vals and stores such samples for iuture handling or analysis.
Examples of suitable sensing means include, among o-thers,
dissolved oxygen sensor, conductivity sensor, ammonium ion
sensor, p~ electrode, and the li~e. Actually, any sensing
means can be used which will detect measurable di~erences
in the organic waste-containing aqueous medium which are the
result oi the biochemical conversions taking place in the
apparatus ior determining 30D.
As contemplated by the pre~ent invention, a sampling and
sensing means can be any combination oi' a sampling means and
a sensing means. For example, an automated sampling device can
be serially connected to an automated device i'or determining
COD by a chromic acid oxidation procedure. Other variations
and combinations, however, will be readily apparent to one
having ordinary skill in the art.
Finally, the two sampling and/or sensing means need not
be physically discrete or separate. That is, with appropriate
connecting and waste stream directing means, a single sampling
and/or sensing means can be employed in the BOD apparatus o~
the present invention, and such use is within the scope oi
.
the instant disclosure. Thus, when using a single sampling
and/or sensing means, the waste stream or a portion thereof
~irst is passed through the sampling and/or sensing means.
The waste stream then enters the aerobic bioreactor. Upon
exiting the aerobic bioreactor, the waste stream or a portion
-19- ,
-,
:
~L~3~966
thereof i5 directed to the sampling and/or sensing means by
appropriate connecting and directing means which are ~"ell
known to those having ordinary sklll ln the art.
A9 a practical matter, it is advisable to avold the use
of a sampling means which can only add to the complexity and
cost of the BOD apparatus. Thus, the use of a sensing means
only is preferred, and the use of a dlssolved oxygen sensor
is most preferred.
Whether or not the sensing means measures di3solved
oxygen, excess oxygen must be present in the aqueous medlum
since the apparatus depends upon aerobic mlcroblal conver-
slons for the determination of BOD. Thus, the bioreactor
is an aerobic bioreactor and requires microbes capable of
functloning aerobically. Thus, the bioraactor cannot con-
taln only strlct anaerobes. Accordlngly, sultable microbes
include those llsted for the flrst bloreactor of the ~aste
processlng apparatus, strlct anaerobes excluded. Otherwlse,
the descrlptlon of such first bioreactor applies equally to
the aerohic bioreactor of the BOD apparatus.
The present invention further provides a process for the
determination of the biochemical oxygen demand of an organic
waste in an aqueous medium which o~omprises serlally passing
an organic waste-containing aqueous medium through a first
sampling and/or sensing means, an immobilized microbe bio-
reactor, and a second sampling and/or sensing means, in
whlch the bloreactor ls an aeroblc bioreactor containing a
porous lnorganic support which is suitable for the accumu-
lation of a blomass.
In general, the process can be carried out at any tem-
perature at which the microbes remain viable and functional.
Practically, the process will be carried out at a temperature
.
~3~;6
of irom about 10C. to about 60C., wlth amblent tempera-
ture being preferred.
As already indicated, the aqueous medium must contain
excess oxygen. That i9, the aqueous medium emerging from
the aerobic bioreac-tor must contain at least some dissclved
oxygen. The need for excess dissolved oxygen, however, does
not require aeration of the aqueous medium. Normal dis301ved
oxygen levels can be adequate i3 bioreactor size and medium
residence times (flow rates) are appropriately adjusted.
sioreactor size and medium residence times are not
crltlcal and are readlly optlmized by one having ordinary
sklll in the art. While medlul~ 30D levels normally are not
critical, it should be apparent that (1~ higher BOD levels
may require serlal dllution in order to maintaln accuracy
and precision, and (2) bioreactor size and medium residence
tlmes are variables which must be considered for any given
BOD values. 8y way of lllustration, the BO~ apparatus
described in the examples in general works well for the
determination of actual media BOD lettels of from about 1 to
about 10 ppm (or mg/l) oxygen. ~ith such apparatus, residence
times greater than about one hour seldom are required.
The present inventlon ls further descrlbed, but not
limlted, by the followlng examples whlch lllustrate the use
of the processlng method and apparatus of the present invention
in the treatment of sewage. Unless otherwise stated, all
temperatures are in degrees Celsius.
The process employed ln Examples l and 2 is descrlbed
below, with reference to Figure l.
Sewage 1 is pumped from container 2 by pump 3 to
; 30 hydrolytic redox bloreactor 4 via rubber tubing ; sealably
connected to the pump and the hydrolytlc redox bloreactor.
,
~L3~66
The hydroLytic redox bloreactor consl3ts of lnner glas~ tube
6 sealably enclosed wlthin glass ~acket 7. The inner glass
tube contains inorganic carrier 8 such as that described in
U.S. Patent No. 4,153,510, whlch is suitable for the accumu-
lation o~ a biomass. Sewage leaving the hydrolytic redox
bioreactor is transported to anaerobic bioreactor 9 via
~ rubber tubing l0 sealably connected to both bioreactors.
The anaeroblc bloreactor consists of inorganlc membrane 11
and glass jacket 12 having exlt port 13. The inorganic
membrane ls fllled wlth addltional lnorganlc carrier 8 and
is sealably enclcsed within the glass jacket. Rubber tublng
lg, sealably connected to the exit port of the jacket, lead~
to pump 15 which removes gas (methane) from air space 16
enclosed by the jacket. Such gas in turn is aollected by
any suitable means such as by the dlsplacement of water in
an inverted vessel (not shown). Sewage effluent 17 then is
transported via rubber tubing 18 sealably connected to the
anaerobic bioreactor, to receiving vessel 19.
The sewage employed in each of the examples was obtained
from the inlet pipe to the Corning, New Yor~, ~unicipal Sewage
Waste Treatment Plant. The sewage was stored at 4-6C. Prior
to use, the sewage was filtered through cheesecloth and glass
wool to remove coarse particulate matter. Sewage was collec-
ted either weekly or biweekly.
~xample l
Pump 3 consisted o~ a Fluid ~etering pump, ~PlG6CSC
(Fluid ~etering, Inc., Oyster 3ay, ~.Y.), which was connected
; to hydrolytic redox bioreactor 4 with~a 14-inch length of
rubber tubing. A 20-inch length of rubber tubing was attached
to the intake side of the pump and led from a flask con-
taining sewage.
-22-
1~3~166
The hydrolytic redox bloroactor consisted of a Pharmacia
A16/20 column (Pharmacia Fin& Chemlczls, Uppqala, Sweden) with
water jacket; the water ~acket was le~t vented to the atmos-
phere. The column was charg~ with 24 g. o~ cordierlte (CGZ)
carrier havlng a por~ diameter distributlon o,8 2-9~ and an
~verage pore diameter o~ 4.S~. The carrler w~ seeded with
Jewage microbes by flowing through the bloreactor sludge
obtained pr~viou~ly ~rom a ~unlcipal anaerobic ~lgestor.
The inorg~nic membrane 11 o~ ~n~erobic ~ior~actor 9 was
a slllca membrane, prep~red in accordance wlth know~ procedures;
s~e, ~or exa~ple, V.S. Patent Nos. 3,678,144, 3,7a2,982, and
3,a27,893. ~he membrane was approximAtely 18 cm. long wlth
cross-~ectional dimenslons o~ 10.5 mm. l.d. and 15.5 ~m. o.d.
The average pore ~iameter o~ the membrane w~s 3500~ with a
pore di~meter di~tribution o~ 2000-3600A. Wall por~sity was
60 percent and pore volume was 0.99 cc/y. The me~brane was
randered hydrophobic by placiug it in 75 ml. o~ ten percent
soIution of octadecyl~rlchlorosllane in acetone and allowing
it to soak overnight. The me~brane th~n was removed from the
solution, wa3hed with 500 ml. o~ acetone, and ~ir-tried.
~ he membr ne was mounted ln a Ph~macia R16/20 water
jacket by means of the ~tAndard rubber sealing ring and
Uh eaded locking ring and was charyed with ten g. of the CGZ
carrier. Both ~loreactors together had a total void or 81uid
volume of ~bout 30 ml.
The two ~ioreactor~ were coupled with about ou~ inches of
rubber tubing. One of the port3 o~ the anaerobic bioreact~r
jack~t was ealed hy attaching ~ ~hort pioce of Iygon tubinj
ther~to and clo~lng the tubing by means of a cl~mp. The
othe~ port was attached to e ~uchler Polystalti~ Pu~p (Buc~ler
Inst~ents, In~., Fort ~e~, ~.J.J with a length oi thick-walled
`:~
*Trade Mark. -23-
~B -
: ~ ^ - - - - . . . . . , . , .. ., , ., :
~34~;6
Tygon tublng. Gas evolved and passed through the me~brane
W~iJ collected by the dlsplacement of water ln a callbr~ted
cylinder inverted ~ni wat2r~illed, large, ~h~llow ve3sel. ~he
rats of gas evolution was ob3~r~ed and the ooll~cted ga3 was
analyzed ~it ~east dally by ma33 speetroJcopy. ~n addition,
the ~hemlcal oxygen demaind (COD) o~ the sewage u~ed ~is feed
and the e~luent emerglng ~ro~ the nnaerobic bloreactor were
deter~lned perlodically by standard, well-known colorimetric
dlchromate oxidation procedures.
~he process wa5 ru~ ~or a perlod o~ about nine months.
Although data wer~ generated on a ~ally ba~iq, except ~or
COD ant~ly~es, weekly averages o~ the data are preaented ln
Table It ln the table, COD analyses ~re averaged where more
than one analysis w~s o~tained per week.
'
*Trade Mark.
, :
,
:~: : . '
.:
, ~ -
~ ~ ,
:
~g :
: D ~ : -24- ~r
~ 3~ 6
.
,
.~ ~1
Cl
~1
;~
~1
C~ o
cl,,,,,,I,,I
.
C I ~ ~ O cr~ O 1~ ~ c
~ ~ ~ I , ~ I o o o , o ~ o ~ ,,
a
o I co ;r ~ O
~ ol~
o c o~
3 ~ ~- co o ~ o co ~r ~ o
ol @~
'
~;
~ :~, o ~ U~ ~ I~ ~ ~ ~ ~ ~o ~r ~ .
3 ~ ~ ~ ~ o ~ o o
'~ ~ CO CD O It1 O O O r
O 7 ~r
~' ~ -3 o O O O CO e'~ d
~:
; 3~ CO Crl ~O _1
: ~ o~ -25-
:
~.~,
,,~ ' ' .
' . ' ` ', ' . ','`.,: , `~ .. , ' `., .` ,.: '':,.,. : '
~13~6~.;
L~ r r
U I
V I I I n rq ~ ` ~O ~q I o
rr~
r ~ U I ~n~n o o n u~ In c~q
8 I, , , l ~ ~ ~ ~ ~ ,~ , ,~
dl ~oq q q ~ a~ ~ ~or r
n I~ ~o ~r
~r d ~!~r~o 5~,r ~ ~ ~ ~O `O `.0 `~
3 d 0 ~ 1~1 O . r O 3 o O O C~ O _I
d .,1 ~r~~ cr ~ In n
e~ ~_ rl e~i ~r rq ~n ~ ~ r- ~
_ O d ~1 ~n Nrq ~r O
~ ~ U ~ ~ ~r ~q ~ o ~ ~I ol ~ ~n
~3 r~ 3 o l~n~ ~ q ~ r ~ rq ~ ~ rq
~ ~r
L~ O ~I rq~orq r~r~n m ~ q r~ ~ ~n ~r
~ c~ ~~ Ln q ~ C~ ~
V~ 5~f r~~n r~ n ~ .:r o ri ~ ~ ~o
o I tq 2 In .:r In In ~ r~
vr--~ r o c~ ~l ~ ~ n
ro ~ o
:l d r~Lqt~ q ~ .D q ~r
~1 a ~r e~l ~ r 3r ~r ~ 3 c r c~r n
~A I . ,
--2 6--
.......
, .
~L3~66
01
~ r~
. . ~
g ~ ~~ ~o ~ C7 m o~ ~ .
U~ O O O O O C7 ~~ ~
~ .,.
~3 c tl ~:1 ' ` ~ ''' ~ '`' , `-
C ~C~ ~1 1 CO Fl ~
U O c ;~ ~o ~ co r~ ,0~ ,,,
Y ~ ~ r~
~ ~ o ol~ ~ o 'c~~ c~;
6 ~ C t~ ~ co o
0 ~ ~
~ CO CO 00 r-l ~ 'J~
ul ~ r O ~
: ~ : ~ , '.. ' ' :''
P~ ~-
~ _ r~ ~ ~O ~ O ~ O ~ C~ ;r
a a o .~
~ i ,
~s ~
C o ~ C~ CO
a ~ ~ o
~1 : -
3 ~ C~ o ~ ~ ~ f
o~ -27- :
-
.
~: '
3L~3~66
Ul
, ,s~
c .R ~
C
X ~
,sc ~ ~ ~ o
~ s 0
o~ ~ ~ o sc ~ o
X ~ ~ ~
~ o U . ~ s
$ æ ~ h
O ~ '
~0
r~ O ~ ~
1 $ ~ ,0 U
U3 ~ 3 0 ~
1.1 V _I ~ ~1 aJ
C ~ ~ ~ ~- ~ $
~ c c ,1 ~
3 ~ n~ 3 C ~ C ~5 0 ~ ",~ ~ 0
Ql ~c .R ~ u~ 'V U
0 n~ ~ 3 ~0 3 - ~ V O X
~a ~ ~ ~ c ~8 ~ v ~
~J 1~5 C ~J 3 h ~ U ~ 01
~ ~ U ~ 3 ~ U 3 ~ ''~ 3
0 n~ 3~1 3 ~ D S ~ O h l~
h ~ 0 ~ E h ~ . ..
1 ~ 3 $ 3 ~
3 ~ O ~ " o
~U ~ ~ 1 3 ~ U ~ C U ~
.rl 1.1 V
U
UI~rl C (~ 3 ~I c S
3 ~ o ,~
111 ~, C Ul a~ 3,~ ~ 3 3
~ ~ V u ~ 0
n~ h U _I ~0 $~ V ~ ~ ~ 8 ~ ~ -
~ ~ æ ~ ~ ~ ~ h ~ S ~ q~ (~
~SSSSS~ SSSS
V ~ ~ S rl~
C' --28--
'
:
3L~3~6
Example 2
The procedure of E~ample 1 was repeated, except that the
hydrolytLc redox bioreactor was charged with 19 g. of CGZ
carrier, the carrier in the hydrolytic redox bloreactor was
not 3eeded, the lnorganic membrane of the anaerobic bioreactor
was an alumina membrane, and the anaerobic bioreactor was
charged with 18.4 g. of the CGZ carrier.
The alumina membrane was prepared in accordance with well-
known procedures. 3rlefly, 300 g. of SA alumina contalning
three percent by weight of carbowax was isostatically pressed
at 1,758 kg./cm.2 (25,000 psi) in a mold which consisted of
a cylindrical mandrel having a diameter of 1.9 cm. and a
cylinder with rubber sleeve having an inner diameter of 3.65
cm. The resulting cylindrical tube had the following cross-
sectional dimensions: i.d., 1.9 cm., and o.d., 2.62 cm.
The tube was turned on a lathe to an o.d. of 2,4 cm. The
tube was about 36 cm. in length. The tube then was fired in
a furnace as follows: The furnace was heated -to ;00 (from
ambient temperature) at 50 per hour and held at 500 for
two hours. The temperature then was increased to l;iO at a
first rate o~ ;0 per hour to 950 and a second rate of 100
per hour to 1550 , at which temperature the furnace was held
for five hours. The furnace then was cooled at 100 per
hour to 950, and at SO per hour to ambient temperature.
The resulting ~lumina controlled-pore membrane had an i.d.
of 1.43 cm., an o.d. of 1.75 cm., and a wall thickness of
2.Q mm. Pore diameter distribution was from 3500~ to 4500~,
with an average pore diameter o~ 4000~. Wall porosity was
46.8 percent and pore volume was 0.22 cc./g. The membrane
was rendered hydrophobic by placing it in ;0 ml. of acetone
-29-
'
.,
~13~66
containlng ten percent octadecyltrichlorosllane and allowing
it to react overnlght at ambient temperature. The membrane
then was removed ~rom the acetone solutlon and wa3hed ~our
times with 50-ml. portions o~ ac~tone. The membrane was
air-dried ~or ~our hours, and then was heated at 120 ~or
1.5 hours.
The data obtalned from this example are summarized in
Table II, again as weekly averages.
'
:'
-30- ;
; ~
. ~ .
:
~.
~3~96~
nl
c
r~ o
a ~ o N
~ ,.
o Ul o '~ I~ g
C~ O
O O O O
r. CO ~
~ ~1 ~ I ~i ~ o o o ~i
~, 3
æ O ~, O ~ , ,o,
'nl ~ ~ . ~ ~ Y
~3
~ O f`l CO _I 1~ ~ N
c~
CO CO ~ ~ O~
~ I N ~ ~ ~,~ ~ 9 ~
l~i ~`1 ~1 e~ 1 3 3
d~3 3 Sa ~
~ O B
a ~ co ~ O 'i "~
~ ~ v~ o u~ ~i o
I L~ 3 c~l ~ N ~ C~l N 3 ~ CJ
: ~ 3
. 31
'' ' '
~L~34~
Example 3
The procedure of Example 1 was repeated with some changes
in equipment. The hydrolytic redox bLoreactor consi3ted of a
Lab-Crest column, without jacket, 400 x 15 mm. The bioreactor
was charged with 50 g. of CGZ carrier. The anaerobic bioreactor
consisted of an outer ~acket 31.1 cm. in length and a fritted
glass membrane 30.5 cm. in length and 1.6 cmO in diameter. The
membrane, which was fused to the outer jacket, consisted of
three sections of fritted glass tubing of equal length which
had been fused together. The total length of the anaerobic
reactor was 40.6 cm. The membrane had a pore diameter distri-
bution of 3-6~ and an average pore diameter of 4.5~. Ths mem-
brane was made hydrophobic by allowing it to react with 130 ml.
of ten percent octadeayltrichlorosilane in acetone at ambient
temperature for about three days. The membrane then was
removed from the acetone solution and washed successively with
two 130-ml. portions of acetone, two 130-ml. portions of
methanol, and a 130-ml. portion of acetone. The membrane was
air-dried by aspiration. The anaerobic bioreactor was charged
with 23 g. of CGZ carrier. The gas pump was a Cole-Parmer
Masterflex peristaltic pump.
The results are summarized in Table III. The membrane,
however, passed liquid water during the time the process was
in operation, demonstrating that the pore diameters of the
fritted glass membrane in general were too large.
: ~ .
' '
~ -32-
.
. ~
.
~3~6
~1
~1
31
~ , 1,, o ~, ~ o ~ ~,
ul o u~ ~ co ~ O
ol I I I I ` ~ I o~ ~ ~r
~1 ' ' ' ' ~ ' ~ ~ '
~ .
C~
~ te ~ ~ ~Q `~ o
~_~ ~ ~u ~ i ~ o o o o
~ T~ 8 ~ Q ~ O
I o o zl' ~ o ~
Q O ol' I O O O O O O O O O O O
El
O
~1 ~ o ~ o o ~ 1
. ~ ~r ~r _~ ~ ~ ~ ~ ~ C~l Ul
o o ~ ~ co ~ ~ O Q !:~
Q 1~ ~O ~ ~Q ~ O .`1
~ UiOOOOOO~OO
,~
J CO ~ cr~ C`l ~ O CQ ~r O O O~ O
: CO ~ ~ ~
'.
O I~ CO ~ O ~
o --33--
:
1~3~66
3 - : "
U
~1 V
U ,,
O
Q~ O .q
0~ al Oq
t~ O ~ 4
_ S
H rl
H O ~ V
U O.C 8
'~ 'h'~
S~
O ~ Sf
U
Lr O O O
O '~ Ul
~d ~ ~ 3
:: o S
.,.~ ,~1 ~ 3
O
U
,c~
~ ~ O :'
X ~ ~ ~ . ' ' ' .i .
::
--3 4--
: `
:
~134~
Example 3 also lllustrate3 a preferred embodiment of the
process of the present invention, which embodiment comprises
establishing an additional microbe colony on the gas-space
side of the inorganic membrane of the anaerobic bioreactor.
Most preferably, such microbes will be photosynthetlc microbes,
examples of which include, among others Rhodospirillum rubrum,
ChromatLum Sp., Chlorobium thiosuliatophilum, ChloroPseudomonas
ethylica, Chorella Sp. Scenedesmus So., Chlamydomonas Sp.,
Ankistrodesmus Sp., Chondrus S2., Corallina ~e~ Callilhamnion
Sp., and the like.
The process employed Ln Examples 4-7 is descrlbed below,
with reference to ~igure 2.
5ewage (or other waste) 1 is pumped from container 2 by
pump 3 via rubber tubing 5 sealably connected to the pump.
The discharge from the pump ls led to hydrolytic redox bLo-
reactor 4 via rubber tubing 7 having inserted thexein prassure
gauge 6, the rubber tubing being sealably connected to the
pump, gauge, and bioreactor. The hydrolytic redox bloreactor
conslsts of inner glass tuba 8 sealably enclosed wlthin glass
jacket 9. The inner glass tube contains inorganic carrier 10
such as that described in U.S. Patent Mo. 4,153, 510, which is
suitable for the accumula-tion of a biomass. The glass jacket
is sealably connected via rubher t~lbing 11 to constant-tempera-
ture water-bath 12. Sewage (or other waste) leaving the
hydrolytic redox bioreactor is transported to anaerobic
bioreactor 13 via rubber tubing 14 sealably connected to
both bioreactors. The anaerobic bioreactor consists of
glass jacket 15 having exit port 16. The glass ~acket is
partially filled with additional inorganic carrier 10 and is
sealably closed at each end. Rubber tubing 17, sealably
connected to the exit port of the ~acket, leads to pump 18
-35-
: ~ '
3~
which removes gas (methane) from air ~pace 19 enclosed by
the jacket. Such gas ln turn is collected by any 3uitable
means such as by the displacement of water in an inverted
vessel (not shown). The glass ~acXet of the anaerobLc
bioreactor i3 fitted with liquid level sensing means 20
which i9 connected electrically to liquid level controller
21. The controller in turn ls electrically connected to
pump 18. Sewage effluent 22 then is transported, vla rubber
tubing 23 sealably connected to the anaerobic bioreactor and
fitted with check valve 24, to receiving vessel 25.
Example 4
The procedure of Example 1 was repeated, except ~or -the
following modifications. The hydrolytic redox bloreactor was
charged with 24.5 g. of cordlerite carrler having an average
pore diameter of 3~ and a pore diameter distribution o~ 2-9~.
~he anaerobic bioreactor was a 250 x 15 mm. Lab-Crest jacketed
column havlng about 125 mm. of the lnner coIumn or cylinder
removed. Thus, the jacket became the bioreactor, with the
end pieces of the inner column serving only to seal the ends
of the bioreactor. The anaerobic bioreactor then was charged
with 51 g. of the cordierite carrier and the bioreactor was
mounted in a substantially horizontal position. a presgure
gauge was inserted in the tubing connecting pump 3 to the
inlet of the hydrolytic redox bioreactcr. The water ~acket -~
of the hydrolytic redox bioreactor was connected to a constant-
temperature water-bath. The total fluid volume of the pump,
tubing, and bioreactors was 120 ml.
The apparatus was seeded as follows: The tubing leading~
from the pres3ure gauge was disconnected from the inlet of
the hydrolytic redox bioreactor. To such inlet then was
-36-
' ~ - " ,
:: :
.
' `
6~;
attached the tubing leadlng ~rom the anaeroblc bloreactor
of the operatlonal apparatus o~ Examp]e 1. U31ng sewaqe a~
feed, the two apparatuses were malntained in the coupled
configuration and operated essentially as described in Example
l for 13 days. During thi3 period, apparatus per~ormance was
monitored as summarized ln ~able IV.
.~ :
-37-
.
:
..... .
::: ::
~13~
_ ~:I,ooooooo
~i N ~ 1~ ` O
13 Nl I ~ C~ ~' ~ en N O
_ ~I N ~1 ~`I
~ ~ ~ ~D ~ ~ _1 ~`7
O ~ I
~? U ol O _, ~1 0 0 0 0
..,
( 3 t~l N O In ~ ~`1 ~ 0
~ a ~ r ~ N N N C~
~ W Ul .--1 0 ~ U~ _I N q~
3 ~ ~ ~ o ~ c ,
W ~ h
~ Q3
o qo . , .
.r ~ , , ' '.
~ O .,.
U~ I !13 S . ,:
: ul ~ ~ r~ r ~ N O
~1 N U~ 7 ~) er N
'
,
. , .
~ S ~ C~ ~ ~ C~ ~ ~ . .
a " .~ N r` r. ~O ~ U7
: '
Q ¦ --I N U'l ~ I` 0 ~ ~1
'I 33- :
, :.
,
:': '"' "; ' "' ' ' , ' ,., ' ;`' `. :'.' ". '. `' ,. i'"; ' . '' ''` '; ,"';: "."' ~ ' ",` ;~,' ''' `, '"' ,:, ,,. : .'
66
The apparatus then was disconnected ~rom the operational
apparatus of Example 1 and the tubLng leading from the pressure
gauge was re-attached to the lnlet of the hydrolytic redox
bioreactor. The apparatus then was operated independently,
using sewage adjusted to a pH of 8.6-8.9 (with aqueous sodium
hydroxide) as feed. ~he data th~ls obtained are summarized in
Tables V and V~. ~able V su~mari.zes the operating parameters
and gas composition, and Table VI summarizes apparatus per~orm-
ance and carbon balance calculations.
-3g-
: '
,
-
:,: , ,~ !: ~ i . , ;`
~13~6~
~;
^Idl O O O O O O O O O O Cl o
a~ r~ ~ co Io~ I ~ ~ I~~ In co ~ ~o
~ ~ ~ ~ ~ ~ ~ C~l C~l ,, ~ ~ ,
_ ,, ~ ~ ~ CO ~~ ~
~,, . , o , o ~ o o oo o
O ~0~ ~ ~ I ' I r~ I l O cj ~O
~ 3 ~
.
~1 ~ - ~1 ~ ~ ` ` , , ~` ~ -
~ I.~ rl ~1 ~ CO C~ co 5~ ~ 3 co c~ co
i~ O 'O ~:
O C~ :1 IJ ~o o ~ o ~ o
h c~l~1 C~ CO ~ CO ~ CO CO CO C2 CO CO C2 CO ~ `
~ ~ '
u~ ~
oJ
3 I I I , ~ o C~ ~ o .~ U~ ~ ~ o ~
^ I
L~C~ O. o ~ ~ ~O ~ ~ ~O .
~` c~l o o o o -I o o ,i
c~ . :
~, ..
r. rt' ~ ~ 2 0 ~ ~ `I O O
CS~ ~i I~ O r-~ OC~ CJ1 11'1 ~i O
o -40-- o
:
~ ~ "
~3~66
~Ioooooooooooo ooo
1~ r, ~ 1 r,~ r~ ~ r7 _1 :r r.~ D r~
3 2~ r, ~ r, ~ r, ~ r. ~ r; O r~ 2 ~o r~ ~ I r; ,-~ r,
_ ,~
C~OOOOO_iOOOOOO~OOO
O r 1 5~ r~ Cr~ r~ o~ r, ~ r,~ r~
3 C~ ¦ r;~ ~ r~ r. ~ rl r~ ~O .;r ~ u~ ~ ~ .:r
t~ 7 ~ ~ r, ~ o r~ ~ r~ Co ~ ~ r~ _~
t~ ~ r; ~ r, i r r r r; I~ ct~ r~ r,
3 3 ~ r, ~ O ~ ~o O O O r~ r. ~ r~
c æ I r,~ ri CO ri CO r~ ri co r,~ ~o r~ co ~ ~
_ ~ ~ O r~ ~o O O ~ ~
C ri ~ ~ oO ri r,~ ~ ri :~ Co r,~ I CO r~ ro
:~ I r, I ~ r~ r O o u~ ~o rJ O Cr~ ~O
o~ ~ ~ ~ r~ ~ _I ~ cn r~ r~ r~
~n ~ ~o r~rJ ~o ~ri r~ O r~ ~r ~ ~ ri r; ~ ~
C~
s~ o o a~ r ~ r~ rJ r. ~ X X ~ r~
1~ 3 ~ ~ ri ri O i r r~ r. ~ ~ O ~ r I r~
~ ~0 r~ O I r~ ~ r~ X ~ O ~ ~ r~
o --41--
.
~3~66
Yl
~ c~
â~ Cl O O I C; ,
a ~ O~
o o~t o o I o o o o
c~l co ~ I ~ a
c~
~ -T ~ ~ ~ ' ~ ~
~ ~, .
~ ~ 3 ~ c , ~ ~ ~ o
_
~ , o~
~ ~ ~1 ' ~a I a:) ~o ~o ~a
~: ~ :
~ u~ ~ I o o o o
~4^
~ ~c~i ~" I c ~
~î
8 ca o ~ c~
~; ~O I ,
~ o ~
. .
-42- _~
66
~,
C)
~ dO C C
.
~" ..V o
~:: O A O
o s~
~ ~ O S
c ,a ~ S
u~ o ~ ~a ~1 .rl
CO U ~ 3
o h ::1 3 ~
1 0
O JJ Q.
~ 3 , ~ ~ ~ o ~
~ Y ~ J'B
~ o o ~ ~ U
~
r~ ~ rl
A o ~ J
C B n ~
OqJ ~ 1~ ~ O O ~ 3
c S A
3 AF~
~' e o h h al O '
Orl ~ C ~ ' O
c 0 5 ~ ~ ~
~ ~ 8 ~
VW ~ O C ~ OX
Ll o ~ O ~ V (J ~ ~ ~
B ~ C ~ 3 ~ ~
3 S ~ O 'O 3 f~
S c ~ ~ ~ ~ U~ s
worO ~ C ~ 3 C A
a) So ~0 0 ~ ~
,~C ,~ ~ ~ 0~ ~ 3 O~ ~ 3
~, 03 Q' ~ 1 ~ aS O O
O Y ~ 0
S S ~ ~ S C ~ ~
~U ~ 'I 3 C
--4 3--
.
~34~366
.~,
~ . ,,
o ., CO
~D g
C~
U
O ~
=;Q O~
I~
~:r ~ ~ ~ o r~
~C~I ~ CO ~ o o O
0~ ~ ~
C ~ _,
3 ~3 ~: ~1 ~ O U~ O C~
~I gg _ r1 ~
~rl I ~:1 . '"~
~J ~O Oc) O
": (U ,_1 V~ O ~ ~, O~ ~O.. ~ U') ~ U~
U~ ~ ~
f . , .
~ ~ , '. '
C
C~ ~
V~ ,., C3 0 ~ ~
~S
I , : .
_
~ L- ,
e c o O O O ~ ~o ,~ ,-~ U ~ ~ ~ ~
8 w ~ ~
~ ooooooooooo
_l I o co o o o O ~o ~ oO ~o oO
~ r1
~ u~ o r~ o o U~ I~
o 44
'
:
" "~, ,, "~ ~,s ~ " ~
1~34~66
~1
o U 'o
U ~
L ~; V'l 1'~ ~
C~IQ ~ ~ ~
r(
a~ ~
_ ~ ~
~ , ~ U
:~ ~lcO~
'
o Ul CO
CS o ~ ':
: ~ 3 ~ O ~ O
~ O O O ' '
~1 O~ C
~1 ~ l ~ ~
-4;- -
~34'~6
Example 5
The procedure of ~xample 4 was repeated, except that
the carrier employed was Duralite Rouge (F. Guery, Ramber-
villers, France) having a pore diameter distribution of 0.4~
6u, an average pore diameter of 4.5~, a pore volume of 0.4
cc./g., and a porosity of 51.5%; the amounts of carrier
employed in the hydrolytic redox bioreactor and the anaerobic
bioreactor were 22 g. and 52.5 g., respectively.
The apparatus was seeded as descrLbed in Example 4, except
that the water-bath temperature was adjusted to 31 and opera-
tion in a coupled configuration was maintained for about 9iX
days. Additionally, a one psi check valve was inserted in the
end of the effluent tubing leading from the anaerobic blo-
reactor. Although the performance of the apparatus was moni-
tored over the next 33 days, satisfactory per~ormance was not
observed until the fortieth day of operation tincluding the
six days of operation in the coupled oonfiguration). On the
twentieth day of operation, the one psi check valve was
replaced with a three psi check valve. Table VII summarizes
the operating parameters and gas composition from the fortieth
day of operation and Table VIII similarly summarizes apparatus
performance and carbon balance calculations.
,
'
~34~6/6
rn
~1 0 0 o r~ O O
1~1~ ~ O~ r O 0~~0 ~ ~ CO O O
a z~ co ~ ~o
~ o~oooooooooooo
,n Ih a 8~ u~ ~ o ~ ~ r o ~ r~
~ c rn o ~ ~ J r~ ~ rJ ~o ~ ~ ~ ;r
a a ~ ~ of~ r~o~ rco ~ r~o~ o ro a~ O CO ~ '
~r
r~r~ ::: J~
h r~ a ~ I ~ ,1 ~ ~ o o ~ ~ o ~ r~
~ 0~ C
~ o r~ c u~ , o ~o co o
~8 ~ ~or~cocor~,or"~ o,~.
r.~
rf ~ o o o o r~ -l ~ o co ~ f~
flf
~o
,~ f U~ f_ ~O ~OCO f_f ~ O ~:r C7~ fr~j f~
~a ~ t~ ~o f~ o~~o ~ t~ft. f~ o
~J .
~c f~ f". f" t~ ~ f'~ O f' tr. o~ f~ f~ ~o f.~f
, ~ , t~i f~ f~
O -1 ~ f~ ~cf f` to f~ o ,- ~:r f~- ~o
~ o~ -47-
~34~
~o
o . ~
0 1 0 0 5
a ~ ~. u ~ 0
~: - :~ o O
.~, ~
O
1-&1 0 0 0 0 o o o o
I ~~ U~ ~ ~ O O ~ r~
3o z~ i ~ O~I O ~ ~- t3
lo~ o o o~ o o c~ o o
~ o.-1 r~ O ~
~
c~ ;r ;r o o ~ _1 ~7 o
_ c~ ~ 3
.-~
C~ ~ _~ I~
1_~ Isl ~ 1 O--
~1 O C~ ~ o o ~ ~ W ~ ,
i~ _ ~ I~ r` c~ I` ~ ~ A
O~ ,~ O
3 ~ ~ a~
A r~O c~l O O O O ~ 1 0 Ti A 3
h A ~ ~ ~ ~ oJ ~ ~ O
~:1 3 ,~ Ul 'A
C~ .
~i w w ~ ,~ ?
_ ~ ~ ~ ~ ~ ~ ~ _i a
o ~~ e
Il -- C~
U _I 1(~ ~ 0 t'7 0 U S
:1 El ~ O w"
~ O o ~ Q a`~
co ~ ~ ~ ~ 8 o o
-48- :
,:
,,
''', ~ -
~ ~3~96~
..
~i ~ ~o , , o o
o C i ~,,, ~ o
,
,, ~
1:1 ~; r1 0 1~ .1 ('I
5 ~ ~~ ,,~
O ~ ~~ r1 r1 ~ 1 r1
C ~ O
OJ
~:
~ a ~ g ~
~ ~ ~ C ~
O 1--~ ~ ~ ~ ~ ~ ~ ~
U~ ~
c 31
~ ~ X
, ~
C ooooooooo
c~ ~ a~ oO ~7 ~ ~ o o o oO
: ~1ooooooooo
~ ~ ~, o
r` o` ~ ~ ~o ~o ~o
rt --49--
~ '
Example 6
The proaedure of Example 4 was repeated, except that
the carrier used was Duralite Noire (F. Guery, Rambervillers,
France) having a pore diameter clistribution of 0.8-30~, an
average pore diameter of 6~, anci a porosity of 34.1%; the
amounts of carriar charged to the hydrolytic xedox and
anaerobic bioreactors were 20 g. and 50 g., respectively.
The apparatus was set up and see~ded ~or ten days as described
in ~xample 5. Appreciable reduc:tions in COD were not observed
until the 34th day of operation; consequently, the tabular
summaries begin with the 34th day. Table IX summarizes
operating parameters and gas composition and Table X summarizes
appaxatus performance and carbon balanoe calculations.
,.
-50-
.
.
.
: - : :,
~34~6
_ ¢looooooooooooooo
8 z~ ~ ~ u~ ,.7 u~ u~ ~ u~ ~ ~ ~ u~ ~ ~ ri .
ol O O O O O O O O O O ~i o o o o
co ~ u~ O ~ r~ ~ ~o o~ ~ r7 e
s l ~ o
s~ @~ ~ I o
~c
iS ~c e ::: u o~ o~ ~ ~ o O Cr~ ~ o~ O~ ,1 ~ O O -
~ u ,~ 3
i~ o ~ ~
O C~ 1 ~1 ~ 3 "~ 3
3 3 3 eo ~ ~o 3 r~ 3 3 3 3 3 3 3
~q ~
W OOOOOOOOOOOOOOO
: ~êl
1~; 3 0 1~ 0 Cl~ O ~D O O Cr~
w S ~r ~1i 3 0 0 1~ 3 r_ 0 3 3
X
~ c ~ l O
8 ,, u~
_51
- ": - ' ' ' - "~
~3~36~;
, ~
, ~Iooooooooooooo
CO ~ ~O C~ ~ O O ~ CO ~ L~ O
8 ~ ~ , c~ c~
~_ ~ r ~~ ~ ~ co ~ ~
5 ol' O O O O O O O O O O O O
~;r c~ ~a r~ o co ~ o~
o3 co~ I c~i ~i ~i ~ ~ r~i ~ u~
C.~ ~ r~ ~I~ ~ c~l ~ c~l 1~ co r~ ~ c~
~t sif o ,i o . ~ ~ ~ ~i
C~ C.71 CJ~ ~ CJ~ ~ Cr~ CJ O~ CJ~ C~ C~ C7~ O~ C~
=
G 5 ci~ ,, 0 ~ o o c~ ~ co
I ~ _~ I~ co 1~ c~ c~ r~ co 1~ co
:C :E: C~
o~ 5 ~ cJ~ co ~ C~
--H CO CO ~ CO CO CO CO CO CO CO CO CO
u~ cO U~
a O O O O O O O O O O O O O
~, :
~i
~'i ~ ~ _i c~ ~r O CJ~ Cl~ O U~ ~ O V' O
_ o co a~ ri 1~ ~ co 1~ , i c i ~ 1~ CT~
~ ~ : ~ ~ c~i c~
3i~
cr. .-i CJ~ ri ~ :r ~ O C7~ ~ i co 1~ ~ i
~i E ~ ~ C~ ~ c~i CO 1~ c~i cj CO 1~ c~
I~ C~ O ~ Il~ ~ I~ O 'i C~ CO
'
.. ~ ' '
'
~ 13~66
N
~0 ~ O` ~ ~t 0, 0 0 ~t `O ~1
O ~ o~ o o ~o Co O O
::'
U '1:1
a ~, t ~t ~ t t 0~ 1`1 t
C C '`I ~ I` ~ 0 `O `O ~t 1~ 1~ Itl rl
:~ ~ ~ ~ ~ t 1
C_I i;~
~U~ 13 ~ ~ ~t ~o C~ ~ o ~ o OD
#: ~ ~5 ~ lil
JJ
~c Is~ 3
3 ~ ~ o ~ o
a ~ o o o o O O o ' o o o o o o o
o ~ o o o ~ ~ -' ~ ~ ~ ~ ~ ~ ~ o ~
C
~ oooooooU~ooooooo~
;~ ~n t ~ ~ ,O" U7 CO ~ ~o ~
~0 ' ': ' ' .
t ~ '
~t ~t ~ t ~O
O --53--
.
:'
'
L3~66
Exam~le 7
The procedure of EXample 4 was repeated, except that
the carrier employed was Johns-Manvi11e Insulating Firebrick
JM-23 (Johns-Manville Corp./ Denver, Colorado) having a pore
diameter distribution o~ 2-lS~, an average pore diameter o~
9~, a pore volume o~ 1.0 cc./g., and a porosity O~c 68%. The
amounts of carrier employed in the hydrolytic redox and
anaerobic bioreactors were ten g. and 15 g., respectively.
Again, the apparatus was set up and seeded Cor seven days as
described in Example 5. Although satis~actory per~ormance
was observed on the 29th day, periodic leaks were a problem
until the 37th day of operation. Beglnning with the 29th
day, Tables XI and XII summarize operating parameters and
gas composition, and apparatus per~ormance and carbon balance
calculations, respectively.
-: - , , : . . :,, .:
~3~6
~1 ~
~1
C~ ~ o ~ ~ , , , ~ ~ ~ ~
cl~OOOOOOOoo
-1 ~ O ~ r o cr~
_ ~ ~ o ~ ~ ~ ~ ~ ~ ~ ~
o o~ooto.,,oooooo~ooo
u~ ~ 'æ ~~1 o o ~-i o .~ N ~
~ ~ ~ C~ C~ o
E~ ~ o o~ O ~I O O
~3 ~ 111 Vl 4.1
~; 0 3 ~ ~::
O ~ O O 0~ CO ~O11'1 IJ~ ~CO ~ 1~ 1~ 3
I~ ~ ~ _l CO CO CO ~ CO CO ~ CO CO CO CO CO CO CO
~ ~ ~_1
_~ O ~ ~ co a~ ~ c ~
~:.3 L ~ 11-1 0 ~i ,r~ ~o r~ CO tO ~O 1~ 1~ 0~ ~
C:~ I
~! I :.
L, O C7~ t`'l '.3 U~l cr~ ~O C~l O CO O ~ O
C ~ i ~ ~ 0
0 ~ ~O ~ cO ~ c~ r ~ ~ cr. _
55-
.
66
~1
o
a~7 <1~ 1 0 0 0 0 0 0 0
9 æl' r~ 0 ~
ol' o _l o o o o o o o o
o O ~O O o ~ O~
~~ O
~, ~ ! . '` ~
_ ~ ~f o a~ u o
o
~1 ~: ~ ~ o o ,~
~7 9 w r~
a~ ~: Tl ~
0~ ~ ~ O ~ ' ` "
~: c~
o ~
æ5 u~ ~ ~o co ~
c~ ~ ui ~ ~ ~ ~ u~ ~ o
53 u
_ 1-l ~ ~ ~ ~0 ~ ~ ~ ~ :1 ~ 3
~3~1ti6
.. I
o I C~
~ ~ D O O
o ~
CO o ~ o ~ ~ C
~¦a o~ ~ r7 U~ o
dl
~ ~J ~ O ~ ~
, ~ `~, C
x u~ 1~ u~ ~
~ ' ,,
a ~ ~ ~ ~ o~ o o
a~ c) O ~ O O c~ c~ ~
o ~ . '
C o ~ o o o ~
U
~ C`~ D o~ cO
2 ~1
.ci ~1~
Uc 5
:1 OOOOOOOOOOOO
C ~ r~ u1 ~ ~o ~ ~ cU~ co ~ O 0
1_~ t'l ~ Q~
o~ - 5 7 - .
: : :
~; ,
! 1 ~ 3 ~ 6
The example~ which lc\llow illustrate one e~odiment of
the B4~ ~pparAtus ol' the E~resent invention.
Ex~mple 8
A two-liter reagent bottle with a side ~r~ at the ~ottom
W35 connected, via a l~ngl~ of mygon tubing ~ttached to the
~ide arm, to the inlet port ol' a Pluid Metering, Inc. Model
~P G-6 pump (Fluid Metering, Inc., Oy~ter Bay, Naw York). ~he
outlet port of the pu~p was attached, aga~n via ~ygon tubing,
to th~ bot'om o~ A vertically-mounted 9 x lSO mm. Fisher and
Porter chromatographic colu~n (obt2in~d l'rom Arthur ~. Thom~s
Co., Philadelphia, PA.). m~he column was charged wlth 6.5 g.
of the CGZ carrier described ln Ex~mple 1. ~he top oi' the
column was con~ected by Tygon tubins te the inlet port o~' a
cell having sealably mounted therein the dissolved oxygen
sensor of a Dif1'usion Oxygen Analyzer (International Bio-
physics, Corp., Irvine, Cal.). The outlet port of the cell
was connected with Iygon tu~ing to a r~ceiving vessel.
~nother di-~solved oxygen ~ensor was pl~ced in the reagent
bottle which ~erved as waste stre~m reservoir. ~ach tis-
,~olved oxygen sensor was standardized against air-saturated
~ater nt 21.9~ saturati~n.
~he column W~5 secded by continuously recir~ulating a
volume of sewage through the column at ~ ~low rate of 1
ml./min. ior iive days. A ~ter~le, stand rd BOD solution
cont~inlng l50 mg/liter each o~ glut~mic acid and ~lucos~ was
passed tbrough ~e column at 0.37 ml/min~ ~'or 24 hours as a
preconditioning to insure adequate bioaccu~ulation priox to
collectlng oxyge~ uptak~ data. The standard BOD ~olution
then was pa~sed through the oolumn or immobili2ed aerobic
mlcrobe bioreactor. The e~fluent percent saturation was :
~;Trade Mark.
-58
: ~:
: . ,.. ~ ~ : ,
- ~L3~3~
,
; measured at three different flow rates. In each case, the
percent saturation of the feed in the reservoir was 21.9%
and the effluent percent saturation reading stabilized within
20-60 min. aiter changing the flow rate. The results are
summarized in Table XIII.
:
TABLE XIII
Oxygcn Uptake in an Aerobic
Bioreactor BOD A?~paratus
Flow Rate (ml./min ) Effluent ~ Saturation
10 0.19 7a
0-37 10
2.07 18.5
aDecreased to 4.5 after an additional 12 hours.
From Table XIII, it is apparent that oxygen uptake is
inversely proportional to the flow rate. Oxygen uptake,
. expressed as the percentage of dissolved oxvgen consumed, is
summarized in Table XIV and was calculated in accordance with
the following formula:
% 2 consumed = Feed % Sat nd- ESft,~ Sat n x 100
TABL~ XIV
Percentage of Dissolved Oxygen Consumed
In An Aerobic Bioreactor BOD A??~aratus
Flow Rate, ml.~min. ~ 2 Consumed
0.19 68a
0.37 54
2.07 16
Increased to 79~ after an additional 12 hours.
.
-59-
.:
il~ :
~ :~ : :
~39~ 6
Example 9
The procedure of Example 8 was repeated, except that
the column was seeded with 200 ml. of an overnight tryptic
soy broth culture of Escherichia coli (109 cells/ml.) and
the standard BOD solution was replaced with sterile broth.
After the 24-hour preconditioning period, the effluent
percent saturation was measured and found to be 0~; the
broth percent saturation originally was 21.9%. Thus, 100%
of the dissolved oxygen was consumed.
Examples 8 and 9 clearly demonstrate the feasibility of
measuring a difference in an organic waste-containing aqueous
medium, which difference is the result of biochemical conver-
sions (oxidations) taking place in the BOD apparatus aerobic
bioreactor.
Such a measurable difference then is readily correlated
to BOD by known procedures. For one example of such a
correlation, see I. Xarube et al., Biotechnol. Bioenq., 19,
1535 (1977). Thus, for a given aerobic bioreactor, passing
standard solutions having varying concentrations of organic
material at a given flow rate will yield a set of, for
example, oxygen uptake data. The BOD values of such standard
solutions can be determined by conventional methods to give
a set of conventional BOD values. The two sets of data then
can be combined in graph form to give a standard curve for
each flow rate employed. The BOD of any organic waste in an
aqueous medium then is determined quickly and simply by
passing such aqueous medium through the BOD apparatus and
comparing the data obtained with the appropriate standa~d
curve.
-60-
:
,: ~
