Note: Descriptions are shown in the official language in which they were submitted.
7~577
B~ CKGR OUND OF THE INV:~ N~ ION:
The demand for water purification does not arise solely from the
need for treating sewage or noxious industrial waste, nor is it necessar-
ily directed merely toward obtaining potable water for humans and animals.
Recent environment control regulations have restrained the discard of
water such as that w~ ',through ordinary industrial use has appreciably
increased its content of dissolved solids (which are generally inorganic or
mineral compounds) as well as inhibiting discard of such liquid which has
accumulated or concentrated particular toxic components.
For example, the body of water which is circulated as a coolant in
10 many industrial or chemical plants, is then returned to a heat exchanger
where part of it is evaporated in order to reduce the temperature of the
remainder, which remainder is then recirculatedO This evaporation step
itself would increase the concentration of contained solids merely by re
ducing the volume of liquid. However, in its travel, the liquid picks up
deposits or sediment from the plumbing system, and in addition, in order
to minimize corrosion, foaming and scale formation (such as resulting
from "hard water "), various inhibitory additive s are mixed into the cir -
culating stream. These obviously contribute further to the dissolved solid
content and after the latter has built up to the maximum allowable for
20 continued circulation, it becomes necessary to discard part of the fluid
mixture and replace it with fresh water (and new additives).
However, this heavily loaded discard has now become an illegal
pollutant when released into flowing streams or ocean. The problem is to
purify it before release; and hopefully if such purification process is suf-
ficiently successful or complete, the water may be reused indefinitely and
need not be released at all.
~ particular contaminant in such cooling water system is chromium
which is a component of many anti-corrosive or biocide additives.
-2- ~S
1~D7~577
rrhUs hexavalant chromium is a toxic substance not releasable ~to the
environrnent, Other toxic components of common cooling water additives
are cyanides and phosphates, which must be detoxified before release.
Purification of polluted water for purposes of reuse, whether start-
ing with agriculture /municipal sewage or with industrial waste, has been
concerned primarily with recovery of potable water, only after the initial
separation and disposal of solid components in an inert state, this being
considered a necessary and preliminary step for any subsequent treatment.
~he solids may have then been utilized to a small extent as plant support
10 base or land fill, but such product is not a primary purpose for effecting
the separation and for the most part the undifferentiated sludge is simply
separated in bulk and discarded in the manner most convenient. Purifica-
tion of the aqueous phase then takes place (if at all) as a successive,
rather than concurrent, procedure. However, it will be rea-lized that the
aqueous run-off from many and probably most water-treating procedures,
(even if only involving flushing) carries a quantity of solid and potentially-
solid ingredients having tangible economic value if such could only be re-
covered in concentrated form without great expense.
Further, treatment of such masses of contaminated water in the past
20 has been primarily on a batch basis; large bodies of water being treated
with acid or other reagent in a "settling basin" or even in successive
chambers and chen allowed to stand for a prolonged period until spot
checks show that the supernatent was clarified. In brief, it has not been
realized that by careful regulation of the parameters of a flowing stream
containing charged particles, separation/purification of an impure squeous
medium could be effected in a fraction of the previous time, and also that
the controls could be shifted so as to maximize the withdrawal of specific
contaminants which it was desired to concentrate in the solid stateO Some
~L~7~57 ~
substances it may be desired to destroy -- as microorganisms, herbi-
cides, pesticides and inorganic toxins -- or to recover, such as nitro-
genous compounds, precious metals, etcL. Accordingly, the control para-
meters of such flow treatment can now be accommodatad to a particular
feed stock and with a view as to how it is wished to dispose of specific
c ontaminants .
It has long beeD known to plarify waste wate r by oxidizing it in the
joint presence of iron plus sulfur dioxide or an o~idizing a~ The im-
purity is then removed by flocculating the iron in alkaline media. How-
eve r, 'to the extent ~hat this process has been used, bulk solids necessar-
ily were first removed as by filtration, and as to the remaining filtrate,
past treatment does not remove dissolved impurities Isuch as inorganic
salts typified by NaCl) or substances incapable of oxidation (such as metal
particles): each of chese classes may include such undesirable toxins as
arsenic, mercury, cadmium, lead, selenium, boron, etc.
SUMMARY OF TE~E INVENTION:
It has now been found that this dual oxidation/precipitation step can
be incorporated into a composite treating process whereby essentially any
flowable, polar liquid medium containing (:Einely fractionated) waste/refuse,
as well as soluble salts and non-oxidizable impurities, can have all non-
gaseous impurities removed as solids, leaving a sterile, pure, oxygen-
containing liquid (e. g., potable water, which is also capable of supporting
fish and other marine life). The precipitated material is also sterile and
if desired can be further fractionated to recover substances of economic
value, such as precious metals, fertilizer-enriched sludge, etcO
In brief, in a primary reaction vessel or multi-unit apparatus, all
of which is electrically insulated, there is provided (in the absence of any
~7~5~
externally imposed electric current) a self-generated galvanic cell formed
by "soluble" or free electrons resulting from acidic oxidation of a contain-
ed heavy metal capable of alkaline flocculation, suc:h as iron and/or
aluminum, as well as by free electrons produced by disassociation of
water (or other polar media) by introduction of sulfur dioxide, A minimum
suspension of minute particles (as hereafter definedj is also deliberately
provided, ither by addition or by f ractionation of bulk solids initially
presentO Such dispersed particles (preferably constituting all of the solid
material present except for the electron-producing metal) inherently possess
10 random movement in the liquid medium (which movement is the Van der
Waals effect resulting from an internally generated spin of an unsymmet-
rical molecule). In conjunction with the moving electrons, this results in
a distribution of charge to other particles and adhesion between charged
microparticles and minute gas bubbles, which ultimately results in co~n-
plete oxidation of all oxidizable material present. ~his necessary cross-
distribution or random mixing of electrons with both charged and uncharged
particles in the insulated cell may be accentuated by bubbling gaseous
oxygen (air) and/or sulfur dioxide through the liquid, as well as by agi-
tation of the body of liquid as by means of pump or stirrer. Electrical
20 insulation of each reaction vessel is necessary in order to keep such
charge (maintained by pH regulation) from grounding through a conductive
reaction vessel or flow conduit.
Under the step-wise oxidizing conditions and imposed galvanic flow
pattern, metallic ions agglutinate with particulate matter and are replaced
in the aqueous medium by other cations, i.eO ,hydrogen ions, at the same
time maintaining the selected concentration of acidity. Among other reac-
tions, part of such hydrogen ions couple with available nitrogen to form
cJJ ~I ~Such ammonium ion then couples with ferrous ion to form (green)
ferrous ammonium ion.
~ ~7~.S77
Successive cher~lical reaction steps can be effected by batch proce-
dure, as long as sufficient agitation is provided to keep the ingredients
from settling out prior to the ultimate and de sired flocculation. However,
it is usually desirable to effect the process as a continuous flow, particu-
larly when a continuing supply of feed stock is available, as from a muni-
cipal sewage collection stream or similar industrial/agriculture waste flow.
Accordingly both the liquid medium and an associated gas stream are
moved to and through successive treating zones or chambers. Ihe body of
reactant gas (which should include oxygen) is channeled to contactingly
e
10 overlie or flow through t~ lisLuid medium as the case may be.
Accordingly, by relating the size and shape of the reaction vessels
and connecting conduits, a series of dimensionless parameters has been
obtained for both the liquid and gas streams, by use of which controlled
flow rates the material being treated is moved in a substantially contin-
uous but step-wise pattern of reaction which prevents phase-separation
while enabling or promoting electron clistribution until complete oxidation
is effected. ~he final chemical-treatment step is then accomplished by
~JK~ 0~
all~i~ of the medium with avoidance of potential phase-separation
during a preliminary digestion period followed by electrical grounding of
20 the medium concurrent with joint precipitation/flocculation of the metallic
ions and the coagulated impurities. In addition, such grounding of the
medium, which may be effectuated by grounding the insulated reaction
vessel containing it, produces a noticeably more firmly-packed precipi-
tate than would otherwise result.
When the composite impurity is composed of both (a) cellulosic
material (eO g. ,food residues, waste paper or cartons, etc. ) and (b) sus-
pended minerals or metals and/or soluble salts (e.g.,brackish water) the
final alkaline flocculation tends to segregate "a" and "b" into successive
layers with the "b" material being precipitated first or underneath the "al'
~- ~07~577
material. ~he procedure can thus be used to concentrate small quantities
of precious metals from slurries and the like; in the event that "a"
material is not already mixed with it, the minimum charged particulate
matter is added as described.
Separation of all potentially-solid components from such a flowing
galvanic cell, by groundin~g and cessation of movement or agitation, in
addition to re~noving in the flocculate such impurities as might previously
be expected from the chemical reaction alone, now also draws soluble
salts such as sodium chloride out of solution as well as precipitating sus-
10 pended non-oxidizable particles. The only requirements for participating
substances are that the liquid be a polar liquid, ancl the ~lid or potentially-
solid substarlce be capable of the Van der Waals effectO In addition to water,
other polar liquids are alcohols, acids, bases and other substances which
ioniz;e or conduct an electric current. ~he dispersed particulate matter
should constitute a minimum of about 0.1% w. and have a particle density
of about 1. 05 to about 2. 0 and a1~e of about 30 to about 225 microns
with free surface energy of about 100 to about 500 ergs/cmZ.
In this conne ction it will be realized that the smaller the particle
size, the greater the relative surface area and the greater the forces of
20 surface attraction (relative to weight), so that the relative influence of
gravity on the particle is correspondingly diminished. T hus the specific
surface energy of a given solid can multiply more than 8000 times in
going from approximately two inch di~eter to one micron. Its unit sur-
face energy at the same time increases more than 600%. Accordingly, the
greater the fractionation (maceration) of the bulk material into small par-
ticles, the greater effect the increased surface energy will have on reaction
and flow properties. Ihis factor is the same of course whether ~he material
constitutes matter which (in addition to its carrier f~mction) is to be oxi-
dized, or whether it is particulate matter added merely for its function of
30 carrying a charge in the flowing galvanic stream.
--7--
7~LSi77
However it will be apparent also that such fractionated particles,
possessing Brownian movement and increased unit surface energy, have
a strong tendency to coalesce if brought together; that is, they become a
non-free-flowing mass rather than acting as independent discrete particles.
Such potential coagulation is prevented by (1~ pump action, mechanical
agitation, and passage of gas currents through the liquid, each applied at
a particular critical location, and (2) by moving the galvanic flow stream
at a varied and deliberate rate in accordance with Reynolds Numbers and
other dimensionless parameters selected to prevent phase separation. Thus
10 when later such suspended particles (galvanically charged) are finally di-
rected to settle out, in cooperation with a flocculating ion, cancellation or
grounding of the galvanic charge tremenduously reinforces this final (de-
sired) phase separationO Thus one particularly notable and totally unexpec-
ted result from this flowing galvanic cell and from the ~an der Waals sur-
face effect exhibited by the particulate dispersion, is that by the present
process soluble salts (in particular NaCl or other alkali halides) present
in the liquid, also leave their state of solution and enter into the separat-
ing flocculateO Such desalinification may be explained in part by continu-
ation of the suspended flocculate in an oxygen-saturated medium until the
20 reduced flocculating ion (ferrous) is itself completely oxidized (to ferric
ion).
To restate the present process: flowable contaminants of a liquid may
be either or both soluble and ~olid (the latter being held suspended by a
moving stream). They may or may not be in a condition of lower valence
o~ be subject to having toxicity destroyed by oxidization, but in any e~irent
the flow is exposed to a strong oxidizing treatment (initially in a strongly
acidic environment which is then shifted to a highly alkaline environment)
in a moving ionic exchange medium which characteristic is furnished by a
combination of ~fan der Waals surface action of particulate matter and by
7~5'77
galvanic charge imposed on such particles; one result of this is that gas
bubbles (of air and suLfur dioxide) surface-adhere to and react with oxidiz-
able particles and are repleni~hed by inert particles (carriers) transfer-
ring similar bubbles to them. The flow is moved through successive treat-
ing units at rates of flow determined by dimensionless numbers such as
Reynolds, Schmidt Numbers, Peclet Numbers, Lehman Reaction ~umbers,
Weber Numbers, Stanten Numbers and certain b~contact numbers. After
alkaline treatment and continued gaseous oxidation, the non-liquid compo-
nents are flocculated and separated as a sterile solid sludge. The latter
10 may then be digested and/or fractionated ~o concentrate and retrieve par-
ticular ingredients of value, by use of known methods.
Whereas in the past it was only dimly appreciated that the SO2-iron
oxidative reaction required the presence of~.free electrons (apparently trans-
ferring between ions), it is now realized that it is highly desirable to pro-
vide such a "gal~anic exchange " condition throughout the whole procedure
and particularly in conjunction with (a3 turbulence or agitation, and (b)
the intimate presence of gaseous oxygen continuing through successiv
steps until the flocculating ion itself is oxidized. As already noted, the
galvanic charge imposed on the particulate matter by the added electro-
20 lytes (acid and basic reagents) promotes or accentuates the surface ad-
hesion of gas to particle, and enables the interchange of electrons. Such
a reacting state is then maintained, and phase separation prevented, by
movement at a tailored flowl rate.
I~ypical surface-adsorbent particulate matter may be either oxidiz-
able or non-oxidizable and includes cellulosic or other organic matter as
well as inorganic compounds such as metallic oxides (alumina, magnesium
oxide, calcium oxide, etc. ) and especially compounds of atoms which have
a ~an der Waals packing radii of about 1. 9 or less. Additional examples
of particulate matter include infusorial earth, diatomaceous earth, bentonite,
30 and siliceous matter such as free-flowing sand, silicones, etcO
_9_
~L~7~LS77
In summary of the above, therefore, the present
invelltion ma~ ce broad`y defined as that process for remov.iny
~rom a flowable polar-liquid as a solid substance, a dispersed
soluble or .suspended con.taminant, of whi.ch any suspended
par~icles thereof are characterized by Van der Waals effect
and which contaminant is capable of solid existance at ambient
operating temperature and pressure, the process compri.sing (a)
di3pe.rsing in the liquid a minimum of about 0.1% w. random-
mo~ing~particulate matter, which may either be added or be formed
by fractionatlon of the contaminant when the latter is initially
present in bulk, which dispersed particles thereof have a density
of about l.OS to about 2.0 and a size of about 30 to about
225 microns diameter with free surface energy of about 100 to
about 500 ergs/ cm2, and also reducing an~ additional solid
matter present to such particle size, (b) providing a~ oxidation
medium for such of the contarninant and added particles as
may be capable of oxidation, by ma]cing such li~uid acidic,
intirnately dispersing gaseous oxygen therein~ and providing a
supply of free electrons as by acidic dissociation of the polar
2~ uid and by oxidation in situ of a heavy metal provided therein,
which metal is characterized by the capacity of subsequentlv
forming a flocculant precipitate in alkal.ine media, whereby a
~alvanic charge is imparted to the moving particles by random
distribution and attachment of the electrons thereto, (c) maintainin~.
the cllarge on the moviny particles and restraining coagulation
and phase separation of particles and soluble contam:inants during
successive oxidative reaction periods by agitation effected at
least in part by flowing the liquid and its contents through
ele~trically-insulated and flow-connected reaction vessels in
intimate rnixture with gaseous oxygen and at a variable flow rate
defined by dimensionless parameters derlved from the internal size
and shape of the respective vessels and their connectin~ conduits,
~ - 9a -
,~,~1"
,s,
"~,,", ,,~
697~577
(d) making the liquid alkaline~ subsequently ceasina aaitation and
electrically grounding the alkaline liquid, whereby flocculating
ions of the heavy metal provided therein, mutually precipate
the charged particles, the metal ions and soluble contaminan~s,
thus yie].ding an oxygen-containing supernatent pure liquid.
The process as indicated hereinabove may be ca.rried
out broadly in an assembly for purification of contamirlated
liquid, including liquid flow control means and comprising in
combination the following sequentially connected units: (a) liquid
container means including associated means for selectively
~macerating solid components of a thus-contaminated liquid, and
gas delivery/aeration means for passing gas into intimate
admixture with the contaminated liquid and macerated components,~b~
acidic treatment means, flow connected to the container means,
and including means for regulation of pH by selective introduction
of acidic and gaseous oxi.dizing reagents to the contaminated liquid,
: ~c) container and reactant means, flow connected to the
last treatment means, and comprising a source of soluble heavy
metal ions adapted to mingle with the :Liquid flow stream, and
-means for subsequently aerating the liquid flow by passing gaseous
oxygen therethrough, (d) neutralization means, flow connected to th~
last aerating means, and including proximate means for introducing
alkaline reagent into the liquid flow, and a plurality of
successively distal means for intimately mi~ing gaseous o~ygen
into the alkaline flow stream in amount adapted to restrain
precipitation of contaminants by agitation thereof, (e) means for
~locculating separable contaminant components of the alkaline
flow stream, substantially concurrent with electrical grounding
of the stream, and switch means for electrically grounding the
alkaline flow stream, each of the units starting with (b) being
electrically insulated from ground support, and the floccu].ating
means (e) being electrically insulated from the preceding flow
ywl/ ~ - 9b -
,,, .i
~ 7~7
connected unit, whereby a galvanic charge may be imparted t.o
solid particles of the liquid flow by pH regulation and electrons
of the soluble heavy metal lons and such charge maintained
until discharged by the switch means.
Ywl/ - 9c -
~7~ 577
BRIEF DESCRIPTION OF THE DR~WINGS:
Figures 1, 2, 3 show in semi-schematic representation, a process
and apparatus embodying the present invention, with the various flow con-
nections being horizontally alignable when the three sheets are placed
side by side in~this order.
Figure 4 is a horizontal sectional view taken on line 4--4 through
the soda ash treatment unit of Figure 1.
Figure 5 is a vertical sectional view on line 5--5 of the homogen-
izer tank of Figure 2.
Figure 6 is an enlarged fragmentary detail of an end outlet segment
10 of an air delivery conduit of tanks 70 and 72.
TYPICAL FLOW PATTERN AND ~REATMENI UNITS:
In the illustrated apparatus, a flowable feed stock such as raw sew-
age is introduced through an inlet conduit 10 into a wet well or ~f,ragment-
ation chamber 12 where a chopper pump 14 reduces the solid matter to
the required particle size (30 to 250 microns)O Liquid level in this chamber
is regulated by an automatic control unit 16 which opens and closes a pinch
valve 17 in the line~ From the wet well the particulate dispersion is moved
to a primary or marshalling tank 18 through a conduit 19 as regulated by
a liquid level control 20. In the absence of any or sufficient solid matter
in the feedstock, the required particulate matter, which may be any inert
20 material which will hold a galvanic charge (e. g. shredded cellulose) is
added to the wet well from a supply hopper ZZ by a conduit 23.
~ he comminuted feed stock is ultimately withdrawn from the primary
tank 18 through conduit 24 at a rate determined by a suction pump Z5 and
conveyed to a pulsation damper tank 27. A controlled quantity of exhaust
gas is released from the top of the closedi:tank 18 through a wet charcoal
-10-
~1~7~577
filter unit 26 and vented (odorless) to the atmosphere. Within the pri-
mary tank 18 is a submerged transfer pump 28 which is operated to
maintain a continuous flow of fluid and suspended particles. ~urbtllence
within tank 18 is contributed in part by the presence of internal baffles
29 and by continuous bubbles of a (recycled) gas mixture from conduit 30
which enter through perforations in the piping adjacent the flooring 31 of
the tank. ~o the extent that the liquid medium is clear enough, it is vis-
ually discernilble~ that small gas bubbles here adhere to the surface of
the mo~ing solid particles within the liquid, and their gaseous oxygen con-
10 tent (derived initially from air) plus SO2 pretreats or conditions oxidizableparticles for subsequent oxidation. In the case of highly oxidizable matter
such as fecal debris, a residence~ time in the preliminary chamber 18 on
the order of about one and a half to about two hours is indicatedO
From the pulsation dampener tank 27, the flow, at the rate controlled
by mass flow meter 21, is moved through conduit 34 to a mixer tank 35
where it is intermingled with a gaseous mixture of sulfur dioxide and air,
~ ~7~~ '1/27~ ~;7)
~e rintroduced by drop lines 37 from an overhead gas mixing chamber 36. Re-
cycled gas is introduced to the mixer chamber 36 through the line 38 com-
4/
ing fronl a co}npressor 40 which receives exhaust gas through line 4~;3,
20 passing through a silencer unit 43. Both the gas mixer 36 and the flow
mixer tank 35 are at times supplied with liquid sulfur dioxide through
line 45 from a supply tank 46 (which may be heated), in response to a
pH meter 44 which maintains the tank 35 within the pH range of about 2. 0
to about 2. 5. Alternately or concurrently sulfur dioxide gas is supplied to
the gas mixer 36 from supply source 47 through conduit 48, controlled by
pH meter 44 and/or the mass flow meter 21. In tank 35, Peclet Numbers
will range between g and 25. Lehman Reaction Numbers of the blow tubes
37 vary from 3.5 to 8; for eductors 25 to 30.
5~7
Exhaust gas from the tower 39 is continuously introduced into the
iron rqaction chamber 50 as astream of bubbles through conduit 49, while
at the same time the liquid flow containing a controlled amount of free gas
bubbles is passed through an outfall conduit 52 and introduced through line
53 into the reaction chamber 50 below the porous bed. It is very important
that gas inlet valve 49 be partially closed and thus used to mix its flow
with the fluid flowing throug h the line 53. The gas mixture which is passed
jointly through the scrap iron bed (which furnishes both ferrous and ferric
ions to the medium) and through the liquid flow stream, should contain a
10 mixture of both nitrogen and oxygen (i. e., air). Vaporous mixture fro~n the
stack 51 of the iron chamber is passed through the conduit 54 which separ-
ates the non-gaseous components (i. e., liquid droplets) and returns them to
the mixer tank 35 of the main flow by way of conduit S7 or into the dis-
charge from tanks 70 or 72; the gaseous portion is recycled through the
compre s s or gO by the line 570
Liquid outflow from the reaction tank 50 has a pH of about 3. 0 to
about 30 5 and is passed through conduit bO to a blow tank 62 where air
from a reservoir 63, by conduit 64 and manifold 65 is passed upward
through the liquid so asto separate it and to again provide a fluid system
ZO saturatecl with dissolved oxygenO The flow is generàlly red from ferrous
ionsO Gaseous take-off from stack 61 by donduit 66, and gases from tanks
70 and 72 by lines 67, 68 are returned by line 30 to primary tank 180
From the blow tank, liquid outflow is conveyed to the lower level of the
neutralizer tank by conduit 69. A conduit 74 connects a mixing throat 75
of the outflow conduit 69 to a caustic supply tank 76, and a conduit 78 con-
nects a lime slurry source 79 and circulating pump 80 to the mixing throat
75, the alkali flow to the neutralizer 70 being controlled by a pH meter 77.
Instead of gradually neutralizing the acidic flow and progres sively bringing
-12-
~L~7~577
it to the required alkalinity of about pH 11, it has been found advantage-
ous to introduce ~hrough the throat 75 at one time, substantially the whole
quantity of alkali required to achieve the final pH for that immediate vol-
ume of flow with which it is mixed.
The air reservoir 63 initiates a plurality of air delivery lines 83 to
the neutralizer tank 70 and a similar series 88 to the homogenizer tank
72, which individual lines are disposed to emit a bubbling shearing air
stream from indieidual sparger or wedge-aperture nozzles at their distal
ends, thus agitating the churning or foaming mass of liquid and charged
10 particles at the same time that they supply oxygen and nitrogen. Conse-
quently, the emerging outflow through conduits 71 and 73 is oxygen-satur -
ated and the adsorbed gas on the particulate surface continues to be re-
activeO ~he flow of air through the several lines 83, 88 is controlled by
individual (manual) valves or orifice plates so that it can be adjusted to
the"step by step" progression of the increasingly viscous flow and thus
continually pre~rent agglomeration and sedimentation. A residence time of
about 15 to 17 minutes in each $ank is t~pical; total about 30 to 40 minutes
at about 60 - 80 F .
The air reservoir 63 is supplied by conduit 59 from an air com-
20 pressor 89 connected to a silencer 91. The compressor processes freshair and in some instances may pass it~ough an ozonizer 98, such as the
non-sparking, low voltage, AC, face-separated insulated-plate type describ-
ed in U.S.Patent No.3,948,774. However, the basic procedure is sufficient-
ly effective in most cases without the ad~itional oxidation provided by ozone.
~-o,7~/6
As seen particularly in Figure 2~` the several air lines 83, 88, each
angularly dispose their terminal segment 100 transversely within the tank
70 or 72. It is formed with a closed end 101 and a blow outlet mouth 102
is cut wedge-shaped into the hemi-cylinder which is oriented downward
-13-
. . .
~C~7~577
when disposed in the tank at a transverse angle to ~he longitudinal ver-
tical plane of the chamber. Such positioning of the outlet minimizes the
possibility of liquid back~low and consequent solid deposition or encrust-
ation therein. Successive segments lO0 are mounted cri~sscross or at
~~ ` different~angles so that their outlet mouths are angularly staggered rela-
tive to the longitudinal axis of the tank. Functionally, the flow-aligned
tanks 70, 72 can be considered to provide the same continuing and accel-
erating reaction process in tandem structural units -- that is, supporting
completion of the neutralization process while keeping in suspension the
lO forming flocculate in the increasingly viscous flowstream so as to restrain
phase separation.
When it is desired to maximize removal of hardness components
and silica, the outflow conduit 73 from the homogenizer tank 72 receives
a soda ash increnlent from a supply tank 99 through line 84 and then
passes through a heating zone or unit 85 where ~he flow is raised to a
temperature of about 90 to about l 20F before introductLon to the treat-
ment tank 82 where it is agitated by a motor driven agitator or marine
type impeller 86. Location of four intermediate-length upstanding baffles
87 in the tank enables or directs the li~uid suspension to circulate in
20 closed paths of generally vertical ellipses between adjacent baffle s.
From the treatment tank 82, a conduit 90 carries the flow to a floc-
culation chamber 92 which may have inclined walls and/or corrugated floor
segments separated by upstanding baffles which form a convoluted pathway
for descending sediment and liquid. Individual floor segments are movable
by pneumatic actuators 93 driven by air lines 94. Each unit of the appar-
atus has been electrically insulated from the ground and from successive
(adjacent) units, being connected together by plastic conduits, the chambers
preferably being formed of non-conductive material ~concrete, wood, etc. )
and in any event lined with corrosion-resistant layer such as plastic or
30 glass fiber.
-14-
~7~577
~he flowstream or liquid medium may now be grounded by closing a
switch 95 connected to an electrode 96 which is exposed to (i. e, inserted
within) the fluid of the chamber 92. Consequent discharge of the galvanic
charge carried by the particulate matter (which should now be oxidized
to the extent possible), and cessation of agitation and flow, initiates a
relatively rapid precipitation of the potentially solid components from the
liquid medium. Residence time in the f~cculation chamber is on the order
of about 30 to about 90 minutes. Distally the sludge, dark red-black from
ferric ion, falls into a screw conveyor 97 which passes it through a screen
classifier (not shown) and returns the liquid component to the system.
The liquid of the flocculation chamber 92 passes over an air-locked
weir 104 into a decanted water tank 106 where a submerged pump 107
moves it through conduit 108 to woven strainer units 109, 110, which re-
move colloids, and thence to an upper inlet of a packed tower 112 where
it percolates down through raschig-like rings countercurrent to a stream
of (possibly ozonized) air and is then introduced through the conduit ~3 to
a holding tank 116. Air from the top of the tower is conveyed by line 114
to the decanted water tank 1060
Liquid outflow from the tower 112 passes through conduit 115 to a
holding and aeration tank 116, which latter may be connected by a line 117
to a source of chlorine for optional use in particular circumstances (e. g.
when required by local ordinance)~ A compressor 120 with silencer 121
delivers fresh air through conduit 122 to the aeration tank 116 through
lines 123, 124, and to a filtered water tank 125 through lines 126, 127, 128.
A gas take-off line 129 connects the filtered water tank 125 with a
charcoal-filter exhaust unit 130. ~he latter is also connected by gas line
131 to the aeration tank 116. ~he tank 125 has a submerged pump 132
which move s liquid through conduit 133 to an ultimate polishing or holding
tank 134. ~he aeration tank 116 is connected by pump 135 and liquid
-15-
~L0~577
conduit 136 to dual or alternate activated~charcoal filter tanks 137, 138,
having drain lines 139, 140, which are joined to conduit 144 which termin-
ates in the holding tank 125. A backwash line 142 collects fluid from filter
tank 134 and delivers it to the decanted water tank 106. ~ return line 146
, ,~7~"~
connects the backflush outlets of the two filter tanks 137, 138 to the ~t~
~I water tank ~. Pump 132 in tank 125 provides product water or water
for backwash through line 133 to filters 137, 138 and to product filter
tank 134. A backwash line 146 connects the filter tank to the primary
tank 18.
~he solids collected in the bottom of the flocculation tank 92 may
contain toxins (which have not been detoxified by oxidation). Such can be
metals such as mercury, arsenic, boron, lead, iron, gold, silvex, etc.,
as well as some biocides. Non-oxidative pyrolysis may be used to re-
move organic materials such as petro-chemicals. Pre cipitates such as
carbonates and su.lfates are decomposed and removed as carbon dioxide
and sulfur dioxide. Nitrogen is removed as an inert gas. The metals may
be volatised and recondensed or removed in a carbon matrix and then
calcined/roasted in the presence of oxygen to prepare a composite of
various metallic oxides~ The noble metals are recovered as a combined
20 metal concentrate. The particular procedure for any flowstream will be
adapted of course to the specific components shown by analysis to be
present and which it is desired to re~ov~r.
F LOW P~T TE RN:
container D velocity of density of
Reynolds Number (NRe)=diameter( ) Xflowing fluidlv) x fluid media(P)
Viscosity of flowing media (~
For example, the iron reaction chamber S0 has the characteristics --
-16 -
- ~7~57~
Diameter- Liquid Liquid Mass Air Mass NRMass Flow Ratio-
feet velocity- Flow- lb/ft~hr Flow-lb/ft~/hr liquid/air
ft/ se c.
lo 5 0~ 0143 1763 210 9678~ 395
2 ~ 0 0.0121 1984 Z30 14528~ 626
2~ 5 0.0124 2540 210 232012.095
2~ 75 0O 0116 2600 210 2613120381
3 ~ 00 0.0118 2645 252 2900 10.496
A critical factor for such sewage or waste water treatment in the
10 presence of particulate matter and sulfite/sulfate ion or hydroxyl ion is
defined as Shape Factor (SF) = ~1) DA wherein ~ = particulate
HFA
concentration factor~
DA~ = norninal air lift Disengaging [Area
HFA = waste fluid hydraulic flow area
An operative SF range is from about 9~ 5 to about 11. 3; optimu~nlO~O. 5.
EXAMPLE:
l!~[unicipal sewage with the bulk solids reduced in size to the desig-
nated particulate diameter was flowed through a processing assembly such
as here illustrated, the initial acidity made pH 1. 5 to 2. 5 by introduction
20 of liquid and/or gaseous sulur dioxide. Ihe liquid flow was then moved
through the serpentine flow pattern of tank 35 (shapè factor 9-10) at NR
of about 5000 to about 10, 000 when in contact with the gaseous flow and
about 7000 to about 18,000 when not in contact with the gaseous flow; the
gas mixture of S02 and air was moved at about NRe 400 to about 500~
After about 7-1/2 - 15 minutes residence in the iron reaction chamber
50, the flow was passed through the air-blow tank 62 and thence to the
neutralizer tank 70 where the pH was increased from about 8. 5 to about
10. 0 during a period of about 15 minutes; it continued through the homo-
genizing tank 72 for about 15 minutes while the pH increased to a maximum
30 of about 11.
~L~7~577
When the operation is particularly directed to removal of calcium
and magnesium ions ("hardness" components) and also to reduce the con-
centration of silica, 15-30% of the sludge removed from the screens (sub-
sequent to flocculation) is returned to the homogenizer tank to augment
the particulate concentration and increase interfacial surface area, thus--
lype In Liquid System
Particulate Particle size Density 3 Amount Interfacial Surface
Dia.microns mg. /cm gO /liter area, cm2/liter
Solution born 30-225 192-15000~ 3-0. 9 660-13000
Flocculants 100-350 300-35000 . 04-0. 3 25-4500
Precipitates 200-700 250- 5000~ 07-0. 09 14-135
Additive s &
soda ash 75-250 3Z0-1700 0O 10-16 40-4800
Recycle sludge 30-700 192-3500 0O 01-4.8 250-3360
Additives of such size include fly ash, carbon black, infusorial earth,
etc.
The flow is then moved through an agitation and heating zone 82 at
NRe of about 30, 000 to about 40,000 with addition of soda ash. Alternate
;~s to use of mechanical propellors, comp:Lete agitation with blown air may be
, .
b.,`.'" 20 achieved when there is 1. 5-3. 0 CFM/~H~ft2 of cross section area.
Finally, the fluid flow is moved at NRe of about 2000 to about 3700
for about 30 to about 90 minutes through the flocculation tank or sediment-
ation zone 92.
In retrospect, the addition of particulate matter b~ the present pro-
cess may be distinguished from various incidental additio~s of particles to
liquids in the past in that the latter were (a) for removal of dispersed
colloids by adding charged particles in order to agglomerate the two sub-
stances, or (b) f or removing a solute by addition of a substance which
decreases the solubility of one or more of the dissolved components.
30 Neither of these treatments contemplates (or obtains) a continuing reaction
~7~5'77
( oxidation) between the dispersed particles and a gaseous component
adhered to the added particles, and/or the interplay of free electrons in
such environment, which electrons take part in the desired continuing re-
action. Nor do they contemplate deliberately maintaining such dispersion
and preventing agglomeration during a necessary (multi-step) reaction
period; nor final precipitation by introduction of a flocculating ion. In
brief, the provision and utilization of an insulated flowing body of polar
liquid constituting a galvanic or ionic exchange module (cell) the contents
of which is continually manipulated both to prevent phase separation (pre-
10 cipitation~ and to effect a desired chemical reaction (ultimately resultingin joint liquid purification and separation of solids) seems to have been
entirely overlooked or unappreciated. Ihe necessary polar solvent such
as water, contrasts with non-polar solvents such as mineral oil, paraffine,
kerosene, etc., which are not suitable because of being incapable of trans-
mitting an electric current.
It should be appreciated that the intended and necessary result from
applying the dimensionless flow parameters related herein, is that (l)sedi-
mentation and agglomeration are prevented, and (2) at their active surface
area, the dispersed particles maintain the intermoleoular attraction, often
20 referred to as the Van der Waals effect, which attracts to and causes to
adhere thereto clusters of moving air molecules (bubbles). ~he result is
not only the progressive oxidation of the flowing particles, but also sub-
sequently the electrical and interatomic field force which is thus continued,
appears responsible for "drawing otlt~ of solution the dissolved electrolytes
of both positive and negative charge, such as the halide (chlorine) ions and
alkali (sodium) ions which finally are separated from the medium as one
component of the flocculateO
In addition to the Reynolds Number which relates the fluid density
and velocity with the container configuration, the following parameters
-19-
- 1~17~L5~7
should be taken into account ~-
The heat transfer and energy retaining properties of the flowing
fluid are defined by the Peclet Number = DV~ Cp/k or Cp S~ R
k*4/ 3 D~
Cp = specific heat; ~ = surface tension
k = thermal conductivityO The Peclet Number for tanks 70 and 72 is in
the range of 12 to 32, and gas escape velocity at the surface is 0.18 to
0. 24 ft. /sec.
The Schmidt Number relates viscosity, density and container diameter
(hydraulic diameter in an awkwardly shaped vessel) NSc =~ 1 DV.
The Stanton Number relates the coefficient of heat transfer (h) to
the specific heat, velocity and density. NSt = h/C Vp.
The Stanton Number for the liquid flow gas mixing tank 35 is 35. 50 to
36. 20; for the neutralizer and homogenizer tanks 70, 72 the Stanton Number
is 28.60 to 10,160.
The Weber Number relates the shape of the container (length of flew
path L), the density, the velocity, and surface tension. NWe = Lfvj~ gc.
(:;ontact Number Nc = (UZ/~ g~ (NR ) (NS ) /
The iron tank 50 has an operable range Schmidt Number 4 x 10 to
1. 3 x 10 ; the contact number is 2Z8 to 446.
F~;action gases (air, sulfur dioxide, nitrogen, ozone, etc. ) can be
introduced into the stream of particulate-laden fluid by eduction, sparge
lines, or blow-shear tube. Each of these operates within a precise Lehman
Reaction Number and ~Weber Number range. The dimensionless Lehman Re-
action Number relates the System Shape ~actor and the mass flows of fluid
and gase s .
System LRN Webe r
Eductor system 25-30 1. 0-1. 7
Sparge Lines 3. 4-4. 4 0. 92-1. 98
Blow-Shear Tube 6. 7-7. 7 0. 98 1. 85
-20
~7~5~7
~he terminal velocity of spherical and non-spherical droplets of particles
settling in the vapor space will vary from 0O 4 to 30 ft. /sec, Particles up
to 85 microns will be entrained and are removed prior to gas flow to the
iron tank 50.
Flow conditions within the heater tank 85 are defined by a Reynolds
Number of 3(), 000 to 40, 000 and a Grashof-Prandtl Number product within
the range of 25, 600 to 230, 000 on the water-particulate matter side. Ihe
Grashof Number = (L f gl~ b ~ r) where L equals length of reaction
chamber; f - density; g = 3Z. 2 ft/ sec. ; ~ = viscosity;
10 b = coefficient of thermal expansion; T = temperatureO The Prendyl
Number =~ where Cp is specific heat; ~ is viscosity; K is
thermal conductivityO In removing hardness components, the heater tank is
operated at a temperature of 105F ~5aF, the fluid leaving the tank between
100F and 110F. Introduction of additional particulate matter by line 103
into the line 73 (effluent from the homogenizer tank 72) as noted earlier,
provides 3~to 85% more surface area in the final stages of magnesium
conversion to magnesium carbonate and then to magnesium hydroxide (a
solid). Magne~sium uxide and magnesium hSrdroxide also promote silica re-
moval. The reintroduced sludge at this point, composed of mechanically
zo formed particulate matter, flocculants and precipitates~ is very effective
in assisting the soda ash in final removal of silica and magnesium. The
electrical charge on the particulate matter also increases the rapidity and
effectiveness of silica removal. Magnesium and calcium chlorides, sulfates
and nitrates are converted to solid magnesium hydroxide and calcium car-
bonate. Since ~a and Mg exist in hard water primarily as chloride, bi- -
carbonate and sulfates, they are removed by che present process.
The way the present system handle hexavalent chromium and cyanides
is of particular interest. As the recirculating gas stream of oxygen, nitro-
gen and sulfur dioxide contacts the particulate matter and soluble salts, the
-21 -
~7~5'77
sulfite ion reacts with any metallic ions present. Hexavalent chromiumis reduced to trivalent chromium in about 15 minutes at pH 2.0 to Z.5.
As a reductant, the sulfur dioxide consumes oxygen but the latter is con-
tinually oeing replacedO In the iron reaction tank, ferrous sulfate is pro-
duced, which also acts as a hexavalent chromium reductant. This insures
complete conversion to trivalent chromiumO As the latter flows into the
neutralization tank (with an initial pH of 8. 0 to 8. 5) its coupling with hydroxyl
ion results in a light and voluminous precipitate which is continually mixed
with the ferrous hydroxide thc~ is changing to ferric hydroxide (a heavier
10 precipitate). In a total residence time of about 30 minutes in tanks 70 and
7Z, this reaction goes to completion -- the precipitate continuing to be sus--
pended as a result of air drive "churning" which maintains an oxygen-
saturated medium-- the pH eventually reaching about 10. 5 to 10. 8 or 11.
Discharge conduit 73 delivers a finely dispersed, charged particle ~hat ag-
glomerates rapidly in the region of the flocculation/sedimentation zone 92.
When cyanides are present it i9 necessary to oxidize them to cyanate
a nd thence to free carbon d~oxide and nitrogen gas (both of which could be
vented freely)~ IE cyanide ion were oxidized in acidic medium, cyanide gas
would result and require special handling precautions. Alternately, if cyan-
20 ide is oxidized to cyanate in highly basic medium, it requires an extendedreaction period. However, in the presence of the great amount of reactive
oxygen carried by the particulate dispersion, cyanide can be oxidized to cy-
anate at pH 8. 5 in approximately 5 minutes (in tank 70). If then this cyan-
ate is exposed (i. e. returned by line 105) to oxygen and ferrous ion of the
iron tank, an iron cyanate complex is formed. After passage through the
blow tank 62, the flow reenters the neutralization tank 70 where hydroxyl
ions react with the cyanate complex forming carbon dioxide and nitrogen.
At -the same ti~ne ferric sulfate is hydrolysed to ferric hydroxide; Fe(S04)3
+ 6H2O = 2Fe(OH)3 + 3H2SO4O Upon grounding of the fluid, the ferric
-22-
~7~S~7
hydroxide separates as platelets which are as large as a quarter-inch
across, dark red to black and firmly compacted in comparison with the
fine, greyish, amorphous precipitate~ formed by ferrous hydroxide.
Waste water treatment by the pre sent system
~roduced the followin~--
WA'rER PRIOR to 5'0 reduction of Initial con Sludge concentrate:
T:RE~1MEN~ centration found in Productspectrographic analysis
Water prior to filtration
pH 5.1 pH 7~ 2 pH 8. Z; sp. gr. l. 094
Al 430~ 0 mg/l 0. 5 mg/l 99~ 9% 33~ 700 % by wt.
Ca 616.0 536~ 0 13.0 1.080
Mg 145~ 8 53~ 5 63~ 33~ 230
Boron 105.0 16~ 6 84~ 2~ 190
Cu
Iron 700~ 0 70~ 0 90~ 06~ 670
Silicon 1. 660
Titanium . 640
Mn 1.3 o20 84~61~030
Sodium 137500 1550.0 88~ 748~ 230
Potassium 240~ 14~ 5 94~ 02~ 810
99~ 249 %
Ammonia 5~ 85 96~ 6
T otal har dne s s
(as CaCo3) 2140.01560.0 27~ 2
Fluoride 113.0 6~ 25 9~ 5
Chloride 1240~ 152.0 87~ 8
Sulfate 320004050~ 0 87~ 4
Phosphate . 2 ~ 2
T otal Organi c
Carbon (TOC) 16. 018. 0 mg/l
Free Carbon Dioxide
(as CO2) 20~ 0 5~ 0
Total Di~solved
Solids 62338~ 7598~ 87~ 8
Total Solids
69514 7652 89~ 0
Suspended Solids
717654~ 0 99~ 25
Chemical Oxygen
Demand 765~ 0 38~ 3 95~ 00
~olatile Solids
1599464~ 71
Di~ ss olved Oxygen
0 4~5
Surfactants 2~ 0 ~ 6 70~
Turbidity 18500 JTU35~ 0 JTU 99~ 8
units
Spe cific conductance
@ 25 C~ 45000 micromhos/
cm 7600 29.100
-23 ~
5~7
~ he unexpected usefulness of the present (water)treating process in
killing and a~glomerating viral and other monocellular life forms may be
attributed to the cumulative effect or concurrence of a number of individual
factors, at least some of which have a unique effect even alone. Ihese fac-
tor s ar e - -
(1) ~he broad band shit from extreme low to extreme high pH (i. e., 1. 5
to 11), as well as residence at each end of the spectrum, effects the range
of organisms of which individual groups may be re sistant to acidic or basic
media only, but not to extreme s of both pH.
10 (2) In this connection, the rapidity (e. g. 15 to 30 minutes)as well as the
range or strength of the shift of pH appears important. An organism could
better acclimate or survive slow or mild change.
(3) Residence time during which the whole medium or environment is under-
going treatment at each end of the flow-process, comprising gaseous inter-
change, continued suspension/agitation, oxidation and ion exchange, is sig-
nificant~
(4) Relative density and composition of particulate matter in the flow-medium,
compared to tl~ volume of water being treated is an important parameter.
(~otal area particles cm2/lO ~ 130 to 13, 280. )
20 (5) ~he additional effect (attraction to living or newly deadcells) contributed
by the galvanic charge which is carried by the particles is effective. In this
connection, it is preferred to obtain the initial low adicity (plus galvanic
charge) by introduction of sulfur dioxide, rather than by addition of formed
acid, since the SO2 produce~ hydrogen ions and shifting electrons by dis-
as s ociation of water .
(6) Detergent action results from sulfonation of fat and oil components of
the medium and especially from such ingredients which may form part of
the viral/bacterium capsule/membrane. Protenaceous components of the
rnembrane may also co~ugate; subsec!uent salting out of the organic salts
-Z4-
~3~73~5~77
then exposes the cell contents to caustic attack or saponification.(7) Under these critical conditions, lime is particularly effective against
some viruses.
(8) Rapidity and completeness of flocculation is impoIltant, e. g. 5 to 7
minutes after grounding, in comparison with a minimum of 25 to 35 min-
utes or more which might be required in "merely" clarifying murky water
by flocculating with Al or Fe ions.
(9) The total kill is achieved without recourse to chlorine or other toxic
agent, and wi$hout need to modify the treatment so as to target it at a
10 specific organism first determined to be present. Such process can be
used to "harvest" pestilential life forms for identification and study; by
extracting samples from successive process steps, the susceptibility of
the cell to each step is learned.
-25 -
