IM- PROVEMENTS IN THE PURIFICATION OF LIQUIDS AND IN THE UTILIZATION AND PREPARATION OF CERTAIN WASTE AND BY PRODUCTS OF ART AND MANUFACTURE AS PURIFYING AGENTS
Year: 1878

page_text: LETTERS PATENT to George Mackay, of Edinburgh, in the County of Mid
Lothian, North Britain, Manufacturing Chemist, for the Invention of "IM-
PROVEMENTS IN THE PURIFICATION OF LIQUIDS AND IN THE UTILIZATION
AND PREPARATION OF CERTAIN WASTE AND BY PRODUCTS OF ART AND
MANUFACTURE AS PURIFYING AGENTS."
Sealed the 28th December 1878, and dated the 5th July 1878.
PROVISIONAL SPECIFICATION left by the said George Mackay at the Office
of the Commissioners of Patents on the 5th July 1878.
GEORGE MACKAY, of Edinburgh, in the County of Mid Lothian, North Britain,
Manufacturing Chemist. "IMPROVEMENTS IN THE PURIFICATION OF LIQUIDS AND
IN THE UTILIZATION AND PREPARATION OF CERTAIN WASTE AND BY PRODUCTS
OF ART AND MANUFACTURE AS PURIFYING AGENTS."
This Invention relates firstly to the purification of water and other liquids
effluent from paper pulp and fibre mills; bleaching, dyeing, scouring and finishing
works; cotton, woollen, and linen manufactories; gas, tar, oil, glue, gelatine, and
size works; tanners', skinners', and curriers' yards, and works or situations generally
where industrial arts and manufactures are carried on, and in its application for
such purposes it is a development of the Invention for which Letters Patent were
granted to the said George Mackay, bearing date the 11th day of January 1875,
and numbered 91.
As set forth in the Specification filed in pursuance of the said Letters Patent,
the impure water or liquid is first treated or agitated with per-salts of iron until
combination of the iron salt solution with the vegetable, animal, or mineral matter
or "sludge" contained in the liquid is effected. A quantity of alkali or alkaline
earth (preferably lime) is then added, and the stirring or agitation continued until
combination or chemical union of the lime and salts of iron takes place. The
liquid is then allowed to settle, and the matter or "sludge "held in solution therein
becoming precipitated, and so rendered capable of removal, is recovered for
further use.
In practising the method set forth in the aforesaid Specification the water or
liquid is for some purposes not sufficiently purified by the process, and it is one of
the objects of this Invention to further purify the said water or liquid after treat-
ment as described.

page_text: Under one modincation of the invention this is erected by passing the water or
other liquid after the "sludge" has been precipitated from it through one or more
filter beds or strata composed of the following materials or their equivalents in
superimposed layers, whose thickness varies according to the nature or quality of
the water or other liquid under treatment.
For the first or under layer.-Rough gravel or broken stones, broken bricks,
broken pottery, or equivalent materials.
For the second layer.-Fine gravel or any of the first-mentioned material broken
small.
For the third layer.-Sand.
For the fourth layer.-Pounded, distilled, or roasted shale, technically known as
oil works waste shale.
For the fifth layer-Fine sand, perforated tiles, iron, zinc, or other equivalent
material capable of freely passing the water or other liquid, and at the same time
preventing the shale from rising or being displaced.
The distilled shale or shale charcoal (which is the principal and active ingredient
in this process) may be obtained by subjecting that species of shale called oil shale
to a red heat in close vessels until all the volatile products are dispelled or driven
off; but for the purposes of this Invention I prefer to use that obtained under the
technical name of "waste shale" from the retorts at paraffin oil works, that is to
say, the distilled or roasted shale as drawn from the retorts and thoroughly quenched
with water or otherwise cooled before being exposed to the air.
Under another modification of the Invention in lieu of employing distilled or
roasted shale as a purifying or filtering agent, the "sludge" precipitated and
recovered from the impure water or liquid, either as herein-before set forth or by
other means, may be used for the purification of the efiluent liquid whilst flowing
through the filtering or purifying strata. To adapt the "sludge" for this purpose
it is first dried or pressed and then burned or calcined in any suitable arrangement
of furnace or hearth.
When sufficiently burned the "sludge" is pounded or broken up into small pieces
and formed or spread into a layer or bed in the filtering strata in the same succession
as herein-before described witli reference to the distilled or roasted shale, or the said
prepared "sludge" may be otherwise used.
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1
In percolating through filtering strata whose active constituent is composed of
either of the materials herein-before set forth, the remaining impurities are removed
from the water or other liquid, and the latter flows away from the filtering medium
in a clear or pure condition, and may thereafter be allowed to run to waste, or where
an inadequate supply of water is experienced it may be re-utilized in the art or
manufacture from which the impure liquid was an effluent.
When the active constituent of the filtering-strata has become charged or choked
with impurities a fresh quantity of the same material is substituted, and the
material removed is, with or without previous drying, burned to ashes in the furnace
of a steam boiler or other furnace, or it may be disposed of in any other convenient
inanner.
Although the improvements constituting the present Invention are herein-before
described as auxiliary to the Invention for which Letters Patent were granted to
the said George Mackay as aforesaid, it is to be understood that these improvements
are not dependent on the said previous Invention for their efficiency, and that the
present Invention may with advantage be employed as a separate and independent
process for the purification of water and other liquids effluent from works or
factories; and further, the present Invention under either of its modifications may
be employed in the purification of water influent for domestic purposes or for
employment in the arts and manufactures, or otherwise where a clear supply or
stream of water is required.
The method of filtration by means of "sludge" prepared as herein-before described
may also be used for the purification of town sewage.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Mackay in the Great Seal Patent Office on the 4th January
1879.
GEORGE MACKAY, of Edinburgh, in the County of Mid Lothian, North Britain,
Manufacturing Chemist. "IMPROVEMENTS IN THE PURIFICATION OF LIQUIDS, AND
IN THE UTILIZATION AND PREPARATION OF CERTAIN WASTE AND BY PRODUCTS
OF ART AND MANUFACTURE AS PURIFYING AGENTS."
My said Invention relates, firstly, to the purification of water and other liquids
effluent from paper pulp and fibre mills, bleaching, dyeing, scouring, and finishing
works, cotton, woollen, and linen manufactories, gas, tar, oil, glue, size, and gelatino
works, tanners, skinners', and curriers' yards, and works and situations generally
where industrial arts and manufactures are practised or carried out.
In its application to such purposes my said Invention is a development of the
Invention for which Lettors Patent were granted to me boaring date the 11th day
of January, A. D. 1875, and Numbered 91.
As set forth in the Specification filed in pursuance of the said Letters Patent the
impure water or liquid to be operated upon is first treated or agitated with per-salts
of iron until combination of the iron salt solution with the vegetable, animal, or
mineral matter or "sludge" contained in the impure liquid is effected. A quantity
of alkali or alkaline earth (preferably lime) is then added, and the stirring or
agitation continued until combination or chemical union of the lime with the salts.
of irou takes place. The liquid is then allowed to settle, and the matters or
"sludge" held in suspension therein being precipitated, and so rendered capable of
removal from the tank or receptacle, are recovered for further use after the super-
natent and partially-purified liquid has been decanted or run off.
In practising the process constituting my said former Invention it is found that
in some cases the effluent water or liquid is not sufficiently purified. One of the
objects then of my present Invention is to further purify the misuse waters or
liquids effluent from such works or factories as are herein-before mentioned, after
the matter or "sludge" has been precipitated from the said waters or liquids as
aforesaid.
Under one method of practising my present Invention this further purification is
effected by passing the water or liquid effluent from the settling tanks or ponds,
wherein the "sludge" is precipitated, through one or more filter beds or strata,
composed of the following materials or their equivalents in superimposed layers,
whose thickness varies according to the nature and quantity of the misuse waters
or liquids to be treated.
For the first or under layer.-Rough gravel or broken stones, broken, bricks,
broken pottery, rough furnace ashes, broken clinker, or the equivalents .of such
materials.
For the second layer.— Fine gravel, or any of the first-mentioned materials or their
equivalents, broken small enough to pass through a mesh or riddle having 8 to
16 squares to the inch.
'
For the third layer.-Coarse sand.
For the fourth layer.-Distilled or froasted shale, technically known as oil works
waste shale broken or pounded sufficiently small to pass through a mesh or riddle
having from 10 to 30 squares to the inch.
For the fifth layer.-Fine sand, perforated tiles, perforated iron, perforated zinc, or
other materials or metals, placed together with sufficient openness or looseness to
permit of the misuse water or liquid passing freely through the openings or inter-
stices, whilst at the same time such openings or interstices must not be so large as
to permit of the broken or pounded distilled shale rising from its bed, or being
otherwise displaced.

page_text: Under a modification of the filter the second and third layers or strata may be
dispensed with, and the coarsely pounded or broken oil works waste shale directly
superposed upon the first layer or stratum. When this form of the filtering strata
is adopted it is preferred to place a layer or stratum of finely pounded or ground
waste shale directly upon the coarsely ground or pounded waste shale; also to
employ, in lieu of the fifth layer of materials herein-before referred to, a thin layer
of sifted furnace or coal ashes, or a piece of coarse canvas cloth; but it is to be
understood that instead of such materials the materials herein-before mentioned, or
other equivalent materials capable of preventing the layer of finely-ground shale
from being displaced by the inflowing water or liquid, may be employed. The
upper layer of the filter bed, wherein a coarse and fine layer of shale are employed,
may entirely cover the layer of finely-ground waste shale, or it may cover and
protect such portion of it only as is subjected to the first or falling action of the
water or liquid.
The filter constructed under either of the modifications herein-before described is
situated in a tank, pond, or receptacle, which may be conveniently placed in juxta-
position to the settling pond, tank, or receptacle wherein the "sludge" is precipitated
from the water or liquid, as hercin-before set forth, and in the bottom of the said
filtering pond, tank, or receptacle, ordinary drain tiles formed into a network by
placing them in parallel or transverse rows are situated immediately below the first
or lowest stratum of the filter, for the purpose of speedily carrying off the purified
water, and so promoting the flow through the filter.
The distilled shale or shale charcoal may be obtained by subjecting that species
of shale called oil shale to a red heat in close vessels until all the volatile products
are dispelled or driven off, but for the purposes of my said Invention I prefer to
use that obtained under the technical name of waste shale from the retorts of
paraffin oil works, that is to say, the distilled or roasted shale as drawn from the
retorts and thoroughly quenched with water, or otherwise cooled before being
exposed to the air.
With the form of filter bed first described, that is to say, with the waste shale
all of one fineness, when the filtration becomes choked or impeded, by removing or
partially removing the upper layer or stratum, and then rousing or casing up tho
waste shale with a pronged fork or equivalent instrument the flow will be renewed
until the shale becomes entirely exhausted or loses its effect, when it can either be
replaced by a fresh layer, or renewed or revivified by calcination in a close vessel or
furnace, or by exposure to the air for a sufficient length of time, and then replaced
in the filter bed as before.
When a coarser and a finer layer of waste shale are employed in the filter bed, as
under the second arrangement herein-before described, the upper or fine layer of
shale is removed from time to time as it becomes exhausted or charged with
impurities, and replaced by a fresh layer of new or revivified waste shale of like
fineness.
"
In treating the impure waters or liquids effluent from mineral oil, chemical, dye,
and other works, where the misuse or effluent water or liquid is of an acid nature,
it is preferred to omit the treatment of the said water or liquid with per-salts of
iron, as described in the Specification filed in pursuance of my said former Letters
Patent, and to agitate the said water or liquid merely with waste alkali or alkaline
earth (preferable lime) for the purpose of precipitating the matters or "sludge
previous to passing the partially purified liquid through one or more filter beds, as
herein-before set forth. The waste alkali or alkaline earth is used in excess, and
although I do not restrict myself to such proportions, I find that from 240 to 280
grains of the waste alkali or alkaline earth to one gallon of water or liquid is a
good proportion to employ.
Under another method of practising my said Invention, in lieu of employing
distilled or roasted shale as a purifying or filtering agent, as herein-before described,
the "sludge" precipitated from the impure water or liquid, either by means of my
former Invention herein-before referred to, or by other means, is used for the

page_text: purification of the effluent or misuse water or liquid whilst flowing through the
filtering of purifying strata. To adapt the "sludge for this purpose it is first dried
or pressed, and then calcined or burned in any suitable arrangement of furnace
or hearth from which the atmospheric air is excluded.
When sufficiently burned or calcined the "sludge " is pounded or broken up into
pieces small enough to pass through a mesh or riddle having from 10 to 30-squares
to the inch, and then formed or spread into a layer or bed in the filtering strata
in the same succession as herein-before described with reference to the first arrange-
ment of the distilled or roasted shale filter; or two layors of the prepared "sludge
may be employed after the manner of the two layers of waste shale, in which case
the second and third layers or strata may be dispensed with, as described with
reference to the employment of the said two layers of shale.
"
The "sludge" recovered from the impure water effluent from paper pulp and
fibre mills is especially applicable for the purposos of my said Invention.
In percolating through filtering strata constructed under any of the arrangements
herein-before described, the impurities remaining in the water or liquid after the
matter or "sludge "has been precipitated therefrom, as set forthi, are removed, and
the water or liquid flows away froin the filtering medium in a clear or pure con-
dition, and may thereafter, where an inadequate supply of water is experienced, be
re-utilized in the art or manufacture from which the impure liquid was an effluent,
or it may be otherwise used or allowed to run to waste. .-
In constructing a filtering bed according to my said Invention the superficial arca
and the depth or thickness of each stratum will be regulated by the quantity and
quality of water or liquid to be purified at any given situation, and as the amount
of impure liquid discharged in one manufacture is greater than that in another, or
in a different situation where the same manufacture is carried on, it is difficult to
specify precise dimensions for such filter beds. I therefore do not confine myself
to the proportions of such filter beds hereafter given, but for a discharge of from
400,000 to 450,000 gallons per 24 hours from a paper mill I have found a filter
bed having a superficial area of 60 by 60 feet, and a thickness or depth of 6 to 12
inches for the first or lowest stratum, of 3 to 6 inches for the second stratum, of
1 to 3 inches for the third stratum, of 9 to 18 inches for the fourth stratum, and a
mere covering of the materials constituting the upper stratum to give satisfactory
results.
When both coarse and finely pounded shalo or "sludge " are employed I have
found that a depth of from 10 to 18 inches of the coarse, and 6 to 12 inches of the
fine is efficient.
It is preferable to employ two or more filter beds, so that when one is being
renewed or is out of operation the purification of the discharge may be effected by
the other or others.
Although the improvements constituting my said Invention are herein-before
described as auxiliary to the Invention for which Letters Patent were granted to
me as aforesaid, it is to be understood that my present Invention may also be used
with any other analogous process of precipitation, and, further, that it is not depen-
dent on the said previous Invention or other process for its efficiency, but that the
present Invention may be employed as a separate and independent process for the
purification of waters and liquids effluent from works and factories generally; and,
further, under either of its modifications it may be used in the purification of water
influent for domestic purposes, or for employment in arts, manufactures, or other-
wise where a clear supply or stream of water is required.
The method of filtration by means of "sludge," prepared as herein-before described,
may also be used for the purification of town sewage, and by reversing the stratifi-
cation of the several layers of the filters the filtering beds may be employed for
upward filtration.
Having now described and particularly ascertained the nature of my said Inven-
tion, and the system, mode, or manner in or under which the same is or may bo
used or carried out in practice, I would observe in conclusion that I do not claim as

page_text: novel and original the employment of mineral oil works, waste shale per se, and
either reduced to a coarse or fine state of division, in the purification of impure
water or liquid, as I am aware that it has been previously unsuccessfully attempted
to employ that material for such purpose; what then I do consider to be novel and
original and therefore claim as the Invention secured to me by the herein-before in
part recited Letters Patent is,-
First. The filter beds constructed and arranged substantially as herein-before set
forth, and in which mineral oil works waste shale constitutes one or two layers, and
the employment of the said filter beds either alone or in combination with the
processes of precipitation herein-before referred to, or with analogous processes of
precipitation in the purification of impure waters or liquids, either by downward
or upward filtration.
Second. The filter beds constructed and arranged as herein-before described, and
in which matter or "sludge " recovered from impure water or liquid, and prepared
as set forth, constitutes one layer, and the employment of the said filter beds either
alone or in combination with the processes of precipitation herein-before mentioned,
or analogous processes in the purification of impure waters or liquids, and of town
sewage by downward or upward filtration.
In witness whereof, I, the said George Mackay, have hereunto set my hand
and scal, this 2nd day of January, One thousand eight hundred and seventy-
nine.
GEORGE MACKAY. (L.S.)