Improvements in the Preparation of an Agent for Use in the Treatment of Sewage and other Liquid or Semi Liquid Putrescent or Putrescible Matters, and Improvements in the Treatment of such Matters.
Year: 1884

page_text: Improvements in the Preparation of an Agent for Use in the
Treatment of Sewage and other Liquid or Semi Liquid
Putrescent or Putrescible Matters, and Improvements in the
Treatment of such Matters.
We JOHN WILLIAM SLATER of N° 36 Wray Crescent Holloway in the County
of Middlesex Analytical and Consulting Chemist and WILLIAM STEVENS of
No 29 New Bridge Street in the City of London Secretary to the Native Guano
Company (Limited) do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE 'PREPARATION OF AN AGENT FOR USE IN THE TREATMENT
OF SEWAGE AND OTHER LIQUID OR SEMI LIQUID PUTRESCENT OR PUTRESCIBLE
MATTERS AND IMPROVEMENTS IN THE TREATMENT OF SUCH MATTERS to be as
follows:-
"
Our Invention consists first of the method hereinafter described of preparing
muriate of alumina for use in the purification of sewage and other liquid or semi
liquid putrescent or putrescible matters.
We take the mineral known as Gibbsite or any other naturally occurring
terhydrate of alumina or we take clay or other mineral containing a considerable
quantity of terhydrate of alumina and reduce it to powder and add to it muriatic
acid and heat the mixture until the alumina and oxide of iron present are dissolved
and then run off the solution from the residue which in the case of Gibbsite consists
of silica or silicate of alumina.
Our invention consists further of the method or process hereinafter described of
treating sewage and other matters such as the waste liquors from dye works and
tanneries and other waste liquors and such other liquid or semi liquid putrescent or
putrescible matters as are capable of purification by precipitation In the following
description sewage only is referred to. The process is however similar in the case
of other matters except as regards the quantities or proportions of the agents used
which vary according to the quantity of the putrescent or putrescible constituents
of the said matters.
We add to the sewage to be treated a quantity of clay and carbon or charcoal
ground together with water and a quantity of the muriate of alumina prepared
as herein before described and thus produce precipitation of the putrescent or

page_text: putrescible constituents of the sewage. We prefer to add the mixture of clay and
carbon first and after they have become thoroughly incorporated with the sewage
we add the muriate of alumina. The clay and carbon and muriate of alumina may
however be mixed together before being added to the sewage where from any reason
it is more convenient to do so than to add them separately.
The muriate of alumina being acid it is necessary to neutralize the sewage if it
be acid. This may be done by adding lime to the sewage either before or after
adding the mixtures thereto.
Lignite or carbonized peat moss or any refuse charcoal or carbon may be used in
preparing the mixtures.
The proportions in which we use the mixtures hereinbefore described depend on
the nature and quality and condition of the sewage or other matter to be treated.
In the case of sewage of average quality we add to every ten thousand gallons
thereof as much of the muriate of alumina as is obtained by treating from eight to
twelve pounds weight of Gibbsite as hereinbefore described and from forty to
eighty pounds weight of carbon or charcoal and from forty to eighty pounds weight
of clay containing the average amount of moisture i.e. about forty per cent. We do
not however limit ourselves to these proportions.
In preparing the muriate of alumina it is important that only those minerals be
used which contain terhydrate of alumina. The monohydrate of alumina (known
as Diaspore) and the bihydrate of alumina (known as bauxite and beauxite) are
unsuitable being only very slightly soluble in muriatic acid. By the term
terhydrate of alumina we refer to naturally occurring alumina consisting of a
combination of three or more molecules of water and one molecule of the oxide of
aluminium.
The muriate of alumina prepared as herein before described is cheaper than that
produced in the ordinary way.
The use of muriate of alumina in the purification of sewage and other matters of
the kind hereinbefore referred to is preferable to the use of sulphate of alumina the
result being superior.

page_text: Improvements in the Preparation of an Agent for Use in the
Treatment of Sewage and other Liquid or Semi Liquid
Putrescent or Putrescible Matters, and Improvements in the
Treatment of such Matters.
16
We JOHN WILLIAM SLATER of N° 36 Wray Crescent Holloway in the County
of Middlesex Analytical and Consulting Chemist and WILLIAM STEVENS of
No 29 New Bridge Street in the City of London Secretary to the Native Guano
Company (Limited) do hereby declare the nature of our said invention for
IMPROVEMENTS IN THE PREPARATION OF AN AGENT FOR USE IN THE TREATMENT
OF SEWAGE AND OTHER LIQUID OR SEMI LIQUID PUTRESCENT OR PUTRESCIBLE
MATTERS AND IMPROVEMENTS IN THE TREATMENT OF SUCH MATTERS" and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement :—
Our invention consists first of the method hereinafter described of preparing
muriate of alumina for use in the purification of sewage and other liquid or semi
liquid putrescent or putrescible matters.
We take the mineral known as Gibbsite or any other naturally occurring
terhydrate of alumina or we take clay or other aluminous mineral containing a
considerable quantity of terhydrate of alumina and add to it muriatic acid and
heat the mixture until the terhydrate of alumina present has combined with the
acid.
The acid used may be the crude muriatic acid produced in alkali manufacture on
the Leblanc process and known in commerce as "Tower salts." Where this acid is
readily obtainable wo prefer to use it on account of its cheapness. If the Gibbsite
or the clay or other mineral selected for use contain much water we dry it in order
to facilitate its reduction to powder and to avoid dilution of the acid by the water
contained in the said matter. The quantity of acid necessary to be added to a
given quantity of the Gibbsite or other aluminous mineral to be treated depends
on the strength of the acid and the proportion of alumina present in the mineral
When these are ascertained the acid should be added to the mineral in such quantity
that there shall be three equivalents of actual muriatic acid to two equivalents of
the terhydrate of alumina. The temperature to which the mixture should be heated
is about that of boiling water. In order to ascertain when the whole of the
terhydrate of alumina has combined with the acid small quantities of the
undissolved mineral in the mixture must be tested from time to time by analysis
or otherwise. When the period necessary for the treatment of any given sample
of Gibbsite or other mineral has been thus ascertained it may be noted and in
treating further quantities of the same mineral the heating of the mixture may be
continued for a like period further analysis of the said mineral while under treat-
ment being then unnecessary.
It is important that only those minerals be used which contain terhydrate of
alumina. The monohydrate of alumina (known as Diaspore) and the bihydrate of

page_text: alumina (known as bauxite and beauxite) are unsuitable being only very slightly
soluble in muriatic acid. By the term terhydrate of alumina we refer to naturally
occuring combinations of alumina consisting of three or more molecules of water
in combination with one molecule of the oxide of aluminium.
In selecting clay or other aluminous minerals of the kind hereinbefore referred
to we reject those containing an appreciable amount of carbonate of lime and in
some cases we also reject those containing as much as five per cent and upwards of
any compound of iron for the following reasons. The acid used combines with
carbonate of lime more readily than with alumina consequently when carbonate of
lime is present a greater quantity of acid is required for producing the required
action on the aluminous mineral than is required when carbonate of lime is not
present. The presence of iron in the aluminous mineral causes a yellow tint in
water treated (as hereinafter described) with muriate of alumina prepared from a
mineral containing iron which yellow tint is in some cases objectionable. As
however this is the only effect produced by the presence of iron minerals in which
it occurs in association with the required constituents may be used in preparing the
muriate of alumina if the appearance of the water after treatment with it be of
slight importance.
Muriate of alumina prepared as herein before described is cheaper than that
produced in the ordinary way.
Our invention consists further of the method or process hereinafter described of
treating sewage and other like matters such as the waste liquors from dye works
and tanneries and other waste liquors and such other liquid or semi liquid putrescent
or putrescible matters as are capable of purification by precipitation. In the
following description sewage only is referred to the process is however similar in
the case of other matters except as regards the quantities or proportions of the
agents used which vary according to the quantity and nature of the putrescent
or putrescible constituents of the said matters.
We add to the sewage to be treated a quantity of clay and carbon or charcoal
ground together with water and a quantity of the muriate of alumina prepared as
herein before described and thus produce precipitation of the putrescent or putrescible
constituents of the sewage. We prefer to add the mixture of clay and carbon first
and after they have become thoroughly incorporated with the sewage we add the
muriate of alumina. The clay and carbon and muriate of alumina may however
be mixed together before being added to the sewage where from any reason it is
more convenient to do so than to add them separately.
The muriate of alumina being acid it is necessary to neutralize the sewage if it
be acid. This may be done by adding lime to the sewage either before or after
adding the mixtures thereto. The lime being used only to correct acidity of the
sewage and not as a precipitant care must be taken that-it is not used in excess
that is it must not be used in such quantity that the effluent shall have an alkaline
reaction.
In preparing the mixtures herein before described any kind of carbon or charcoal
may be used such as the refuse charcoal or carbon resulting from certain manu-
factures or carbonized peat or carbonized peat moss. Lignite (otherwise known as
Bovey-coal" and "Moor coal" and "wood-coal") is also suitable for use as carbon
in preparing the said mixtures.
The proportions in which we use the mixtures bereinbefore described depend on
the nature and quality and condition of the matter to be treated. In the case of
sewage of average quality (i,e sewage containing per gallon about one hundred and
twenty grains of excrementitious or other putrescent or putrescible organic matter
in suspension or solution) we add to every ten thousand gallons thereof as much of
the muriate of alumina as is obtained by treating from eight to twelve pounds
weight of Gibbsite as hereinbefore described and from forty to eighty pounds
weight of carbon or charcoal and from forty to eighty pounds weight of clay
containing the average amount of moisture (about forty per cent). We do not
however limit ourselves to these proportions.

page_text: In treating sewage or other matters containing a smaller or larger proportion of
excrementitious or other putrescent or putrescible organic matters we use a pro-
portionately smaller or larger quantity of the purifying agents or mixtures. In all
cases where the sewage or other matter to be treated is in a highly fermented state
a larger proportion of the said agents or mixtures is required than where the said
matters are in the ordinary condition.
Where a very great degree of purity of the effluent is not required as where it
is to be run into the sea or into a tidal river the muriate of alumina may be used
alone the mixture of clay and carbon being dispensed with.
The sewage may be conveniently treated in a tank or other receptacle in which
it may be allowed to remain until the impurities have been precipitated when
the supernatant water may be allowed to run off and the precipitate removed and
disposed of in any convenient way. Or the sewage may be treated as it flows to
or through a series of tanks in which the impurities are precipitated and from
which the supernatant water passes continuously.
The use of muriate of alumina in the purification of sewage and other like
matters is preferable to the use of sulphate of alumina the result being superior.
One objection to the use of sulphuric acid in any combination is that the growth
of "sewage fungus" (Beggiatoa Alba) is favoured thereby and this objection does
not attend the use of combinations of muriatic acid.
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed we wish it to be
understood that we do not limit ourselves to the precise details herein before
described as they may be varied without departing from the nature of our
Invention but we declare that what we claim is
First. The preparation of muriate of alumina for use in the purification of
sewage and other like matters by treating minerals containing terhydrate of
alumina with muriatic acid substantially as hereinbefore described.
Secondly. The use in the treatment of sewage and other like matters of
muriate of alumina prepared by treating minerals containing terhydrate of alumina
with muriatic acid as herein before described.
Thirdly. The use in the treatment of sewage and other like matters of muriate
of alumina prepared as herein before described in conjunction with clay and charcoal
or carbon or lignite substantially as hereinbefore described.
Dated this twenty eighth day of August 1885
W. T. WHITEMAN,
Agent for the Applicants.