IMPROVEMENTS IN THE TREATMENT OF SEWAGE, AND IN DEODORIZING AND DIS- INFECTING SUBSTANCES RESULTING THEREFROM AND OTHER OFFENSIVE MATTERS
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by Charlton James Wollaston at the
Office of the Commissioners of Patents on the 25th July 1877.
CHARLTON JAMES WOLLASTON, of Kensington, in the County of Middlesex.
"IMPROVEMENTS IN THE TREATMENT OF SEWAGE, AND IN DEODORIZING AND DIS-
INFECTING SUBSTANCES RESULTING THEREFROM AND OTHER OFFENSIVE MATTERS."
The object of this Invention in the treatment of sewage is the acquisition of a
deodorized and disinfected sludge and effluent water, freed from tendency to after
decomposition; the materials used being also applicable to the deodorization and
disinfection of the contents of drains and cesspools, and of all substances and matters
which give out offensive or injurious exhalations or effluvia.
It is well known that in the treatment of sewage by the ordinary methods in
one or more catch pits or tanks, whether by the use of alum, lime, or other agents,
a certain, and in some cases considerable portion of the organic and polluting
matter is deposited by precipitation and subsidence, leaving a sediment or sludge,
to be removed from the tanks or pits by mechanical means as often as may be
required, and that at the time of this removal, and during the subsequent drying of
the sludge, much inconvenience and annoyance is caused by the emanation of foul
and noxious gases.
According to this Invention I utilize the well known disinfecting and deodorizing
properties possessed by sulphurous acid and by chlorine; and I attain the object
aimed at in my Invention by making use of one or other, and at times the two of
these agents, combined with lime, or with that substance and magnesia.
In carrying out my Invention I sometimes use ordinary lime, but I prefer
dolomite or magnesian limestone calcined in the usual manner of lime burning. I
subject this calcined dolomite after partial slaking to the action of hydrochloric
acid or chlorine gas in suitable apparatus, as in the manufacture of bleaching powder
from ordinary lime; or I slake the magnesian lime with hydrochloric acid diluted
with water to such an extent as may be necessary to form the desired proportions
of chloride of lime and magnesia, and of ordinary hydrated lime. In like manner I
treat the calcined limestone with sulphurous acid gas, or with dilute sulphurous

page_text: acid, and convert such portion as I may desire of the lime and magnesia into
sulphites of these bodies.
As the proportions of chlorides and sulphites and of the unconverted lime
required to precipitate, deodorize and disinfect sewage depends greatly upon the
strength or quality of the sewage to be treated, I vary the proportions to suit the
circumstances.
The prepared lime and magnesia reduced to powder I add to the sewage, either
dry or mixed with water, and the more thoroughly to incorporate the lime with
the sewage I cause the sewage to flow along passages or troughs, in which
obstructing or deflecting appliances are so placed as to separate the flow into two or
more streams, again uniting and becoming perfectly intermingled.
For deodorizing and disinfecting sewage, sludge, or the offensive matters from
drains or cesspools, I find it to be a convenient and economical plan to mix the
disinfecting material with the powdered "char" of bituminous shale, fine dry earth,
sifted ashes, coke breeze, charcoal or tan dust, or some such absorbent substance, as
the moisture is not only absorbed thereby but the action of the disinfectant is
rendered more thorough, and the foul matters may be at once removed without
causing inconvenience or annoyance.
By my Invention I secure an inexpensive and efficacious deodorizer and dis-
infectant, ready for use by sanitary authorities and others, for all purposes of sewage
precipitation and purification, and in the removal of night soil and noxious
substances.