The citizen. [volume] (Berea, Ky.) 1899-1958, 1911-10-26
SEWERAGE PURIECATlON
Remarkable Results Attained by Mod
ern Filtration Methods Report by
United States Geological Survey.

/ "O''~' Nsc'c VOsuNs Stt@'VeobN Woe
ern Filtration Methods Report b
United States Geological Survey.
As the population Of cities snt
towns becomes more and more con
gested, the public health requires
that some methods be adopted that
will change the chemical composition
" the sewage so that II will no
putrefy when discharged into water
courses. In some places IL is ever
necessary to disinfect the sewage NC
that all disease germs will be destroy
ed. Distinction is demanded because
OF the possible pollution of water
supplies and of shellfish beds. Ths
methods adopted for sewage disinfec-
ton are described at length in q pub
LEGATION issued by the United States
Geological Survey as Water-suppiy
Paper 229, entitled THE Disinfec-
ton of Sewage and Sewage Filter
Effluents,' by Earl b. Phelps.
Sewage publication as practiced to-
day Is but the artificial and intensive
application OF the process used every
where by nature to reduce putresci-
bic organic matter to inert inorganic
matter. II is well known that IL any
dead animal Is left exposed upon the
ground, 1t putrefies or rots for a
considerable period. giving off naus-
eous odors in the meantime. After
a while the rotting is complete. the
cdor disappears. and the material be-
comes mineral matter exclusively.
The process Is scientifically defined
Ly saying that the organic matter
las become oxidized. that is. oxygen
has united with the organic matter
TO produce the desired result. The
process Of sewage publication Ia pre-
c.sely the same except that In the
publication work conditions are pro-
vided under which naturs IL assist
ed In her work and the result 10 &C
complished In . much shorter space
Of time.
GREAT CAPACITY OF IMPRov-
ED FILTERS
The improvements made In meth
DDS Of treating sewage have therefore
cot involved the discovery or appli"
cation of new principles; those e.
tablished since the world began are
utilized. The constant aim Of the
has been to increase
the rate at which sewage can be puri-
fled. From the old-time sewage irri-
cation field. with Its maximum capa-
city OF purifying possibly 10000 gal
ons of sewage on an Acre in "a hours.
70 the present-day trickling filter
capable of dealing with two or three
million gallons a day on an acre Of
liter surface. the march Of improve
Ient has been steady and continuous.
The later Investigators have found
hat efficient publication can be &C
without carrying the pro-
:ess to the point Of complete oxida-
ion. The fluid flowing from a mol
I'm trickling filter. according to Mr..
helps. looks TO the unframed eye
Ike the original sewage: indeed.
here is almost as much organic mat
or in the effluent as In the raw sew
ge, and sometimes more, but this
rganic matter has been sufficiently |
hanged or oxidized to rob II of It's |
Dulness. In other words, its cheml-
al composition has been SO altered |
hat 1t is no longer capable OF IN
ergoing rapid putrefactive decompo-
Ition.
Although 1t may appear inconceiy-
BILE that the chief object Of sewage
ification-prevention Of the foul
* Of streams-can be attained by
lch invisible changes In the nature
I the organic matter. nevertheless
he discharge from efficient sewage
sposal plants may be permitted TO
lter a stream without fear OF caus-
lg a nuisance. The work OF purifi-
,tion also proceeds In the stream
self, as II does In the soil and In
lie publication works. until the oxi-
alton is complete. Oxygen for that
Irpose is sufficiently abundant IN
reasonably clean stream, but IL the
ream is overloaded with putresci-
q sewage there will not be oxy-
m enough and the stream will
come putrid. II all the putrescri-
o organic matter should not be re-
owed from the sewage by the purifi-
.tion works the remainder. II 1t Is
IT too large In amount, will be puri-
ed In the stream. So the purifica-
On AT sewage has come TO mean
the removal of the tenden-
TO putrefy and not the total oxi-