Note: Descriptions are shown in the official language in which they were submitted.
1054728
Thi8 invention relates to landfill op rations, and
in particular to a method of recovering and treating
thQ leachate~ therefrom before discharge.
~ early 90 per cent of the solid ~aste generated
in Canada is disposed of in a landfill of on sort or
another. The ban on op~n burning at these site- has
led to the contamination of underground and ~urface
~aters by ~aters draining from the~e fills. Referred
to a~ leachate, this contaminat~d ~ater is presu~ed
to result from thc percolation of precipitation through
the landfill and or by the direct interception of the
~ater table ~ith the buried refuse.
When municipalitie~ dump their garbage thcy oft-n
o~erlook the hydrogeology of an area, yet~they may have
kno~n for years that ~hen ~a~te i- di~posed of beneath the
the ~oil, dissolvcd solids, bacteria and viruse~ can
nter and tra w l in the ground~ater.
Part of the problem has been that the old--tyl-
garbage dump never app ared to cau-e a hQalth problem-
It ~a~ al~o kept fairly acceptable by op~n burning, and~a- usually in an out of the ~ay location. m us the
publi~ had little reason to complain.
Ground~ater i~ the ba~ic ~ater source for ~any
millions of CanQdian~. Leachate from solid ~aste fills
is gaininq recognition aJ a ~ounting threat to ground-
~at-r purity. It is eJtimated that, leachate, mainly
consi-ting of rain and the contamination it 80a~8 up
a~ it percolates through the refuse fill, contains
about as much BOD a8 the nation's ntire di~charge
of untreated ra~ sevage.
-2- 10547Z8
Soil and water are said to be polluted ~hen the
health of humans or animals i8 ~mpaired b~ consuming
the ~ood gro~n on the soil or by drinking the ~ater
that had contact ~lth the 80il.
Wh-n ~a-te- are applied to a 80il, our exp~rtis~
in protecting ground~at-r from landfill leachate
mu-t take into con-ideration the develop~ent of
by-product~ or derivatives from th- leachate that
may ~Q toxic or that may accumulate and threaten
our food chain.
A ~a~te applied to a soil should only be consid-
sred safely di-posed of ~hen
a) m. EOD ha~ been lo~sred to acceptable limlt-~
in the order of 4 pp~ for liquid effluent-~
b) ~ater flo~ing over or through ths oil ~ t-
th rsquired tandard~ a- to che~ical parity
ta~t-, colour and odour~
c) Soil and ~ater hav- nnt been polluted and it
has ~esn demonstrated that the ~aste, or its
b~-products, are not building up to to~ic
levels in ~oil or ~ater.
Apparently, few ba~ic studie~ related to gaining
an understanding of the basic characteristics of
leachates hav~ ~een reported. So~e studies done on
the Pacific coast, indicate that ~leach te quantity
and character i8 dependent upon the amount of moisture
traveling through the ~ystem aa ~ell as the time
and place~ent of the material in the landfill
-3~ 10547Z8
An analysi- of leachat- froa t~o la~df$11 sit-
~hav~ been carr$ed out in coop ration ~ith the in-
vantor, the results of the-e ~ea-ur ment- are sho~n
in the follo~ing TableJ 1 and 2.
Table 1
Rang_ of Concentration - Sanitary Landfill Leachat-
Concentration - ng/litre
~on Range
Iron 200 - 1700
~0 Zinc 1 - 13S
Pho-phat~ 5 - 130
Sulfat- 25 - 500
Chlorld~ 100 - 2400
Sodiu~ 100 - 3800
Nitrog n 20 - S00
Hardn--- (a- CaC03) 200 - S250
Che~lcal oxyg n D mand 100 - 51,000
~ota~ R~-idu 1000 - 45,000
Nick~l 0.0~ - 0.8
Copp~r -0.10 - 9 0
pH 4.00 - 8 5
An analyois o~ the ~norganic iono pre~-nt in
leachat- omanating fro~ the t~o conv-rted landfill
di-po-al it~ given belo~. m e firot ~it~ $-
i8 locat-d on ba~altic b drock thoreby ~llo~ing littl
penetration of run off ~ater into the underground
~at-r table me r -ult- of analy~i- of a elected
nu~ber of inorganic ion~ in the ~ite leachate i-
a- follo~
4- 10547Z8
Compound Parts per Million pH
Ammonia 55 5 7 8 to 8 0
Copper 0.05
Chromiun 0 02
Chlorid~ 400
Caleium 132
~luoride 0.42
Iron 1.72
Mhnganeae 0.10
10 Nitrate 14
Pho-phat- 0 65
Siliea 22 5
Sulfate 10.0
Zinc 0.05
At the seeond ~ite, th~ upper and lo~er li~it-
of the coneentration of v~riou- inorganie ions ~re
analy- d during the u mer ~onth~. ~h- results are
glv-n b~lo~.
Co~pQ~g~ PartJ per Million pH
Iron 2.0 to 5.8 6.6 to 7.4
Fho8phat- (Ortho) 0.04 to 0 68
Caleium 160 to 240
Nagnesiu~ 80 to 150
Nitrog n (nitrate
~ Nitrite) 12 to 24
Sulfate 50 to 225
Siliea 36 to 60
Chloride 75 to 80
~oth sulfate and iron oeeur in eoneentrations ex-
e-eding the limits set by Publie Health Authorities
-5- lOS4728
Con~iderable data applieablo to the deconta~in-
ation of l-aehate i8 available inee the treatm nt
of eonta~$nat-d ~ater represont~ a problo~ of great
eon¢ern to a ma~or portion of industrial and public
ent-rpri-e~ and th- proble~ ha- been ~tudied ~xten-
lvely. Conventional prlmary and aoeondary tr~atm~ntproe-a-e- ~ay not provid- the roquir d degro~ of
eonri-t-ney, nor do they provide suffiei-nt tr at~ent
for the proteetion of natural ~at-rs fro~ a vari-ty of
organie and inorganic pollutanta, mat-rial~ ~hieh
eontribute to th- ehemieal oxygen d mand, tha bio-
eh-~ieal oxygen d ~and, colour, ta-te, odour~ aa ~ 11
a~ e-rtain pathogens.
R-~-areh and dev~lop~ent on advanced physioch-mieal
proe -se~ for ~a-te ~ater treat~ nt ha- b -n centorod
primarily on tertiary treatment proe~--e- for ~a-te
alr ady ub~ et-d to convantional ~ocondary biolog-
ieal tr atm-nt m. addition of t~rtiary-le~ l p ys-
ioeh-~ieal process-~ to eonv~ntional eondary tr at-
nent ineurs ~ignifieant additional oxpenso- ofton ~ith-
out providing a eo~plet-ly atiafaetory re-ult
Cl-arly, a lo~ cost, highly effoetive ~ethod ofr ~oving
eontaminant~ fro~ ~ater ~ould represent a ~ignificant
eontribution to the ~olution of one of ~ankind's ~oat
pro-aing environmental problema
A variety of approachos to ~aste ~ater treat~ent
have b~ n proposed and e~p~ri~ent-d ~ith in rec-nt
yoars.
-6- 1054728
Sever~l important develop~ents have giv~n a ne~
impetus to the use of activated carbon for larg-
~cal- ~at~r treatment application, Activated carbon
filtration constitutes a step in the t-rtiary tr at-
ment proceso at the South Tahoe~ U.S., se~age treat-
Dent facllity. Other inv~stigations of proces~ing
ra~ ~e~ag by a t~o-step proc -- of clarification
Dnd carbon ad~orption have dramatically demonstrated
the potential of the techniqu- m e~e investigations
have demonstrated the econoDic and practical advantage
of u-ing carbon in the ~ater tr atment pr~ce~-. m-
co-t of activated carbon i-, ho~ever, a large factor
in the economic viability of adsorption technigue-
~regeneration of the carbon when pent, is an import-
ant factor in most presently co~ercial sch-m--.
A~ pr -ent, activat-d carbon i- one of th- no-t
pro~i-ing olid adsorb nts o~ing to its comnercial
availability, high adsorptive cap city and affinity
for a broad p~ctru of ch-Dical compound-. Organic
compounds that can be re~oved from aqu-ou~ solution
by active carbon include phenol~, cre-ol~, alkylbenz-n-
sulfonates, nitrochlorob nzenes, chlorinat-d paraffins,
butadiene as ~ell a~ certain ~ynthetic d~e~, insectic-
ides, and fungicides.
A~ an additional benefit, further r moval of cont-
aminants has been observed as a re~ult of biological
activity in carbon filter beds. It i~ thought that the
highly adsorb~nt carbon surface actually enhance- the
gro~th of biological organisD- because of its large
surface area and it~ capacity to hold nutrient~.
lOS47Z8
With$n recent years, a large naturally occurring
depDsit of carbon posse~sing propertie- ~imilar to act-
ivated carbon has been located A- a re-ult of thou~ands
of ch ~ical tests and practical application in th
fi-ld the r ~ult- e-~ to indicate that the n tural
active carbon may be as effective as the ~ynthetic-
ally produeed aetivated carbon in ~a~te ~ater p~rif-
ication of both organic and inorganie eonta~inant~.
If 80~ becau~e the carbon ~ay be produced at a fraction
of the eo~t of high grade aetivat-d carbon, th- dr m-
atic cost r duction ~ill allo~ many ne~ uses in ~at-r~
purification n eds, pr viously found economically
unfea~ible.
Unlike synthetic acti~ated carbons the t--t results
clearly de~on~trate a ~ignificant ad~orption capacity
of th natural ~Q~ 0 activ~ carb~n for ~o-t cations
and -varal anions The tests alJO suggeJt adsorption
capaciti-~ comparable ~ith the best aetivated earbon-
in the ea-- of phenols.
me follo~ing table ho~s the valu- of the natural
carbonJ ln the treatment of conta~inant-.
Inorganic Ion Adsorption
One of the unusual properties of the natural active
earbon i8 its apparent ability to adsorb a variety
of inorganic ions me proeedure ~ollo~ed in testing
the ad~orption properties of the carbon in~ol~es (1)
preparation of standard solution~ (2) s~ving of the
earbon to a 1/4~ to 1/16" particle oize~ (3) three
dlfferent ~ashing procedures invol~ing (a) a di~tilled
-8- 10547Z8
~ater ~ash, (b) a HCl acid ~ash, (c) a N~OH base ~ash,
(d) a base then acid ~ash.
(PPM)Neutral Acid Ea~e Ea3e then Contact
Initial Wash ~a~h Wash acid tl~e Hr~.
concentr tion
zinc 30 0.6 1.0
Zinc 30 0.3 3.0
Eariu~300 22 1.0
Eariun300 5 2.0
Copper 10 0.08 4.5 6.5 1.1
Iron 10 .51 3.7 1.1 1.7 1.5
Mangane~o 1146.30 81.0 6.3 43.0 1.0
Chromate105.00 .2 .1 .1 1.0
Chromate10.025 18.0
Sulfat-2002SO.00 120.0 150.0 1.0
Ph08ph~t~ 50 37.50 33.8 1301 . 1.0
Fh08ph~t~ 50 6.0 11.1 3.0
Chloride 30 32.50
Nitrate200249.00 115.0 90.0 5.0
Nitrite109105.00 1.5
Cyanide7010.00 1.0
Cyanide70 8.00 2.0
Cyanide70 1.10 20.0
A~monium 30 5.0 1.0
A~monium 30 2.8 4.0
_9 1054728
m e results shown heretofore, clearly indicate
a strong adsorption tendency to~ard mo~t cations and
the anion-, CN-, Cro~ and to some extent P04 Both
nitrate and phosphate have been ~igi~cantly removed
by thc car~on ~hen a biological community $- devel-
oped. The acid and base treated carbons appear to
hav~ onhanced ability to adsorb nitrates, phos p ates,
and sulfates. It should be pointed out that longer
contact times ~ill pro~ably l~ad to increased adsorpt-
ion since equilibrium appear to require -veral
hour~ (-.g., 8ee chromate results) in oome cases.
95~3!~ k~ ption
m e follo~ing ~tud$es hav~ been carried out using
ph~nol and nitrobenzene Ten grans of neutral ~ashed
carbon ~a- treated ~ith ten grams of pure nitrob nzene
and t-n gramJ of 90X aqueou- solution of ph~nol for
one hour. By ~eighing the carbon before and after
xpo~ur~ to the organic the follo~ing result~ ~ere
obtained~ i
g of organic adsorbeq/g of carbon
Phenol 0.19
Nitroben~ene 0.16
The~e results compare favorably ~ith the reJult-
of a study in ~hich phenol and nitrobenzene ~ere ~d-
~orbed on a larg~ ar a commercial activated carbon.
mi8 activat-d carbon, ~hich posses~ed a surface ar a
of 1200 m /g, adsorb~d 0.094 grams of phonol/gram of
carbon and 0.22 grams of n$trobenz~ne/gram of carbon.
m e~e re~ults sho~ that the natural carbon adsorption of
the8e t~o organics i8 equal to that of a high grade
~ynthetic activated carbon.
-lo- 1054728
The following tests were done to determine the treat-
ment effectiveneso of the natural carbon in which a biol-
ogical community ha~ built up, and which had been in use
in the treatment of meat packing house wastes for a period
of 26 months without regeneration or rePlacement.
Contaminant Removals- Before Treatment After Treatment
Phosphate (ortho) 65.0 ppm .08 ppm
Phosphate (total) 85.0 ppm 2.1 ppm
Biological Oxygen Demand 750 ppm 10 ppm
This invention relates in Part to Canadian Patent Appl-
ication NO. 228,069 Filed May 29, 1975.
I have outlin~d heretofore the disadvantages assoc-
iated with the collection and treatment of solid wastes
and the leachates issuing therefrom, in both controlled
and uncontrolled landfill operations, and have outlined
herein by laboritory tests the benefits to be gain~d from
the use of ad~orbent natural carbons for such landfill
leachate treatment.
It is an object o~ the invention to provide a n~w and
improved process for the collection and treatment of land-
fill leachates i~suing from both controlled and uncontrolled
landfill operations, that ~ill effectively ramove a variety
of contaminants from the leachate.
An important objective is to remove the greater percent-
age of BOD and COD from the leachates.
Another object is to remove from leachates the heavy
metals therein.
A prime objective of the invention is to provide an
~`,
OS47z8
adsorptive curtain wall of carbon to surround old land-
- fill operations, 90 placed as to intercept and treat the
horizontal flow of leachate originating from the refuse
therein.
An additional object of the invention i8 to provide
a process for treating landfill leachates which will re-
move offensive odours therefrom.
A still further object of the invention is to provide
a process for removing harmful bacteria, pathogens and
vuruaes from the landfill leachates to prevent them from
passing into the groundwater~-
Still other objects and advantages will become appar-
ent hereinafter.
I have found that the aforementioned disadvantages may
be overcome and the objectives achieved by providing treat-
ment for the landfill leachates as i8 shown and described
in the following numbered drawings and description-
In accordance with the present invention, therefore, thelandfill leachates are treated within a prepared landfill
site comprising a drained impervious base, which is over-
laid with an impervious liner, covered by layers of ad-
sorbent carbon. A plurality of intarconnected perforated
flexible pipes are laid within the carbon, and serve to
gather and conduct the leachate to the collecting sump-
wells, which extend vertically to the surface of the land-
fill. m e refuse is placed upon the carbon, and in use the
leachate passes through the refuse and is conducted
through the perforated pipe to the col1Qcting well
`~ `
-12- 1054728
and then pump~d to a plurality of ~eparation bed~, bio-
logieal treatmant bed~, and tertiary treat~ent bed-
for treat~ nt
Referring no~ to Dra~ing 1 of Sheet 1, indieated
at 10 i- aurface ~atcr into ~hich landfill leaehates
from a typieal uncontrolled landfill op~ration ~ay
ba -eping. Indieated at 11 i- a v~rtieal curtain ~all
d-~igned to top the hori~ontal flo~ of ground~at-r
earr~ing leaehat-~ th-r in indicat-d at 13. The eurtain
~all 11 eomprising t~o vertieal ~all eetiona, an inn r
~all indieated at 8 formed by pQrviou- polyvinal chlor-
ide (P~C) heavy h~eting on the landfill ~ide, and an
outer ~all for~ed by i~perviou- polyvinal ehlorid-
(P~C) heavy sh--ting indieated at 9 Indicated at ~
is ho~n an inner eore of granular ~eleeted ad-orbent
Coal. within the inner eore -etion 7 leaehate reeov~ry
118 lndieat-d at 12 ara r ee-~-d into tha ~a~e th-r~-
of. In pr etiea th- l-aehat--ground~ater indieat-d at
13 i8-U-8 fro~ th- landf~ll ar a~ indleated at 14 and
Pa---- lnto the curtain wall indieat~d at 11 through
th- pervioua ~all indieated at 8. Th- l-aehat- i~ pre-
vent d from pa~-ing into the ~urfae- ~at-r indieat d
at 10 by the imp~rviou~ outer ~all of th- eurtain ~all
indicated ~t 9, and i~ eolleeted therein for r~moval
by ~ean~ of pu~plng the leaehate fro~ the ~ell~ 12.
Referrlng no~ to Dra~ing 2 of Sheet 1, indicat-d
at 16 i~ a ~ell croJ~-section. Indicated at 19 i8 land-
fill refus- ~ithin ~hich a ~ell 12 ~ay be ~it~d outside
the eurtain ~all 11 ~he refus- leaehate 22 pass-- thr-
ough the rigld p~rviou~ ~a~ 21 to b come the leachat- 23
At 24 is the 8ump section of th- ~ell and indic-
_13_ 1054728
ated at 20 i8 bodrock or ~ase of the landfill aroauithin the ~oll m e leaehate 23 i- ~ithdra~n fro~
th- ~ 11 16 through th- pipe indieated at 15, at
th- botto~ nd of pipe 15 i~ a ~tandard ~at-r~ell
cr -n indicated at 18. The ~ithdra~al pipo 15 i~
~ad of stiff black plastie PVC indicat-d at 17.
R-ferring no~ to Dra~ing 3 of Sh -t 2, indieated at
25 i~ a controlled typ~ o~ landfill operation. Indie-
at-d at 26 i- a Olid ba-e of undi~turbsd sarth, into
~hich a ground~ater eollection trap i- r~ea-~-d,th
trap i- indicated at 30~ The ~all- of the trap 30
ar made of p~rviou~ ~aterial 31 within the tr~p
i- laid p rforat-d ground~ater eolleetion pips- ~hieh
ara indieat d at 270 ~nclooed ~ithin th- trap and
forming a urround for the p rforated pipe 27 ara
eleet-d ad~orb nt natural eoal ~atorials indieat d at
29. On oith-r id- of th trap 30 i~ paaced optionally
a layer of p r~iou~ and or naturally adsorb-nt aeti~e
earbon 29 to tbo top of the trap 30. Ov~rl~in~ th
201 ~olid ba~- 26, trap 30 and l-v-l fill indieat-d at 28
! eo~prising ith-r perviou~ ~and or natural earbon 29
i~ a thiek icp~rvious sh-et of poly~inal ehlorid ~PVC)
indieat-d at 31. A 8iX inch ba~- co~er of ~ et-d 29
naturally aetive ad-orbent coal i~ laid o~r the ntire
landfill ite, into ~bieh l-aebat- trap~ 32 ar r~e~ d
at interval~ acros- the refus- d~sp~-al araa 25. P-rf-
orated eoll-ct~on p~pss iddieat d at 33 are laid ~itbin
tho l~achate- traps 32 ~itb a surround of -l~ct-d
naturall~ active ad~orbent coal 29. A solid layer of
clayey 80il i8 plac~d over the entire ~or~ing aroa of
-14- 1054728
the landfill as indicated at 34. At ~uitable spaced
intervals perpendicular well piping indicated at 35 i8
~oined to gether w$th the leachate collection pip~s 33
and sump 22 from which the leachate and ~ludge ~ay be
pumped. Indicated at 36 i8 the refuse of the landfill
operat~on.
Referring now to Drawing ~ of Sheet 2, indicated at 37
18 an uncontrolled landfill operation, the greater major-
ity of this type of refuse disposal have limited if any
controls governing their operations. If site plans are
available for this type of landfill it is best to sink
leachate recovery wells at low points indicated on the
plan- Since water doe~ not always flow downhill becau~e
of certain geological and impen~eable strata, it will
likely be found that almost any well drilled into an old
garbage dump will draw water to it, even up hill. Indicated
at 38 are w 118 for the removal of leachates for treatment.
Referring now to Drawing 5 of Sheek 3, indlcat d at 40
i8 a landfill area. Indicated at 41 is the l~achate coll-
ction and recovery well. The leachate i8 pumped from thewell by pump indicated at 42 and iB pa ~ed into the line
indicated at 43 through ~hich i8 received the leachate
to be treated. If th- leachate iB carrying large amounts
of easily settled solids, it is preferably pa~ed through
a settling tank, indicat d at 44, to Permit such solids to
settle out. Optionally the leachate ~fflu~nt is treated
with a polyelectrolyte prior to the passage of the
leachate into a biological treatment bed comprising
a smaller sand section indicated at 45
-15- 1054~Z8
and a larger filter section indicated at 46. The flrst
treatment bed i9 shown as a dual media bed as i8 indic-
ated at 47, having a first smaller section of relatively
fine filter material and a larger filter section o~ rel-
atively coarse filter medla. m e difference in the part-
icle sizings of the media may vary according to the nature
of the leachates and the type and amount of pollutants
therein. Preferably the particles in the longer sQction 46
are of materials of lower density than that of the smaller
section 45 Particle6. The di~ference in the density helps
to maintain separation between the sections particularly
during bacXwashing operations. While the desirable size
range of the filter media may vary as afOrementiOnQd~ the
particles o~ the coarse section 46 should be substant-
ially larger in diameter than those Particles of the finer
media in section 45. The coarse particles may range, for
~xa~ple, from about 1/8 inch to about 3/4 inch- m e coarse
sectlon 46 should pre~erably have a depth of not more
than about 12 inches and tho level of the ef~luent in
the treatment bed should not be above about 8 inches as
me~Jured from the bottom of the bed to provide odour
control therein.
The section 45 i8 Preferably ~onmed of a relatively
dense material such as silic~ sand. m e particle size
should be substantially small~r than the Particle size
of the coarse media in section 46. The and may range
in size from about 0.04 to 0.01 inch. m e rection 4S
~hould have a depth of at least 6 inche and preferably
a depth of between about 6 to 12 inches.
. .
~ "~^
-16- lOS4728
After a period of about a month or when a backpressure
develops which tends to restrict the free flow of the eff-
luent through the treatment beds, a cleaning procedure in-
volvlng the backwashing of the beds to remove normal degrad-
ation materials and windblown debris therefrom is carried out.
m is is done by passing a reverse flow of water through the
beds indicated at 47. Clean water from any available source
is pumped into and through the treatment beds in a reverse
flow pattern to dislodge and remove the effluent degradation
material8 and windblown debris from the adsorbent coal treat-
ment media in the beds as an effluent sludge, and then the
backwash water and effluent sludge is discharged from the
treatment beds indicated at 47 and carried through the carry-
ing line indicated at 48 and returned to the settling tank
indicated at 44 for settling. The effluent from settling tank
indicated at 44 is then passed into the biological treatment
bed 47 in the direction through the smaller sand filter sect-
ion indicated at 45, to remove any solids there~rom and then
through the longer filter section containing selected adsorbent
natural coal carbon in coarse particle sizing~ therein. A
biological community is developed naturally within the bed
and is enhanced by returning part of the bacteria laden out-
flow from the bed to the inflow of the longer bed section 46
for the purPose of inoculation. The removal of BOD and COD
producing ingredients is carried out in the first beds indic-
ated at 47 without the production of any odours therefrom by
maintaining the effluent level within the beds below that of the
top of the carbon indicated at 49 therein. As is indicated in
a following table the bacterial content of total coliform and
~0 faecal coliform are removed by the selected natural carbon
~.
-17- 10 S 47 2 8
in contact therewit~ Provision is made for the removal
of phosphate containing ubJtance- in the effluents
by providing in the plurality of treatment beds a bed
or a ~ection of a bed ~hich ~ill contain a selected
natural ad~orbent carbon h~ing an affinity for po~-
phatea in the effluent to renove it therefrom. me
ef~lu-nt flo~ is indicated at 53 and the bacX~a~h flo~
i~ indicated at 54 me effluent from bad indicated at
47 is pa~-ed through second biological treat~ent bed
47 or a plurality of such bsds, and i~ then pa~-ed into
a plurality of treatment bad~ by means of carrier line
indicated at 55, ~herein tertiary treat~ent is prov-
ided the leachate effluents to remove any remaining
pollutant- therefrom me tertiary treatment beds
indicated at 48 contain a selected natural adsorbent
carbon having an affinity for tertiary type pollutant~
~hich may r main in the l-achate ~ffluents to r move
thom ther~from The traated leachate e~fluent~ are
then di-charged from the treatment bed of the treat~ent
y-tem by means of di~charge pipe indicated at 56 for
discharge to urface ~aters indicated at S2 or to be
re-cyclad to the landfill operation indicated at 51.
me aforementioned ~ater discharged from the final
troatment bed ~ill be of a standard of quality suitable
and acceptable to pollution control agencie~ for uch
discharg-s me back~as~ing of the syste~ is carried
out by means of the pu~p indicated at 50 and tha ~ater
carriage lines indicated at 55
-lB- 10547Z8
An idea of the treatment effect~veness of a Jelected
naturally adsorbent carbon in the removal of harmful
bacteria from ~a-tenater after such tr~atment ~ay be
seen from the follo~ing report.
~ xc-rpt- from a letter ~on file) concerning test~
Dade by the B.C. Pollution Control Branch, a~ r ported
to the Chief Health In pector, Capital Ragional Dist-
rict, Victorla, B.C Dated January 22, 19~5.
~Attached are the re~ult- of test~ on th~ coal -y-tem
of ~age treatment~ e ran the t-~t~ for our o~n
information a~ to ho~ the material ~orked on doJe-tic
e~age, ho~ever, ~e thought you might bQ intere-t-d
in the r sults.~
~Ret Tr atment of Dome-tic Se~ag ~ith Pulveri~ed Coal.
A high degree o~ reduction has b~en achiev d for om
p~ra~tor- includlng total and faecal colifor~ level8-
h- m d-gr e of tr at~ nt prbvided by thi- ~yst-
~ll better than l-vel ~A~ of the ~Mini~u~ R-quir ~ent~
for di-po~al of Municipal and do~ -tic ~astenater
to Jur~ace ~ater-~.
~...JUly 3, 1974.
T. Coliform Infl. 9.2x106Eff. 9.2x104 Red. 99X
F. Colifor~ ~ 4.9x105~ 7 x103 ~ 99X
-
In 8U_ ry the proce~ of the inv-ntion involve-
th~ step4 of
1. Providing a suitable ~ay of collecting and rcm-
oving leachates ~rom both controlled and uncont-
rolled land~ill operations.
-19- ~0547Z8
2. Collecting leachate oriqinating within a controlled
landf$11 operation by conducting the leachate by means
of perforated piping laid within adsorbent coarsely
sized coal, to recessed filter traps containing there-
in the coarsely sized adsorbent coal.
3. Providing a means of settling out solid6 from the
leachates by forming well sections extending to the
surface of the refuse from the reces~ed filter trap
where the well has a lower sludge sump and an upper
effluent section.
4. Collecting the leachate within the well which origin-
ates from the perforated piping, the filter traps and
through the pervious wall of the wells.
5. Removing the collected leachate from the wells in both
controlled and uncontrolled landfill operations by
means of pumps and conducting it to a settling tank.
6. Removing any r~aining effluent solids in the leachate
by the addition to the leachate of an adsorbent powd-
ered coal flocculating agent with agitation, and then
optionally adding as required a polyelectrolyte sett- -
ling agent.
7. When found necessary removing the settled sludge from
the well sumps and from the settling tank and inter-
mixing the sludge with - further addition of powdered
adsorbent coal and recycling the coal sludge mixture
back to the landfill operation.
-20- 10547Z8
8. Passing the effluent from the settling tank into a
dual media filter comprising firstly a smaller sand
section wherein the ~and particl~s have a sizing
ranging in size from about 0.04 to 0.01 and i8
placed within the filter to a depth of between 6
inches and 12 inches.
9. The effluent is then passed into a longer filter B
section containing therein coarse sizings of sel-
ect~d adsorbent coal having a range of sizings
ranging from about 1/8 inch to about 3/4 inch, whe-
rein the leachate organic matter is oxidized by
biological activity, and where the biological act-
ivity may be enhanced by re-inoculating the biolog-
ical community in the treatment bed by r~-cycling
the outgoing effluent from the bed back to the first
section of the coal filter m d ia.
10. Maintaining odour control within the treatment beds
by keeping the effluent level in the bed below that
of the top of the coal treatment media.
11. Selectively removing the total coliform, faecal col-
iform and pathogenic bacteria from the landfill
leachate by treatment with the selected adsorbent
coal materials-
12. Removing BOD and COD causin~ pollutants ~rom thelandfill leachate~ by treatment with selected adsor-
bent coal materials.
-21- 10547Z8
13. Providing tertiary treatment a8 a final polishing
stage of leachate treatment to remove any remaining
pollutants therein.
14. Di~charging after treatmQnt an effluent having a
water quality of acceptable standard suitable for
discharge to surface waters or for re-cycling back
to the landfill operation.
lS- Provid~ng a plurality of biological and tertiary
treatment beds using a plurality of differing
select~d adsorb-nt coal mat-rials, for use in rem-
oving pollutants from landfill leachat~s.
16. Determining the pollutant content and concsntration
thereof by analysing the landfill leachates.
17. Selecting the most suitable adsorbent coals for u-e
in the tr-atment o~ landfill leaehaees cho~en from
the group of coals consisting of most ranks of coal
and coal waste~ exeepting anthracite coal. In deter-
mining the coal suitable for use in the l-achate
treatment procedure thin seetions of coal are exam-
ined by microphotograph study to deter~ine the phy~-
ieal characteristie~, the content of surface chem-
icals ~nd crystals thereon, and the adsorptivity of
the eoal to remove the polluting leachat- contam-
inants as found by afor~entioned analy is.
18. Crushing, pulv-rizing and sizing the selected co~ls
to provid2 treatment sizings which may rang-
from 3 in~hes down through -200 screen mesh size.
~,~
-22- 10547~
19. Improving the adsorptive affinity of the selec~ted
coal by a proce~ ~hich involves artificial weath-
ring ~hich comprioes boiling the coal particlesin watQr for from about S to 30 minutes, or ub-
~ecting the coal particle- to a steam bath, or
wa-hing the coal particles ~ith ~olvent eolutions
chosQn from hot or cold ~ater, an HCl acid waah,
a NaOh base ~aoh, or a base then acid ~aeh. m n
optionally drying the coal particle- at a temp~r-
ature of from about 100C to 200C for a sufficient
p~riod of time to effect the removal of the moist-
urs and or ea~ily volatilized ~ub tances or gases
therein, or from about 1 to 10 houro.
20. Providing selected adsorbent coal in size range-
~uitable for u-e for the purpo-e intended of the
invention ~herein a sizng of from about 3/4 iach
up to about 3 inche- may be u-ed in the filter
trap-, ao a cover for th- landfill ba~e, and for
a coal ~urround for the perforated coll ction
pip~- ~ithin the controlled land~ill operation.
And ~herein a powdered ~izing of the adsorbent
coal i- used in the treatment of the leachate
effluent passing into the settling tank for uee
a~ a flocculating agent, this po~dered ~izing
includes all those pulverized ad-orbent coal
~at-riala in ~hich the maxi~um size i8 that pa---
ing a standard 200 mesh size ~creen. And ~herein
the sizing o~ the ad~orbent granular coal mater-
ials used in the biologi~al treat~ent bede and the
- tertiary treatment beds a~ well a~ the curtain wRll
i8 preferably of from about 1/8 inch to 3/4 inch
or selected sizings ~ithin that range.
-23- 1054728
21. A further additional step is the conversion of an
uncontrolled landfill operation to a control~ed
landfill operation wherein a vertical impervious
curtain wall is provided to surround or cut-o~f
the horizontal flow of leachate is6uing from the
landfill operation, within which a second vertical
wall of pervious construction is placed, and wherein
the pervious vertical wall and the impervious vert-
ical walls are separated one from the other by an
inner core comprising adsorbent granular coal in
predetermined sizlngs. Leachate recovery w-lls are
recessed into the base of the landfill and the
aforesaid inner core section separating the two wall
sRCtions. The wells consisting of a lower sump sect-
ion for the collection of settleable solids from the
leachate, and an upper section for the collection
of the ~ettling lea~hate effluent. m e wells, ext-
tending vertically from the recessed sump area through
the land~ill refuse and adsorbent coal treatment
m~dia to the landfill surface, are formed from rigid
pervious non-degradable material. The leachate from
the solid refuse percolates through the inner perv-
ious vertical wall and thence through the inner core
~ection of adsorbent granular coal and is then passed
through the pervious rigid wall of the collection
well, and ~hen the solids are settl~d therefrom the
settled effluent is then pumped from the well to a
settling tank and i8 then treated by the aforement-
ioned leachate process outlined heretofore.
22. Backwashing the biological treatment beds and the tert-
iary treatment beds when a backpressure i9 found build-
ing up within the beds which restricts the free flow of
the leachate effluent therethrough and conducting the
wash-debris back into the settling tank.
,-1~
-24- 10547~
22. Backwashing the biological treatment bsds and ths
tertiary treatmsnt beds when a backprsssure is found
building up within the beds which restricts the free
flow of the leachate effluent thersthrough and cond-
ucting the wash-debris from ths beds back into the
~ettling tank.
Having illustrated and described a pr~ferr-d embod-
imsnt of the invention, it should be apparent to those
skill~d in th~ art that the invsntion penmit~ of modific-
ation in arrang~ment and detail. I claim aa my inv~ntionall such modifications as come within the true spirit and
scope of the appsnded clains.
~3 .
