DE2456225A1 - METHOD OF DISPOSAL OF SEWAGE SLUDGE AND THE USE OF IT - Google Patents

Description

Dr. Hans-Heinrich Villrath

Dr. Dieter Weber Diploma in Phys. Klaus Seiffert

PATENT AGENCIES File 1262-74

D- 62 WIESBADEN P ° ^{stfach 1327}

Gustav-Freytag-Strasse 25 S (06121) 3727 20 Telegram address: WILLPATENT

November 27, 1974

IU Conversion Systems, Inc., 1616 Walnut Street,
Philadelphia, Pennsylvania / USA

Process for removing sewage sludge and

its use

Priority date November 30, 1973 in USA,
Serial-No. 420 364 and
August 2, 1974 in USA,
Serial-No. 494 338

The invention relates to a method for the disposal and use of waste material from municipal sewage systems, in particular the digested sewage sludge,
which occurs in the usual way in the treatment of urban wastewater, namely by combining such sludge with certain types of hardening reaction components

/ 2

509824/0820

and, if necessary, further additions of other compounds or inert substances. The invention relates to also the treated masses and their hardened products.

One leaves in a customary primary treatment of wastewater

raw sewage to settle, the underflow in a sealed from the atmosphere chamber is anaerobically ausgefault at a temperature in the order of 35 ⁰ C (95 ° F). The residence time of the wastewater in this chamber is generally about 5 to 30 days. Digested coagulated underflow or sludge is removed from the bottom of this chamber. Biological activity and heavy metal components in this sludge are just two of a number of possibly harmful properties which must be taken into account when it is disposed of / treated or stored.

In some sewage systems, the overflow is primary treatment or deposition of aerobic decomposition e.g. B. subjected to aeration or drip filter treatment. This secondary treatment can also be a sludge return include, and in this case the sludge product commonly referred to as activated sludge. As a result of the aerobic bacteriological decomposition of the less persistent organic compounds in the primary overflow, the secondary sludge is generally stabilized or not

609824/0820

rotting. To the extent that this secondary treatment decomposition is incomplete and unstable organic compounds remain in the secondary sludge * it can also be anaerobic with the primary sludge to be rotting. The elimination of this secondary sludge

- - "-. -. ■ she.. Offers difficulties similar to those described above with reference to primary sludge.

So far, sewage sludge is used as an agricultural fertilizer used, for use in cement products - at times in connection with fly ash - sintered, submerged in the sea or filled into waste ponds. Each of these elimination methods have serious drawbacks.

The object of the invention is therefore to create a useful one Process for the disposal of sewage sludge in an ecologically and economically viable manner especially for the use of such sludge products for Creation / use of artificial hardenable materials curable compositions prepared in this way for the prevention of environmental damage, as is the case with certain current Methods of Disposal and Reclamation of rural districts now occupied by sewage sludge ponds.

In particular, the invention relates to a practical method for mixing sewage sludge with relative

60982470820

cheap materials for the production of hardenable compounds, which in turn can be used for land replenishment or as basic building materials.

According to the invention sewage sludge is mixed with slaked lime and ash, so that the obtained Mass calculated in percent by weight solids contains: 5 to 50% water, 1 to 15% lime (or equivalent materials listed below), 1 to 50% sewage sludge solids, 20 to 90% fly ash (or equivalent materials as set out below) 0 to 60% earth and 0 to 10% calcium sulfate (usually but not necessarily in anhydrite form). This hardenable mass can be open to the atmosphere in a suitable manner Site where sand backfill or a road pad is needed to be dumped during a To harden period. Depending on the composition and the intended use as landfill or road foundation, compaction may be necessary before hardening.

Alternatively, instead of lime, other sources of alkaline earth hydroxides such as flue dust from the basic oxygen furnace can be used Lime kiln dust or cement kiln dust can be used, and other raw materials can be used instead of fly ash of pozzolanically active materials and / or AIu-

509824/0820

245622

minium or ferric ions can be used. Materials, which can be used as a supplement to or instead of fly ash are for example "aluminum (alum) -

/ waste "/ like that which occurs in a water treatment plant By-product, red mud; d. H. the high aluminum waste product from chemical Bauxitaufschiußverfahren and the amorphous silicic acid residue from waste incineration, in particular those from petroleum refineries.

Finely divided blast furnace slag quenched with water can also be included in these masses as a cementitious reactant. Preferably this includes The method and product of the invention are those mixtures in which as percent by weight of the solids 15 to 30% Water, 2 to 6% lime, 4 to 20% sewage sludge solids and there is 30 to 80% fly ash. These compounds preferably also contain calcium sulfate (1.5 to 3% calculated as anhydrite) and 20 to 45% earth.

For a better understanding of the invention, it is described in more detail below.

Sewage putrefactive sludge is the anaerobically or aerobically digested one Product of a municipal wastewater treatment plant. Such a system can also provide coagulation and

5 0 9824/0820

456225

include setting processes. A final product of these plants consists of a wet sludge with a solids content in the range from 3 to 8% by weight, After such sludges have been deposited for a long time, their solids content can be somewhat higher and approaching 35% after extended periods of time.

In general, the invention encompasses the incorporation of such sewage sludge material in a matrix or matrix consisting primarily of alumina-silica material such as fly ash. The occurring chemical reactions have since been responsible for the connection of substantial amounts of water from the Sludge and encapsulation or other definition or structural stabilization of the sludge solids responsible for making them relatively non-reactive and non-leachable · Der Degree of non-reactivity or non-leachability and also the strength of the products obtained depends on numerous variables such as the properties of the reactants, sludge solids and water in the masses, their degree of compaction, etc. When the reactants are highly concentrated and the mass is compacted before the reaction, the result is this stabilizing or fixing process

509824/0820

a tough monolithic material for landfilling or structures. * If, on the other hand, the cementation reaction in a sufficiently diluted and / or not

State

compacted / and / or in combination with sufficient quantities of other sprinkled materials such as If the ground takes place, the hardening reaction takes place only on a local scale within the mass and that The product is not monolithic but has a grainy or earthy consistency. Such a grainy one non-monolithic product can be used for landfilling and in some cases superior to all soil be; it can also be used as a substructure material with low compressive strength with a very desirable shelf life, Stability, compactability and moisture tolerance.

As used herein, "hardenable", "hardened" and "cementitious" and similar expressions are intended to include all forms of the Cementation stabilization reaction which is an integral part of the invention. These expressions are therefore not intended to imply any restriction to the formation of a hard monolithic mass.

As for the nature of the materials to be used in the invention, sewage sludge solids are the remaining Residue when all the water out of such a

509824/0820

w ft η

Mud has been removed. As for the meaning of the Information on the composition, which affects certain amounts of such sewage sludge solids, see above This includes the determination of the pesticide content of the sewage sludge before such sludge is added to understand the curable mixture. "Solids content" here means the remaining solids fraction, when water is driven off in the sludge by heating it to about 38 C for 24 hours, while it is exposed to a circulating air flow at about the same temperature. This number can can also be determined by analyzing the finished product for constituents that are caused by others Starting materials are added including water and the difference between the total weight of the mass and calculated on the total weight of the sources other than the constituents attributable to the sludge ^.

Chemically, the compositions include these waste sludges very different organic and inorganic substances, however, obviously to the exclusion of highly soluble ones low molecular weight sugar-like compounds. Previously, cement materials were like those in the mixes according to the invention are not found useful in association with typical organic materials viewed. For reasons that are not yet fully understood

509824/0820

this proves to be incorrect in the case of the invention, those on the mixing of sewage sludge with puzzQlanic cements including lime and Plug ash and also usually including sulfates and inert substances such as soil or aggregates is based. The absence of sugary organic compounds in the sewage sludge waste products, to which the invention relates is believed to be a significant factor in the superior results obtained according to the invention by the association of such pozzolanic materials achieved with such organic waste products.

Other possible factors contributing to the surprising The compatibility of sewage sludge with the cementitious reaction components can contribute, are the metal ions and the cellulose content of these slurries.

Heavy metals such as zinc, Chromium, lead, and mercury are among that normally extremely difficult in an environmentally sustainable manner must be removed, and other metal ions such as aluminum and ferric ions ^ some of which are used as coagulants in is added to any stage in the treatment process. All of these ions and especially the aluminum and

5Q9824 / Ö82Ö

Ferric ions can participate in the cementation reaction and therefore facilitate the overall union of mud solids with cementing materials on which the invention is based. It seems possible that only sludges that are chemically z. B. have been modified by adding coagulants, as well as in higher levels of sludge and water and lower levels of aggregate components of the invention have been.

The cellulose content in sewage sludge can also be meaningful. Usually this turns out to be around 5 Accepted up to 25% of the sludge solids. The celluloses are generally fibrous and their hydroxyl content can be surface or hydrogen bonding the cellulose in mud with the cementing materials so that they actually act like reinforcement within the cement-like framework.

The invention also depends on the incorporation of fly ash or equivalents into the admixture the sewage sludge product. The fly ash is called known waste material usually obtained from the flue gases of pulverized coal incinerators and is a finely divided one Material that includes some unburned carbon but mainly consists of various kinds

509824/0 8 20

Silica, alumina and iron compounds exist in various forms, e.g. B. as finely divided spherical glass particles are present.

As far as other materials can replace the fly ash, their required amounts (the fly ash equivalent amount) must be determined mainly by experiment according to the respective nature of such materials and the
Variation in possible properties, for example
for the reaction speed and compressive strength, intended use, etc. can be determined. These "fly ash equivalent amounts" of those available for selection
Materials as mentioned above can, however, by experiments e.g. B. according to the "Pozzölanic Activity Test With Lime" method according to ASTM Test Method C-618 and the Available Aluminum-Ferric-Ion Test Procedure of US Pat. No. 3,720,609. The latter approach is particularly useful when a significant amount of sulfate is to be included. In this regard, "a substantial amount of sulfate" becomes about 0.5% by weight or molar calcium sulfate anhydrite
Equivalent amounts of other alkaline earth metal sulfate compounds, based on the total mass, viewed.

Within the range of 0.5 to 2% sulfate can the above tests may be necessary in order to

5 0 9 82A / 0820

from
ash equivalent "/ any other material that may be used in place of fly ash. In general," fly ash equivalent "means that amount of a fly ash substitute that gives a reactivity equivalent to that of a particular amount, concentration or range of fly ash.

The lime used in the masses according to the invention
can be more ordinary hydrated dolomitic or
high calcium lime or a mixture of such hydrated limes. In addition, the lime component can consist entirely or partially of various other materials, including available and reactive alkaline earth hydroxides or oxides in one of the

Su hydroxides include hydrogenatable form. / Such other

Materials include quicklime (hydratable quicklime
Dolomite or limestone) cement kiln dust and lime kiln dust,
which is usually 25 to 35 wt .-% reactive calcium or

Contain magnesium oxides) and dust from the oxygen blower furnace.

the lime content

If other material than slaked lime / in the masses after of the invention represents in whole or in part, the required concentration of the lime substitute is based on the weight percent of that material is calculated that is necessary to make an amount more available or reactive

509824/0820

To provide alkaline earth oxides or hydroxides, which is the same as those obtained from slaked lime within the Limits of the invention would be provided.

Finely divided water-quenched blast furnace slag can somewhat reduce the amount of lime required in the compositions of the invention. Generally this is based on
the tendency of the amorphous silica constituents of these materials to act as a hydraulic cement to form hydrated silicates and ettringite. Lime is not required in these reactions.

In the preferred mixtures of the invention and especially those in which soil or other is inert
Material is incorporated, or those that are used for
Use as road construction material in contrast to
Landfill require less strength,

the inclusion of alkaline earth sulfates is very desirable. Although these sulfates can be any variation of calcium or magnesium sulfate, either hydrated or unhydrated _; is
Calcium sulphate dihydrate is the preferred material simply because of its accessibility! .

The blends of the invention can, of course, include a variety of other inert or ancillary materials

ORIGINAL INSPECTED

lock in. These can serve to absorb water, add strength, provide early setting properties, or simply add bulk enlarge. This includes soil, aggregates, and Portland cement. Possible additional supplements include sulfite compounds or masses that Contain compounds that increase or promote the cementing reactions.

The quantity of materials in the bulk and the Measures according to the invention can be modified within wide limits.

For example, as far as water is concerned, there must be enough water for ion conversion of the various hardening substances. The minimum amount appears to be 5% moisture content (water = 5% of the total solids weight) required although at lower moisture levels below about 35% it will be within the allowable range It may be necessary to compact the cementable mixture and allow it to harden. on the other hand the moisture content can be as high as 50% (water = 50% of the solids or 33.33% of the total composition.) Above the concentration, excessive water can cause such a dilution of the cementing material.

509824/0820 original inspected

lien cause the necessary cementation reaction to be disturbed. The moisture content is preferred within the range of 15 to 30% by weight. At higher moisture contents, especially close to 50% as a maximum, higher proportions of fly ash and lime in the mass are necessary in order to bind the additional water. If there is an excessively high level of cementing reaction ingredients or if the Sewage sludge itself contributes significantly to the cementation reaction, e.g. B. due to inclusion of Aluminum or ferric ions in an added coagulant, so a higher moisture content can be acceptable be. In some trials, masses with moisture levels approaching 100% are sludge solids been stabilized, which brought the solids content in the order of 50%.

In general, the lime should be in the hardenable mixture are present at a concentration of 1 to 15 percent based on the weight of the solids. Economic Feasibility is a major consideration in setting this upper limit. Preferably the Lime content in the range of 2 to 6%. As far as other materials than ordinary slaked lime, dolomitic or calcium-rich lime should be used

509824/0 8 20

456225

Materials with available reactive alkaline earth hydroxides or hydratable alkaline earth oxides mostly but their molar equivalence to the required lime proportions defined above should be included.

For the pozzolan reaction on which the invention is based, the mixture of the invention is said to have at least 20% fly ash, with 30% being preferred. The upper limit of fly ash is close to about 90%, although 80% is preferred as the upper limit. Even higher levels of fly ash can be useful in some cases depending on the chemical nature of the fly ash or other use be. It goes without saying that more fly ash than necessary for the hardening reaction as filler and / or water abs orpt ion smittel is.

Appropriately, the masses of the invention and those that result from the method of the invention, a considerable amount of sewage digested sludge solids included, since it is the main object of the invention to remove and recycle such solids. Shows So the invention such masses down to a lower limit of sludge solids of 1%, a minimum amount preferred by 4%. In general, the upper limit for sludge solids can be 50% and one upper limit of 20% is preferred (as already said,

509824/0820

all percentages are based on percent solids by weight unless otherwise stated). As with water, the sludge solids concentration should be higher Avoid masses with lime and fly ash concentrations near the lower end of the relevant permissible ranges will.

In a case where, for example, with high concentrations of water (moisture content about 42%) and also of the solids content of non-chemically treated sewage sludge was worked by about 18%, it turned out that

at
that / leave acceptable compressive strength for land

Filling at least 55% fly ash and 2% lime were required, with an inclusion of 1% calcium sulfate also very much was appropriate. With 50% moisture content and 20% sludge solids, even higher additions of fly ash and lime can be achieved to be required. This of course depends on a number of variables, ζ. B. the chemical and physical Properties of the sludge and the fly ash (which in turn depend on the origin and the treatment and Generation methods vary), reactivity and absorbency of other materials in the mixture as well as the Curing times and the compressive strength required in the end product.

509824/082 0

The compositions according to the invention can be incorporated, in particular with regard to their early hardening properties calcium sulfate or any other reactive alkaline earth sulfate. As a result of the relatively low cost and easy accessibility, gypsum or calcium sulfate dihydrate becomes sufficient Amount preferably around the molar equivalent of 1 to 10% of the solids weight of calcium sulfate anhydrite to be provided. The particularly preferred range is 1.5 to 3%. When other alkaline earth sulfates, such as magnesium sulfate can be used in equivalent ranges on a molar basis to the weight percent ranges indicated be mistaken for calcium sulfate anhydrite.

In one of the preferred compositions and methods of treatment According to the invention, the mixture contains soil / such as ordinary dirt, sand, gravel or other solid matter non-monolithic »naturally occurring materials from the earth's crust / and the mixture is passed to one against the Air brought to open space as land backfill material; This Material generally requires a certain degree of compaction before hardening, especially with moisture contents of about 35% and below. Such soil can be used in an amount of 10 to 60% of the solids weight, preferably of 20 to 45% are present in the mass. This soil can be mixed in in a mill or other system. Instead of this can also be added to the soil by adding the mixture

509824 / 082Q

an earth pad and mixing on the spot be incorporated. Various other materials, such as aggregate, can also be included in the mixture after the Invention are introduced.

In the following Tables 1-5 various lime-fly ash wastewater compositions are listed together with their product properties in order to demonstrate their usefulness for landfilling or as a hardenable starting material. The methods of the invention may involve the use of such compositions in an amount as required by compressive strengths or other properties. It should be emphasized that minimum compressive strengths of 0.9 to 1.4 kg / cm ² (13 to 20 PSI) are required for landfill purposes, while for road construction materials the compressive strength should exceed about 21 kg / cm (about 300 PSI).

It should also be noted that Table 3 is based on Cement waste materials. Such cement kiln dust generally contains considerable concentrations reactive hydratable alkaline earth oxides and therefore wijfct in the invention as lime partner or lime substitute.

Table 4 refers to similar masses using waste lime as an accessory material. This waste lime is that

509 824/0 820

Dust from a common lime kiln and contains substantial amounts of hydratable alkaline earth oxides.

60 98 24/0820

TABLE J Lime Fly Ash Wastewater Compositions

Compressive strength of 10 cm cylinders

Mixture of% dolomitic monohydrate caustic

% Wastewater% airborne (moist) ash% moisture

Cured days cured 7 days at 38 ^° C at 38 ^° C

3 3 6

30th 67 30th 67 30th 64

psi kg / cm psi 4th kg / cm psi kg / cm I.
NJ
_j 15th 1.05 58 4th , 08 _. I. 24.6 1.73 58 4th , 08 100 7.0 15th 1.05 60 , 22 —— -

cn

CD

TABEL

Lime-fly ash-sulphate sewage masses

Compressive strength of 10 cm cylinders

Mixture% dolomitic monohydrate lime

% Wastewater% Flight% Calcium% Moist (moist) ash sulphate susceptibility

third waste

Daily at

8 ° C

psi

Day

^bt : o

7 days at

7 days ^{b <} &

23 ^U C 38 ^U C 54 ^U C

psi »si

/ 1 t Z \

7 days at 23 ^° C

28 days at 23 ^° C

(kg / cm) (kg / cm) (kg / cm

cn
0 1 3 30th 64 3 15th (3 50 (2 _llir 142 _ 102 - ι co , 5) (9.98) (7.17) to
ro 00 2 3 30th 64 3 30.6 (3 50 (2 - - - - 108 _ I ro , 5) (7.59) 3 6th 30th 61 3 15th (5 80 - 452 _ - 71 - , 6) (31.78) (4.99) CO 4th 6th 30th 61 3 25.7 (5 80 - 251 239 87 - , 6) (17.05) (16.80) (6.12) O 5 6th 30th 61 3 28.6 - - 298 (20.95) 6th 6th 30th 61 3 29.9 - 36 - 195 .53) (13.71) 7th 4th 30th 64 2 29.9 - 36 - 171 .53) (12.01) 8th 3 30th 65.5 1.5 29.3 - 36 - 219 ro .53) (15.4O) -C- 9 2 30th 66 2 25.4 - - cn
ΓΤ ")

TABEL

Cement kiln dust masses

Compressive strength of 10 cm cylinders

Mixture% cement% waste water% flight% moisture 2 days at 23 ° C
Waste (moist) ash

dust ₂

psi kg / cm

Days at 23 ^{above sea} c
psi - '- 2

1 2

3 6

30 30

31.1
31.1

1.69 2.25

26 32

1.83 2.25

TABEL

Lime masses

Mixture Waste% Waste% DoIo-% Ab-% Flight-% CaI-%

Lime type lime miti- wash ash cium damp

shear sulphate activity psi kg / cm

Mono- (wet) anhydrite hydrate (waste)

lime

Compressive strength of 10 cm cylinders

Days at 21 ° C 28 days at 23 ° C

psi kg / cm ''

Crt 1 DoIo-
mitisch 10 860 2 Dolo
mitisch 8th 3 DoIo-
mitisch 6th 082 4th Calcium
rich 3 ο 5 DoIo-
mitisch 3 6th DoIo-
mitisch 6th

30 30 30 30 30 30

57 , 5 3 23.2 59 , 5 3 24.3 61 , 5 3 24.5 65 1.5 26.1 65 1.5 25.6 62 1.5 28.5

56 1 3.94 52 1 3.66 44 3.09 164 1.53 162 1, 39 48 3.37

333 23.41 I. 299 21, 02 N) 202 15.47 I. 329 23.13 368 15.87 90 6.33

ro

cn cn

KJ?

he?

TABEL

% DoIo- waste%
mitischer kalkart waste
Monohydrate lime
lime Masses with soil 30.8 % Ab ^
water
(wet) % Flight
ash % Earth
rich
(wet) Compressive strength of
10 centimeters -. Cylinders Tg * at 28
V 23
2
kg / cm psi 88 Days bd
2
kg / cm 3 - - 32.9 30th 22nd 43.5 7th
23
psi 2.53 255 6.19 mixture 3 % Calcium% moisture
SuIfate anhydride
(Waste) 36.0 30th 43.5 22nd 36 4.64 119 17.93 C TY 3 - - 1.5 35.6 30th 32.5 33 66 3.80 108 8.37 ο 2 50% calcium 3
rich
50% Dolomi
table 1.5 39.3 30th 32.5 33 54 3.66 36 7.59,
ro
Ul
I. CD
co 3 Calcium rich 3 1.5 32.5 30th 22nd 43.5 52 1.48 21 2.53 ji ⁴
O
CD Calcium rich 6 ^ 1.5 41, 0 30th 22nd 43.5 21 1.40 15th 1.47 ro
r ~ \ 5 Calcium rich 3 1.5 30th 22nd 43.5 20th 0.56 1, 05 6th 3 8th 7th 1.5

Waste lime had been stockpiled in the plant for some time.

CD K) NJ

_ 2 c

As an example of a typical and preferred use of the invention, deposited primary digested sludge from municipal sewage of various ages over
Periods of a few weeks to decades had been stored with a mixture that consisted of 31.3%
wet sewage sludge (the heaps consisted of various sources of the materials consisting of 13 to 33% sewage sludge solids), 31.3% fly ash, 31.3% soil, 3% glue and 3% calcium sulfate anhydrite. This material is mixed and then compacted in place and on a steep part of the terrain that was previously occupied by the mud pile. After a
Period of time this mixture has been exposed to air sets it to a compressive strength and above that required for use as landfill. The product obtained is suitable as a land fill for the purpose of a base for a driveway on modern motorways
can be built. This hardened mass has been tested on a laboratory scale and appears to be free of undesirable leaching properties.

Tests on comparable mixtures led to the following Results:

Summary of test results in the treatment of deposited Sewage sludge and manufacture of hardened landfill material therefrom

50982 4/0820

1. Strength results - 23 C hardened in closed canisters:

3 days - 41 PSI - 2.88 kg / cm '

7 days - 86 PSI - 6.05 kg / W

Days -167 PSI -11.74 kg / cm '

Days -338 PSI -23.76 kg / cm '

2. California load capacity ratio - not fully soaked, hardened at 23 ⁰ C in sealed plastic bags:

immediately 4 PSI - 0.28 kg / cm ²

3 days -20 PSI - 1.40 kg / cm ²

7 days -93 PSI - 6.36 kg / cm ²

Days -95 PSI- 6.68 kg / cm ²

3. Permeability of hardened 23 C in saturated state 3 days - 1.88 χ 10 ⁶ cm / sec.

9 days - 1.28 χ 10 cm / sec.

Days - 1.22 χ 10 cm / sec.

Those involved in the manufacture of building material from sewage sludge Surprising results obtained also emerge from certain external leaching tests Test material. In these Auslaügversuche was a monolithic sample of hardened sample material of g with 2000 mm of deionized water for 48 hours

50982A / 0820

ORIGINAL INSPECTED

shaken. Then the samples were filtered and that Filtrate on metal ions, bacteriological activities etc. investigated.

As for bacteriological activity, so had the deionized water as! est control one level Coliform and Fecalform counts of 110, 23 and 0 while the leach test filtrate had comparable counts of 3,600, 23 and 0. So there was no increase found in coliform or fecal bacteria in the leachate.

As for the metal ions, Table 6 shows the ranges of certain metal ion contents which were observed in a series of tests with the sludge used in the previous test compositions with contents of the same ions in the leaching (based on the leaching test just described) of 3 samples of the previous test composition. Each test resulted in several hardening stages.

TABLE 6

(All contents in parts per million)

A.
• Zn Cu Cr Pb CD Ed mud 2340-4410 674-926 929-1730 805-2280 18-33 93-233 sample
in 24 hours <opi 1.6. 0.03 0.02 <0 _f 01 <0 , 001

50 9 β 24/0820

Zn Cu Cr Pb Cd Hg

mud 28 24 24 A.
Days 2340-4410 674-926 929-1730 805-2280 - · 0.01 18-33 93-233 sample
in 7 sample 7th 7th Days <0.01 1.4 «0.01 0.01 <0.01 ^ 0.01 «-0.001 in in 28 28 B. <0 ^) 1 0.64 * O, O1 0.01 <0.01 «0.01 0.0OI in sample Hours. in in Days <0.01 1.0 0.03 0.03 <0.01 <0.001 in Days <0.01 1.3 <0.01 <0.01 <0.01 <0.001 in C. <0.01 0.8 <0.01 <0.01 <0.01 <0.004 Hours. - - φ Days 0.01 20th 0.05 0.01 0.001 Days 0.01 12th 0.01 0.01 0.001 <0.01 1.3 <0.01 <OK, O1 0.006

In further tests, stored digested sewage sludge from Pond B of Southwest Philadelphia Treatment Plant C containing 21-25% sludge solids was found in various mixtures with fly ash from the mechanical collection system of the Eddystone plant of the Philadelphia Electric Company and the Titus Station plant of the Metropolitan Edison Company in Reading, Pennsylvania. In some of these attempts, soil was incorporated into the mass. The soil, as indicated, was either in excess from a limestone quarry owned by G. & WH Corson Company of Plymouth Meeting, Pennsylvania, or sand and / or gravel from Penn's Grove, Pennsylvania as supplied by the Pennsylvania Transportation Department. The lime used in these experiments was hydrated dolomitic lime from G. & WH Corson Company. The other waste materials included in some of these masses were incineration residue from the Marple

509824/0820

Township waste incineration plant in Lawrence Park, Pennsylvania, lime dust, partly fresh and partly deposited manufactured by Bethlehem Steel's Annville Pennsylvania facility and calcium sulfate anhydrite as an industry by-product in Paulsboro, New Jersey.

Following these various compressive strength tests, the moisture content and density of the sample at the time determined during sample production. In standardized Proctor shapes, test pieces were made using a hammer of about 2.6 kg (5.5 pounds) were made three layers of sample material compacted with 25 blows per layer. These samples were in sealed canisters cured and then soaked in water for four hours before being tested for compressive strength.

In a first series of tests, several masses were prepared in the test program, each of which was 20% sludge contained. The sludge contained 21% sewage sludge solids, fly ash ranging from 35 to 40% and soil, especially corson waste with 23% water in a range of 35 to 40%. The variables in this series were lime including calcareous material from construction waste and calcium sulfate anhydrite. The results in this series can be found in the following table:

509824/082

Material sample

lime

Annvilie Staub
(dry)

AnnviHe dust
(from the dump)

Anhydrite
, Mud

cnflight ash (dry)
f—>

P ^ drying unit S's
£ l weight lbs / foot ³

"Compressive Strength
> * —'— * (PSI)

Table 7
(Wt%)

, 4

10

11

12th

6 4 6 4 6

1 1 1

20 20 20 20 20 20 20 20 20 20 20 20

39.5 39 38.5 39 38 38.5 37.5 36.5 37 36 38 37

39.5 39 38.5 39 38 38.5 37.5 36.5 37 36 38 37

13th

20th

14th

20th

37.5 36.5 37.5 36.5

79.9 78.6 82.0 81.0 81.0 81.2 80.9 79.1 82.8 79.5 .80.8 82.1 80.9 80.2 31.6 32.5 27.8 27.8 29.6 28.5 30.4 31.6 28.3 33.0 29.7 29.6 30.5 31.3

Age when tested at Temp. PSI,

2 days at
7 days at
7 days at
28 days at

(kg / em *)

(34) (32)

55 ° 2.74 2.11

(39) (30)

23 ° 2.11, - (30)

23 ° 2.53 2.53

(36) (36)

PSI ₂ PSI PSI PSI PSI PSI PSI PSI

(kg / cm) (kg / cm) (kg / cm) (kg / cm)

F 2.81 3.37 5.06 6.47 2.53 2.53 2.11 3.09

(4.0) (48) (7.2) (9.2) (36) (3.6) (3.0) (44)

F 3.66 4.22 5.34 5.62 2.67 2.25 2.25 3.66

(52) (60) (76) (80) (38) (32) (32) (52)

F 3.45 3.23 4.50 - 3.09 * 3.66 2.67 3.37

(49) (46) (64) - (44) (52) (38) (48)

F 4.50 3.52 7.52 4.78 2.81 3.09 3.37 4.92

(64) (50) (107) (68) (40) (44) (48) (70)

F sample when sucking up, likely to collapse due to insufficiently reactive alkaline earth hydroxide or hydratable alkaline earth oxide.

Samples 4, 5 and 6 apparently did not provide sufficient compressive strength. This results in the Need for a certain amount of reactive chalk materials. The dry Annville waste dust is apparently burned hard and therefore not reactive. In contrast, samples 11 to 14, in which deposited annville dust were used as Kalkquelle was used, satisfactory compressive strength established. This is probably due to the weathering effect during storage on the dump near the Änviliestaub attributable to. Su note is that no lime as such one of the masses of samples 4 to 6 and 11 to T4 was added.

Another series of tests was carried out with sand as an inert aggregate, the range of compositions otherwise being similar to those in the previous series, with the exception of two cases in which fly ash contents of 20 and 151 were tested (see sample nos. 6 and 7 in the table below). In both of these particular tests, the compressive strength was such that the masses apparently only a marginal usefulness h & L uses of interest according to the invention have would "Besides, there are the results of these tests ■ in Table 8 below

S09824 / 0820

oo ro ο

Samples- ^

lime

Anxxville dust (dry)

Annville dust (dump)

Anhydrite

Sludge (21% solids)

Fly ash (Eddystone B dry)

PennDOT sand

with 5% H ₀ O 2

dry unit x w. 1 pound / foot

Moisture content

Compressive strength in kg / cnT C? SI) at Test duration and temp.

2 days with 55 ⁰ C for 7 days at 23 ⁰ C for 7 days with 23 ⁰ C 28 days 23 ° C

T _- PART 8. (% By weight) <- Continuation with sample "Γ3-24

3;

10

11

12th

. · 1 . 4th , 4 1 ' ^: 1 , 5 1 .1 • , 0 1 ■ ■ ι ' ,, 9 1 6th 1 - 1 / 0 1 2 ,1 ' , 6 ,1 9 7th , 5 9 4th 20th 2 4th 4th 4th 4th * 4th 4 " 4th , 6 4th 4th 38 20th 38 20th 20th 20th 20th 20th , 4 20th · ■ 20th 20th 20th ^; 20th 37.5 84 38.5 30th 25th 20th 15th , 3 25th 25th 25th 30th 30th 37.5 24 38.5 45 50 55 60 50 50 50 45 45 84.7 83.7 82 92.0 . 9.1 93 .88, 88 91 90 89 23.0 28.3 33 22.0 25th 24 24, 21 11 24 16,

(PSD

(ΜίΓ

| ρβϊ>

(pI? { ^CI ? psi)

2.

(PSD

2.53 2.25 .2.25 OT56 1 , 6Ψ 0.70. 0.84 0.70 4.22 3, O9 1.12 2.95 (36) (32) (32) (8) (24). (1o) (12) (10) (60) (44) (16) (42)

3.09 2.32 2.39 0.84 1.83 (44) (34> (34) (12) (26>

.0.70 1.12 2.39 2.53 2.2b
(10) (16) (34) (36) (32)

(46)

AdI

WoTU

18 days break

K) N> Cn

-Continuation-

Samples- ^
No., lime Anmri lie
dust (dry) • Annville ™
Dust Anhydrite mud
(21% fixed rate) ο Fly ash
(Eddystone B
dry) 982 PennDOT · sand
with 5% H ₂ Q

TABLE 8 (wt%),

-J ^ dry. Uniform

^ wt. 1pfd »/ foot ^J ο

oo moisture content

Compressive strength in kg / cnr PSI at test duration and temperature,

2 days with 55 ⁰ C for 7 days at 23 ⁰ C for 7 days with 23 ⁰ C 28 days 23 ° C

1 1 3 . 4, ' 15th 16 2 17th 18th 1. 19 20th 21 22nd 23 24 ; i 2 1 '■ 20th 0.5 " 0.5 0 _f 5. 0.5 4th 20th • • 20th 39. 4th 2 ' * 1 37.5 4th 38 2 • 39 2 4. " 4th 4th 20th 37, 5 2 38 1 98.3 0.5 0.5 1 0.5 • 0.5 1 37 "101.4 20th 100.4 20th 18.5 20th 20th 20th 20th : 20 20th 37 16.5 37 17.6 .38.5. 38.5 37.5 37.5 38.5 37.5 37.5 97 37 '38, 5 38.5 37.5 3.7.5 38.5 37.5 37.5 i 17, 3 99.4 99.3 98.5 96.5 95.5 99.5 86.5 81.5 3 16.8 17.6 16.2 17.0 14.8 15.8 25.5 31, 0

fs) -P- cn CO K) JSJ) Ol

6.68
(95) 3.80
(54) : 3.81
(40) 2.53
(36) 8, (79
f ί 25> 2.39
(34) 2.67
(38) 3.09
(44) 3.09
(44) 2.81
(40) 1.62
(24) 13.15
Π87Ϊ 3.94
(56) 3.66
(52) 2.25
(32) 2.53
(36) - 3.09
(44) 2.81
(40) 2.53
(36) 4.50
• (64) 1/83
• (26) 3.66
L52J_ 8.08
(115) 3.37
(48) 2.95
(42) 2.81
(40) 2.81
(40) 4.43
(63) 2.53
(36) 3.52
(50) 2.81
(40) 2.95
(42) 2.25
(32) .3.94
. (5β8 10.33
(147) 6.47
(92) 6.26
(89) 4.43
(63) 5.77
(82) 4.78
(68) 6.96
(99) 3.37
(48) 5.06
(72) 5.91
(84) 4.7
(68

Dry PennDOT sand, ⁺⁺⁺ Moist Elugash (10%)

In the table above, tests 11 and 12 have higher sand content without any visible influence on the compressive strength Compositions with only 5% lime and 2% dry Annville dust together with 0.5% calcium sulphate anhydrite delivered mixtures with compressive strengths in the usual ranges. In this regard, the sample numbers 19 and 22 are referred to.

In yet another series of tests, mud and Water contents close to the upper half of the useful composition range tested according to the invention. From the table 9 it can be seen that at 39 and 50.4% moisture content and 40 and 50% sludge concentration (45% solids sludge or 18 and 22.5% sludge solids concentration in of the total mass) in samples 2 and 3 were kept at the limit with only 1% lime. If the

en

Samples 5 and 6, however, were / were sludge content and only had 2 1 lime. It is currently believed that these are the upper limits of the useful compositions according to the invention insofar as it is not chemical treated sludge and water content. It should again be noted that at or near the upper limits of the In mud and water areas, relatively high levels of fly ash and lime are necessary for stabilization the lime-fly ash or lime-fly ash sulfate reaction .zu cause. The influence of the use of combustion residue instead of part or all of the Plugascheg-

60 9824/08 2 0

Haltes in mixtures according to the invention can be seen from the data for a further series of experiments are given in Table 10 below, from which it can be seen that even with 0% fly ash with 40% Combustion residue and above mixtures with useful properties in terms of compressive strength are generated (“is demonstrated especially in this case on samples 10, 11 and 12).

509824/0820

'COPY

τ A ü Yes JLi Ju js.

Sample no.

(Weight percent)

lime

Ca Rich Anville Dust

Ga-rich Annville Dust '. ■■; from Halde

Anhydrite (Paulsboro)

«> Sludge (45% solids) co

■ ^ Fly ash (Titus Station)

^ Unit weight (dry)

° (pounds / feet ³ )

Moisture content

Compressive strength kg / cirT (PSI) Age at test and temp.

2 days at 55 ^° C

7 days at 55 ^° C. 7 days at 23 ^° C. 2 8 days at 2 3 ^° C.

1 1 1 1 1 40 50 30th 40 50
I. 1 * +5 8 + 48 +67 +57 +47 30th 71.8 63.5 66.7 66.4 61.2 +68 39 50.4 33.0 42; O 51.4 76 32

1.97 (28)

2.25 (32)

4.22 (60)

4-K

0.28 (4)

4.64 (66) 2.25 (32) 0.35 (5)

0.42 (6)

1.41 (20) 0 (0)

Fly ash with 10% moisture content_

3 , 37 (48) 1 , 97 (28) 0 , 56 (8th) 4th , 50 (64) 3 , 66 (52) 0 , 42 (6)

'Prnho oinrroqnnVon Κοί

TABEL

10

cn ö co

sample

(Percent by weight) 4 5 6

11

12th

lime

Ca Rich Annville Dust

Ca-richer

Anhydrite

Sludge (25% solids)

Fly ash (Titus Station)

Burn residue ■

Dry unit weight (Lbs / feet ^J )

Humid go.

Compressive strength in kg / cnr (PSI) age at test.

2 2 2 2 2 2 6th 1 , 3 1 1 1 1 1 3 4th , 5 4th 4th 4th 4th 4th η dump 1 1 1 1 1 1 1 1 1 1 1 1 t-
25th 25th 25th 25th 25th 25th 20th 20th 20th 20th 20th 20th +52 + 42 +32 +52 +42 +32 30th 20th 10 0 0 0 ++ 20 ++ 30th ++ 40 +++ 20 +++ 30 +++ 40 10 20th 30th 40 74 73 71.5 72 , 4 87.1 72, 1 80.7 79 84 86 85 86.3 77.7 78.6 25.8 28 , 0 24.6 42 30th 31, 28 28.1 31.1 30.2 34.5 29.4

Uli
2 u J. a
Days at -UJL
55 ° C 2.95
(42) 2.39
(34) 133
(26) 5.62
(80) 2.25
(32) 2.53
(36) 1.12
(16) 2.80
(39.8) 1.12
(16) 1.41
(20) (8th) 1.41
(20) TnO 7th Days at 55 ⁰ C : mm 3.09
(44) 2.81
(40) 2.53
(36) 1.41
(20) 1.97
(28) 2.81
(40) -F-
cjn 7th Days at 23 ° c 3.09
(44) 1, 97
(28) 3.30
(47) 5.20
(74) 2.53
(36) 3.09
(44) 3.66
(52) 3.01
(44) 2.53
(36) 1, 97
(28) 1.97
(28) 3.01
(44) cn
ro
ro
cn 28 Days at 23 4.78
(68) 3.09
(44) 4.01
(57) 3.66
(52) 4.64
(66) 3.94
(56) 2.81
(40) 2.11
(30) 1, 69
(24) 2.11
(3O) 3.01
(44) Fly ash with 10% Moisture content ++ _ _,
; 5 years
at 20 old combustion residue
% Humidity

Year old incinerator residue with 20% moisture content

In another series of experiments, the results of which are given in Table 11 listed were undeserved mixes with 33% moisture content in atmospheric conditions 0 days to 28 days without compaction stored and then compacted and 7 and 28 days after compaction checked. The purpose of this experiment was then to prove that the masses according to the invention in one and usable waste disposal processes can be stacked for long periods of time before use. During such stacking, some of the reactants are consumed and (without compression) they do not deliver strength-imparting basic structure. This is why there are higher proportions of reactants in such stacked storage necessary. It can be seen from Table 11 that Hassen with insufficient lime (sample no. 1) is less significant are even if you take them immediately after mixing condensed while others were able to sizeable Develop compressive strengths even if they have been piled up for up to 28 days.

50982A / 082

TABEL

11

(Weight percent)

sample

cn ο co oo

Damp flight
ash 37.5 37 37.5 38 Sand and gravel 37.5 37 37.5 38 lime 0 1 2 3 Moist Ann-
a lot of dust 4th 4th 2 0 Anhydrite 1 1 1 1 mud 20th 20th 20th 20th

Dry unit weight

humidity

0 days

3 days

7 days

14 days

28 days

78.6 / 33

78, O / 33

75.5 / 31.7

81.9 / 28.3

79.5 / 32.3

78 / 34.3 80.4 / 31.3 81.8 / 27.8 82.8 / 29.0 82.5 / 29.1

78.6 / 32.5
79 _r 4 / 32.7
83.0 / 27.4
81.9 / 29.6
81.4 / 30.3

78.7 / 32.5 80.5 / 31.8 81.5 / 30.5 82.1 / 29.1 74.0 / 30.4

TABLE 11, Part II

ο co OO ro

CD co

sample Time «or he
poetry Curing conditions
after compaction 1 2 3 4th Time - temp. 0 days 7 days 55 ⁰ C
28 days 23 ° C 3 days 7 days 55 ° C
28 days 23 ⁰ C 8th
50 30th
60 56
80 96
80 7 days 7 days 55 ⁰ C
28 days 23 ⁰ C 6th 26th
30th 44
40 86
72 14 days 7 days 55 ° C
28 days 23 ⁰ C VO VO 24
30th 44
44. 96
76 28 days 7 days 55 ⁰ C
28 days 23 ⁰ C F.
6th 12th
20th 36
40 80
64 8th 24 32 32

CD N) K)

From the above it can be seen that the invention is a new and unique process both in terms of Economy as well as environmental protection for the disposal and reuse of the sludge product from a municipal wastewater treatment plant. It was also shown that the products and methods of the invention are very valuable for land reclamation as they cause further environmental damage prevent and correct previous environmental damage. It should also be noted that while the invention is related has been described with specific measures and examples, but is not necessarily limited thereto.

5 0 9824/0820

Claims (1)

- 43 claims 1. Hardenable water-solids mixture, characterized in that that the solids in percent by weight dry matter consist of: 1 to 15% lime 1 to 50% digested sewage sludge solids up to 90% fly ash and water to provide moisture content (again based on weight percent dry solids) from 5 to 50%. 2. Mixture according to claim 1, characterized in that the moisture content TS is up to 30% and the solids contain: 2 to 6% lime, 8 to 20% digested sewage sludge solids 30 to 80% fly ash 3. Curable mixture according to claim 1, characterized in that it additionally contains 1 to 10% calcium sulfate anhydrite 50982A / 0820 - Contains 44 (based on percent solids by weight). 4. Curable mixture according to claim 2, characterized by an additional content of 1.5 to 3% Calcium sulfate anhydride (based on percent solids by weight). 5. Curable mixture according to claim 3, characterized by a further content of 10 to 60% soil (based on weight percent solids). 6. Curable mixture according to claim 4, characterized by a further content of 20 to 45% soil, (based on percent solids by weight). 7. Method of treating sludge from an urban Sewage system, characterized in that the sludge is mixed with lime and fly ash so that the final composition of the mixture has a moisture content of 5 to 50% and the solids consist of 1 to 15% lime, 1 to 50% digested sewage sludge solids 20 to 90% fly ash, 509824/0 82 0 and allowing the mixture to harden under atmospheric conditions. 8. The method according to claim 7, characterized in that that an alkaline earth metal sulfate is added to the mixture, the amount of which is the molar equivalent of 1 to 10% (Solid weight) calcium sulfate anhydrite. 9. The method according to claim 8, characterized in that the Michung also soil ^; is added in an amount of 10 to 60% of the solids. 10. The method according to claim 7, characterized in that the moisture content is below 35% and the mixture is compacted after it has been deposited and before it has hardened. 11. The method according to claim 7, characterized in that calcium sulfate and soil are included in the mixture and comprise 1.5 to 3% (as calcium sulfate anhydrite) and 20 to 45% of their solids, respectively. 12. The method according to claim 11, characterized in that the moisture content is below 35% and the Compound after laying and before hardening will. 509 824/0 82 0 13. A method of making a load bearing material from urban sewage sludge, thereby characterized in that the sludge is mixed with lime and fly ash, so that the finished mass one Has moisture content of 5 to 50% and also 1 to 15% lime, 1 to 50% putrefied sewage sludge Solids and 20 to 90% fly ash (all based on the weight of solids) / and you have the Let the mixture harden under atmospheric conditions. 14. The method according to claim 13, characterized in that that the mixture also contains alkaline earth sulfate in an amount is added, which corresponds to the molar equivalent of 1 to 10% calcium sulfate anhydrite. 15. The method according to claim 14, characterized in that that the mixture also contains soil corresponding to 10 to 6O% of the solids content of the mixture is. 16. The method according to claim 13, characterized in that that in the mixture calcium sulfate and soil in an amount of 1.5 to 3% (based on calcium sulfate anhydrite) or 20 to 40% of their solids content are included. 509824/0820 17. Hardenable water-solids mixture, characterized in that that it contains, in percent by weight of dry solids: 1 to 15 % lime or lime substitute, the a molar equivalent amount of hydrating available alkaline earth oxide or alkaline earth hydroxide delivers, 1 to 50% digested sewage sludge " Solids 20 to 90% fly ash or equivalent amounts of fly ash of other waste material with pozzolanic Activity and water to provide a moisture content (based on the dry weight of the solids) from 5 to 50%. 18. Mixture according to claim 17, characterized in that the content of digested sewage sludge ~ solids- fen IbJs is 15% and 1 to 10% calcium sulfate anhydrite or other alkaline earth sulfates in an amount equivalent to 1 to 10% calcium sulfate anhydrite by molar Base is in place. 19. Composition according to claim 17, 18, characterized by 20 to 90% pozzolanically active Kieselscvurerück- 509824/0820. stood out of a petroleum refinery waste incinerator as wing bottles <| equivalent. 20. Mixture according to one of claims 17 to 19, characterized by a content of alum waste coagulant from a water treatment plant and / or red mud (By-product of a bauxite reduction process) as a fly ash equivalent. 21. Mixture according to claim 17, characterized by 20 to 90% fly ash and a lime substitute, consisting from lime kiln dust and / or cement kiln dust in an amount equal to the molar equivalent of hydratable alkaline earth oxide or alkaline earth hydroxide on 1 to 15% slaked lime. 22. The method according to claim 7, characterized by the use of a lime substitute consisting of quick lime, basic oxygen kiln dust, lime kiln dust and / or cement kiln dust in an amount which is the molar equivalent of alkaline earth hydroxides or hydratable alkaline earth hydroxide from 1 to 15% slaked lime results. 5 09824/0820 23. The method according to any one of claims 7-16, characterized in that 5 to 25% of the digested sewage sludge solids consist of fibrous cellulose material. 24. The method according to any one of claims 7-16, characterized in that the mixture is soil corresponding to 10 to 60% solids content and 5 to 25% of digested sludge solids are fibrous Contains cellulosic material. 509 8.2 A / 0820