Patent Description:
Wastewater treatment in the treatment of wastewaters by oxidative biological purification in aerobic granular sludge blanket (AGSB) reactors, wastewater flows in an upward direction through an oxidation chamber in which micro-organisms are present. Movement of the suspension of wastewater and micro-organisms within the wastewater chamber is provided by the introduction of an oxygen-containing gas which also serves to mix the suspension of biological material and wastewater. Within the reactors are inner zones of regulated settling which cooperate in the removal or accumulation of granules of a specified size range.

One problem with oxidative wastewater treatment in reactors of this type is the lack of cohesion between the unsupported biomass thus making the handling of the biomass generally difficult. In particular, removing the biomass from the treated wastewater and producing biomass which is suitably robust to be used as a seed for other reactors, has proven to be difficult.

In recent years, aerobic granular sludge, such as disclosed in <CIT> or <CIT>, has become a promising technology for wastewater treatment. The granular sludge is used as an inoculant to seed bioreactors to facilitate and/or speed up the separation of the sludge from the treated liquid.

It is recognized that the use of such granules has the potential to improve the purification efficiency of reactors, thus allowing the use of smaller reactor systems. If the biomass of aerobic granules can also be produced to a commercially acceptable level, it is expected that the use will reduce suspension and mixing energy requirements and give rise to less erosion of equipment.

The Nereda®Technology<NUM> has been deemed one of the most innovative process for producing such aerobic granules. However, inconveniences of this technology come from the fact that the in-situ formation of the granules can be long to start. The process involves multiple repetitive steps and depending on the characteristics of the influent wastewater, it can take as long as <NUM> months to start-up properly.

Furthermore, the concept of adding dried granular sludge obtained from anaerobic UASB reactors as an inoculum to anaerobic bioreactors is known from, for example, <NPL>).

The present invention hereby provides alternative reagents for wastewater treatment.

The current invention concerns an aerobic process for treating wastewater according to claim <NUM>, wherein anaerobic granules in dried form are contacted with the wastewater to form a wastewater:granules mixture, said granules comprising a mixture of anaerobic and facultative anaerobic bacteria and at least about <NUM>% of archaea microorganisms.

The method includes treating wastewater comprising the steps of: contacting the composition as defined herein with wastewater to be treated to form a wastewater: granules mixture; incubating the mixture for a period of time sufficient to decrease a COD of the wastewater to at least about <NUM>%; and separating said granules from treated wastewater.

COD: chemical oxygen demand; MLSS: mixed liquor suspended solids; MLVSS: mixed liquor volatiles suspended solids; SV30: suspended volume as <NUM> minutes; SVI: sludge volume index.

AGSB (Aerobic Granular Sludge Blanket), AMBR (Anaerobic Membrane Bio Reactor), EGSB (Expanded Granular Sludge Bed), MBR (Membrane Bio Reactor), MMBR (Moving Bed Bio Reactor), SBR (Sequential Batch Reactor), UASB (Upflow Anaerobic Sludge Blanket).

As used herein the singular forms "a", "and", and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a cell" includes a plurality of such cells and reference to "the culture" includes reference to one or more cultures and equivalents thereof known to those skilled in the art, and so forth. All technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs unless clearly indicated otherwise.

The terms "about" or "around" as used herein refers to a margin of + or - <NUM>% of the number indicated. For sake of precision, the term about when used in conjunction with, for example: <NUM>% means <NUM>% +/- <NUM>% i.e. from <NUM>% to <NUM>%. More precisely, the term about refer to + or - <NUM>% of the number indicated, where for example: <NUM>% means <NUM>% +/- <NUM>% i.e. from <NUM>% to <NUM>%. When used in the context of a pH, the term "about" means + / - <NUM> pH unit.

The term "up to" as used herein refers to a margin of greater than <NUM> but no more than about the number indicated.

As used in this specification and claim(s), the words "comprising" (and any form of comprising, such as "comprise" and "comprises"), "having" (and any form of having, such as "have" and "has"), "including" (and any form of including, such as "includes" and "include") or "containing" (and any form of containing, such as "contains" and "contain") are inclusive or open-ended and do not exclude additional, un-recited elements or method steps.

In this specification, the term" methanization" is used loosely such that methane production can also be interpreted as wastewater treatment in the absence of oxygen. Every wastewater treatment process where there is organic matter degradation results in the production of biogas. CO<NUM> and CH<NUM> mainly, along with fewer other nitrogen related gas such as N<NUM>. In the absence of oxygen CH<NUM> is the main component of the biogas. In the presence of oxygen, CO<NUM> is the most abundant gas.

One aspect of this disclosure, which is not part of the claimed invention, provides two main components for wastewater treatment, each component being capable of being used alone, or in mixed combination for greater effectiveness and better stability of the system. A first component comprises conditioned dried granules consisting essentially of a consortium of anaerobic bacteria (called anaerobic granules) in agglomerated form. The second component comprises silica beads (zeolite) activated with Fe<NUM>+ and Al<NUM>+.

In accordance with a first example, there is provided a composition comprising microbial granules for inoculating a bioreactor. Particularly, the microbial granules are initially isolated from bioreactor sludge, and then fully characterized. These granules were later reproduced under controlled conditions to provide a consistent composition, in sufficient quantity for commercial use. According to the invention, the microbial granules comprise a consortium of communities comprising a mixture of anaerobic and facultative anaerobic bacteria. Particularly, those microorganisms may be selected from Table <NUM> below.

The microbial granules comprise at least about <NUM>%, in particular <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>% or <NUM>% of archaea microorganisms. More particularly, the archae microorganisms may comprise Crenarchaeota and/or Euryarchaeota microorganisms.

The microbial granules are dried from fresh bioreactor's microbial granular sludge, and thus present themselves in dry form. Particularly, the granules have less than about <NUM>% humidity, more particularly less than about <NUM>% humidity, most particularly less than about <NUM>%, <NUM>% or <NUM>% humidity. This dried granular form allows much easier handling of large amounts of inoculant in much lower volumes i.e. lower energy costs of transportation and easier manipulation.

After drying, the microbial granules are then crushed and sieved to the desired particle diameter size, between about <NUM> microns to about <NUM>, more particularly between about <NUM> microns and about <NUM>, still more particularly between about <NUM> microns and about <NUM>.

The composition as defined herein may be used as an inoculant for wastewater treatment bioreactors.

This invention relates to the application of anaerobic granules, conditioned and dried to be applied in aerobic technologies. These dried anaerobic granules offer the same performance as technologies using in situ formation of aerobic granules without the disadvantages of liquid inoculants, such as high volumes, low reproducibility and long lag times. These performances include:.

Moreover, dried anaerobic granules provided by this invention applied in aerobic technologies offer the following advantages compared to the prior art Technology:.

The use/application of dried granules of the present invention can be extended to any bioreactor technologies such as MBR (Membrane Bio Reactor), AMBR (Anaerobic Membrane Bio Reactor), MMBR (Moving Bed Bio Reactor), SBR (Sequential Batch Reactor), AGSB (Aerobic Granular Sludge Blanket), UASB (Upflow Anaerobic Sludge Blanket) EGSB (Expanded Granular Sludge Bed) or any type of reactor for wastewater treatment.

In accordance with a further example (not part of the claimed invention), there is provided a composition for wastewater treatment comprising silica beads activated with Fe<NUM>+ and Al<NUM>+. Particularly, the beads are made of any type of natural zeolite, such as for example, clinoptilolite. More particularly, when producing the activated beads, the ratio Al+<NUM> over Fe+<NUM> is about <NUM> to <NUM>, particularly about <NUM>, and more particularly <NUM>, whereas the zeolite quantity is about <NUM>, particularly <NUM> and more particularly <NUM> x (Fe + Al).

In accordance with a particular example (not claimed), the beads have a size around <NUM> to <NUM> mesh, more particularly around <NUM> to <NUM> mesh, most particularly around <NUM> mesh.

An alternative example (not claimed) is directed to the use of the silica beads activated with Fe<NUM>+ and Al<NUM>+as a reagent for wastewater treatment.

In accordance with a further example (not claimed), a reagent mixture comprising the microbial granules as defined herein in admixture with the activated silica beads as defined herein is provided.

Particularly, the percentage of each component depends on the intended application.

For example, for aerobic and anaerobic reactors, the reagent can be <NUM>% dried microbial granules, or the reagent can be a mixture in a ratio where the microbial granules are present from <NUM>% to <NUM>% compared to the silica beads. Particularly, the ratio granules/beads can be about <NUM>%/<NUM>%, more particularly about <NUM>%/<NUM>%, or most particularly, about <NUM>%/<NUM>%.

The mixing of the granules and beads may be achieved prior to inoculation and premixed in bags or containers ready-to-use. Alternatively, each component may be prepared in separate containers or bags and added to the bioreactor (in the desired ratio) simultaneously or sequentially for wastewater treatment.

For application in septic tanks or other types of wastewater treatment the ratio of components in the reagent mixture can vary anywhere between from <NUM>:<NUM> to <NUM>:<NUM>, particularly about <NUM>% granules and about <NUM>% activated silica.

In accordance with a further example (not claimed), the present invention provides the use of the reagent mixture as defined herein, as an inoculant for wastewater treatment.

In accordance with the invention, there is provided a method for treating wastewater according to claim <NUM>, comprising the steps of: a) contacting the composition of microbial granules as defined herein with wastewater to be treated to form a wastewater: granules mixture; b) incubating the mixture for a period of time sufficient to decrease a COD of the wastewater to at least about <NUM>%; and c) separating treated wastewater from said granules.

A further exampe (not claimed) provides a method for treating wastewater comprising the steps of: a) contacting the composition of activated beads as defined herein with wastewater to be treated to form a wastewater: beads mixture; b) incubating the mixture for a period of time sufficient to decrease a COD of the wastewater to at least about <NUM>%; and c) separating treated wastewater. from said beads.

Particularly, as will be recognized by a person skilled in the art, the activated beads may be used for coagulation and flocculation of suspended matter. Alternatively, other materials can also be added such as other microbial granules or other coagulating material.

A further example (not claimed) provides a method for treating wastewater comprising the steps of: a) contacting the reagent mixture as defined herein with wastewater to be treated to form a wastewater: reagent mixture; b) incubating the mixture for a period sufficient to decrease a COD of the wastewater to at least about <NUM>%; and c) separating treated wastewater from said reagent.

In accordance with a particular embodiment, the processes as defined above may be carried out wherein the composition or reagent is added to the wastewater at a ratio of VSS substrate to inoculum of between about <NUM> to <NUM>, particularly at about <NUM>.

According to the invention, the incubating of step b) is carried out by introducing an oxygen containing-gas with or without mixing. Alternatively, when the process is anaerobic (not part of the claimed invention) then the incubating of step b) is carried out without the introduction of an oxygen containing- gas, with or without mixing.

Particularly, in accordance with a particular embodiment of the process, the separating step c) may be carried out by decantation or sedimentation.

According to a further embodiment, the process may be carried out in continuous batch or by sequential batch.

In accordance with a particular embodiment, step b) of the process is carried out until COD is reduced by at least about <NUM>%, more particularly until COD is reduced by at least about <NUM>%.

In accordance with a particular embodiment, the process is carried out at a temperature from about <NUM> to about <NUM>, more particularly from about <NUM> to about <NUM>.

In accordance with a further embodiment, the reagent mixture may comprise a ratio of granules to beads ranging from <NUM>: <NUM> to <NUM>:<NUM>. Particularly, the ratio granules: beads can be from about <NUM>:<NUM> to about <NUM>:<NUM>, more particularly from about <NUM>:<NUM> to about <NUM>:<NUM>, or most particularly about <NUM>:<NUM>.

There is provided a process for making activated silica beads comprising the steps of: a) mixing dry zeolite with FeCl<NUM>; and b) slowly adding dry powder of NaAlO<NUM>. In particular, the NaAlO<NUM> is added at a ratio of <NUM> FeCl<NUM>; and the zeolite is added in a quantity of about <NUM>, particularly about <NUM>, more particularly <NUM> × (FeCl<NUM>+ NaAlO<NUM>).

The following examples are put forth as to provide those of ordinary skill in the art with a complete disclosure and description of how to make and use the present invention, and are not intended to limit the scope of what the inventors regard as their invention nor are they intended to represent that the experiments below are all or the only experiments performed. Efforts have been made to ensure accuracy with respect to numbers used (e.g. amounts, temperature, etc.) but some experimental errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, molecular weight is weight average molecular weight, temperature is in degrees Centigrade, and pressure is at or near atmospheric.

The granules were recovered from excess granular anaerobic sludge from a biomethanization processing plant (Quebec). The sludge was drained from the bioreactor liquid phase to stop the biological activities. The sludge can come from any granular sludge bioreactor, preferentially UASB reactors. Other UASB reactors include paper mill effluent fed, cheese processing plant effluent, or any type of wastewater effluent.

The granules were then conveyed to a conventional air dryer. The temperature of the air generated can reach a temperature comprises between <NUM>° to <NUM>, preferably <NUM>. The granules were then crushed and sieved to the desired particle diameter size, between about <NUM> microns to <NUM>. They were then sampled for DNA sequencing. Table <NUM> lists the bacteria communities found on the dried granules.

The dried bacterial granules can be bagged and stored in order to be used later as seeds or additive components for wastewater treatment systems, in anaerobic as well as aerobic technologies.

A sample of the dried microbial granules was sent to IDAC (International Depository Authority of Canada) in Winnipeg, Canada and registered as number <NUM>-<NUM> on February <NUM>th, <NUM>.

The study of speed and of rehydration rate of dried granules was carried out in two series of trials under different soaking conditions (soaking solution and temperature).

The analysis of the initial dryness (dry matter - MS %) was carried out as soon as the material was received. Two trials of the rehydration rate of the dried granules were carried out under the following conditions:.

The methodology used for the rehydration trials is summarized as follows:.

As shown in Table <NUM> and in <FIG>, partial but important rehydration takes place during the first hours, or even the first minutes, and this then varies less significantly until the end of the trial.

In trial <NUM>, the moisture level of the granules jumped from <NUM>% to <NUM>% during the first two hours of soaking. This moisture level then continued to increase slightly with relation to the soaking time to reach <NUM>% after <NUM> days of soaking (<NUM>).

During trial <NUM>, smaller time intervals were chosen at the start of the trial in order to better evaluate the first minutes of soaking. During the first <NUM> minutes, the humidity rate rapidly increased from <NUM>% to <NUM>%. After <NUM> hours, it was <NUM>%, which compares with trial <NUM>. At the end of the trial, after <NUM> days (<NUM>), the humidity level reached <NUM>,<NUM>%.

There thus appears to be better rehydration of the granules with trial <NUM>. This could be explained by the fact that the synthetic wastewater soaking solution and the mesophilic temperature represent conditions of use more suited to the microbiology of the granulated bacteria, which seem to favor better rehydration of the dried granules.

It is interesting to note that for each of the trials, the final dryness of the dried granules (<NUM>% and <NUM>% for trials <NUM> and <NUM> respectively) at no time reached the dryness of the fresh granules (<NUM>%).

The granule samples were stored under an atmosphere of nitrogen / carbon dioxide, at <NUM>. A characterization of MS and MSV (dryness and organic matter) on the <NUM> types of granules (fresh, dry and control) was also carried out.

In order to carry out the methanogenic trials, a synthetic wastewater was prepared. This water serves as a substrate for the granules during the trials. It is a substrate rich in carbon (mixture of glucose, yeast extract and peptone) and balanced to microbial nutrient needs (N, P, trace elements such as Ca, Mg, Zn, Cu, Fe, Mn, etc., pH and buffering capacity). The exact composition of the manufactured synthetic wastewater can be consulted in Massalha (<NUM>)<NUM> by doubling the concentration of the inorganic compounds and multiplying by <NUM> the concentration of organic compounds (glucose, yeast extract and peptone). The theoretical COD (chemical oxygen demand) of this synthetic water is <NUM><NUM>/L. Once prepared, the following parameters were characterized to confirm the values:.

The method used is inspired by the methods DIN <NUM> TL8 and ASTM D <NUM>, modified by Angelidaki (<NUM>)<NUM> and OFEN (<NUM>)<NUM>.

Briefly, a reaction liquor was prepared with the granules to be analyzed and with the synthetic wastewater at a ratio of organic matter (MSV) of the substrate (wastewater) to the organic matter (MSV) of the inoculum (granules) of the order of <NUM> (S/I ratio = <NUM>). <NUM> of this liquor was placed in a <NUM> bottle and placed in a thermostated bath at <NUM> for <NUM> days. Biogas produced during this period was accumulated in specially designed gas-tight <NUM> sampling bags. <FIG> shows the installation used for the trials.

The composition (CH<NUM>, CO<NUM> and H<NUM>S) of the biogas was analyzed and the volume of biogas produced was measured (volumetric measurement subsequently normalized according to temperature and gauge pressure) three times during the trial: after <NUM> days , after <NUM> days and at the end of the trials, after <NUM> days of methanization.

The analysis was carried out in triplicate and the calculated methanogenic potential corresponds to the average value of the three trials.

From Tables <NUM> to <NUM> and from <FIG>, it is possible to make the following observations:.

The fresh granules produced more than <NUM>% of their cumulative volume of biogas during the first <NUM> days. More than <NUM> of methane, or <NUM>% of the total methane was produced during the same period (<FIG> & <FIG>). This corresponds to the highest production period of the fresh granules.

The dried granules produced only about <NUM>% of the cumulative volume of biogas during this period, and this biogas contained no methane yet (CO<NUM> production only).

The fresh granules produced their last <NUM>% of biogas, and this biogas was very rich in methane (<NUM>%). <NUM>% of total methane was produced during this period.

The dried granules produced slightly less than <NUM>% of the total volume of biogas, which had a methane content of <NUM>%. This represents nearly <NUM> of methane or just over <NUM>% of the total methane produced by these granules (<FIG>).

There was no production of biogas by the fresh granules during this period. The methanization of the substrate was complete.

The dried granules produced slightly more than <NUM>% of the total volume of biogas, and this had a high methane content, i.e. <NUM>%: more than <NUM> of methane (<FIG>), or nearly <NUM>% of the total volume of methane produced by these granules. This corresponds to the highest production period of the dried granules.

The control granules had a profile of production of methane and biogas halfway between these two behaviors (<FIG>: higher methane production between the <NUM>rd and the <NUM>th day). Finally, at the <NUM>th day, the three types of granules had a very similar total biogas production, both in volume and as a percentage of methane (Table <NUM> and <FIG>). The fresh granules obtained the best production.

Our qualitative observations show that the production of biogas started in the first <NUM> hours with fresh granules (ours and control): an effervescence of biogas bubbles was clearly visible in the bottles, particularly with the fresh granules, which already showed a very strong activity. On the other hand, with the dried granules, the first signs of significant gas production (large release of bubbles) were observed after about a week. On the <NUM>th day of methanization, there was significant activity in the bottles containing the dried granules. These observations are in full agreement with our biogas characterization results (Example <NUM>).

<FIG> shows bottles of fresh granules and dried granules on the <NUM>th day of methanization. Two elements must be observed:
There is almost no bubble release in the left bottle (faint presence of foam on surface), which suggests that the methanization of the substrate (synthetic wastewater) is for all intents and purposes already completed in this bottle. On the other hand, in the bottle on the right, there is a strong effervescence that has just begun, after a little more than a week of methanization.

The initiation of methanization with the dried granules is accompanied by a strong black coloration of the reaction liquor. The three bottles of dried granules all became of this color after a dozen days, unlike the fresh and control granules, the supernatant of which remained relatively clear throughout the trials. It appears that the dry granules had not been sieved to remove the fine particles (<<NUM> microns) before carrying out these experiments, which caused the high turbidity of the supernatant.

Our results and observations show that the dried granules take a certain time to activate and begin to produce biogas. With the fresh granules, the production of biogas is fast and intense in the first <NUM> days. But with the dried granules, it takes ten days before biogas production takes place and this production, both in volume and methane content, comes to its maximum between the <NUM>th and the <NUM>th day of methanization. Despite this latency, or delay compared to fresh granules, there is nevertheless a significant production of biogas and methane, as much as with the control granules and a little less than with the fresh granules. The calculated methanogenic potentials (Table <NUM>) confirm this latter observation.

For COD removal (Table <NUM>), the dried granules appear to be somewhat more effective than the control granules, but less effective than the fresh granules. However, these results should be interpreted with caution since our observations show some degranulation of the control granules, resulting in greater turbidity in the supernatant of the bottle, which in turn has influenced the COD measurement of the treated water. On the other hand, with the dried granules, there was coloration of the water. This black coloration may be due to carbonized or partially carbonized organic matter through the drying process of the granules. This organic matter, whatever it may be, has also surely influenced the measurement of COD in the supernatant.

The trials clearly demonstrate that the drying of the granules and their storage in the presence of oxygen do not irreparably affect the microbial biomass and that it is capable, after rehydration, of stimulating the production of biogas in anaerobic reactor, with an efficiency identical to that of the control granules and with an efficiency almost as good as the fresh granules. However, these dried granules need a latency or acclimatization time of about twenty days to fully recover their metabolic activity.

Table <NUM> reports the measurements for the SVI (Sludge Volume Index). This parameter indicates the settling characteristics of sludge in activated sludge systems. While conventional activated sludge has a SVI around <NUM>/g, the Nereda® technology has reported an SVI between <NUM> and <NUM>/g. As can be seen in the last column, the SVI of the present additive with anaerobic granules is <NUM> to <NUM> times more effective than the reported Nereda® system.

The granules of the present invention applied to aerobic technologies have the advantage of a better settling speed, which makes it advantageous over regular activated sludge systems. Typically, the settlement speed in a regular activated sludge is <NUM> meter per hour, while the settlement speeds of our additive can reach <NUM> to <NUM> meters per hour or more compared to <NUM> for the Nereda® Technology. Observe the settlement after only <NUM> minutes in <FIG> shows a picture of the resistance of the dried granules to shear testing.

This additive can also be convenient for bioaugmentation purposes in simple non-aerated tanks such as septic tanks. The composition of the additive can be adjusted to allow more flocculating power. The advantage of bridging (flocculate) all suspended mater with the bacteria consortium contained in the anaerobic granules down, is to assure that the bacteria will not leave the wastewater treatment system with the streams unlike simple addition of floating bacteria spores alone. This allows a higher retention time of the bacteria so they can easily digest the sludge along with organic matter presents in the wastewater tank. In this manner, the anaerobic and facultative anaerobic bacteria will thrive in the decomposition of the organic matter into CO<NUM> and CH<NUM> gases.

The inconveniences of the Nereda® Technology come from the fact that the in situ formation of the granules can be long to start. The process involves multiple repetitive steps and depending on the characteristics of the influent wastewater, it can take as long as <NUM> months to start-up properly.

The dried granules of the present invention have the advantage of quick rehydration and activation in less than <NUM> hours. Quicker start means less energy, more environmental safety and better economic profile.

This invention is applicable in aerobic activated sludge-type wastewater treatment technologies as well as in fully anaerobic operated systems such as methane production plants.

The activated silica beads are made by mixing dry zeolite with FeCl<NUM> and by slowly adding dry powder of NaAlO<NUM>. The reverse is possible. No solutions are involved in the surface modification of the zeolite. Water molecules naturally contained inside the zeolite clusters react with the other molecules to promote ions dissociation, diffusion and neutralization. The micro chemical reactions are exothermic resulting in high temperature rise, more than <NUM> KJ per mole. It is therefore necessary to control the temperature by slowly adding the Sodium Aluminate powder to the mix of zeolite and iron chloride powder.

The composition of the mix is obtained proportionally to the following equations <NUM> & <NUM>:.

FeCl<NUM> + 3NaHCO<NUM> → 3NaCl + Fe(OH)<NUM> + 3CO<NUM>     eq.

NaAlO<NUM> + CO<NUM> + <NUM><NUM>O → NaHCO<NUM>+ Al(OH)<NUM>     eq.

One mole of FeCl<NUM> consumes <NUM> moles of bicarbonate to produce <NUM> mole of coagulant (Fe(OH)<NUM>). The CO<NUM> resulting from the equation <NUM> reaction is in turn consumed by <NUM> moles of the sodium aluminate (NaAlO<NUM>) to produce <NUM> more moles of coagulant (Al(OH)<NUM>) with <NUM> more moles of bicarbonates which will fuel the reaction in a continuous cycle. In other terms, the composition of the mix is based on a factor involving <NUM> (<NUM> moles) of Sodium Aluminate (NaAlO<NUM>) and <NUM> (<NUM> mole) of ferric chloride (FeCl<NUM>) and <NUM> of clinoptilolite or any type of natural zeolite of any grain size (but preferentially around <NUM> mesh). This yields a general formula of NaAlO<NUM>/FeCl<NUM>=<NUM> and Zeolite = <NUM> × (FeCl<NUM> + NaAlO<NUM>).

Coagulation trials (jar test) were carried out in order to evaluate the performance of two products: activated silicate and dried microbial granules, on two types of wastewater: municipal wastewater (City Rivière-du-Loup, QC) and industrial wastewater after aeroflotation (Cabano, QC).

The coagulation trials were carried out using a Phipps & Bird <NUM>-position flocculation bench model PB-<NUM>. The volume of wastewater used for each trial was <NUM> placed in <NUM> beakers. After decantation, aliquots of supernatant were removed using a tube under the surface of the supernatant for analysis.

The scale of qualification of the aspect of the flocculation used is that proposed in the Technical Memento de l'eau de Degrémont<NUM> (see Table <NUM>).

The residual turbidity and pH were measured immediately after the settling period in the supernatant samples taken. The turbidimeter used is the Hach Model 2100P.

The ammoniacal nitrogen was assayed in spectrophotometry by the Nessler method after homogenization of a diluted sample and filtration over <NUM> to eliminate the turbidity (Standard Methods for the Examination of Water and Wastewater).

The total phosphorus was analyzed after acid digestion with potassium persulfate. The contents were assayed on the mineralization in spectrophotometry with the method of ascorbic acid (Standard Methods for the Examination of Water and Wastewater).

Production conditions: Fast mixing (<NUM> rpm): <NUM> minutes Slow mix (<NUM> rpm): <NUM> minutes Decantation (<NUM> rpm): <NUM> minutes.

It is this stable alkalinity provided by the activated silica beads that brings an advantage for the microbial granules when added to treat COD.

Production conditions: Fast mixing (<NUM> rpm): <NUM> minutes
Slow mix (<NUM> rpm): <NUM> minutes
Decantation (<NUM> rpm): <NUM> minutes.

From Table <NUM>, one can see that a) ammoniacal nitrogen decreases (from <NUM> to <NUM>), b) phosphate decreases (from <NUM> to <NUM>), while c) the pH remains higher than <NUM> showing sufficient alkalinity to allow optimal miocrobial activity.

<FIG> and <FIG> show the formation of small flocs with a dosage of <NUM>/L of granules (see last beaker at right), whereas <FIG> shows a control beaker (no granules) making it possible to observe the natural color and turbidity of the wastewater. Of note, no flocs and sludge accumulation is apparent.

This product mixture allows a coagulation action and phosphate removal without consuming the water alkalinity. This allows for simultaneous coagulation and phosphate reduction while maintaining the alkalinity for maintaining microbial activity of the granules presented in Examples <NUM> to <NUM>.

In short, <NUM> % of granules were soaked (<NUM> in <NUM>) in synthetic wastewater (Massalha, <NUM>) for <NUM> hours under aerated agitation. In a conventional sequence of: Iddle, Fill, React, Settle and Draw, the granules were allowed to settle for an hour and <NUM> of supernatant was drawn (<NUM>/<NUM> of reactor's volume). After <NUM> hours iddle time, <NUM> of fresh synthetic wastewater was then added, and a fresh aliquot was immediatly sampled for analysis at time (to). Once a day, a cycle of Iddle, Fill, React, Settle and draw, under aeration and agitation, was carried out (in duplicates for <NUM> reaction times of: <NUM> and <NUM>) for a total of <NUM> cycles.

The same protocol was reproduced for the <NUM>nd and <NUM>rd cycle each day. Table <NUM> shows the results obtained from these <NUM> cycles, whereas Table <NUM> shows the interpretation of the COD consumption from Table <NUM>.

In the simulated SBR (Sequential Batch Reactor) with a saturated oxygen environment, the granules showed <NUM> COD consumption for <NUM> of granules per day. Denoting an activity averaging <NUM> unit of COD per unit of granules per day. For example: Z <NUM> (<NUM> Lbs) of Archaea granules spends <NUM> (<NUM> Lbs) of COD per Day in an oxygen saturated environment.

From a synthetic carbon source, the granules' microorganisms feed on this source of carbon whether in an aerobic or an anaerobic environment and multiply at a rate of about <NUM>% of the consumed COD. The particular granules of the present invention (IDAC number <NUM>-<NUM>) constitute the original inoculant with a VSS substrate to inoculum (S/I) ratio of <NUM>.

Hence, the production process for these granules is carried out continuously with a hydraulic retention time of less than <NUM> days, a controlled carbon source at a mesophilic temperature and a minimal alkalinity level of <NUM> ppm.

The granules are reproducible and the resulting consortium corresponds substantially to the profile as defined in Table <NUM>, particularly in anaerobic mode.

Claim 1:
An aerobic process for treating wastewater comprising the steps of:
a) contacting a composition with a wastewater to be treated to form a wastewater: granules mixture, wherein the composition comprises anaerobic granules in dry form, wherein said granules comprise a consortium of bacterial communities comprising a mixture of anaerobic and facultative anaerobic bacteria, and wherein said granules comprise at least about <NUM>% of archaea microorganisms of the dried granules, as determined by DNA sequencing;
b) incubating the mixture for a period of time sufficient to decrease a COD of the wastewater to at least about <NUM>%, wherein said incubating is carried out with the introduction of an oxygen-containing gas; and
c) separating said granules from said treated wastewater.