Biofilter block and use thereof for wastewater treatment

Abstract

The present application relates to biofiltration materials for filtering a fluid. More specifically, the present application relates to a biofilter material comprising consolidated organic material, and use of such biofilter material for wastewater treatment. Provided is a biofilter bloc for wastewater treatment comprising a porous consolidated assembly of at least 20% w/w of organic materials, and wherein the consolidated assembly shows a density of about 35 kg/m.sup.3 to about 275 kg/m.sup.3.

Claims

1. A biofilter block for wastewater treatment comprising a porous consolidated assembly of at least 20% w/w of organic material and a binder, wherein the consolidated assembly has a density of about 60 kg/m.sup.3 to about 275 kg/m.sup.3, and wherein the organic material comprises elongated fibers having an elongation ratio of width: length of about 1:2000 to about 1:750.

2. The biofilter block according to claim 1, wherein a surface area of the block is about 0.25 m.sup.2 to about 8 m.sup.2.

3. The biofilter block according to claim 2, wherein the surface area is about 0.5 m.sup.2 to about 6 m.sup.2.

4. The biofilter block according to claim 2, wherein the surface area is about 0.5 m.sup.2 to about 6 m.sup.2.

5. The biofilter block according to claim 1, wherein the density is about 60 kg/m.sup.3 to about 200 kg/m.sup.3.

6. The biofilter block according to claim 1, wherein the density is about 75 kg/m.sup.3 to about 150 kg/m.sup.3.

7. The biofilter block according to claim 1, wherein the consolidated assembly has a total porosity is about 70% to about 97% v/v.

8. The biofilter block according to claim 1, wherein the consolidated assembly has a total porosity is about 80% to about 95% v/v.

9. The biofilter block according to claim 1, wherein the consolidated assembly has a total porosity is about 85% to about 90% v/v.

10. The biofilter block according to claim 1, wherein said organic material has an index of exogenous organic carbon (EOC) of about 36 to about 95.

11. The biofilter block according to claim 1, wherein said organic material has an index of exogenous organic carbon (EOC) of about 50 to about 75.

12. The biofilter block according to claim 1, wherein the consolidated assembly comprises about 25% w/w to about 100% of organic material.

13. The biofilter block according to claim 1, wherein the consolidated assembly comprises about 40% w/w to about 80% w/w of organic material.

14. The biofilter block according to claim 1, wherein the organic material is a plant-origin material.

15. The biofilter block according to claim 1, wherein the organic material is selected from coconut fibers, hemp fibers, woodchips, wood fibers, flax fibers, rice residue, straw, peat, and mixtures thereof.

16. The biofilter block according to claim 1, wherein the binder is selected from latex, polylactic acid, polyester, polyurethane, and mixtures thereof.

17. The biofilter block according to claim 16, wherein the binder is latex.

18. The biofilter block according to claim 1, further comprising a protective shell surrounding all faces or leaving one face unprotected.

19. The biofilter block according to claim 1, wherein the consolidated assembly has a total porosity is about 92% to about 96% v/v.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) The embodiments of the application will now be described in greater detail with reference to the attached drawings in which:

(2) FIG. 1A, FIG. 1B, FIG. 1C and FIG. 1D show perspective views of various shapes of a biofilter bloc according to exemplary embodiments of the application.

(3) FIG. 2A and FIG. 2B show perspective views of irregular geometries of a biofilter bloc according to exemplary embodiments of the application.

(4) FIG. 3A, FIG. 3B, FIG. 3C, FIG. 3D, FIG. 3E and FIG. 3F show perspective views of organized patterns of a biofilter system according to exemplary embodiments of the application.

(5) FIG. 4A, FIG. 4B, FIG. 4C and FIG. 4D are a perspective view, a top view, a side view and a front view, respectively, of a biofilter bloc within a protective shell according to exemplary embodiments of the application.

(6) FIG. 5 a graph of median BOD.sub.5 removal performance as a function of hydraulic load, according to exemplary embodiments of the application.

(7) FIG. 6 shows a graph of median BOD.sub.5 removal performance as a function of bloc density, according to exemplary embodiments of the application.

(8) FIG. 7 shows a graph of median BOD.sub.5 removal performance as a function of bloc height, according to exemplary embodiments of the application.

(9) FIG. 8 shows a graph of median TSS removal performance as a function of hydraulic load, according to exemplary embodiments of the application.

(10) FIG. 9 shows a graph of median TSS removal performance as a function of bloc density, according to exemplary embodiments of the application.

(11) FIG. 10 shows a graph of median TSS removal performance as a function of bloc height, according to exemplary embodiments of the application.

DETAILED DESCRIPTION

I. Definitions

(12) Unless otherwise indicated, the definitions and embodiments described in this and other sections are intended to be applicable to all embodiments and aspects of the present application herein described for which they are suitable as would be understood by a person skilled in the art.

(13) As used in this application 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 include and includes) or containing (and any form of containing, such as contain and contains), are inclusive or open-ended and do not exclude additional, unrecited elements or process steps.

(14) The term consisting and its derivatives as used herein are intended to be closed terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, and also exclude the presence of other unstated features, elements, components, groups, integers and/or steps.

(15) The term consisting essentially of, as used herein, is intended to specify the presence of the stated features, elements, components, groups, integers, and/or steps as well as those that do not materially affect the basic and novel characteristic(s) of these features, elements, components, groups, integers, and/or steps.

(16) The terms about, substantially and approximately as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. These terms of degree should be construed as including a deviation of at least 5% of the modified term if this deviation would not negate the meaning of the word it modifies or unless the context suggests otherwise to a person skilled in the art.

(17) As used in the present application, the singular forms a, an and the include plural references unless the content clearly dictates otherwise. For example, an embodiment including a component should be understood to present certain aspects with one component, or two or more additional components.

(18) In embodiments comprising an additional or second component, the second component as used herein is different from the other components or first component. A third component is different from the other, first, and second components, and further enumerated or additional components are similarly different.

(19) The term and/or as used herein means that the listed items are present, or used, individually or in combination. In effect, this term means that at least one of or one or more of the listed items is used or present.

(20) The term composition of the application or composition of the present application and the like as used herein refers to a composition comprising one or more material or component of the application.

(21) The term suitable as used herein means that the selection of the particular composition or conditions would depend on the specific steps to be performed, the identity of the components to be transformed and/or the specific use for the compositions, but the selection would be well within the skill of a person trained in the art.

(22) The present description refers to a number of chemical terms and abbreviations used by those skilled in the art. Nevertheless, definitions of selected terms are provided for clarity and consistency.

(23) The term porous as used herein refers to a material comprising pores or voids dispersed therein.

(24) The term consolidated assembly as used herein refers to elements assembled into a unified whole in a cohesive manner, i.e. assembled elements that require a reasonable force to un-assemble the elements.

(25) The terms an index of exogenous organic carbon or EOC as used herein refer to an indicator of biodegradability of an organic material.

(26) The term wastewater as used herein generally refers to domestic wastewaters, including greywaters, partially treated wastewater and treated wastewater.

II. Materials and Compositions of the Application

(27) It has been advantageously shown herein that a biofilter bloc of the present application provides for a consolidated assembly which is more resistant and has a controlled porometry. The blocs of the present application further provide for easy handling and installation. Comparable filtering media did not display the same properties, highlighting the results obtained with the biofilter blocs of the application.

(28) Accordingly, the present application includes a biofilter bloc for wastewater treatment comprising a porous consolidated assembly of at least 20% w/w of organic materials.

(29) In some embodiments, the consolidated assembly has a density of about 35 kg/m.sup.3 to about 275 kg/m.sup.3. In some embodiments, the density is about 60 kg/m.sup.3 to about 200 kg/m.sup.3. In some embodiments, the density is about 75 kg/m.sup.3 to about 150 kg/m.sup.3.

(30) In some embodiments, the consolidated assembly has a total porosity of about 70% to about 97% v/v. In some embodiments, the total porosity is about 80% to about 95% v/v. In some embodiments, the total porosity is about 85% to about 90% v/v, about 90% to about 96% v/v or about 92% to about 96% v/v.

(31) In some embodiments, the consolidated assembly has a surface area of about 0.25 m.sup.2 to about 8 m.sup.2. In some embodiments, the surface area is about 0.5 m.sup.2 to about 6 m.sup.2. In some embodiments, the surface area is about 1 m.sup.2 to about 5 m.sup.2. It may be desirable to provide blocs with smaller or larger surface areas, based on the intended uses. As such, it will be understood by a skilled person in the art that the surface area of the bloc is not hereby to be limited. However, one will appreciate that for a surface area too small, it may be difficult to obtain the consolidated assembly of the desired density, and larger surface areas may be difficult to handle. It would be within the purview of a skilled person in the art to select appropriate surface areas for a specific application, while maintaining the desired properties of the consolidated assembly. The biofilter bloc may also take various shapes, such as those shown in FIG. 1A, FIG. 1B, FIG. 1C and FIG. 1D, for example. The present application is not intended to be limited to a specific shape or dimension of the bloc.

(32) In some embodiments, the organic materials have an index of exogenous organic carbon (EOC) above about 36. In some embodiments, the organic materials have an index of exogenous organic carbon (EOC) of about 36 to about 95. In some embodiments, the organic materials have an index of exogenous organic carbon (EOC) of about 40 to about 85. In some embodiments, the organic materials have an index of exogenous organic carbon (EOC) of about 50 to about 75. In some embodiments, the organic materials have an index of exogenous organic carbon (EOC) of about 60 to about 85. A skilled person in the art will appreciate that any organic material having this EOC may be selected or organic material may be modified to provide for a desired EOC, according to known methods in the art and this would be well within the purview of the skilled person.

(33) In some embodiments, the consolidated assembly comprises about 25% to about 100% of organic material. In some embodiments, the consolidated assembly comprises about 30% to about 90% of organic material. In some embodiments, the consolidated assembly comprises about 40% to about 80% of organic material. A skilled person in the art would appreciate that using organic material will lower the carbon footprint of the consolidated assembly by avoiding or reducing the use of higher carbon footprint material, such as plastics. As such, a higher proportion of organic material will provide a lower carbon footprint, and selecting a suitable proportion while maintaining the desired properties of the biofilter bloc would be within the purview of a skilled person.

(34) In some embodiments, the organic material is a plant-origin material. In some embodiments, the organic material is selected from coconut fibers, hemp fibers, woodchips, wood fibers, flax fibers, rice residue, straw, peat, and mixtures thereof. In some embodiments, the organic material is stabilized by heat to provide an EOC above about 36. In some embodiments, the organic material is stabilized by torrefaction or pyrolysis. In some embodiments, the organic material comprises elongated material. In some embodiments, the organic material has an elongation ratio of width:length of about 1:3000 to about 1:300, or about 1:2500 to about 1:500, or about 1:2000 to about 1:750. In some embodiments, the organic material comprises elongated fibers.

(35) In some embodiments, the biofilter bloc further comprises a binder. For example, the binder may assist in forming the consolidated assembly of a desired density and porosity. It would be well within the purview of a skilled person in the art to select an appropriate binder for achieving the desired properties, according to the specific intended uses of the bloc. In some embodiments, the binder is selected from latex, polylactic acid, polyester, polyurethane, and mixtures thereof. In some embodiments, the binder is latex.

(36) In some embodiments, the consolidated assembly of said organic materials is by a mechanical method, a chemical method, or a combination thereof. In some embodiments, the mechanical method is selected from pressing, molding, heating, needled punching, and combinations thereof. In some embodiments, the chemical method is selected from vulcanization, polymerization and combinations thereof.

(37) In some embodiments, the biofilter bloc has a regular geometry or an irregular geometry on at least one face. In some embodiments, the irregular geometry is such that the biofilter bloc is to be used according to a given orientation, with a top and a bottom, and left, right, anterior, and posterior sides. In some embodiments, the irregular geometry is on the top face and defines at least one concave portion. In some embodiments, the irregular geometry is on the top face and defines at least one v-shape surface, u-shape surface, w-shape surface, dimpled surface, embossed surface, or combinations thereof. In some embodiments, the biofilter bloc comprises at least one localized densification of the consolidated assembly. Without being bound to theory, the irregular geometry will restrict the wastewater from flowing towards the sides of the biofilter bloc and thus ensure filtration through the bloc. It would be within the purview of a skilled person in the art to select an appropriate configuration to achieve the same. For example, a v-shape top surface is illustrated in FIG. 2A. FIG. 2B also shows a v-shape top surface, and additionally complementary L-shape extremities such that one extremity of a bloc would conform to the complementary L-shape extremity of a second bloc. As such, it can be seen that irregular geometries may also serve to assist in stabilizing/supporting/securing together a plurality of blocs.

(38) In some embodiments, a plurality of biofilter blocs are disposed according to an organized pattern to form biofilter systems. In some embodiments, said organized pattern comprises disposing the plurality of biofilter blocs side by side, consecutively, or superimposing the plurality of biofilter blocs one onto the other, or a combination thereof. Exemplary organized patterns are presented in FIG. 3A, FIG. 3B, FIG. 3C, FIG. 3D, FIG. 3E and FIG. 3F. For example. FIG. 3A shows a superimposed pattern, FIG. 3B shows a side-by-side pattern, FIG. 3C shows a consecutive pattern and FIG. 3D shows a combination of superimposition, consecutive and side by side pattern. FIG. 3E shows an alternate pattern of longitudinal/transversal superimposed blocs, such as a quincunx-type pattern. FIG. 3F shows a consecutive pattern of blocs having irregular geometries such as a v-shape top surface and an L-shape extremity complementary to the adjacent bloc. It would be within the purview of a skilled person in the art to select an appropriate pattern based on intended application and specific environment parameters.

(39) In some embodiments, wherein the biofilter systems have a height of about 100 mm to about 1000 mm. In some embodiments, the biofilter systems have a height of about 200 mm to about 800 mm. In some embodiments, the biofilter systems have a height of about 300 mm to about 700 mm. It will be appreciated that the dimensions of a final biofilter system is tunable by combining a plurality of biofilter blocs as required, selecting different shapes, geometry, etc.

(40) In some embodiments, the biofilter bloc further comprises a protective shell surrounding all faces or leaving one face unprotected. The protective shell is configured to ensure integrity of the bloc, for example by protecting against compression thereof, and also ensure proper aeration of the system, through a circulation space thus created between the shell and the bloc. In some embodiments, the face unprotected is the bottom face. An unprotected face will allow the treated water to flow towards a further treatment zone, such as another biofilter bloc or filtration media. The protective shell may be configured to be complementary one to another to allow stacking of a plurality of shells, or configured to enclose a plurality of blocs within one shell. An exemplary system including a biofilter bloc within a protective shell is shown in FIG. 4A, FIG. 4B, FIG. 4C and FIG. 4D. However, it would be within the purview of a skilled person in the art to design an appropriate protective shell according to intended uses, environment, configuration of the blocs, etc.

(41) The present application also provides a kit for the treatment of wastewater comprising: at least one biofilter bloc; at least one protective shell; and instructions of installation.

(42) Further included is a biofilter system comprising a plurality of biofilter blocs of the present application.

(43) The present application also includes a biofilter system for wastewater treatment, comprising a plurality of biofilter blocs, each biofilter bloc comprising a porous consolidated assembly of at least 20% w/w of organic materials, and wherein the consolidated assembly has a density of about 35 kg/m.sup.3 to about 275 kg/m.sup.3, wherein the plurality of biofilter blocs are disposed according to an organized pattern, and at least one protective shell.

III. Methods and Uses of the Application

(44) The biofilter blocs of the present application provide for a consolidated assembly which are more resistant and have a controlled porometry. The blocs of the present application further provide for easy handling and installation.

(45) Accordingly, the present application includes use of a biofilter bloc, a kit or a biofilter system of the present application, for wastewater treatment.

(46) The present application further includes use of a biofilter bloc, a kit or a biofilter system of the present application, for wastewater treatment in a drain field.

(47) A method for treating wastewater is also provided, the method comprising: disposing a biofilter bloc or a biofilter system of the present application in a wastewater environment, receiving the wastewater on the biofilter bloc or the biofilter system to separate contaminants from the wastewater, optionally recovering treated water.

(48) In some embodiments, the method is for treating wastewater in a drain field.

(49) The present application further includes a method for installing at least one biofilter bloc in a wastewater environment, the method comprising: disposing the at least one biofilter bloc in the wastewater environment, for receiving the wastewater; wherein the at least one biofilter bloc comprises a porous consolidated assembly and the consolidated assembly has a density of about 35 kg/m.sup.3 to about 275 kg/m.sup.3.

(50) In some embodiments, the at least one biofilter bloc is disposed on a filtration media. In some embodiments, the filtration media is a sand bed, biochar, recycled glass, native soil, or combination thereof.

(51) Also included is a method for installing at least one biofilter bloc in a drain field to optimize filtration, the method comprising: disposing the at least one biofilter bloc on a filtration media of the drain field, for receiving the wastewater; wherein the at least one biofilter bloc comprises a porous consolidated assembly and the consolidated assembly has a density of about 35 kg/m.sup.3 to about 275 kg/m.sup.3.

IV. Methods of Preparing the Compounds and Compositions of the Application

(52) The biofilter bloc of the present application may be prepared according to various methods for consolidation of the organic materials into a consolidated assembly.

(53) Accordingly, the present application further includes a method for producing a biofilter bloc comprising forming sheets of organic material with a binder, disposing a plurality of sheets in a mold and compressing to provide a consolidated assembly having a density of about 35 kg/m.sup.3 to about 275 kg/m.sup.3.

(54) In some embodiments, forming sheets comprises mixing of the organic material with the binder on a moving air-permeable belt, and/or using needle-punching.

EXAMPLES

(55) The following non-limiting examples are illustrative of the present application.

General Methods

Method 1Molding/Compression

(56) The consolidated assembly of organic material of the present application may be obtained according to the following general procedure: Organic fibers are air laid onto a moving air-permeable belt and bound using latex; Superimposed sheets of latex-binded organic fibers are molded and compressed to the targeted density to form a consolidated assembly; The latex of this latex-binded consolidated assembly is stabilized using heat; Shapers may be used during stabilization to mold depressions on the assembly surface.

Method 2Needle Punching

(57) Alternatively, the consolidated assembly of organic material of the present application may be obtained according to the following general procedure. Organic fibers are air laid onto a moving air-permeable belt and bound using needle-punching and latex. The use of needle-punching allows for less latex for the assembly consolidation; Superimposed sheets of latex-binded organic fibers are molded and compressed to the targeted density to form a consolidated assembly; The latex of this latex-binded consolidated assembly is stabilized using heat; Shapers may be used during stabilization to mold depressions on the assembly surface.

Example 1Organic Materials

(58) Organic materials have been tested for EOC (Table 1).

(59) TABLE-US-00001 TABLE 1 Stability index of various organic materials Materials EOC value (Premier Tech internal analysis) Coco 80 Wood 60 Hemp 36 Bark 82 Bagasse 55 Peat 85 Corn fiber 30

(60) Many organic materials have been tested because of their availability, low costs, and intrinsic properties (Ghazy et al., 2016; Loh et al., 2021), but were not monitored long enough to assess their stability over time within a biofiltration process. Coir, peat, and bark show the highest EOC values of Table 1, suggesting a lower biodegradability as compared to other organic materials. These were selected by Premier Tech as filtering material for its products, not only because of their intrinsic properties, their costs, or their availability, but also because they showed good stability over time within domestic wastewater treatment applications. Other materials showing higher biodegradability, such as hemp, have shown their ability for wastewater biofiltration with acceptable lifespan despite their lower stability (Premier Tech PCT/FR2016/000120). An organic-based filtering material showing an EOC value equal or higher than hemp can thus be considered stable enough for its use in such application.

(61) As stated above, porometry is of high significance for water biofiltration, since it has great impact on many key parameters that allow reaching a given treatment efficiency, reliability, and system longevity. For a bulk material, that porometry will mainly be dependent on the pores within the pieces of the material, the size distribution of these pieces and bulk density. The latter is closely related to the filtering materiel pieces size and inherent density, but also to the filtration bed compression level. That will drive, for a given organic material, the size pores distribution around the filtering material pieces and their spatial organization, strongly impacting the retention time of a fluid or a particle within the filtration bed, and thus treatment quality. Densities ranging between 60 to 275 kg/m.sup.3 were reported for bulk organic material used for biofiltration (Table 2), but values between 85 and 200 kg/m.sup.2 are more typical of the industry depending on filtering material pieces intrinsic density. Rock et al. (1984) showed that using peat densified above 150 kg/m.sup.3 led to premature clogging of the material, whereas Lens et al. (1994) found similar treatment capacity for peat between 75 and 100 kg/m.sup.3, and for bark between 150 and 175 kg/m.sup.3. A skilled person in wastewater biofiltration will understand that under a density threshold, the restriction to the flow may be insufficient for retention times fit for wastewater treatment whereas over another higher threshold, materials will be more prone to premature clogging due to too many small pores to accumulate particles and produced sludge over an extended period. Typically, an organic material bulk density used for biofiltration can hardly be under 60 kg/m.sup.3 because of a much lower resistance to compaction that leads to shorter lifespan and poor treatment quality, whereas bulk densities above 150 kg/m.sup.3 for lighter materials, such as peat, and 275 kg/m.sup.3 for denser materials, such as coco husk and bark, may lead to shorter lifespan due to premature clogging. Hence, the optimal density for an organic filtering material to get the right combination of pores sizes, resistance to compaction and flow restriction for biofiltration applications should be within 60 to 275 kg/m.sup.3. These densities represent the average bulk density, but it must be reminded that obtaining homogenous densification of a bulk material requires filtering material setting methods to be developed and rigorously followed during product assembly, thus requiring additional optimization for manufacturing such products. Not rigorously following these methods can promote uneven water movements within the filtering bed through less compressed zones, and thus a non-optimal use of the filtering material.

(62) TABLE-US-00002 TABLE 2 Density ranges for organic materials used for wastewater biofiltration Dry bulk density for water biofiltration Materials (kg/m.sup.3) References Coco 75-275 EP2322487 60-140 Premier Tech.sup.a Wood chips 75-100 Lens et al., 1994 Hemp 100-114 PCT/FR2016/000120 Bark 150-175 Lens et al., 1994 200 Premier Tech.sup.a Peat 60-80 U.S. Pat. No. 5,206,206 90-150 Rock et al., 1984 75-100 Lens et al., 1994 130-170 Kennedy, 1998 Cocoa shell 105 Turcotte, 2009 .sup.aDensity values within Premier Tech's biofiltration products

(63) For a consolidated filtering bloc, the porosity is related to its density value and will depend on the intrinsic density of the organic material used and its quantity within the bloc. The total porosity of consolidated filtering blocs composed of coco fibers and latex, having densities ranging from 67 to 141 kg/m.sup.3, was measured, and varied from 87 to 94% v/v. For this material, it should be expected that the porosity, from the extrapolation of the relationship between density and total porosity, will vary from 70 to 97% v/v within densities ranging from 35 to 275 kg/m.sup.3.

Example 2Biofilter Blocs Performance

(64) Small-scale and full-scale experimental units were fed with primarily treated domestic wastewater, at daily hydraulic loads between 0.10 to 0.75 m/d, under a feeding regimen providing hydraulic peaks between 0.013 to 0.100 m/h. Results are shown in Table 3. Tested filtering blocs were either composed of coco fibers bonded using vulcanized natural latex (80/20% w/w) or hemp fibers bonded using polyester (92/8% w/w), for organic materials' EOC value ranging from 36 to 80. Tested densities varied between 35 to 145 kg/m.sup.3, as shown in Table 4 and filtration heights ranged between 100 mm to 800 mm, as seen in Table 5. Materials were tested either as a stand-alone filtering material or disposed on top of different heights of filtration sand of 50 to 450 mm, as shown in Table 6. These experimental units were tested over a 5- to 12-month period for their pollutant's removal efficiency, using the biological oxygen demand after 5 days (BOD.sub.5) and total suspended solids (TSS) as pollutant surrogates.

(65) TABLE-US-00003 TABLE 3 Hydraulic load on biofilter blocs treatment performance BOD.sub.5 removal TSS removal Hydraulic load applied (Median) (Median) 0.10 m/d 34% 47% 0.20 m/d 47% 57% 0.30 m/d 28% 26% 0.50 m/d 28% 23% 0.75 m/d 6% 0% Stand-alone 200 mm high/90 kg/m.sup.3 coco fibers blocs

(66) TABLE-US-00004 TABLE 4 Biofilter blocs density on treatment performance BOD.sub.5 removal TSS removal Biofilter bloc density (Median) (Median) 35 kg/m.sup.3 hemp fibers 41% 48% 70 kg/m.sup.3 hemp fibers 65% 70% 40 kg/m.sup.3 coco fibers 27% 19% 80 kg/m.sup.3 coco fibers 27% 33% 90 kg/m.sup.3 coco fibers 47% 57% 100 kg/m.sup.3 coco fibers 48% 70% 145 kg/m.sup.3 coco fibers 61% 72% Stand-alone 200 mm high blocs/Hydraulic load fixed at 0.2 m/d

(67) TABLE-US-00005 TABLE 5 Biofilter blocs height on treatment performance BOD.sub.5 removal TSS removal Biofilter bloc height (Median) (Median) 100 mm 35% 29% 200 mm 47% 57% 500 mm 70% 63% 800 mm 86% 76% Stand-alone 90 kg/m.sup.3 coco fibers blocs/Hydraulic load fixed at 0.2 m/d

(68) TABLE-US-00006 TABLE 6 Biofilter blocs treatment performance when combined with a sand layer Sand layer height BOD.sub.5 removal TSS removal underneath the blocs (Median) (Median) 50 mm 77% 92% 150 mm 88% 91% 300 mm 97% 98% 450 mm 95% 98% 200 mm-high coco fibers blocs density 90 kg/m.sup.3/Hydraulic load at 0.2 m/d

(69) Graphs presenting results of the above parameters (hydraulic load, bloc density and bloc height) on BOD.sub.5 removal performance are presented in FIG. 5, FIG. 6 and FIG. 7, and on TSS removal performance are presented in FIG. 8, FIG. 9, and FIG. 10.

(70) While the applicant's teachings described herein are in conjunction with various embodiments for illustrative purposes, it is not intended that the applicant's teachings be limited to such embodiments as the embodiments described herein are intended to be examples. On the contrary, the applicant's teachings described and illustrated herein encompass various alternatives, modifications, and equivalents, without departing from the embodiments described herein, the general scope of which is defined in the appended claims.

REFERENCES

(71) AFNOR, 2018. Norme FD U44-163. Amendements organiques et supports de cultureCaractrisation de la matire organique par la minralisation potentielle du carbone et de l'azote AFNOR, 2016. Norme FD U44-162. Amendements organiques et supports de cultureCaractrisation de la matire organique par fractionnement biochimique et estimation de sa stabilit biologique. AFNOR, Paris. Ghazy, M. R. et al. 2016. Performance of agricultural wastes as a biofilter media for low-cost wastewater treatment technology. Advances in Research, 7(6): 1-13. Kennedy, P. 1998. Investigation of flow through peat filters. M.Sc. Thesis, Carleton University, Canada. Lens, P. et al. 1994. Direct treatment of domestic wastewater by percolation over peat, bark and woodchips. Water Research, 28(1): 17-26. Lashermes, G. et al. 2009. Indicator of potential residual carbon in soils after exogenous organic matter application. European Journal of Soil Science, 60:297-310. Loh, Z. Z., et al. 2021. Shifting from Conventional to Organic Filter Media in Wastewater Biofiltration Treatment: A Review. Appl. Sci. 2021, 11, 8650. https://doi.org/10.3390/app1118865 Renang, W. A. et al. 2018. The effectiveness of a fabricated bio-filtration systeme in treating the domestic wastewater. Malaysian Applied Biology, 47(10): 65-71. Rock, C. A. et al. 1984. Use of peat for on-site wastewater treatment: I Laboratory evaluation. Journal of Environmental Quality, 13:518-523. Spychaa, M. et al. 2021. A Preliminary Study on the Use of Xylit as Filter Material for Domestic Wastewater Treatment. Appl. Sci. 2021, 11, 5281. https://doi.org/10.3390/app11115281 Turcotte, V. 2009. Utilisation d'cailles de cacao comme matriau support pour la biofiltration d'effluents agroalimentaires. M.Sc. Thesis, Universit du Qubec, INRS-ETE, Canada.