DESC:FIELD OF THE INVENTION:
The present invention relates to molecular filter/s for removal of anions from waste water, ground water or sewage and a method for preparing the same.

More particularly, the present invention relates to regenerable molecular filter/s having high selectivity for anions.

The present invention also relates to a method of treating waste water to remove anions using the molecular filters.

BACKGROUND OF THE INVENTION:
General water treatment operations and processes have insufficient purification effect on contaminants present in groundwater, wastewater or sewage. Inorganic materials including inorganic salts and complex organic synthetic materials are the main perpetrator over there and various advanced wastewater treatments are required for the same. Ion exchange extraction, biological de-nitration, chemical reduction and electric dialysis are some of the techniques used for removing these substances and among them, ion-exchange extraction and biological de-nitration can be actually used for large-scale water treatment.

Sodium chloride or sodium bicarbonate is used in the ion exchange process for reproducing the used-up resins, and consequently, the waste solution concentrated with high concentration of nitrate ion, sodium chloride or sodium bicarbonate should be re-treated or wasted. However, it is difficult to remove nitrate salt selectively from the underground water which contains a lot of other anions besides nitrate ion. Although, it is the best method in terms of cost, due to the difficulties in processing concentrated byproducts, such method can be applied only in a seashore area or in an area having no possibility of eutrophication. Further the operational cost also increases as a lot of salts should be added. In addition, high concentration of chloride ion in the treated water may cause corrosion. While ion exchange beds can be regenerated, salt water is sent directly into the environment during this process. Besides issues with the resin fouling and thermal resin degradation, there are issues with the limited capacity and lifespan of ion exchange resins, necessitating periodic replacement.

References have been made to the following literature:
US2004256597A1 relates to a resin for removal of perchlorate, methods for manufacturing the resin, and methods and systems using the resin. The resin has a high selectivity coefficient. The method includes loading into and/or unloading from the water treatment system a perchlorate removal resin having the high selectivity coefficient. In one aspect, the perchlorate removal resin has quaternary alkylamine functionality.
WO2016012815A1 relates to a method of removing chromate ions from an ion- exchange effluent, the method comprising: (i) providing an ion-exchange effluent comprising chromate ions obtained from the regeneration of an ion-exchange material, (ii) admixing the ion-exchange effluent with a source of alkali metal dithionite to form a first precipitate, and (iii) removing the first precipitate.
US2004188348A1 relates to a metal containing waste water treatment method introducing a metal containing waste water from above into a submerged membrane separation tank in which a reaction section, a submerged membrane section having a submerged membrane and a precipitation section are arranged in order from top to bottom, causes a reaction by adding a pH adjuster to the reaction section, subsequently separates water from metal by the submerged membrane of the submerged membrane section and subsequently precipitates and concentrates the metal in the precipitation section. According to this treatment method, the pH adjuster is added to the reaction section, and therefore, solid-liquid separation can be effected by the submerged membrane with a hydroxide formed. Moreover, the metal can be precipitated and concentrated by the action of gravity without using energy in the precipitation section.

It is evident that despite the presence of wide variety of ion exchange resins in the market for the treatment of waste water, ion exchange resin treatments face several concerns regarding resin fouling, inadequate regeneration of resins, oxidation of ion exchange resins as well as the high operational costs, particularly for large-scale applications or when treating highly contaminated water. Thus, the present invention envisages to overcome the drawbacks of the above-mentioned prior art and provide a medium and a regenerable molecular filter/s that can be used for effectively removing the anions from the waste water as per the requirement.

Chemical and allied industries generate huge amounts of wastewaters which is characterized by contamination with organic compounds, halogenated aliphatic and aromatic compounds, agrochemicals, high concentrations of heavy metals, sulphur and nitrogen-containing compounds, high COD, TDS and TSS. The conventional wastewater treatment largely focuses on managing the COD or BOD levels. The nitrogen content, measured in the form of ammoniacal nitrogen, is a serious problem in many industrial wastewaters due to limitations of both biological and conventional physico-chemical methods. Ammoniacal nitrogen is a measure for the nitrogenous organic matter as ammonia, a toxic pollutant that can directly poison humans and upset the equilibrium of water ecology systems.

The permissible limit for ammoniacal nitrogen is required to be below 30–50 mg/L, though the limit can vary depending on location. There are many industries such as dyes and pigment, nitrogenous fertilizers, specialty chemicals that generate wastewaters having high ammoniacal nitrogen (1500–3000 mg/L) and demand specific solutions for wastewater treatment. Similarly, industries such as fisheries generate huge volumes of wastewaters, easily treatable using conventional biological treatment methods but end up in “treated wastewater” having high ammoniacal nitrogen of the order of 400–600 mg/L that needs to be again brought down to well below 50 mg/L using cost-effective physico-chemical methods.

The effluent treatment prior to discharge should pass through the stringent norms on Chemical Oxygen Demand (COD), Biological oxygen demand (BOD) and Ammoniacal Nitrogen (NH4-N). Industrial wastewater treatment is important for the sustainability of environment and ecology and at times can threaten the very existence of the industry, if the pollution norms are not complied with. But removal of ammoniacal nitrogen has received sparse attention barring standard biological methods of treatment.

References have been made to the following literature:
US9725338B2 relates to a method for treating effluent which involves providing the effluent as an input to an apparatus having a vortex diode with aeration. The apparatus induces a cavitation assisted with aeration for the high rates of ammoniacal nitrogen in an orifice and the vortex diode with or without inserts/stabilizers to generate radicals, which reduce ammoniacal nitrogen of wastewater effectively during effluent treatments.
US11077432B2 provides a catalyst composition includes a metal ion-exchanged molecular sieve ion-exchanged with at least one additional metal, which reduces the number of metal centers often present in metal promoted zeolite catalysts. The catalyst article made from such composition is useful to catalyze the reduction of nitrogen oxides in gas exhaust in the presence of a reductant.
Joshi et al (2019 JETIR April 2019, Volume 6, Issue 4) relates to the Magnesium Ammonium Phosphate process applied to pharmaceutical wastewater for removal of Ammoniacal Nitrogen. The effect of pH, different mixing time, and different reagents for Mg source were tested in this study. The stoichiometric ratio of Mg2+: NH4 + : PO4 2- was controlled of 1:1:1 for effective removal of Nitrogen present in form of Ammonia.
Pani N et al. (Appl Water Sci 10, 66 (2020)) investigates the effectiveness of Fenton reagent in simultaneous treatment (removal) of ammoniacal nitrogen and COD present in the wastewater by varying the parameters like pH, concentration of Fe 2+ and H2O2 and their molar ratio.
Seruga P et al (Molecules. 2019 Oct 9;24(20):3633) investigated the removal of ammonium ions using ion exchange on various commercial minerals, in 3 h long batch ion-exchange experiments. The screening of the mineral with the highest removal potential was conducted taking into account the adsorption capacity (q) and maximal removal efficiency (E), based on the NH4+ ions changes determined using the selective electrode and spectrophotometric cuvette tests. The highest adsorption capacity (q = 4.92 mg/g) of ammonium ions with the maximum removal efficiency (52.3%) was obtained for bentonite, with a 0–0.05 mm particle size.
Patil PB et al (Ultrason Sonochem. 2021 Jan;70:105306. doi: 10.1016/j.ultsonch.2020.105306) reported improvements in the removal of ammoniacal nitrogen from wastewater using hydrodynamic cavitation. The hydrodynamic cavitation technology with aeration and vortex diode as a cavitating device was suggested for industrial wastewater treatment, specifically for the removal of ammoniacal nitrogen.

It is evident that despite the presence of wide variety of ion exchange and biological methods available in the market for the treatment of waste water, most of the methods are based on managing the COD or BOD levels. However, effective methods or filters for the removal of ammoniacal nitrogen have not been disclosed in the art. Accordingly, the present invention envisages to overcome the drawbacks of the above-mentioned prior art/s and provide a regenerable molecular filters that can be used for the effective removal of ammoniacal nitrogen from the waste water.

The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

OBJECTS OF THE INVENTION:
An object of the present invention is to provide molecular filter/s for removal of anions from wastewater and methods for manufacturing anion removal filter/s having high selectivity to remove anions from wastewater.

Another object of the present invention is to provide molecular filter/s for removal of ammoniacal nitrogen anions from waste water and methods for preparing the high selectivity molecular filters to remove ammoniacal nitrogen from wastewater/ effluent.

SUMMARY OF THE INVENTION:
The present invention discloses medium and high selectivity molecular filters for removal of anions from wastewater and method for manufacturing filters having high selectivity to remove anions from the wastewater.

The present invention provides high selectivity molecular filter/s for removal of ammoniacal nitrogen from the effluents and method for preparing having high selectivity molecular filters for the removal of ammoniacal nitrogen removal filters from the wastewater / effluent.

According to this invention, there is provided a molecular filter for removal of anions from waste water, and for selective removal of ammoniacal nitrogen from effluents, said filter comprises:
a ceramic substrate in an amount of 50% to 90% by weight;
an activator in an amount of 5% to 20% by weight; and
a binder in an amount of 5% to 30% by weight.

In at least an embodiment, said activator being selectable from a group consisting of a precipitating agent and an immobilizing agent.

In at least an embodiment, the substrate is selected from the group consisting of cordierite, silicon carbide, mullite, cordierite-a alumina, silicon nitride, zircon mullite, spodumene, alumina-silica magnesia, zircon silicate, sillimanite, magnesium silicates, zircon, petalite, alumina, aluminosilicates, alumina, zeolites, porcelain, perlites, zirconia.

In at least an embodiment, the activator is 5% w/v to 15% w/v of Sodium Formaldehyde Bisulphite with 0.5% w/v to 5 % w/v of Sodium Carbonate.

In at least an embodiment, the activator is selected from a group consisting of carbonic acid, phosphoric acid, sulphuric acid, ferric chloride, formic acid, organic acids, and mixtures thereof.

In at least an embodiment, filter comprises a plurality of spherical porous ceramic beads having an average diameter of about 1mm to 8mm.

In at least an embodiment, filter comprises a plurality of spherical porous ceramic beads having an average diameter of about 1mm to 8mm.

In at least an embodiment, the activator being a precipitating agent is selected from a group consisting of alumina, calcium oxide, iron oxide, barium carbonate, aluminosilicate with active ferric chloride, acids, metal ions such as silver and any mixture thereof.

In at least an embodiment, the binder is selected from a group consisting of carboxy compounds, cellulose, gums, glue, agar, formaldehyde, resins, amines, amides and any mixture thereof.

In at least an embodiment, the binder is selected from alumina, silica, zirconium acetate, colloidal zirconia, zirconium hydroxide, associative thickeners, and surfactants.

In at least an embodiment, the activator is impregnated within the porous structure of the ceramic substrate.

In at least an embodiment, the molecular filter comprises a plurality of porous beads made from the ceramic substrate and binding agent impregnated with the activator, wherein the pore size of the beads is in the range of 0.1 Å to10 Å, wherein the BET surface area of the beads is in the range of 100m2/g to500 m2/g, wherein the porous ceramic beads have an average diameter of about 1 mm to 8 mm.

In at least an embodiment, wherein the molecular filter comprises a plurality of porous beads made from the ceramic substrate and binding agent impregnated with the activator, wherein the pore size of the beads is in the range of 0.1Å to 5Å, wherein the BET surface area of the beads is in the range of 100 m²/g to 800 m²/g, wherein the porous ceramic beads have an average diameter of about 1 mm to 8 mm.

In at least an embodiment, the filter is configured as a structured substrate or monolithic substrate.

In at least an embodiment, the substrate is a monolithic substrate configured with a washcoat of an activator and optionally a binder.

In at least an embodiment, the substrate is a monolithic substrate configured with a washcoat of an activator and optionally a binder, in that, the monolithic substrate comprises a honeycomb structure having multiple flow-through channels coated with the washcoat.

In at least an embodiment, the filter is configured as a structured substrate or monolithic substrate, in that, the monolithic substrate comprises a honeycomb structure having multiple flow-through channels defined by walls coated with a washcoat containing the activator.

In at least an embodiment, the filter is configured as a structured substrate or monolithic substrate, in that, the monolithic substrate comprises a honeycomb structure having multiple flow-through channels defined by walls coated with a washcoat containing the activator, said flow-through channels have a cell density of about 60 to 1200 cells per square inch (cpsi).

In at least an embodiment said filter comprises a pH adjusting agent selected from buffer solutions including glycine, NaOH buffer, carbonate buffer, acetate buffer, bisulphate buffer.

In at least an embodiment, said filter comprises a pH adjusting agent in the range of 1% w/v to 5% w/v with pH values ranging from 4 to 10.

In at least an embodiment, the activator being a precipitating agent is selected from a group of agents consisting of:
alumina acidified with sulphuric acid;
a mixture of calcium oxide and alumina;
a mixture of acidified aluminium oxide;
barium carbonate; and
aluminosilicate with active ferric chloride.

According to this invention, there is provided a molecular filter for removal of anions from the waste water, comprising:
a porous ceramic substrate having a BET surface area of about 100 to 500 m²/g and a pore size range of about 0.1 Å to 10 Å; and
an activator impregnated into the porous ceramic substrate, wherein the activator is selected from the group consisting of alumina, calcium oxide, iron oxide, barium carbonate, and mixtures thereof, and is present in the composition in an amount of about 0 to 20% by weight;
wherein the activator reacts with dissolved anions in water to form insoluble precipitates that are retained within the porous structure of the ceramic substrate.

According to this invention, there is provided a process for preparing a regenerable molecular filter comprising porous ceramic beads, said process comprises the following steps:
providing a ceramic substrate material in an amount of 50% to 90% by weight;
adding a binder, in an amount of 5% to 30% by weight, to said ceramic substrate material with said activator;
mixing, extruding, spheroniozing, and shaping to obtain ceramic beads or pellets;
b) annealing said beads at a temperature in the range of 1000 C to 11000 C; and
c) treating the annealed beads with an activator solution, in an amount of 5% to 20%, to obtain the porous ceramic bead impregnated with the activator.

In at least an embodiment, the process comprises step/s of back washing the filter with water followed by treating said filter with the activator.

In at least an embodiment, the ceramic substrate is formed into a monolithic honeycomb structure, and the activator is applied as a washcoat slurry followed by drying.

According to this invention, there is provided molecular filter for removal of anions from an aqueous solution, said filter comprising:
a chemically reactive precipitating agent, in an amount of 50% to 90% by weight, configured to induce precipitation of a target anion upon contact with the aqueous solution;
a porous or semi-porous substrate, in an amount of 50% to 90% by weight, hosting the chemically reactive precipitating agent;
a binder, in an amount of 5% to 30% by weight, configured to fix the chemically reactive moiety onto the substrate and enhance the mechanical stability of the filter material;
a pH adjusting agent in the range of 1% w/v to 5% w/v with pH values ranging from 4 to 10, configured to control or modify the local pH conditions within or around the filter material to optimize the precipitation reaction of the target anion
wherein the filter material facilitates selective binding and immobilization of the precipitated anion species,
and the filter maintains structural integrity during repeated exposure to aqueous streams.

DETAILED DESCRIPTION OF THE INVENTION:
While the embodiments of the disclosure are subject to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is intended to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure. Further, the phraseology and terminology employed in the description is for the purpose of description only and not for the purpose of limitation.

The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure, are intended to cover a non-exclusive inclusion, such that a device, apparatus, system, assembly, method that comprises a list of components or a series of steps that does not include only those components or steps but may include other components or steps not expressly listed or inherent to such apparatus, or assembly, or device. In other words, one or more elements or steps in a system or device or process proceeded by “comprises… a” or “comprising …. of” does not, without more constraints, preclude the existence of other elements or additional elements or additional steps in the system or device or process as the case may be.

The present invention discloses medium and high selectivity molecular filters for removal of anions from wastewater and method for manufacturing filters having high selectivity to remove anions from the wastewater.

It is found that the micro pores of the molecular filters act like reaction centres and the slow releasing precipitating agent / immobilising agent present in these filters react with the anions present in the waste water. The precipitating agent / immobilising agent in the molecular filters may be intrinsic or an extrinsically infused reagent on the ceramic molecular filter.

Regenerable molecular filter:
In one aspect there is provided a regenerable molecular filter for removal of anions from the waste water.

In one embodiment, the filter is in the form of porous bead/s or granule/s or pellet/s or ball/s or particle/s.

In one embodiment, the molecular filter comprises:
at least one ceramic substrate;
at least one activator [precipitating agent / immobilising agent]; and
at least one binder.

In one embodiment, the molecular filter for removal of anions from the waste water, said filter comprises:
a ceramic substrate in an amount of about 50 to 100% by weight;
an activator [precipitating agent / immobilising agent] in an amount of about 0 to 20% by weight; and
a binder in an amount of about 0 to 10% by weight.

In one embodiment, the filter further comprises a pH adjusting agent.

As used herein, the term “regenerable molecular filter” refers to the molecular filter which can be back-washed and again loaded with the activator [precipitating agent / immobilising agent] for efficient re-use.

In one embodiment, said substrate is selected from the group consisting of refractory materials. The refractory materials include but are not limited to cordierite, silicon carbide, mullite, cordierite-a alumina, silicon nitride, zircon mullite, spodumene, alumina-silica magnesia, zircon silicate, sillimanite, magnesium silicates, zircon, petalite, alumina, aluminosilicates and the like.

In one embodiment, the precipitating agent is selected from a group consisting of alumina, calcium oxide, iron oxide, barium carbonate, aluminosilicate with active ferric chloride, acids, metal ions such as silver and any mixture thereof.

In one embodiment, the binder is at least one selected from a group consisting of carboxy compounds, cellulose, gums, glue, agar, formaldehyde, resins, amines, amides and any mixture thereof.

In another embodiment, the binder in the form of alumina, silica, zirconium acetate, colloidal zirconia, or zirconium hydroxide, associative thickeners, and/or surfactants (including anionic, cationic, non-ionic or amphoteric surfactants). Other exemplary binders include bohemite, gamma-alumina, or delta/theta alumina, as well as silica sol.

Porous Beads:
In one preferred embodiment, the molecular filter comprises a plurality of porous beads made from the ceramic substrate and binding agent impregnated with at least one activator [precipitating agent / immobilising agent].
As used herein, “impregnated” or “impregnation” refers to permeation of the at least one activator [precipitating agent / immobilising agent] into the porous structure of the ceramic substrate.
In one more preferred embodiment, the molecular filter comprises a plurality of spherical porous ceramic beads.
In one embodiment, the pore size of the beads is in the range of 0.1A to10A.
In one embodiment, the BET surface area of the beads is in the range of 100m2/g to500 m2/g.
In one embodiment, the porous ceramic beads have an average diameter of about 1 mmto8 mm.

Structured substrate / monolithic substrate:
In one embodiment, the filter is a structured substrate.
As used herein, the term “substrate” refers to the monolithic material onto which the precipitating agent is placed or coated or impregnated, typically in the form of a washcoat / liquid / slurry. In one embodiment, the structured substrate is monolithic substrate.
Reference to “monolithic substrate” means a unitary structure that is homogeneous and continuous from inlet to outlet.
As used herein, the term “washcoat” has its usual meaning in the art of a thin, adherent coating of an activator [precipitating agent / immobilising agent] or other material applied to a substrate material, such as a honeycomb-type carrier member, which is sufficiently porous to permit the passage of the waste water stream being treated.
A washcoat is formed by preparing a slurry containing a certain solid content of particles (such as activator [precipitating agent / immobilising agent] optionally with binder in a liquid vehicle, which is then coated onto a substrate and dried to provide a washcoat layer.
In one embodiment, the substrate contains one or more washcoat layers, and each washcoat layer is different in some way (e.g., may differ in physical properties thereof such as, for example particle size or crystallite phase) and/or may differ in the chemical functions.

The molecular filter may be “fresh” meaning it is new and has not been exposed to any heat or thermal stress for a prolonged period of time. “Fresh” may also mean that the filter was recently prepared and has not been exposed to any waste water. Likewise, an “aged” molecular filter is not new and has been exposed to waste water for a prolonged period of time.

According to one or more embodiments, the substrate of the molecular filter of the presently claimed invention may be constructed of any material typically used for preparing molecular filters and typically comprises a ceramic monolithic honeycomb structure. The substrate typically provides a plurality of wall surfaces upon which wash-coats comprising the activator [precipitating agent / immobilising agent] containing compositions described herein above are applied and adhered, thereby acting as a carrier for the compositions.

Ceramic materials used to construct the substrate may include any suitable refractory material, e.g., cordierite, silicon carbide, mullite, cordierite-a alumina, silicon nitride, zircon mullite, spodumene, alumina-silica magnesia, zircon silicate, sillimanite, magnesium silicates, zircon, petalite, alumina, aluminosilicates and the like.

Any suitable substrate may be employed, such as a monolithic flow-through substrate having a plurality of fine, parallel liquid flow passages extending from an inlet to an outlet face of the substrate such that passages are open to fluid flow. The passages, which are essentially straight paths from the inlet to the outlet, are defined by walls on which the medium material is coated as a washcoat so that the waste water flowing through the passages contact the precipitating material. The flow passages of the monolithic substrate are thin-walled channels which are of any suitable cross-sectional shape, such as trapezoidal, rectangular, square, sinusoidal, hexagonal, oval, circular, and the like. Such structures contain from about 60 to about 1200 or more inlet openings (i.e. "cells") per square inch of cross section (cpsi), more usually from about 300 to 600 cpsi. The wall thickness of flow-through substrates can vary, with a typical range being between 0.002 and 0.1 inches. However, it will be understood that the invention is not limited to a particular substrate type, material, or geometry.

Preparation of the regenerable molecular filter:
In one aspect there is provided a process for preparing the regenerable molecular filter.
In one embodiment, there is provided a process for preparing the regenerable molecular filter comprising porous ceramic beads, said process comprises the following steps:
providing a ceramic substrate material;
adding at least a binder to said ceramic substrate material, mixing extrusion, spheroniozation and shaping to obtain ceramic beads or pellets;
b) annealing said beads at a temperature in the range of 100to11000C;
c) treating the beds with at least one activator [precipitating agent / immobilising agent] solution to obtain the porous ceramic bead impregnated with the activator [precipitating agent / immobilising agent].

In one embodiment, the process of preparing the molecular filter comprises a technique selected from incipient wetness impregnation technique (A); co-precipitation technique (B) and co impregnation technique (C).

In another embodiment, the process for preparing the regenerable molecular comprises step/s of back washing the filter with water followed by treating said filter with the activator [precipitating agent / immobilising agent].

In yet another embodiment of the present invention, the precipitated anion can often be backwashed in the filter or undergoes an anion exchange with a regenerant.

The anion specific activators [precipitating agent / immobilising agent] are incorporated into the ceramic beads/filters i.e. activator [precipitating agent / immobilising agent] having desired selectivity for a particular anion to be removed from the waste water is selected.

The molecular filters in the form of porous ceramic beads can be provided / packed inside an enclosed housing or unit.

Exemplary embodiments:
In a first exemplary embodiment, alumina slightly acidified with sulphuric acid can be used as a precipitating agent for the removal of phosphate anions from the waste water.
In a second exemplary embodiment, a mixture of calcium oxide and alumina can be used as a precipitating agent for the removal of chloride anions from the waste water.
In a third embodiment, a mixture of acidified aluminium oxide can be used as a precipitating agent for the removal of fluoride anions from the waste water.
In a fourth embodiment, barium carbonate can be used as a precipitating agent for the removal of sulphate anions.
In a fifth embodiment, aluminosilicate with active ferric chloride can be used as a precipitating agent for the active removal of nitrate anions.
In a sixth embodiment of the present invention, the filer and/or precipitating agent is free of chlorine, iodine, hypochlorite or ozone.

Treating of waste water:
The present invention also provides a method of treating waste water to remove anions using the molecular filter/s in accordance with the present invention.
In one embodiment, the method comprises passing the waste water through a unit comprising the molecular filter.

The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.

According to a non-limiting exemplary embodiment, there is provided a table as below:
Anion Media / Base Binder Reagent Heated at, with time Regenerate
Sulphate KH (5%) Barium Carbonate 300? for 2hrs
Phosphate Alumina balls (5-8mm) heated at 500? for 1hr. 25% H2SO4 25% H2SO4
Chloride Alumina balls (5-8mm) heated at 750? 1% PVP 1.7g Silver Nitrate 350? for 1hr.
Nitrate Calcium Oxide : Aluminium Oxide (1:1) mixed and heated at 200? Ferric chloride
(If media is 2gm then 1gm FeCl3)
Flouride Alumina balls (5-8mm) heated at 500? for 1hr. 25% H2SO4
Add 30% 25% H2SO4

According to another non-limiting exemplary embodiment, a fluoride reduction experiment was conducted:
Fluoride Solution Prepared: 1000 ppm (2.210 g NaF dissolved in 1 L of water)
Media: PureAnion fluoride media (Used), washed and dried before usage.
Quantity of Media: 100 g of media was added to the system for fluoride reduction.
Sample Volume Passed: 100 ml

Reaction:
Al2(SO4)3 + F- ? AlF3 + SO42-

Regeneration:
AlF3 + Na2SO4 ? Al2(SO4)3 + NaF

Sample Fluoride (ppm)
Initial 1500
After 100 ml 450

Conclusion:
A 70% reduction in fluoride concentration was observed after 100 ml of the fluoride solution passed through the 100 g of fluoride media.

According to another non-limiting exemplary embodiment, a fluoride reduction experiment was conducted:
Fluoride Solution Prepared: 1000 ppm (22.10 g NaF dissolved in 10 L of water).
Media: PureAnion fluoride media (Used), washed and dried before usage.
Quantity of Media: 200 g of the used media was added to the system for the fluoride reduction process.
Sample Volume Passed:
Sample Fluoride (ppm)
Initial 840
After 1000 ml 550
After 2000 ml 480
After 3000 ml

Inference:

According to another non-limiting exemplary embodiment, a fluoride reduction experiment was conducted:
Fluoride Solution Prepared: 1000 ppm (22.10 g NaF dissolved in 10 L of water).
Media: PureAnion fluoride media (Used), washed and dried before usage.
Quantity of Media: 200 g of the used media was added to the system for the fluoride reduction process.
Regenerant: 1% H2SO4 ( 2.5 ml – in 250 ml)
Volume of Regenerant: 250 ml
Soaking Time: 1.5 hours
Sample Volume Passed:
Sample Fluoride (ppm)
Initial 1200
After 500 ml 580
After 1000 ml 590
Inference:

According to another non-limiting exemplary embodiment, a fluoride reduction experiment was conducted:
Fluoride Solution Prepared: 1000 ppm (22.10 g NaF dissolved in 10 L of water).
Media: PureAnion fluoride media (Used), washed and dried before usage.
Quantity of Media: 200 g of the used media was added to the system for the fluoride reduction process.
Regenerant: 1% H2SO4 (2.5 ml – in 250 ml)
Volume of Regenerant: 250 ml
Soaking Time: overnight soaking
Sample Volume Passed:
Sample Fluoride (ppm)
Initial 1200
After 500 ml 580
After 1000 ml 590
Regenerant
After 1000 ml 590

Inference:

According to another non-limiting exemplary embodiment, a fluoride reduction experiment was conducted:
Fluoride Solution Prepared: 1000 ppm (22.10 g NaF dissolved in 10 L of water).
Media: PureAnion fluoride media (Used), washed and dried before usage.
Quantity of Media: 200 g of the used media was added to the system for the fluoride reduction process.
Regenerant: 1% H2SO4 (2.5 ml – in 250 ml)
Volume of Regenerant: 250 ml
Soaking Time: 1.5 hours soaking
Sample Volume Passed:
Sample Fluoride (ppm)
Initial 1200
After 500 ml 580
After 1000 ml 590
Regenerant
After 1000 ml 590
Regenerant
After 1000 ml 640

Inference:

According to another non-limiting exemplary embodiment, a nitrite reduction experiment was conducted:
Flow Mode:

Media 25% Sulphuric alumina balls (500? pre-heated) Balls
Media Quantity 50 g
Flow rate 20 ml/min
Physical appearance of sample Clear and transparent
Analysis Through aquasol kit

Observation table:

Sample Nitrate in ppm Observation
Initial 50 Clear and transparent
After 0 Slight ppt due to which solution become turbid

Conclusion: There has been 99% reduction in nitrate level of the solution observed.

According to another non-limiting exemplary embodiment, a chloride reduction experiment was conducted:

Date of sample received 20/11/2024
Company
Type of Water STP Treated Water
Process Open Flow
Experiment:
Through 20 g of pure Anion Chloride powder 100 ml of sample solution just passed. The after sample was filtered before analysis.

Observation table :

Sample no. Sample Description pH Chloride in ppm (using aquasol) before
Chloride in ppm (using aquasol) after
Sample colour
Before
01 Phase:1 Old STP treated (ACP) water 5 750 4 Colourless
02 Phase:4 STP treated water 8 145 15 Slight yellow
03 Phase:5 STP treated water 9 190 5 Turbid with slight yellow

Inference:

According to another non-limiting exemplary embodiment, a phosphate reduction experiment was conducted:
Media: Phosphate media
Experiment: 60 ml of sample pass through 5g of media twice. Filter and Analyse.
Phosphate analysis:
Analysis: Through Aquasol kit
End point: Colourless to yellow.
Observation table:

Sample pH TDS Colour ?PO?_4^(3-) in ppm Sample sent to Ashalini Lab
Sample ID Result
Initial
( DM Plant-Water ) 7 1 Colourless 0-5 TP1 0.41
After
( DM Plant-Water ) 6 59 Colourless 0-5 TP2 0.29
Initial
( Single rinse Water ) 7 1 Colourless 0-5 TP3 0.83
After
( Single rinse Water ) 6 35 Colourless 0-5 TP4 0.43

Inference:

The current invention provides a dual functional mode: Precipitation + Filtration. Prior art filters usually rely on:
adsorption (surface capture) or
ion exchange.
This invention’s filter promotes in-situ precipitation inside a porous matrix, allowing both chemical reaction and mechanical filtration to happen in the same unit — which is inventive, especially for complex wastewater scenarios.

The current invention provides reusability via simple regeneration. The process, as claimed in this invention, which includes a synergistic effect of regarding backwashing in conjunction with re-impregnation gives the current invention economic and environmental advantages over:
ion-exchange resins (limited cycles, require acid/base regeneration),
membranes (prone to fouling).
This invention’s regenerable material filter that can be returned to full capacity without complex chemical or physical treatments is a significantly more contribution.

The current invention provides flexibility in form and application:
bead form for packed beds, OR
monolithic form for high-flow industrial use.
This flexibility makes the current inventio’s filters deployable in a wide range of treatment setups — the filter is not just a “material” but part of a reusable, configurable treatment platform.

Advantages over Prior Art:
The present invention offers a number of advantages over conventional anion removal systems employed in the treatment of wastewater and industrial effluents.

First, the filter media of the present invention is capable of undergoing multiple regeneration cycles without significant degradation in performance. Unlike conventional ion-exchange resins, which typically require chemical regenerants and exhibit limited operational lifespans, the impregnated filter media can be regenerated by simple physical backwashing followed by re-impregnation of the precipitating agent. This reduces consumable requirements and minimizes the generation of secondary waste.

Second, the invention utilizes a precipitation-based mechanism for the removal of anions, as opposed to purely adsorption or ion-exchange based methods common in the prior art. This enables the system to maintain high removal efficiencies across a broad range of anion concentrations and under variable pH and ionic strength conditions, thereby improving operational robustness.

Third, the use of a ceramic-based substrate, such as cordierite, zircon-mullite, or aluminosilicate, provides superior mechanical integrity, thermal stability, and chemical resistance relative to polymeric membranes or conventional ion-exchange media. This allows the filter media to withstand harsh operating conditions and mechanical stress without deformation or fouling.

Fourth, the present invention enables both chemical reaction and solid-liquid separation to occur within the same filter structure. Dissolved anions react with the precipitating agent impregnated within the porous filter matrix, and the resulting precipitates are retained within the media. This integrated design simplifies the treatment process and eliminates the need for downstream clarification and sludge separation equipment.

Fifth, the pore structure of the ceramic filter media minimizes fouling and clogging, even in wastewater streams containing high levels of suspended solids or biological matter. The filter media can be readily cleaned by backwashing without mechanical failure, thereby extending its service life.

Sixth, the filter media can be manufactured in a variety of geometries, including monolithic bodies, spherical granules, and honeycomb configurations. This flexibility enables easy adaptation to different reactor designs and hydraulic conditions, which is not readily achievable with conventional ion-exchange beds or membrane modules.

Seventh, the present invention enhances environmental sustainability by reducing both the volume of disposable media and the need for chemical regenerants. Further, the precipitation mechanism immobilizes anionic contaminants as solid-phase products, facilitating safe handling, disposal, or further processing.

The INVENTIVE STEP, of this invention, lies in is combining a solid-phase activator [precipitating agent / immobilising agent] embedded in a porous ceramic structure with the ability to be regenerated via backwash and re-impregnation, thus:

The TECHNICAL ADVANCEMENT, of this invention, lies in the particular combination of:
porous ceramic substrates (known for thermal stability and mechanical strength),
activator [precipitating agent / immobilising agent] (active compounds that trap anions via precipitation rather than mere adsorption), and
binders (which control mechanical properties and permeability).

The TECHNICAL ADVANCEMENT, of this invention, lies in:
precipitation-based anion removal + porous ceramic substrate + regenerability by simple backwash and recharging — which leads to longer life, lower cost, and reduced environmental footprint compared to traditional ion-exchange or membrane systems.

The present invention also discloses high selectivity molecular filter/s for removal of ammoniacal nitrogen from the effluents and method for preparing having high selectivity molecular filters for the removal of ammoniacal nitrogen removal filters from the wastewater/effluent.

The present invention also discloses high selectivity molecular filter/s for removal of ammoniacal nitrogen from the effluents and method for preparing having high selectivity molecular filters for the removal of ammoniacal nitrogen removal filters from the wastewater/effluent.

In the context of the present invention, the term Total Nitrogen (TN) is the sum of all nitrogen forms, or Total Nitrogen = Ammonia Nitrogen (NH3) + Organic Nitrogen (Nitrogen in amino acids and proteins) + Nitrite (NO2) + Nitrate (NO3), or Total Nitrogen = TKN + NO2 + NO3 (This is the formula used to measure nitrogen at wastewater plants). The present invention covers all possible permutations and combinations of total nitrogen.

In an embodiment, the regenerable molecular filter/s according to the present invention work by removal of ammoniacal nitrogen by the chemical precipitation reaction.

In an embodiment of the present invention, the precipitating agent / activator / immobilising agent may be intrinsic or an extrinsically infused reagent in the substrate.

In an embodiment of the present invention, the molecular filters are regenerable and can be regenerated by addition or treatment with an activator.

In yet another embodiment of the present invention the precipitated ammoniacal nitrogen can often be backwashed in the filter or undergoes ion exchange with the activator.

Molecular filter:
In one aspect there is provided a regenerable molecular filter for selective removal of ammoniacal nitrogen from effluents, said filter comprises:
at least one ceramic substrate/sieve;
at least one binder; and
at least one activator.

In one embodiment, the regenerable molecular filter for removal of anions from the waste water, said filter comprises:
at least one ceramic substrate / sieve in an amount of about 50 to 90% by weight;
at least one binder in an amount of about 1 to 10% by weight; and
at least one activator in an amount of about 1 to 50% by weight.

In one embodiment, the filter further comprises a pH adjusting agent.

As used herein, the term “regenerable molecular filter” refers to the molecular filter which can be back-washed and again loaded with the activator [precipitating agent / immobilising agent] for efficient re-use.

In one embodiment, said substrate is selected from the group consisting of ceramics such as alumina, zeolites, porcelain, perlites, zirconia and combinations thereof.

In one embodiment, said activator is selected from a group consisting of carbonic acid, phosphoric acid, sulphuric acid, ferric chloride, formic acid, organic acids and any mixture thereof.

In one embodiment, the binder is at least one selected from a group consisting of carboxy compounds, cellulose, gums, glue, agar, formaldehyde, resins, amines, amides and any mixture thereof.

In another embodiment, the binder in the form of alumina, silica, zirconium acetate, colloidal zirconia, or zirconium hydroxide, associative thickeners, and/or surfactants (including anionic, cationic, non-ionic or amphoteric surfactants). Other exemplary binders include bohemite, gamma-alumina, or delta/theta alumina, as well as silica sol.

Porous Beads:
In one preferred embodiment, the molecular filter comprises a plurality of porous beads made from the ceramic substrate and binding agent impregnated with at least one activating agent.
As used herein, “impregnated” or “impregnation” refers to permeation of the at least one activator [precipitating agent / immobilising agent] into the porous structure of the ceramic substrate.
In one more preferred embodiment, the molecular filter comprises a plurality of spherical porous ceramic beads.
In one embodiment, the pore size of the beads is in the range of 0.1A to5A.
In one embodiment, the BET surface area of the beads is in the range of 100 m2/g to 800 m2/g.
In one embodiment, the porous ceramic beads have an average diameter of about 1to8mm.

Structured substrate / monolithic substrate:
In one embodiment, the filter is a structured substrate.
As used herein, the term “substrate” refers to the monolithic material onto which the activating agent is placed or coated or impregnated, typically in the form of a washcoat/ liquid/ slurry. In one embodiment, the structured substrate is monolithic substrate.
Reference to “monolithic substrate” means a unitary structure that is homogeneous and continuous from inlet to outlet.

As used herein, the term “washcoat” has its usual meaning in the art of a thin, adherent coating of an activating agent or other material applied to a substrate material, such as a porous carrier member, which is sufficiently porous to permit the passage of the waste water stream being treated.

A washcoat is formed by preparing a slurry containing a certain solid content of particles (such as activating agent optionally with binder in a liquid vehicle, which is then coated onto a substrate and dried to provide a washcoat layer.

In one embodiment, the substrate contains one or more washcoat layers, and each washcoat layer is different in some way (e.g., may differ in physical properties thereof such as, for example particle size or crystallite phase) and/or may differ in the chemical functions.

The molecular filter may be “fresh” meaning it is new and has not been exposed to any heat or thermal stress for a prolonged period of time. “Fresh” may also mean that the filter was recently prepared and has not been exposed to any waste water. Likewise, an “aged” molecular filter is not new and has been exposed to waste water for a prolonged period of time.

According to one or more embodiments, the substrate of the molecular filter of the presently claimed invention may be constructed of any material typically used for preparing molecular filters and typically comprises a ceramic porous structure. The substrate typically provides a plurality of wall surfaces upon which washcoats comprising the activator [precipitating agent / immobilising agent] containing compositions described herein above are applied and adhered, thereby acting as a carrier for the compositions.

Ceramic materials used to construct the substrate may include any suitable refractory material, e.g., cordierite, silicon carbide, mullite, cordierite-a alumina, silicon nitride, zircon mullite, spodumene, alumina-silica magnesia, zircon silicate, sillimanite, magnesium silicates, zircon, petalite, alumina, aluminosilicates and the like.

Any suitable substrate may be employed, such as a monolithic flow-through substrate having a plurality of fine, parallel liquid flow passages extending from an inlet to an outlet face of the substrate such that passages are open to fluid flow. The passages, which are essentially straight paths from the inlet to the outlet, are defined by walls on which the medium material is coated as a washcoat so that the waste water flowing through the passages contact the precipitating material. The flow passages of the monolithic substrate are thin-walled channels which are of any suitable cross-sectional shape, such as trapezoidal, rectangular, square, sinusoidal, hexagonal, oval, circular, and the like. Such structures contain from about 60 to about 1200 or more inlet openings (i.e. "cells") per square inch of cross section (cpsi), more usually from about 300 to 600 cpsi. The wall thickness of flow-through substrates can vary, with a typical range being between 0.002 and 0.1 inches. However, it will be understood that the invention is not limited to a particular substrate type, material, or geometry.

Preparation of the regenerable molecular filter:
In one aspect there is provided a process for preparing the regenerable molecular filter.
In one embodiment, there is provided a process for preparing the regenerable molecular filter comprising porous ceramic beads, said process comprises the following steps:
providing a ceramic substrate / sieve material; adding at least a binder to said ceramic substrate material,
mixing extrusion and spheroniozation to obtain ceramic beads; annealing said beads at a temperature in the range of 100 to 9000C; and
treating the beds with at least one activating agent solution to obtain the porous ceramic bead impregnated with the activating agent.

In one embodiment, the process of preparing the molecular filter comprises a technique selected from incipient wetness impregnation technique (A); co-precipitation technique (B) and co impregnation technique (C).
In another embodiment, the process for preparing the regenerable molecular comprises step/s of back washing the filter with raw water followed by treating said filter with the activating agent.

In an embodiment of the present invention once the effluents are treated with the filter media, the nitrogen and or NH3 rich solution goes to the pores of the filter media. The NH3 reacts with the activator, precipitates out and gets trapped in the microspheres of the beads. This is then backwashed with the activator and the NH3 backwashed compounds can be used as by products for the fertilizer industry. Optionally, gas streams are introduced into the system for the generation of value-added products based upon the requirement of the type of fertilizer. The gas stream is at least one selected from a group comprising H2S, CO2, SOX, NOX and any combination thereof.

In an embodiment the molecular filter after the backwash is regenerated with the specific activator.

In an embodiment the byproducts produced in the present invention after the treatment of the waste water can be converted in to useful value-added products. Thus, besides being economical, produce no threat to the environment.

In one aspect of the present invention there is provided a process for the removal of the ammoniacal nitrogen from the effluents. In one embodiment, the process comprises treating the effluent or waste water with the molecular filter or allowing the effluent or waste water to pass through a unit or system comprising regenerable molecular filter. In one embodiment, the process comprises introduction of gas stream/s optionally into a system for the generation of value-added products.

It is known that many soil bacteria possess the enzyme urease, which catalyzes the conversion of urea to ammonium ion (NH+4) and bicarbonate ion (HCO-3). Major two-component fertilizers provide both nitrogen and phosphorus to the plants. These are called NP fertilizers. The main NP fertilizers are monoammonium phosphate (MAP) and diammonium phosphate (DAP). The active ingredient in MAP is NH4H2PO4. The active ingredient in DAP is (NH4)2HPO4. About 85% of MAP and DAP fertilizers are soluble in water. But these processes besides being high temperature processes, involve a lot of cost and the byproducts end up into land fill sites in turn polluting the environment. Accordingly, the by-products produced by the present invention after the removal of ammoniacal nitrogen can be converted into fertilizers and thus introducing no additional burden to the environment.

Typically, an activator can be precipitating agent, and / or an immobilising agent.

Preferably, the activator is:
5% w/v to 15% w/v Part A + 0.5% w/v to 5 % w/v Part B (20ml) + 10gm media [ceramic balls] + Soaking time 30 mins:
Part A is the molecule Sodium Formaldehyde Bisulphite;
Part B is Sodium Carbonate.

The combination of Part A and Part B results in the in-situ formation of active adducts and buffering compounds that assist in the chemical binding, neutralization, and subsequent precipitation or immobilization of ammoniacal nitrogen species within the effluent matrix. The structured ceramic media, with pores, enhances the surface area for these interactions and acts as a physical trapping medium for precipitated compounds. The pores are reaction centres promoting heterogenous reactions.

Upon completion of the soaking period, the treated effluent demonstrates a significant reduction in ammoniacal nitrogen concentration, validating the synergistic effect of the chemical agents and structured media in facilitating effective nitrogen removal.

The following discloses a non-limiting exemplary operational Method for Ammoniacal Nitrogen Reduction Using a Molecular Filter Media:
In one embodiment, the disclosed molecular filtration system was tested for its effectiveness in reducing ammoniacal nitrogen from effluent waste streams. The system comprised a treatment vessel packed with a specialized molecular filter media, supported by a control assembly that regulates the activation, filtration, and regeneration cycles.
The following operational method was employed:

Activation Phase
Prior to initiating effluent filtration, the system was subjected to an activation process to condition the molecular filter media.
The system was backwashed using 300 liters of raw water at a controlled flow rate of 1000 LPH for 10 minutes to dislodge any trapped particulates or residual matter from prior use.
Upon completion of the backwash cycle, the vessel was drained completely via the bottom drain valve.
An activator solution was prepared by dissolving 30 kg of an activator salt (e.g., sodium carbonate or sodium formaldehyde bisulfite) in 300 liters of water. For daily operation, a top-up solution was prepared using 4.5 kg/day of the activator salt, adjusted to maintain the solution volume at 300 liters.
The multi-port valve was set to the Backwash Mode, and both the bottom drain valve and effluent line valve were closed to ensure recirculation integrity.
The chemical pump was activated, initiating circulation of the activator solution through the filter media bed.
The activator solution was circulated for 1 hour, during which the molecular filter media was conditioned to enhance its affinity for ammoniacal nitrogen compounds.
Upon completion, the chemical pump was deactivated, and the activator solution was recovered into the activator storage tank for reuse.

Filtration Phase
After activation, the system was transitioned to filtration mode.
The multi-port valve was set to the Filter Mode, and effluent wastewater was introduced into the system from the Effluent Inlet Tank.
The system pump was initiated, and the flow rate was manually adjusted using a bypass valve to maintain between 100 to 150 LPH. The outlet stream was monitored, and treated effluent began emerging within approximately 10 to 15 minutes.
Flow rates were subsequently optimized and increased up to 200 LPH based on real-time evaluation of ammoniacal nitrogen concentration in the treated output.
Post-treatment, the outlet line bag filter was subjected to a routine clean-in-place (CIP) cycle to ensure performance consistency during extended operation.

Regeneration Phase
If the effluent analysis revealed insufficient reduction of ammoniacal nitrogen, the system was subjected to regeneration.
The regeneration cycle involved repeating the Activation Protocol described above.
This ensured the molecular filter media was restored to optimal adsorption capacity for subsequent filtration cycles.

Backwash Phase
To prevent clogging and maintain permeability of the molecular filter bed, a daily backwash cycle was performed.
Approximately 300 liters of raw water was flushed through the system at a flow rate of 1000 LPH for a period of 10 minutes.

Routine Backwash Maintenance
A daily backwash cycle was performed wherein the system was set to Backwash Mode, and 300 litres of raw water was circulated at 1000 LPH to remove any accumulated solids or precipitates from the media bed.

Performance Observation:
This operational sequence demonstrated effective removal of ammoniacal nitrogen and other contaminants from the effluent stream and allowed for cyclical reuse of the molecular filter media via the regeneration process.
Utilizing this invention’s method, the system consistently achieved substantial reductions in ammoniacal nitrogen concentrations in the treated effluent, confirming the efficacy of the molecular filter media when properly conditioned and maintained as per the above protocol.

According to another non-limiting exemplary embodiment, the following discloses physical characteristics and regeneration performance of the Molecular Filter Media:
In one embodiment, the molecular filter media designed for ammoniacal nitrogen and effluent treatment applications was prepared in the form of spherical beads. The media was characterized prior to use, and its physical and mechanical attributes were determined as follows:
Physical Parameter Measured Value
Appearance Spherical beads, approximately 5-6 mm in diameter
Color Peach to light pink
Bulk Density Approximately 0.86 g/cm³
Crushing Strength Minimum 15 kg (95% of beads retained integrity)
These physical attributes provide the molecular filter media with enhanced surface area, mechanical robustness, and stability, making it suitable for continuous flow-based treatment of aqueous effluents containing high ammoniacal nitrogen loads.

Regeneration Efficiency Evaluation
The regeneration behavior of the exhausted molecular filter media was evaluated using sodium carbonate solution as the regenerant under varying concentration conditions. The performance of the regeneration process was quantitatively assessed by recording the initial and final burette readings corresponding to ammonia retention capacity, and computing the reduction in activity percentage.
Sr. No. Regenerant Concentration (wt/vol %) Burette Reading (ml) Reduction in Activity (%)
1 10.0% 35 —
2 7.5% 28 20.00
3 5.0% 15 57.14
4 1.0% 6 82.85
The reduction in adsorption activity was calculated using the equation:
[(Initial burette rdg- Final burette rdg) / Initial buretter rdg ] x 100

The data demonstrates that higher regenerant concentrations (10% wt/vol) yielded the most effective media recovery with minimal reduction in ammonia removal activity. In contrast, lower regenerant concentrations (1.0% wt/vol) were insufficient for restoring full functionality, as evidenced by a substantial reduction in activity (~83%).

EXPERIMENT 1: Anion Patent exp:
(Alumina beads are synco 5-8mm beads)
Observation table:
Parameter: Phosphate Anions
Base material Binder Precipitating agent / activator Heating temperature Initial value in ppm After treatment value in ppm % Reduction Comments
Alumina beads -- -- 350°c -750°c 40 40 nil --
Alumina beads -- 25% H2SO4 Base material heated at 500°c 35.4 4.0 88.7% Without activator nil reduction observed.
Inference:
Plain alumina beads showed no reduction in phosphate levels, indicating that untreated alumina alone is ineffective.
When activated with 25% H2SO4 and heated to 500°C, the alumina beads achieved 88.7% phosphate reduction, suggesting that acid treatment significantly enhances the surface reactivity of the beads toward phosphate removal.

EXPERIMENT 2: Parameter: Fluoride Anions
Base material Binder Precipitating agent / activator Heating temperature Initial value in ppm After treatment value in ppm % Reduction Comments

Alumina beads -- 25% H2SO4 Base material heated at 500°c 17.91 6.86 61.7% Using 25% of the activator significantly lowered the solution's pH observed making it highly acidic.
Alumina beads -- 10% Na2SO4 Base material heated at 500°c 17.5 4.7 73.14% The pH became neutral following the application of Na2SO4.
Alumina beads -- 10% NaHSO4 Base material heated at 500°c 17.5 4.2 76.0% NaHSO4 treatment maintained a neutral pH and maximum reduction observed.
Inference:
Alumina beads activated with 25% H2SO4 achieved 61.7% fluoride reduction but made the medium highly acidic (low pH).
Activation with 10% Na2SO4 led to a 73.14% reduction, maintaining a neutral pH, indicating better overall performance.
Activation with 10% NaHSO4 further improved fluoride reduction to 76.0% while maintaining neutrality, suggesting NaHSO4 is the best activator among those tested for fluoride removal.

EXPERIMENT 3: Parameter: Chloride Anions
Base material Binder Precipitating agent / activator Heating temperature
Initial value in ppm After treatment value in ppm % Reduction Comments
Alumina beads --- -- 500°c 184 141 23.7% Minimal reduction was observed when only the base material was used..
25% Aluminium oxide --- 75% Calcium oxide Mixture heated at 1000°c 680 200 70.58 Maximum reduction was achieved after the mixture was calcinated.
25% Aluminium oxide --- 75% Calcium oxide +2%NaOH(regen) Mixture heated at 1000°c 100 40 60% The calcined mixture was regenerated using NaOH through an ion exchange mechanism.
25% Aluminium oxide 5% KH resins
75% Calcium oxide Mixture heated at 1000°c
+ After mixing binder heated at 200°c 680 200 70.58 Optimal reduction was attained following the calcination of the mixture and the incorporation of KH resin as a binding agent.

Aluminium oxide 5% CMC Calcium oxide Mixture heated at 1000°c
+ After mixing binder heated at 200°c 620 495 20.16 When CMC was used as a binder, the reduction observed was significantly lower compared to KH resin.
Inference:
Plain alumina beads at 500°C showed only 23.7% reduction, indicating poor performance for chloride removal.
A calcined mixture of 25% Aluminium Oxide + 75% Calcium Oxide at 1000°C achieved 70.58% reduction, showing that calcium oxide greatly enhances chloride removal.
Regeneration with 2% NaOH gave 60% reduction, showing potential for partial reusability.
KH resin as a binder helped maintain optimal reduction (70.58%), while CMC as a binder led to only 20.16% reduction, indicating that KH resin is superior to CMC for binding and performance.

EXPERIMENT 4: Parameter: Sulphate Anions
Base material Binder Precipitating agent / activator Heating temperature Initial value in ppm After treatment value in ppm % Reduction Comments
Barium Carbonate -- -- -- 700 200 71.4% The reaction of sulfate with barium carbonate forms an insoluble precipitate of barium sulfate giving upto71% sulphate reduction.
Barium carbonate 5% KH resin -- 350°c 100 32 68% reduction of up to 68% was observed with the addition of 5% KH resin.
Inference:
Barium carbonate alone removed 71.4% of sulphate via precipitation of BaSO4, a known insoluble compound.
The addition of 5% KH resin marginally reduced performance (68% reduction) but might offer mechanical stability benefits for future applications.
Overall, barium carbonate remains highly effective for sulphate removal without the need for high-temperature activation.

EXPERIMENT 5: Parameter: Silica Anions
Base material Binder Precipitating agent / activator Heating temperature Initial value in ppm After treatment value in ppm % Reduction Comments
Molecular sieve -- 10% KCl -- 414 360 13.04 NO significant reduction observed.
Zeolite balls -- -- -- 414 314 24.15 NO significant reduction observed.

Alumina beads -- 1% KMnO4 350°c
367 330 10.00 NO significant reduction observed.

Alumina beads -- 1% KMnO4 + 1.8% Glycin + 0.6% NaOH 350°c
414 238 42.51 Better reduction is observed as compared to other media bsed on ion exchange mechanism.
Chitosen -- 10% KCl solution -- 414 302 27.05 NO significant reduction observed.

Carbon (natural amon ) -- 25% H2SO4 367 361 2 NO significant reduction observed.

Alumina beads
-- 2% Percarbonate 500°c
Base material 367 304 17 NO significant reduction observed.

Inference:
Across multiple materials (molecular sieves, zeolite, alumina, chitosan, carbon), only minimal silica reduction (<45%) was achieved.
The best observed reduction (42.51%) was with alumina beads treated with 1% KMnO4 + glycine + NaOH, suggesting that multiple additives with ion exchange activation moderately improve silica removal.
However, overall, no material tested was highly effective against silica anions under the given conditions.

EXPERIMENT 6: Parameter: nitrate Anions
Ppt: precipitating agent
Base material Binder Precipitating agent/ activator Heating temperature Initial value in ppm After treatment value in ppm % Reduction Comments
Chitosan -- NaCl -- 100 36.5 63.5 Good reduction is observed. It works based on ion exchange mechanism.
Alumina beads -- 25% H2SO4 500°c
Base material 439 440 - No reduction is observed and an increase in the pH was observed.
Alumina beads -- 40%FeSO4 + 25% H2SO4 500°c
Base material+ after ppt agent media heated at 350°c 492 315 35.97 Average reduction is observed.
Inference:
Chitosan treated with NaCl achieved 63.5% nitrate reduction, showing that ion-exchange via chitosan is effective for nitrate removal.
Alumina beads alone or even with 25% H2SO4 showed no reduction, with pH increase, indicating alumina is ineffective for nitrate without specific activation.
Combining FeSO4 and H2SO4 with alumina gave an average 35.97% reduction, suggesting some improvement through iron salt-based co-precipitation, but overall, chitosan was the superior material for nitrate removal in this set.

In sum,
Material Activation is Critical:
Base materials like alumina beads alone showed minimal to no reduction for phosphate, fluoride, chloride, and nitrate anions.
Activation with acids (H2SO4), salts (Na2SO4, NaHSO4), or incorporation of binders (KH resin) significantly enhanced removal efficiency by modifying surface chemistry or facilitating ion exchange.
Best Performing Activators and Combinations:
For phosphate and fluoride, acid activation (particularly with 25% H2SO4 and 10% NaHSO4) was essential and highly effective.
For chloride, a calcined mix of Aluminium Oxide and Calcium Oxide at high temperatures (1000°C) achieved maximum reduction, especially when stabilized with KH resin.
Barium carbonate proved inherently effective for sulphate without complex activation steps.
Silica is Difficult to Remove:
None of the tested materials achieved high silica removal. Even the best condition (alumina + KMnO4 + glycine + NaOH) yielded only ~42% reduction, indicating that silica anions are more resistant to conventional ion-exchange or precipitation methods under tested conditions.
Ion Exchange Materials like Chitosan Excel in Nitrate Removal:
Chitosan with NaCl achieved 63.5% nitrate reduction, outperforming all alumina-based treatments.
Iron salt activation helped somewhat but still lagged behind chitosan's natural ion-exchange capacity.
Role of pH Control:
In many cases (especially fluoride), pH adjustment was critical. Activators like Na2SO4 and NaHSO4 helped maintain a neutral pH while enabling higher anion removal efficiencies, improving operational feasibility.
Binder Impact on Performance:
KH resin was superior to CMC as a binder, enhancing structural integrity and maintaining high ion exchange/precipitation activity without compromising performance.

The TECHNICAL ADVANCEMENT, of this invention, lies in the combination of:
Regenerable, structured molecular filters + precipitating/activating agents (carbonic acid, sulphuric acid, ferric chloride) + non-biological, ambient-condition removal of ammoniacal nitrogen.

This results in:
Efficient ammoniacal nitrogen reduction from wastewater.
Reduced chemical consumption versus conventional direct precipitation systems.
Reusable filter substrates.
Compact footprint — unlike air-stripping towers or biological tanks.

While considerable emphasis has been placed herein on the particular features of this disclosure, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other modifications in the nature of the disclosure or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

,CLAIMS:WE CLAIM,

1. A molecular filter for removal of anions from waste water, and for selective removal of ammoniacal nitrogen from effluents, said filter comprises:
a. a ceramic substrate in an amount of 50% to 90% by weight;
b. an activator in an amount of 5% to 20% by weight; and
c. a binder in an amount of 5% to 30% by weight.

2. The molecular filter as claimed in claim 1 wherein, said activator being selectable from a group consisting of a precipitating agent and an immobilizing agent.

3. The molecular filter as claimed in claim 1, wherein the substrate is selected from the group consisting of cordierite, silicon carbide, mullite, cordierite-a alumina, silicon nitride, zircon mullite, spodumene, alumina-silica magnesia, zircon silicate, sillimanite, magnesium silicates, zircon, petalite, alumina, aluminosilicates, alumina, zeolites, porcelain, perlites, zirconia.

4. The molecular filter as claimed in claim 1, wherein the activator is 5% w/v to 15% w/v of Sodium Formaldehyde Bisulphite with 0.5% w/v to 5 % w/v of Sodium Carbonate.

5. The molecular filter as claimed in claim 1, wherein the activator is selected from a group consisting of carbonic acid, phosphoric acid, sulphuric acid, ferric chloride, formic acid, organic acids, and mixtures thereof.

6. The molecular filter as claimed in claim 1, wherein filter comprises a plurality of spherical porous ceramic beads having an average diameter of about 1mm to 8mm.

7. The molecular filter as claimed in claim 1, wherein filter comprises a plurality of spherical porous ceramic beads having an average diameter of about 1mm to 8mm.

8. The molecular filter as claimed in claim 1, wherein the activator being a precipitating agent is selected from a group consisting of alumina, calcium oxide, iron oxide, barium carbonate, aluminosilicate with active ferric chloride, acids, metal ions such as silver and any mixture thereof.

9. The molecular filter as claimed in claim 1, wherein the binder is selected from a group consisting of carboxy compounds, cellulose, gums, glue, agar, formaldehyde, resins, amines, amides and any mixture thereof.

10. The molecular filter as claimed in claim 1, wherein the binder is selected from alumina, silica, zirconium acetate, colloidal zirconia, zirconium hydroxide, associative thickeners, and surfactants.

11. The molecular filter as claimed in claim 1, wherein the activator is impregnated within the porous structure of the ceramic substrate.

12. The molecular filter as claimed in claim 1, wherein the molecular filter comprises a plurality of porous beads made from the ceramic substrate and binding agent impregnated with the activator, wherein the pore size of the beads is in the range of 0.1 Å to10 Å, wherein the BET surface area of the beads is in the range of 100m2/g to500 m2/g, wherein the porous ceramic beads have an average diameter of about 1 mm to 8 mm.

13. The molecular filter as claimed in claim 1, wherein the molecular filter comprises a plurality of porous beads made from the ceramic substrate and binding agent impregnated with the activator, wherein the pore size of the beads is in the range of 0.1Å to 5Å, wherein the BET surface area of the beads is in the range of 100 m²/g to 800 m²/g, wherein the porous ceramic beads have an average diameter of about 1 mm to 8 mm.

14. The molecular filter as claimed in claim 1, wherein the filter is configured as a structured substrate or monolithic substrate.

15. The molecular filter as claimed in claim 1, wherein the substrate is a monolithic substrate configured with a washcoat of an activator and optionally a binder.

16. The molecular filter as claimed in claim 1, wherein the substrate is a monolithic substrate configured with a washcoat of an activator and optionally a binder, in that, the monolithic substrate comprises a honeycomb structure having multiple flow-through channels coated with the washcoat.

17. The molecular filter as claimed in claim 1, wherein the filter is configured as a structured substrate or monolithic substrate, in that, the monolithic substrate comprises a honeycomb structure having multiple flow-through channels defined by walls coated with a washcoat containing the activator.

18. The molecular filter as claimed in claim 1, wherein the filter is configured as a structured substrate or monolithic substrate, in that, the monolithic substrate comprises a honeycomb structure having multiple flow-through channels defined by walls coated with a washcoat containing the activator, said flow-through channels have a cell density of about 60 to 1200 cells per square inch (cpsi).

19. The molecular filter as claimed in claim 1, wherein said filter comprises a pH adjusting agent selected from buffer solutions including glycine, NaOH buffer, carbonate buffer, acetate buffer, bisulphate buffer.

20. The molecular filter as claimed in claim 1, wherein said filter comprises a pH adjusting agent in the range of 1% w/v to 5% w/v with pH values ranging from 4 to 10.

21. The molecular filter as claimed in claim 1, wherein the activator being a precipitating agent is selected from a group of agents consisting of:
- alumina acidified with sulphuric acid;
- a mixture of calcium oxide and alumina;
- a mixture of acidified aluminium oxide;
- barium carbonate; and
- aluminosilicate with active ferric chloride.

22. The molecular filter as claimed in claim 1 wherein:
a. said ceramic substrate being a porous ceramic substrate having a BET surface area of about 100 to 500 m²/g and a pore size range of about 0.1 Å to 10 Å; and
b. said activator impregnated into the porous ceramic substrate, wherein the activator is selected from the group consisting of alumina, calcium oxide, iron oxide, barium carbonate, and mixtures thereof, and is present in the composition in an amount of about 0 to 20% by weight;
wherein the activator reacts with dissolved anions in water to form insoluble precipitates that are retained within the porous structure of the ceramic substrate.

23. A process for preparing a regenerable molecular filter comprising porous ceramic beads, said process comprises the following steps:
a) providing a ceramic substrate material in an amount of 50% to 90% by weight;
b) adding a binder, in an amount of 5% to 30% by weight, to said ceramic substrate material with said activator;
c) mixing, extruding, spheroniozing, and shaping to obtain ceramic beads or pellets;
b) annealing said beads at a temperature in the range of 1000 C to 11000 C; and
c) treating the annealed beads with an activator solution, in an amount of 5% to 20%, to obtain the porous ceramic bead impregnated with the activator.

24. The process as claimed in claim 23, wherein the process comprises step/s of back washing the filter with water followed by treating said filter with the activator.

25. The process as claimed in claim 23, wherein the ceramic substrate is formed into a monolithic honeycomb structure, and the activator is applied as a washcoat slurry followed by drying.

26. A molecular filter for removal of anions from an aqueous solution, said filter comprising:
• a chemically reactive precipitating agent, in an amount of 50% to 90% by weight, configured to induce precipitation of a target anion upon contact with the aqueous solution;
• a porous or semi-porous substrate, in an amount of 50% to 90% by weight, hosting the chemically reactive precipitating agent;
• a binder, in an amount of 5% to 30% by weight, configured to fix the chemically reactive moiety onto the substrate and enhance the mechanical stability of the filter material;
• a pH adjusting agent in the range of 1% w/v to 5% w/v with pH values ranging from 4 to 10, configured to control or modify the local pH conditions within or around the filter material to optimize the precipitation reaction of the target anion,
o wherein the filter material facilitates selective binding and immobilization of the precipitated anion species, and
o wherein, the filter maintains structural integrity during repeated exposure to aqueous streams.

Dated this 28th day of April, 2025

CHIRAG TANNA
of INK IDÉE
APPLICANT’S PATENT AGENT
REGN. NO. IN/PA – 1785