WO2016092124A1

WO2016092124A1 - Methods used in a computer for selecting absorbent materials for purifying water, and applications thereof

Info

Publication number: WO2016092124A1
Application number: PCT/ES2014/000224
Authority: WO
Inventors: Rocío PÉREZ RECUERDA; Francisco Ignacio Franco Duro; José Pascual Cosp; María Del Carmen Assiego De La Riva; Francisco Alaminos Camacho; Jesús CIFUENTES MELCHOS; Manuel Jesús CASTRO DÍAZ; Mónica BENÍTEZ GUERRERO; María Isabel GONZÁLEZ TRIVIÑO
Original assignee: Universidad De Málaga; Empresa Municial De Aguas De Málaga
Priority date: 2014-12-10
Filing date: 2014-12-23
Publication date: 2016-06-16
Also published as: ES2554278B1; ES2554278A1

Abstract

The invention relates to methods used in a computer for selecting absorbent materials for the treatment or purification of contaminated water, which comprise the steps of (1) selecting the adsorption system, (2) identifying the problem, (3) modelling and processing data, and (4) evaluating and deciding, and which provide an indication of efficiency, in particular of the most efficient absorbent material, and, if appropriate, of the necessary quantity or concentration of said material, and, if appropriate, of the cost-efficiency ratio. The invention also relates to computer systems, computer programs, carrier means and transmittable signals. The invention further relates to the use of said methods, computer systems, computer programs, carrier means or transmittable signals in the treatment or purification of contaminated water.

Description

Methods implemented in computer selection of absorbent materials for water purification, and applications thereof

TECHNICAL SECTOR

The present invention relates to methods implemented in computer selection of absorbent materials for water purification. Also, the invention relates to applications associated with said methods. STATE OF THE TECHNIQUE

Water is a limited and indispensable resource for both humanity and the environment and the life that develops in it. For this reason it is necessary to properly manage this resource, ensuring not only the availability but the quality of these waters. These waters can be contaminated through different pathways that encompass natural and anthropogenic mechanisms with a variety, perhaps excessive, of contaminants. Depending on the amount of pollutant that the waters have, they can be adequately purified for human consumption (drinking water) or reused for other purposes that do not require to reach the demanding conditions that a water must have to be destined for human consumption. It is the laws that mark the maximum concentrations of pollutants that may exist in waters intended for human consumption and in purified wastewater (DIRECTIVE 98/83 / EC).

In general, research efforts have been directed towards the search of materials capable of purifying wastewater, leaving in a subordinate plane the purification of drinking water since the use of active carbon had been considered a method with relative efficiency in the elimination of pollutants in these waters (Scholz and Martin, 1997; Nishijima et al., 1997). However, the use of active carbon presents a series of problems that must be resolved (Simson, 2008). For example, its limitation in the adsorption of inorganic pollutants or its lack of efficacy when the molecules are larger than the pores where the active centers are located, in the case of humic acids, fulvic acids, petroleum, oil emulsions etc. there is a blockage of primary micropores (Pelekani and Snoeyink, 1999; Simson, 2008) dropping their efficiency in the adsorption of smaller molecules. In addition, since active carbon is not miscible in polar media, the adsorption of metals from waters is ineffective.

For this reason, efforts have been made in the investigation of methods of purification of water contaminated with synthesized materials using as starting material the clay minerals, generally, minerals from the smectite group. These minerals have particular crystallochemical characteristics that make them have very interesting absorbent properties from an environmental point of view. The crystalline structure of the smectite group minerals is based on the stacking of sheets formed by three layers. Two of them of tetrahedral nature, in which the Silicon tetrahedra use three of their vertices to polymerize in two directions, and a third layer located between the tetrahedral ones, in which we find Al, Fe, Mg ions octahedrally coordinated by the oxygens of the tetrahedra described above and by OH groups. In each sheet there are two tetrahedral and one octahedral layers. For this reason these sheets are called type 2: 1 sheets. Part of the Si ⁴⁺ of the tetrahedral layers (approximately 1 in 8) are isomorphically substituted by Al ³⁺ , generating an excess of negative charge on the surfaces of the sheets that are compensated with the existence of cations in the space between the sheets (interlaminar space). The existence of these isomorphic substitutions that generate negative charges that have to be compensated, together with the location of OH groups on the surface and the existence of other structural defects provide the minerals of the smectite group with active adsorption centers that are going to confer very good adsorbent properties.

These adsorbent properties have been tried to improve, for example, by reacting these smectites with alkylammonium cations by synthesizing the so-called organo-clays. There is a large amount of literature that describes the synthesis of organo-clays and their applications (Sayed et al., 2003; Oliveira Pereira., 2005; Carmody et al., 2007), especially in the adsorption of organic pollutants. However, organo-clays have serious drawbacks. These derive, in the first place, from the uncontrolled reversibility of the adsorption process and the ease with which the alkylammonium cations of the organo-clays are released, transforming into potential contaminants.

All this problem, leads to investigate the development of compounds that were capable, especially, of purifying water intended for human consumption, efficient in the Elimination of inorganic pollutants that cannot be effectively removed with active carbon, which are also effective in the adsorption of organic pollutants, and which, unlike organo-clays, are chemically stable in a wide range of chemical conditions.

DESCRIPTION OF THE INVENTION

The adsorbent materials object of the invention comprise, as raw material or base, clay minerals, preferably smectite minerals, more preferably dioctahedral smectite minerals (aluminum smectites) and / or trioctrahedral smectite minerals (magnesium smectites), more preferably even minerals of montmorillonite (Mont) and / or saponite (Sap), such forms obtainable from bentonites, with antagonistic crystallochemical characteristics, and whose abundance in nature makes them extremely economical. Bentonites such as those referred to are very common throughout the land area, so, given that transport is one of the factors that make the product more expensive, the design of manufacturing systems should be as economical as possible to implement these systems. manufacturing where water purification is required. Indicate that montmorillonite and saponite themselves must be taken into account as part of the catalog of adsorbent materials given their excellent qualities in water purification.

The methods of production have been designed with the aim of generating a wide catalog of absorbent materials, economical, based on natural minerals (clays) and that are capable of removing contaminants from drinking water. In addition, one of the characteristics that influence the design of the methods of obtaining it is the need to easily scale the synthesis according to the quantities required for each specific problem of purification of water for consumption. In order to, in the first place, to economize the processes and, in the second place, to avoid the saturation of the adsorbent centers, the capacities of cationic change of the starting materials are determined by means of the ammonium acetate method (Sumner and Miller, 1996 ). In this way, unlike the classic synthetic methods in the formation of the PILCS (pillared interlayer clays) published, in the design of the synthesis of the OSML (oxides supported on monoláminas 2: 1 of clays) that are described below, reagents (metal oxides) They are not added in excess, but the quantities added to the reactors are always equal to the equivalents corresponding to the cation exchange capacity calculated for each of the smectites used as starting materials. Another important difference compared to the prior art refers to the fact that said methods of obtaining comprise a stage of delamination, after the stage, where appropriate, of conditioning (preferably by ultrasonic cavitation) that allows generating monolayers of the base or starting material ( clay ores, preferably smectite ores, more preferably dioctahedral smectite ores and / or trioctrahedral smectite ores, more preferably even Mont and / or Sap ores).

Additionally, the invention relates to methods implemented in computer for the selection of absorbent materials for the treatment or purification of contaminated water, particularly for the selection of absorbent materials obtained by the processes for obtaining absorbent materials object of the invention. These methods, based on mathematical modeling, allow the selection of the most efficient and most economical type of material for the adsorption of contaminants present in waters intended for human consumption (heavy metals, organic metals, humic substances and mixtures thereof). These methods contemplate two different systems or scenarios: On the one hand, the stationary system (type of complete mixture), referred to the purification of wastewater in settling rafts in which the adsorbent material that is homogeneously dispersed in the water is added to achieve the removal of the contaminant; on the other hand, a system based on the use of column filters that pass the wastewater through a porous bed, comprising a mixture, of suitable proportions, of sand and an adsorbent material from the catalog of materials described in the section previous.

Next, and in accordance with the foregoing, reference is made to different objects of the invention.

Methods of obtaining the materials constituting the first object of the invention are object of the present invention, said methods comprising an ultrasonic cavitation stage, preferably high energy ultrasonic cavitation, an impregnation stage, preferably direct impregnation, and a stage of calcination); stages that allow the addition of metal oxides to the monolamines, said metal oxides, preferably iron oxides and / or aluminum oxides, providing new adsorption centers on those of the monolamines. Studies have shown that The materials, thus obtained, have yields far superior to active carbon in the elimination of a large number of pollutants and a stability far superior to that of organo-clays.

Also object (second object) of the present invention are absorbent materials for the purification of water obtained by means of the obtaining procedures that constitute the first object of the invention, hereinafter referred to as oxides supported on 2: 1 monolamines of clays (OSML), comprising as base material 2: 1 monoláminas of clay minerals, preferably smectite minerals, more preferably dioctahedral smectite minerals and / or trioctrahedral smectite minerals, more preferably even montmorillonite (Mont) and / or saponite (Sap) minerals . Likewise, said second object extends to the intermediate materials of the obtaining processes that constitute the first object of the invention.

Likewise, methods (third object) of the present invention are methods implemented in computer of selection of absorbent materials for the treatment or purification of contaminated water, particularly of selection of absorbent materials obtained by means of the processes of obtaining absorbent materials object of the invention. Said third object extends to computer systems (for example, communication management platforms); as well as to computer programs or program instructions, more particularly to computer programs in or on carrier means, adapted to implement the methods that constitute said third object of the invention. The computer program may be in the form of source code, object code or an intermediate code between source code and object code, such as partially compiled form, or in any other form suitable for use in the implementation of the methods constituting said third object of the invention. The carrier medium can be any entity or device capable of carrying the program. For example, the carrier medium may comprise a storage medium, such as a ROM, for example a CD ROM or a semiconductor ROM, or a magnetic recording medium, for example a ñoppy disc or a hard disk. In addition, the carrier means can be a transmissible carrier medium such as an electrical or optical signal that can be transmitted via electrical or optical cable or by radio or other means. When the computer program is contained in a signal that can be transmitted directly by means of a cable or other device or medium, the carrier medium may be constituted by said cable or other device or medium. Alternatively, the The carrier means may be an integrated circuit in which the computer program is encapsulated (embedded), said integrated circuit being adapted to perform, or to be used in carrying out the methods constituting said third object of the invention. In accordance with the foregoing, aspects of said third object of the invention are computer systems that implement said methods implemented in computer of selection of absorbent materials, as well as computer programs, storage media readable by computer systems, and transmissible signals capable of making a computer system carry out said methods implemented in computer selection of absorbent materials.

A fourth object of the invention relates to the use of the materials that constitute the second object of the invention, or of the intermediate materials of the obtaining procedures that constitute the first object of the invention, or of the methods implemented in computer selection of absorbent materials constituting the third object of the invention (including aspects of said third object) in the treatment or purification of contaminated water.

Throughout the description and claims the word "comprises" and its variants are not intended to exclude other technical characteristics, components or steps. For those skilled in the art, other objects, advantages and features of the invention will be derived partly from the description and partly from the practice of the invention. The following examples and figures are provided by way of illustration, and are not intended to be limiting of the present invention. Likewise, and in order to avoid alternative interpretations, the concepts "capacity for cationic change" and "monolámitas 2: 1" are discussed and defined as they should be understood in the context of the present invention:

- Cation exchange capacity: the minerals of the smectite group have adsorption centers, in which cations are retained, which are generated either by the isomorphic replacement of elements with different loads or by the presence of structural defects. These cations can be exchanged for others that are in an aqueous solution. The cationic exchange capacity expresses the number of moles of adsorbed positively charged ions that can be exchanged per unit of dry mass of smectite. - 2: 1 monolamines: The crystalline structure of the smectite group minerals is based on the stacking of sheets formed by three layers. In two of these layers the atoms of Si and Al are surrounded by oxygen in a tetrahedral coordination, while in the central layer the atoms of Al, Mg, Fe, etc. are surrounded by oxygen in an octahedral coordination. In this way, the sheets of the smectite group minerals are formed by two tetrahedral layers and an octahedral layer. Hence, they are called 2: 1 sheets to differentiate them from other minerals such as those of the kaolinite group (1: 1) whose structure is based on the stacking of sheets formed by two layers, one octahedral and one tetrahedral. The laboratory studies we have conducted indicate that the application of high-energy ultrasound on a smectite suspension causes the complete disintegration of the stacked packages of smectite sheets. In this way, the material that has dispersed in the water is individual sheets of smectite which we have called 2: 1 monolamines.

DESCRIPTION OF THE FIGURES

Figure 1. Stages of a preferred embodiment of the OSML synthesis process

Figure 2. Adsorption isotherms of the adsorbent materials of the catalog and the active carbon against Ni (II).

Figure 3. Adsorption isotherms of the adsorbent materials of the catalog and the active carbon against As (III).

Figure 4. Adsorption isotherms of the adsorbent materials of the catalog and the active carbon against Cd (I).

Figure 5. FeSML-Mont material rupture curves against water contaminated with Pb and Cu.

Figure 6. Preferred embodiment of the method implemented in computer for the selection of absorbent materials for the purification of contaminated water.

EMBODIMENTS OF THE INVENTION

The constitution and characteristics of the invention will be better understood with the aid of the following description of embodiments, it being understood that the invention does not is limited to these embodiments, but the protection covers all those alternative embodiments that may be included within the content and scope of the claims. Likewise, the present document refers to various documents as prior art, being understood by reference the content of all these documents, as well as the complete content of the documents referred to in said documents, in order to offer a description as possible complete state of the art in which the present invention fits. The terminology used below is intended to describe the examples of embodiments that follow and should not be construed as limiting or restrictive.

The different objects of the invention described above are detailed below, without their order of exposure, or where appropriate their aspects and / or preferred embodiments, necessarily implying that some objects are more important than others. METHODS OF OBTAINING ABSORBENT MATERIALS

The following describes a method of obtaining the preferred type of obtaining the absorbent materials object of the invention, outlined in Figure 1. Step 1.- Ultrasonic cavitation. Dispersion and delamination to monolmina.

In this first stage an ultrasonic system is used, preferably a high energy ultrasonic system, more preferably a high energy ultrasonic system that works continuously at 20kHz and 1000W. By means of ultrasonic cavitation the adequate dispersion of the clay particle packages, preferably smectites, which are naturally aggregated in the starting samples, and in turn the total delamination of the dispersed particles in monolilamines 2: 1 is achieved. In this way, all adsorbent centers are exposed on the external surface. Stage 2.- Impregnation of smectite 2: 1 monolamines with the reactive solutions, After the ultrasonic cavitation of continuous flow, the suspension of the 2: 1 monolamines of smectites is introduced into reactors, preferably cylindrical conical-based reactors (to favor the collection of materials), more preferably reactors made of an economic material that, in addition it must be inert in the chemical conditions in which the different reactions are to be carried out and must allow, directly, scaling depending on the amount of material to be synthesized.

Once the 2: 1 suspension of clays, particularly smectites, monolilamines is introduced into the reactor, exactly the amount of reagent equivalent to the cationic exchange capacity of the starting material is added. The following section describes how reactive solutions are generated to obtain the different absorbent materials.

The resulting aqueous suspension is kept under stirring in the reactors, preferably for 24 hours, more preferably with the aid of a 0.5 hp agitator with a 600 rpm output speed reducer and with a rod and propeller made of a material resistant to the physical-chemical conditions in which the impregnation takes place.

Stage 3.- Decantation and washing

After impregnating the 2: 1 monollamines with the reactive solutions, stirring is stopped and the solid obtained is allowed to decant to the bottom of the reactor. Then, the liquid remaining on the solid deposited in the bottom is removed, for example by means of a suction pump, and a volume of distilled water determined according to the amount by weight of the starting clay mineral is added, particularly 30 L of water distilled by Kg of the starting clay ore in the case of the bentonites referred to above, Mont yy Sap.

The same agitator can be used for the washing process at a suitable speed, particularly at 125 rpm in the preferred embodiment described in this section. After a period of stirring, 4 h in the preferred embodiment described in this section, it is left to decant for a suitable time, preferably for 20 h, the liquid remaining on the deposited solid is removed and this process is repeated until the wash water has a suitable conductivity, preferably less than 10 μ8 / αη. Stage 4.- Drying and calcination

The material obtained from the previous stages is a mixed suspension of the 2: 1 monollamines impregnated with the reactive material and a large amount of water. This suspension must be dried in its entirety, for example with the help of a dryer by thermal convection transmission (at 70 ° C in a preferred embodiment; stationary or continuous, depending on the quantity to be manufactured) and allowing the samples to be dried homogeneously in the entrance of a furnace in which the impregnated sheets will be calcined to anchor the reagents on the surface and transform them into new absorbent active centers. Ovens will be used for this.

Stage 5.- Grinding

After the drying and calcination step, the materials are ground, for example in industrial ball mills, preferably inside cylinders (of sizes depending on the amount of material to be ground) with steel spheres (preferably> 10 mm in diameter ) that rotate at constant speed, for example with the help of rollers, until the dispersed particles are obtained. It is important to keep track of the grinding process since excessive grinding leads to the amorphousization of the material and the formation of hard aggregates that would nullify the adsorbent properties of the synthesized materials. The size of this ball mill will be, where appropriate, directly scalable to the amount of material to be manufactured.

Preparation of reactive solutions for the manufacture of absorbent materials

1.- Materials FeSML-Mont, FeSML-Sap: The reactive solutions consist of aqueous solutions of FeCl ₃ -6H ₂ 0 with the amount of equivalents that mark the cationic exchange capacities of smectites that are used as raw material. 2.- Materials FeOSML-Mont, FeOSML-Sap: To prepare the precursor solution it is necessary to prepare two solutions containing the amounts of FeCl ₃ -6H ₂ 0, on the one hand (solution

A), and NaOH, on the other (solution B), equivalent to the cationic exchange capacities of the starting smectites (Mont and Sap). It is then poured, at room temperature and very slowly (Q = l / 12 L / h), the solution B on the solution of A. For this mixing process a continuous and dynamic pH control is required by means of a pump and a pH sensor immersed in the solution A, so that its pH never exceeds 1.75. To ensure that the pH never exceeds that value, the pH pump controls the flow of a solution of HC1 in distilled water (500 ml of H ₂ 0 dest and 100 ml of HC1 at 37%).

3. - Materials AlOSML-Mont, AlOSML-Sap: In this case, Aluminum Polychloride (17% A1 ₂ 0 ₃ ) diluted in distilled water in a 1: 30 volume ratio will be used as a reagent.

4. - (Fe-Al mixed oxides supported in smectite monolilamines) Materials Fe-Al-OSML- Mont, Fe-Al-OSML-Sap: In this case the reactive solutions will be mixtures of suitable proportions of the solutions described in the cases 2 and 3. ABSORBENT MATERIALS

In order to be able to select the best adsorbent material for the removal of contaminants from the water intended for consumption, adsorption isotherms were determined for the different synthesized adsorbent materials, as well as the starting materials (Mont and Sap) and an active carbon commercial. These isotherms that describe the performance of these materials in the adsorption of contaminants. Although the isotherms obtained in the case of the removal of Ni (II), As (III) and Cd (II) are presented as an example, adsorption isotherms at 25 ° C have been determined for a large number of contaminants.

The isotherms (Figures 2, 3 and 4) represent, once equilibrium is reached, the amount in mg of contaminant adsorbed per g of adsorbent material (q _e ), compared to the concentration of contaminant that remains unbound expressed in mg / L (C _e ). In these graphs a greater slope implies a greater yield of the materials in the adsorption of the contaminants.

In the case of the selected examples, the synthesized materials have adsorbent properties markedly superior to those of active carbon. In addition, it can be checked first, that the performance of adsorbent materials depends of the type of pollutant, and secondly, that for each type of pollutant there is a suitable adsorbent.

These adsorption isotherms, together with the economic cost of the synthesis of said materials, are important variables for the selection of the optimum adsorbent material and suitable for the purification of a contaminated water.

Numerous experiments have been carried out to eliminate contaminants in water by passing them through filter columns with porous beds formed by different mixtures of an inert material (silica sand) and the adsorbent materials object of the invention. These analyzes allow to determine the maximum adsorption capacities, for each pollutant, of the columns manufactured with these materials, and in turn, adjust the characteristics of the filter column to the total volume of contaminated water and the final concentration of contaminants desired in the purified water. The rupture curves represent the evolution of the concentration of pollutants in the purified water with respect to their initial concentration (C / Co) with respect to the eluted volume (L). In Figure 5, the rupture curves of the FeSML-Mont material in the adsorption of Cu (II) and Pb (II) are shown by way of example. This figure shows notable differences in the adsorbent capacity of this material in the porous bed against these contaminants.

METHODS IMPLEMENTED IN COMPUTER SELECTION OF ABSORBENT MATERIALS

In a typical, preferred embodiment, said methods implemented in computer of selection of absorbent materials comprise the following steps: 1. Choice of adsorption system.

2. Identification of the problem (type of contaminant, initial concentration, desired final concentration, type of water and volume / flow to be treated).

3. Modeling through the use of different mathematical models and data processing for the choice of one that presents a better fit.

4. Evaluation and decision at the level of the different absorbent materials available, providing information on the efficiency and, where appropriate, the concentration and / or quantity that would be used for each of them, particularly indicating which it would be the most efficient absorbent material and the amount or concentration thereof that would allow the adsorption process to be the most efficient and, where appropriate, entail the lowest possible economic cost. In a preferred embodiment, and in the case of stationary systems, the method implemented in computer of selection of absorbent materials is based on mathematical modeling by adsorption isotherms that relate the amount of contaminant absorbed by the material against the amount of contaminant which remains untained once equilibrium is reached, particularly the amount in mg of contaminant absorbed per g of adsorbent material (qe) versus that of contaminant that remains untapped expressed in mg / L (Ce) once equilibrium is reached. For this, biparametric equations such as Langmuir, Freundlich, Dubinin-Radushkevich, Temkin, Brunauer-Emmet-Teller, Sips and Toth are used. This allows to select the adsorbent material, with greater performance in relation to the economic cost of manufacturing. Likewise, it allows to determine the necessary amount of the selected adsorbent to completely purify the water or only limit its concentration to the value set by the regulations of the countries where these purifications are to be carried out.

In a preferred embodiment, and in the case of column filter systems, the method implemented in computer of selection of absorbent materials manages information about some of the variables that control the design of the filtering columns, such as material selection with higher yield, amount of adsorbent and adsorbent / sand ratio of the porous bed depending on the concentration of pollutant, the flow rate and the total volume of water to be purified, and finally the diameter and height of the column. For the mathematical modeling of column filter purification systems, column adsorption models such as Thomas, Yoon-Nelson, Adams-Bohart (BDST), Wang and Wolborska-Pustelnik are used.

In order to perform all the described functions, the method implemented in computer of selection of absorbent materials includes access by computer means to an updateable database related to the type of clay, pollutant and water, adsorption balance and economic cost of synthesis of the different adsorbents. The scheme of the operation of the computer program is described in Figure 6.

In more detail: The step of choosing the adsorption system allows the user of the method implemented in the computer of selection of absorbent materials to choose the appropriate adsorption system, particularly choosing between a column filter system and a stationary system.

The problem identification stage allows the user to define or identify the type of pollutant, its initial or incoming concentration, its desired final or exit concentration, the type of water to be treated or treated, and the volume and flow of said water to Debug or treat.

In the event that the water to be treated or treated contains more than one contaminant for which it is desired to apply the method implemented in computer of selection of absorbent materials, said step of identification of the problem, as well as the subsequent stages, must be repeated or performed for each of these pollutants.

In the case that the selected adsorption system is the column filter system:

o Once the problem identification stage has been completed, to be carried out for each contaminant for which the method implemented in the computer for the selection of absorbent materials is applied, the expected result is modeled, based on the parameters and variables defined in the step of identifying the problem, of the use of each available absorbent material based on the experimental data, and / or, where appropriate, theoretical, available in relation to each available absorbent material as well as each contaminant, said experimental data, and / or, where appropriate, theorists, stored in a database. The maternal models implemented are column adsorption models such as Thomas, Yoon-Nelson, Adams-Bohart (BDST), Wang and Wolborska-Pustelnik.

In the case that the adsorption system selected is the stationary system:

o Once the problem identification stage has been completed, to be carried out for each contaminant for which the method is to be applied implemented in computer of selection of absorbent materials, we proceed to model the expected result, based on the parameters and variables defined in the problem identification stage, of the use of each available absorbent material based on experimental data, and / or, where appropriate, theoretical, available in relation to each available absorbent material as well as to each contaminant, said experimental data, and / or, where appropriate, theoretical, stored in a database. The modeling is based on the mathematical modeling by adsorption isotherms that relate the amount of contaminant absorbed by the material to the amount of contaminant that remains without retaining once equilibrium is reached, using biparametric equations such as Langmuir, Freundlich, Dubinin-Radushkevich, Temkin, Brunauer- Emmet-Teller, Sips and Toth.

The result of the different modeling and graphic adjustments is statistically analyzed, particularly by means of the chi2 statistical test, generating a list of the different absorbent materials available indicative of the efficiency of each absorbent material in relation to the problem identified and the adsorption system chosen. Said list may also contain indication of the concentration, or particularly of the amount (depending on the parameters defined in the problem identification stage), of absorbent material to be used to purify or treat the water defined in the problem identification stage. and obtain, depending on the rest of the parameters and variables defined in said problem identification stage, the desired final or exit concentration of the contaminant for which it is desired to apply the method implemented in computer of selection of absorbent materials. Additionally, the list of absorbent materials may in turn contain an indication of the economic cost associated with the amount of each available absorbent material, so that the list may be indicative of the efficiency / cost ratio of the available absorbent materials. The method implemented in computer of selection of absorbent materials can allow, in relation to the information related to economic costs, the definition and / or update of the parameters and variables determinants of said economic costs, such as the acquisition or acquisition price of the absorbent material (including base or starting material and, where appropriate, reagents), economic cost associated with its transportation, electricity cost associated with its acquisition and / or use, etc. Based on the foregoing, the evaluation and decision stage provides an indication of the efficiency in relation to all available absorbent materials, particularly the most efficient absorbent material and, where appropriate, an indication of the concentration or necessary amount of said absorbent material, and, where appropriate, the height of the bed to be used (depending on the amount of absorbent material), as well as, where appropriate, indication of the efficiency / cost ratio.

The method implemented in computer of selection of absorbent materials object of the invention can be implemented in a computer system, said computer system comprising for said implementation (a) a configuration module, (b) a processing module, (c) a module of storage, and (d) a decision module. Particularly said computer system is characterized by:

(a) the configuration module is responsible for the execution of the stages of choosing the adsorption system and identifying the problem as well as, where appropriate, allowing the definition and / or updating of the parameters and variables that determine the economic costs associated to the quantities to be used of the different absorbent materials available, particularly of the economic costs associated to the quantity to be used of the absorbent material that would allow the adsorption process to be the most efficient;

(b) the processing module is responsible for the execution of the modeling and data processing stage;

(c) the storage module comprises a database that is accessed by computer means and comprises experimental, and / or, where appropriate, theoretical data, available in relation to each available absorbent material as well as each contaminant; Y

(d) the decision module is responsible for the execution of the evaluation and decision stage. Some examples of the use of a preferred embodiment of the method implemented in the computer for the selection of absorbent materials are described below.

For a stationary system

Case 1: Given an initial As (III) concentration of 30 ppb, an output concentration of 10 ppb (maximum limit established by state regulations) in a stationary system is desired.

The method implemented in computer of selection of absorbent materials adjusts the data previously implemented in the database to the different isotherms and determines which of them has less chi2 for each clay studied and the necessary amount of these:

Incorporating the economic cost of the different adsorbents, the software selects the one that is most efficient, in this case FeSML-Mont, and the necessary amount would be 0.066 g / 1. Experimentally it can be verified that for a quantity of clay of 0.06 g / 1 and starting from 30 ppb of contaminant, the final concentration obtained by means of a stationary system turns out to be 10,146 ppb, thus validating the software. Case 2: To reduce a Ni (II) contamination from 100 ppb to 20 ppb, 0.028 g / 1 of FeOSML-Mont clay would be needed. Case 3: For a contamination of Pb (II), from 100 ppb to 10 ppb, 0.0166 g / 1 of FeSML-Mont clay would be needed.

Case 4: For a contamination of Cd (II), from 65 ppb to 5 ppb, 0.0302 g / 1 of FeSML-Mont clay would be needed.

Case 5: For a contamination of Cr (III), from 80 ppb to 50 ppb, 0.0018 g / 1 of Saponite would be needed. For a column filter system

Case 6: To treat a flow rate of 30 L / min of 50 ppb of Cu (II) and obtain a treated volume of 2000 L with 2 ppb of Cu (II), a bed with a 1000: 1 ratio of sand will be required: FeSML-Mont clay, intimately mixed, with a total height of 1.75 m, corresponding to one or several columns of 22 cm in diameter.

Case 7: A bed with a 1000: 1 sand ratio will be required: FeSML-Sap clay of 1.7 m total height and 21 cm in diameter to treat 15 L / min of 100 ppb of Cu (II) and obtain a treated volume 10000 L with 10 ppb of Cu (II).

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Claims

Method implemented in computer for the selection of absorbent materials for purification or treatment of water comprising (1) a step of choosing the adsorption system; (2) a stage of identification of the problem in which parameters and variables characterizing the problem are defined; (3) a modeling and data processing stage based on both the parameters and variables defined in the problem identification stage, as well as the experimental data, and / or, where appropriate, theoretical, available in relation to each absorbent material available as per each contaminant; and (4) an evaluation and decision stage that provides information on the efficiency of each of them, particularly indicating which would be the absorbent material that would allow the adsorption process to be the most efficient.

Method implemented in computer for the selection of absorbent materials for purification or water treatment according to the preceding claim, characterized in that the step of choosing the absorption system allows choosing between a column filter system and a stationary system.

Method implemented in computer of selection of absorbent materials for purification or water treatment according to any of the previous claims characterized in that the parameters and variables that are defined in the stage of identification of the problem comprise the type of pollutant, its initial concentration or input, its desired final or exit concentration, the type of water to be purified or treated, and the volume and flow of said water to be purified or treated.

Method implemented in computer of selection of absorbent materials for purification or water treatment according to any of the preceding claims characterized in that the modeling and data processing stage comprises the modeling of the expected result, depending on the parameters and variables defined in the stage of identification of the problem, of the use of each absorbent material available based on experimental data, and / or, where appropriate, theoretical, available in relation to each available absorbent material as well as to each contaminant, said experimental data, and / or, where appropriate, theoretical, stored in a database.

Method implemented in computer for the selection of absorbent materials for purification or water treatment according to claim 4, characterized in that the mathematical models implemented during the modeling and data processing stage are column adsorption models such as Thomas, Yoon-Nelson type , Adams-Bohart (BDST), Wang and Wolborska-Pustelnik.

Method implemented in computer for the selection of absorbent materials for purification or water treatment according to claim 4, characterized in that the modeling and data processing step comprises the mathematical modeling by adsorption isotherms that relate the amount of contaminant absorbed by the material in front of to the amount of contaminant that remains without retaining once equilibrium is reached, using biparameter equations such as Langmuir, Freundlich, Dubinin-Radushkevich, Temkin, Brunauer-Emmet-Teller, Sips and Toth.

Method implemented in computer of selection of absorbent materials for purification or treatment of water according to any of the previous claims characterized in that the stage of evaluation and decision at the level of the different absorbent materials available comprises the statistical analysis of the results of the modeling stage and data processing, providing information indicative of the efficiency of each of the available absorbent materials, particularly indicative of which is the absorbent material that would allow the adsorption process to be the most efficient.

Method implemented in computer of selection of absorbent materials for purification or treatment of water according to any of the previous claims characterized in that the stage of evaluation and decision at the level of the different absorbent materials available also provides information on the concentration and / or quantity which would be used for each of them, particularly indicating which would be the amount and / or concentration to be used of the absorbent material that would allow the adsorption process to be the most efficient.

9. A method implemented in a computer for selecting absorbent materials for purification or water treatment according to claim 8, characterized in that the evaluation and decision stage at the level of the different absorbent materials available also provides information on the economic cost associated with the amount that would be used of each of them, particularly indicating what would be the economic cost associated with the amount to be used of the absorbent material that would allow the adsorption process to be the most efficient.

10. Method implemented in computer of selection of absorbent materials for purification or treatment of water according to the previous reindication 9 characterized in that, to provide information of the economic cost associated with the amount that would be used of each of them, particularly of the associated economic cost to the quantity to be used of the absorbent material that would allow the adsorption process to be the most efficient, during the evaluation and decision stage at the level of the different absorbent materials available, the method comprises the definition and / or updating of the parameters and variables determinants of said economic costs, such as the acquisition or acquisition price of the absorbent material, economic cost associated with its transportation, or the cost of electricity associated with its acquisition and / or use.

11. A method implemented in a computer for the selection of absorbent materials for water purification or treatment according to any of the preceding claims 8 to 10, characterized in that the evaluation and decision stage at the level of the different absorbent materials available also provides information bed height to use.

12. Method implemented in computer for the selection of absorbent materials for purification or water treatment according to any of the preceding claims 1 to

11 characterized in that, in the case that the water to be purified or treated contains more than one contaminant for which it is desired to apply the method implemented in a computer selection of absorbent materials, the problem identification stage, as well as the subsequent stages, must be repeated or performed for each of said contaminants.

13. Computer system for the selection of absorbent materials for purification or water treatment characterized in that it implements a method according to any of claims 1 to 12 and for this it comprises (a) a configuration module, (b) a processing module , (c) a storage module, and (d) a decision module.

14. Computer system according to the preceding claim characterized in that

(e) the configuration module is responsible for the execution of the stages of choosing the adsorption system and identifying the problem as well as, where appropriate, allowing the definition and / or updating of the parameters and variables that determine the economic costs associated to the quantities to be used of the different absorbent materials available, particularly of the economic costs associated to the quantity to be used of the absorbent material that would allow the adsorption process to be the most efficient;

(f) the processing module is responsible for the execution of the modeling and data processing stage;

(g) the storage module comprises a database that is accessed by computer means and comprises experimental, and / or, where appropriate, theoretical data, available in relation to each available absorbent material as well as each contaminant; Y

(h) the decision module is responsible for the equation of the evaluation and decision stage.

15. Computer program comprising program instructions capable of having a computer system carry out a method according to any one of claims 1 to 12.

16. Storage medium readable by a computer system comprising program instructions capable of having a computer system carry out a method according to any of claims 1 to 12. 17. Transferable signal comprising program instructions capable of making A computer system carries out a method according to any of claims 1 to 12.

18. Method of purification or treatment of water comprising a stage of selection of the absorbent material to be used in purification or treatment of water, said stage of selection comprising the realization of a method implemented in computer of selection of absorbent materials according to any of the claims 1 to 12. 19. Method of purification or treatment of water comprising a stage of selection of the absorbent material to be used in purification or treatment of water, said step of selection comprising the use of a computer system for the selection of absorbent materials for water purification or treatment according to any of claims 13 to 14.

20. Water purification or treatment process comprising a step of selecting the absorbent material to be used in water purification or treatment, said selection step comprising the use of a computer program comprising program instructions capable of making a computer system Carry out a method according to any of claims 1 to 12.

21. Water purification or treatment process comprising a step of selecting the absorbent material to be used in water purification or treatment, said selection step comprising the use of a storage medium readable by a computer system comprising program instructions capable of having a computer system carry out a method according to any one of claims 1 to 12.

22. Water purification or treatment process comprising a step of selecting the absorbent material to be used in water purification or treatment, said selection step comprising the use of a transmissible signal comprising program instructions capable of making a computer system Carry out a method according to any of claims 1 to 12.