BE1022987B1 - METHOD FOR REMOVING ORGANIC POLLUTANTS FROM WATER - Google Patents

Abstract

The invention describes a method for removing organic impurities from water comprising - contacting water, comprising organic impurities, with thermoplastic elastomer and applying a force field and / or mechanical force to the thermoplastic elastomer while in contact. is with the water; - separating the water, with reduced concentration of organic pollutants, from the thermoplastic elastomer.

Description

METHOD FOR REMOVING ORGANIC POLLUTANTS FROM WATER.

Domain of the invention.

The invention relates to a method for removing organic contaminants from water.

State of the art.

The over-exploitation of natural resources and the widespread use of chemicals have led to the accumulation of contaminants in our environment. Air, soil and water pollution have received increasing attention in recent decades because of their adverse effects on ecosystems and on human and animal health.

Substantial volumes of organic liquids used worldwide in the form of fuel, lubricants, chemicals, solvents, pesticides, insecticides, etc. pollute our planet and cause disturbing levels of pollution.

The increasing worldwide transport of oil makes oil leaks and oil spills an increasingly bigger problem, not only from an economic point of view but also because of the ecological impact of the oil or of the products used to clean up the oil.

The phytotoxicity of a number of chemicals is an acute threat to, among others, the marine fauna.

Recent studies have shown the presence of small amounts of hormones and endocrine disrupting substances, pharmaceuticals and products intended for personal care in surface waters, wastewater and drinking water.

The hormone disrupting substances, which mimic the feminising effects of the female (estrogen) sex hormones, are of great interest. Synthetic estrogens are primarily present in contraceptives and in hormonal replacement therapy preparations. Synthetic estrogens are more stable than natural estrogens, do not biodegrade naturally and therefore end up in the environment.

Various methods are known for treating contaminated water, including mechanical methods such as natural flotation, forced flotation, filtration, centrifugal gravitation separation; electromagnetic methods such as ultrasonic, electrolytic and separation methods based on electrophoresis; other physical or chemical methods such as those based on adsorption, absorption, ion exchange and coagulation as well as biological separation methods using micro-organisms.

The conventional treatment methods for purifying contaminated water have already been described in the technical and patent literature.

US 3,518,183 describes a process for removing oil films from the contaminated water surface wherein finely divided block copolymer is applied to the oil film after which the oil-impregnated block copolymer is removed from the water. The block copolymer is a copolymer of monovinyl arenes and conjugated dienes consisting of at least two non-elastomeric monovinyl arene polymer blocks separated by a conjugated diene block.

US 4,801,386 describes a method for removing organic and / or inorganic components from water using porous material comprising strands consisting of a mixture of a thermoplastic material and an inorganic component such as, for example, barium sulfate, talc or silica. . The thermoplastic material is a homo- or copolymer of ethylene, propylene, styrene, butadiene, isoprene, vinyl chloride, vinyl acetate and acrylonitrile.

US 4,941,978 describes a method for removing oil contamination from water in which an elastomer consisting of a styrene-ethylene / butylene di-block or tri-block copolymer containing 20 to 40 percent styrene is added to the contaminated water .

US 6,541,569 describes an absorbent polymeric material consisting of a mixture of a block copolymer and a copolymer wherein the block copolymer is selected from the group consisting of styrene-butadiene-styrene, styrene-butadiene and styrene-isoprene-styrene and wherein the copolymer is an ethylene-propylene copolymer. The specific polymeric material is used to isolate hydrocarbon-like impurities from water.

US 7,297,267 describes an oil-absorbing filter element consisting of a first part comprising a unitary permeable medium of a first oleophilic polymeric material and a second part comprising particles of a second oleophilic polymer. Both oleophilic polymers are thermoplastic elastomers selected from the group consisting of styrene-ethylene / butylene-styrene, styrene-ethylene / propylene-styrene, styrene-butadiene-2 styrene and styrene-isoprene-styrene block copolymers and combinations thereof. The filter element allows oil, hydrocarbons, solvents and other contaminants to be isolated from a contaminated water stream.

US 6,582,608 describes a method for removing organic contaminants from liquids wherein the contaminated liquids are contacted with dimensionally stable particles of a polymer blend consisting of 55 to 95 percent by weight of a thermoplastic elastomer, from 5 to 45 percent by weight of a thermoplastic polymer and from 0 to 12 weight percent of a filler. The thermoplastic elastomer is selected from the group consisting of polystyrene-butadiene copolymers, polystyrene-butadiene-polystyrene tri-block copolymers, polystyrene-isoprene-polystyrene tri-block copolymers and polystyrene grafts of thermoplastic polymers. The thermoplastic polymer is a polystyrene, a polyolefin or mixtures thereof.

WO 82/02342 describes a process for removing at least one hydrocarbon composition from a mixture comprising this hydrocarbon composition wherein the mixture is contacted with at least one elastomer under conditions that make the elastomer at least a part of the hydrocarbon composition to record. The mixture can be a water / hydrocarbon mixture. An embodiment of the invention is the removal of hydrocarbons from water such as, for example, waste water. The elastomer is natural, recycled, vulcanized or synthetic rubber. Examples of synthetic elastomers are styrene-butadiene rubber, butyl rubber, nitrile rubber, ethylene-propylene copolymers, fluoroelastomers and polyacrylates.

The use of ultrasonic vibration energy for waste water treatment is known.

US 3,537,655 describes a method for treating waste water such as, for example, sewage water by mechanically grinding solid particles present in the waste water, and then further fractionating the resulting particles and partially sterilizing the waste water under the influence of ultrasonic vibration energy.

WO 2013/043046 relates to an ultrasonic separator for separating mud particles from a liquid wherein a liquid channel, provided with an inlet and an outlet, contains one or more probes to obtain a three-dimensional structure of nodes which catches particles and as such separates them from the liquid.

US 4,961,860 describes a method for destroying dangerous microorganisms in water wherein the water is separated in a waste water tank and subsequently subjected to ultrasonic vibrations with a frequency understood between 15 and 150 kHz for a period of minimum 12 seconds. The ultrasonic vibrations come from a plurality of probes mounted on one or more arms, turning around in the recovery tank.

Methods for removing small amounts of hormones and endocrine disruptors (endocrine disruptors) have already been described.

US 2007/0209999 describes a waste water treatment system that comprises a bioreactor which comprises a bacterial population and an adsorbent, in particular powdered activated carbon. The examples in this application illustrate the removal of endocrine disruptors.

EP 1857541 B1 describes estrogen-degrading microorganisms and a method for degrading these estrogenic substances in domestic wastewater and wastewater from livestock farms.

The removal of estrogenic substances from sewage water using cyclodextrin polymers is described by Kyoko Oishi and Ayumi Moriuchi in Science of The Total Environment, Volume 409, Volume 1, December 1, 2010, Pag. 112-115 ”WO 2008/039360 describes a method for destroying pharmaceuticals and products intended for personal care, such as estrogenic substances, antibiotics and other, in aqueous solutions using ultrasonic vibrations.

US 7,491,339 discloses a method for the destruction of harmful substances in water by irradiation with ultra-violet light using titanium dioxide photocatalysis. This method has been shown to efficiently destroy β-estradiol, present in low concentrations in drinking water and domestic water.

The characterization of MIP (molecularly imprinted polymer) and NIP (nonimprinted polymer) submicron particles developed for removing 17β-estradiol from water is described by Edward P.C. Lai, Zackery The Malekiand Shuyi Wu in "Journal of Applied Polymer Science, Volume 116, Volume 3, May 5, 2010, p. 1499-1508 '.

A method and an apparatus for removing organotin components such as tributyltin from a water / sediment mixture is described in DE 19952 558. Herein the mixture is heated to a temperature of 240 ° C under elevated pressure, using a steam therapy. The method leads to the destruction of the organotin components.

Object of the invention.

The various methods as already described exhibit a number of limitations or disadvantages with regard to purification capacity, economic aspects, scaling up, the regeneration of the materials used and the resulting waste.

The main purpose of this invention is to provide a method that is not subject to the limitations or disadvantages of the existing methods.

The object of this invention is to provide an economically attractive method for removing organic contaminants from water, which is characterized by a high purifying capacity, whereby various contaminants can be removed at the same time and the material used in this method on an efficient way can be regenerated.

Main features of the invention.

The invention relates to a method as described in the appended claims.

The invention uncovers a new method for removing organic impurities from water, wherein organic impurities are understood to mean hydrocarbons, mineral oils, organometals and products which comprise a steroid skeleton or skeleton derived therefrom.

The method is based on contacting the contaminated water with a thermoplastic elastomer, preferably a block copolymer, preferably containing styrene-based hard sequences, the thermoplastic elastomer being in contact with the contaminated water, is subjected to a mechanical force and / or a force field. The application of the force and / or the force field results in an improvement in the extraction of the contamination from the water and its storage in the elastomer, compared to a treatment in which no force (field) is applied. The force field is preferably an ultrasonic force field. The mechanical force may be that particles of the elastomer are compressed or otherwise elastically or plastically deformed.

In an additional subsequent step, the thermoplastic elastomer containing the impurities can be stripped of these impurities, for example via an extraction process, by steam treatment or by treatment with hot air, after which the purified thermoplastic elastomer can be reused in the water purification process .

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a method for removing organic contaminants from water wherein a thermoplastic elastomer is contacted with the contaminated water.

In the context of the present invention, contaminated water is preferably understood to mean contaminated surface water, drinking water, domestic and industrial waste water and effluents and / or influents from water purification stations where the concentration of organic pollution is 50 g / l or lower, preferably 10 g / l or lower, preferably 1 g / l or lower, preferably 500 mg / l or lower, preferably 100 mg / l or lower, preferably 1 mg / l or lower, preferably 500 μg / l or lower, preferably 100 μg / l or lower, preferably 1 μg / l or lower, preferably 500 ng / l or lower, preferably 100 ng / l, preferably 10 ng / l or lower or even 1ng / l or lower.

Preferably, the concentration of organic impurity is at least 1 pg / l, preferably at least 10 pg / l, preferably at least 100 pg / l, preferably at least 1 ng / l, preferably at least 10 ng / l, preferably at least 100 ng / l, preferably at least 1 μg / l, preferably at least 10 μg / l, preferably at least 100 μg / l, preferably at least 1 mg / l, at preferably at least 10 mg / l, preferably at least 100 mg / l, preferably at least 1 g / 10, preferably at least 10 g / l.

By organic impurities, the present invention means hydrocarbons, mineral oils, organometallic compounds, and natural or synthetic substances that comprise a steroid skeleton or skeleton derived therefrom.

By mineral oil, the present invention means paraffin oils, naphthen oils, and aromatic oils, including C10 -C60, preferably C10 -C40 n-alkanes, cycloalkanes, and aromatic alkanes.

Specific examples of mineral oils which can be separated from contaminated water using the present invention can be found, inter alia, as crude oil, fuel as used for marine engines, kerosene, gasoline, fuel oil, gas oil, hydraulic oil, lubricant and coolant.

With hydrocarbons, the present invention means C1 - C60, preferably C4 - C50, more preferably C6 - C40 saturated and unsaturated aliphatic hydrocarbons and aromatic hydrocarbons containing one or more oxygen, nitrogen, sulfur, phosphorus ato (o) m and / or keto, aldehyde, ester amide function (s) in the hydrocarbon backbone and / or which may include one or more substituents containing halogen, sulfur, oxygen, phosphorus and nitrogen .

Specific examples of hydrocarbons that can be separated from contaminated water using the present invention are benzene, toluene, ethylbenzene, xylene, naphthalene, anthracene, phenols, nitrophenols, halogenated benzenoid structures which include insecticides and pesticides.

The method of the present invention is preferably applicable for the removal of aromatic compounds such as benzene, toluene, ethylbenzene and xylene and of aliphatic compounds such as hexane, decane and their isomers, from contaminated water.

By organometallic compounds, the present invention means organoaluminum compounds such as diethylaluminum chloride, diisobutylaluminum hydride, ethylaluminum sesquichloride, triethylaluminum and trimethylaluminum, organogermanium compounds such as germanabenzene and tetraethylgermanium, mercury, mercury, mercury, ethyl acetate, dimethyl mercury, mercuric, mercuric, mercury , methylmercury and thiomersal, organolithium compounds such as n-butyllithium, s-butyllithium, tert-butyllithium, phenyllithium, n-hexyllithium, methyl lithium and propynyllithium, organo-lead compounds such as tetraethyl lead and tetramethyl lead, organomagnesium compounds such as allylmagnesium bromide, phenylmagnesium alopromagnesium alumium magnesium mercury such as tris (dibenzylidene acetone) dipalladium (0), organotin compounds such as azocyclotin, dibutyltin oxide, stannabenzene, tributyltin chloride and tributyltin hydride, organozinc compounds such as dimethyl zinc.

A specific example of an organometallic compound which can be separated from contaminated water using the present invention is tributyl tin hydroxide, tributyl tin chloride and tributyl tin oxide.

By natural or synthetic substances which comprise a steroid skeleton or skeleton derived therefrom, the present invention means substances which comprise a 2,3,4,5,6,7,8,9,10,11,12,13,14, 15,16,17-hexadecahydro-1 H-cyclopenta [a] phenanthrene backbone or a backbone derived therefrom which may comprise one or more unsaturated double bonds, which may contain 1 or more methyl, hydroxyl, aldehyde, amine, amide (-NH-CO-R), or oxygen (O = to form a keto function or -O- to form an oxirane structure) may comprise substituents and which specifically comprises in position 17 substituents selected from the group consisting of hydrogen, hydroxyl, oxygen, a hydrocarbon substituent comprising between 1 and 10 carbon atoms, which may comprise 1 or more unsaturated bonds and / or 1 or more heteroatoms and which may form a bond with position 16 and an aromatic substituent that is between 1 and 10 carbon atoms and which has 1 or more heteroatoms and / or or substituents.

The steroidal substances in the context of the present invention include the group consisting of secosteroids, norsteroids and homosteroids and include natural or synthetic hormones which include glucocorticoids, mineralocorticoids, androgens, estrogens, progestogens and vitamin D.

The natural or synthetic substances comprising a steroid skeleton BE2 derived therefrom, specifically meant in the present invention, preferably comprise a 2,3,4,5,6,7,8,9,10,11,12,13 , 14,15,16,17-hexadecahydro-1 H -cyclopenta [a] phenanthrene backbone comprising one or more unsaturated double bonds, one or more methyl substituents, one or more hydroxyl groups, and in position 17 comprising substituents selected from the group consisting of hydrogen, hydroxyl, oxygen (O =, to form a keto function), a C 1 -C 10 saturated hydrocarbon substituent, a C 1 -C 10 unsaturated hydrocarbon substituent comprising 1 or more double and / or triple bonds, and a heteroaromatic.

Specific examples are modified steroids such as, for example, cholesterol, for example, present in cosmetics and personal care products, abiraterone, an anti-androgen, and endocrine disrupting substances, such as estrogens including estriol, estradiol, estrone and ethinyl estradiol.

In one embodiment, the thermoplastic elastomer employed in the present invention is a block copolymer, preferably a tri-block copolymer consisting of hard and soft sequences, the hard sequences being obtained by polymerization of monovinylarene and the soft sequences being obtained by polymerization of alkylenes or by copolymerization of alkylenes and monovinylarene.

In case the alkylene is a conjugated diene, an unsaturated thermoplastic elastomer is obtained; for the case that the alkylene is a monoolefin, a saturated thermoplastic elastomer is obtained.

The monovinylarene is preferably selected from the group consisting of styrene, α-methyl styrene and vinyl toluene. The monovinylarene is preferably styrene.

The alkylene is preferably selected from the group consisting of ethylene, propylene, butylene, isobutylene, pentene, hexene, octene, butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, piperylene, 3-butyl 1,3-octadiene and phenyl-1,3-butadiene. The alkylene is preferably butadiene, isoprene, to form an unsaturated thermoplastic elastomer, and ethylene, propylene, and butylene to form a saturated thermoplastic elastomer.

The block copolymers to be used in the process according to the present invention are preferably selected from the group consisting of styrene-butadiene-styrene, styrene-isoprene-styrene, styrene-isobutylene-styrene, styrene-ethylene-butylene- styrene, styrene-ethylene-propylene-styrene, styrene-ethylene-ethylene-propylene-styrene.

The thermoplastic elastomers preferably employed in the method of the present invention are prepared as described in, for example, WO 1995/35335 or WO 1997/40079 and can be prepared by anionic polymerization in an apolu2 solvent with the addition of a polar cosolvent or a potassium salt .

The thermoplastic elastomer of the present invention preferably contains between 10 and 60% by weight, more preferably between 15 and 50% by weight and even more preferably between 20 and 40% by weight of hard sequences.

The thermoplastic elastomers preferably used in the method of the present invention are characterized by a melt flow rate (ASTM D1238 200 ° C / 5 kg) included between 2 and 50 g / 10 min, preferably between 5 and 20 g / 10 min.

The thermoplastic elastomers preferably employed in the method of the present invention are block copolymers where the soft sequence has a molecular weight comprised between 2000 and 250000 g / mol and a glass transition temperature, as determined by differential scanning calorimetry, of 25 ° C or lower and wherein the hard sequence has a molecular weight comprised between 1000 and 200000 g / mol and a glass transition temperature higher than 25 ° C.

The soft sequences preferably have a glass transition temperature, as determined by differential scanning calorimetry, comprised between 25 and -110 ° C, preferably between 5 and -100 ° C and more preferably between -10 and -90 ° C or even -20 and -90 ° C.

It is self-evident that the thermoplastic elastomers employed in the method of the present invention include other components and / or additives such as thermoplastic homo- and / or copolymers, thermosetting polymers, fillers, wetting agents, surfactants, foaming agents, anti-foaming agents, pigments , dyes, antistatic agents, stabilizers, antioxidants, flow improvers and flame retardants can be included Without being bound by any theory, it is stated that the polymer chains of the thermoplastic elastomers are physically crosslinked by association of the hard polyvinylarene sequences, with the organic contamination is included in the soft sequences.

The glass transition temperature of the soft sequences should be sufficiently low for them to be sufficiently mobile during the purification process to absorb and / or adsorb the contaminants. On the other hand, the glass transition temperature of the hard sequences should be sufficiently high to prevent the thermoplastic elastomers from caking during the purification process.

The density of the thermoplastic elastomer to be used in the method of the present invention is preferably comprised between 0.5 and 1.5 g / cm 3 and more preferably between 0.8 and 1.3 g / cm 3.

The thermoplastic elastomer is preferably employed in BS2 granulate, tube or powder form but can in principle have any form of prevention.

In the method of the present invention, the contaminated water is contacted with the thermoplastic elastomer either stationary with a certain amount of elastomer added to a certain amount of contaminated water, or non-stationary with water, at a certain flow, pumped by the thermoplastic elastomer, in which case, in both cases, ttz stationary or non-stationary, the thermoplastic elastomer, in contact with the contaminated water, is subjected to a force field or a mechanical force. In the first instance the application of a force field is described on the basis of the preferred embodiment according to which an ultrasonic force field is applied.

For this purpose, for example, one or more holders are provided with one or more ultrasonic probes and / or transducers connected to one or more ultrasonic generators with a nominal power included between 100 and 10000 Watt, preferably between 200 and 2000 Watt, which waves generate frequencies in the range of 10 kHz to 1 MHz, preferably from 15 kHz to 500 kHz, more preferably from 20 kHz to 200 kHz. The one or more ultrasonic probe (s) can optionally be provided in combination with one or more reflectors.

In order to achieve maximum efficiency of the ultrasonic treatment, it is important that the ultrasonic force field is used over as much of the thermoplastic elastomer as possible in contact with contaminated water. Preferably, the ultrasonic wave field is applied to the entire portion of thermoplastic elastomer that is in contact with the contaminated water.

In an embodiment of the stationary method, use is preferably made of one or more holders, each provided with at least one opening for filling and / or emptying of the holder, of one or more ultrasonic probes and / or transducers. The one or more containers can each be filled separately and independently of each other with contaminated water and cleaned of pure water.

In the one or more containers, between 10-7 and 100 g, preferably between 10-5 to 80 g, more preferably between 10-3 to 60 g or even between 10-1 to 50 g of the thermoplastic elastomer added per 100 g of contaminated water, depending on the degree of contamination and the type of contamination, the thermoplastic elastomer in contact with the contaminated water being subjected to ultrasonic vibration energy for a period between 1 second and 24 hours, at preferably between 10 seconds and 10 hours, depending on the degree of contamination and the type of contamination in which the ultrasonic force field is applied continuously or provided that one or more interruptions are inserted. The thermoplastic elastomer, in contact with the contaminated water, is stirred continuously or with interruptions during the entire contact period.

The ultrasonic force field is then switched off and purified water is separated from the thermoplastic elastomer, for example by filtration.

Contaminated water can again be added to the thermoplastic elastomer, followed by ultrasonic treatment and separation of pure water. The filling, purifying and separating sequences can be repeated until a decrease in the purifying power of the thermoplastic elastomer is observed.

In an embodiment of the non-stationary method, use is preferably made of one or more holders, each provided with at least one opening for filling and / or emptying of the holder, and of one or more ultrasonic probes and / or transducers and wherein the one or more containers are partially or fully filled with thermoplastic elastomer. Each of the containers is provided to be placed in a flow-through circuit whereby liquid flows through the container. This can be done through the openings for filling and emptying, or through specifically provided flow openings. Means are provided (e.g., sieves or the like) to ensure that the thermoplastic elastomer remains in the containers while the contaminated water flows through the circuit. For the case of multiple holders, these are placed in series and / or in parallel.

In the non-stationary method, the contaminated water is pumped through the thermoplastic elastomer contained in the one or more containers. For example, the water is pumped in an upward direction, the flow rate of the flowing water being understood to be between 10 and 100,000 parts per hour, preferably between 20 and 75,000 parts per hour, more preferably between 30 and 50,000 parts per hour or even between 50 and 20,000 parts per hour, depending on the degree of contamination and the type of contamination, for one or more containers containing a total of 100 parts of thermoplastic elastomer.

The force field is applied to the thermoplastic elastomer while the contaminated water is pumped through the elastomer. The one or more containers can be stirred during the treatment.

The one or more retainers, preferably employed in the stationary and non-stationary embodiments of the present invention, are preferably cylindrical in shape with at one or more levels, preferably along the longitudinal axis of the retainer (s), one or more probe (s) are arranged, preferably in circular formation, wherein the one or more probe (s) can be switched on and off separately depending on, for example, the degree of filling of the container (s) with thermoplastic elastomer. The number of probes and / or transducers that form part of the preferably circular formation is 1, preferably 2, preferably 3, preferably 4, preferably 5, preferably 6.

Figure 1 shows a possible embodiment of a container 1 where the contaminated water can be pumped through input 2 to output 3, while elastomer particles remain in the container by nets or screens 4. Ultrasonic probes and / or transducers 5 are arranged on three levels , each in circular formation around the container 1. One level is shown in section, with three probes and / or transducers 5 arranged around the circumference. At least two probes are installed on the other levels.

Optionally, the one or more containers are provided with a stirring system to optimize the contact between the thermoplastic elastomer and contaminated water and to achieve a homogeneous distribution of the thermoplastic elastomer, in contact with contaminated water, through the ultrasonic force field.

The contaminated water is preferably between 0 and 25 ° C, but can be heated if necessary. In the event that the contaminated water needs to be heated, the one or more containers are preferably adiabatic.

The purifying capacity of the thermoplastic elastomer can be determined, for example, by checking the water leaving the container with thermoplastic elastomer for any impurities still present using, for example, ultra-performance liquid chromatography combined with mass spectrometry.

When a decrease in the purifying power of the thermoplastic elastomer is observed, the thermoplastic elastomer is regenerated.

The thermoplastic elastomer can be stripped of the impurities included, for example, by a soxhlet type extraction using an apolar solvent such as (cyclo) hexane, isooctane, toluene or xylene.

On the other hand, the thermoplastic elastomer can be stripped of the incorporated chemical impurities using steam according to the principle of steam distillation.

The thermoplastic elastomer can also be removed from the incorporated chemical impurities by treating it with cold or warm air; this treatment is preferably applicable in the case of volatile impurities.

The thermoplastic elastomer, stripped of chemical impurities, is then dried, for example at an elevated temperature of, for example, 50 ° C, and under reduced pressure or provided that the heated air is blown through.

The dried thermoplastic elastomer can be reused in a subsequent water purification.

The method of the present invention allows the α 1 IS 2 concentration of organic impurities to decrease by 50% or more, preferably 60% or more, preferably 70% or more, preferably 80% or more, preferably 90 % or more, preferably 95% or more, preferably 97% or more, preferably 99% or more, preferably 99.5% or more, preferably 99.9% or more relative to the initial concentration.

The method of the present invention allows purified water to be obtained with a concentration of residual organic contamination of 10 g / l or lower, preferably of 1 g / l or lower, preferably of 500 mg / l or lower, at preferably from 100 mg / l or lower, preferably from 1 mg / l or lower, preferably from 500 μg / l or lower, preferably from 100 μg / l or lower, preferably from 1 μg / l or lower, at preferably from 500 ng / l or lower, preferably from 100 ng / l or lower, preferably from 10 ng / l or lower, preferably from 1ng / l or lower, preferably from 500 pg / l or lower, preferably from 100 pg / l or lower, preferably from 10 pg / l or lower, preferably from 1 pg / l or lower.

As stated, instead of or together with a force field, a mechanical force can also be applied to the elastomer while in contact with the contaminated water. In practice, this means that particles of the elastomer are brought into physical contact with a moving body whereby they are deformed elastically or plastically. The order of magnitude of the forces is preferably comparable to that exerted by the ultrasonic force field described above. In other words, the force must act on the particles in such a way that it promotes the purifying action of the elastomers, for example by increasing the mobility of the soft polymer sequences.

Figure 2 illustrates a first possible embodiment of a method and device according to the invention in which the elastomer is subjected to a mechanical force. In a cylindrical container 10 in which there are particles of the elastomer, a likewise cylindrical roller 11 is arranged rotatably. The roller has a diameter that is smaller than the diameter of the container and is arranged eccentrically with respect to the axis of symmetry 12 of the container, so that a narrow passage 13 is created between the outer wall of the roller 11 and the inner wall of the container 10. The roller The drawing is not to scale to make the passage 13 clearly visible, but it is actually smaller in comparison to the dimensions of the holder 10 and the roller 11. The width of the passage 13 is of the same order of magnitude as a determining dimension of the elastomer particles. Preferably, the particles are spherical and the determining dimension is the diameter of the particles. The roller can rotate about its axis of symmetry 14. The rotational speed is chosen such that the particles are continuously entrained by a flow through the passage 13, whereby they are slightly compressed by the action of the passage itself in combination with the pressure of the water. This container can be used in a stationary method or non-stationary method, as described in connection with ü2 ultrasonic treatment. The values mentioned above in the case of ultrasonic, for certain parameters, such as the elastomer content, the flow rate, the treatment time and the like, also apply to the embodiment of Figure 2.

Figure 3 shows a second embodiment in which a mechanical force is applied to the elastomer particles. The particles 15 are located in the cylinder 21 of a piston pump 20, comprising a piston 22, a suction line 23 with suction valve 24 and a pressure line 25 with pressure valve 26, means being provided at the level of the suction and / or pressure valve (e.g. sieves or the like) to ensure that the thermoplastic elastomer remains in the cylinder 21 of the piston pump 20 when the contaminated water is sucked in via the suction line 22 into the cylinder 20 and when the purified water is pressed through the pressure line 24 from the cylinder. The suction and pressing is effected by moving the piston 22 away (suction stroke) and backward (pressing stroke), during which the thermoplastic elastomer particles are compressed during the reverse movement, which increases their purifying capacity.

The piston pump can be used in a stationary method or non-stationary method.

In the stationary method, the piston pump, which comprises the thermoplastic elastomeric partikes, is introduced into a container with contaminated water, the water being sucked into the cylinder a number of times and squeezed out of the cylinder until the desired decrease in contamination is achieved. perceived.

In the non-stationary method, the contaminated water flows through the cylinder of one or more piston pumps, in the case of several piston pumps being arranged in series and / or in parallel and optionally provided with buffer tanks.

Without being bound by any theory, it is stated that the application of a force field and / or a mechanical force improves the purifying action of the elastomer due to an increase of, inter alia: - the mobility of the soft polymer sequences, - the diffusion from the organic impurities to the thermoplastic elastomer, - the transport of the organic impurities from the water layer, in direct contact with the thermoplastic elastomer, to the thermoplastic elastomer, - the renewal of the water layer in direct contact with the thermoplastic elastomer, which is the uptake of organic contamination by the thermoplastic elastomer.

For any of the methods described above, both the stationary and the non-stationary methods, salt can be added to the contaminated water to decrease the solubility of certain impurities in the water and to reduce uptake capacity of impurities in the thermoplastic elastomer. increase.

To this end, for example, sodium chloride can be added to the contaminated water to obtain a concentration comprised between 100 and 350 g of salt per liter of water.

For each of the methods described above, both the stationary and the non-stationary methods, a control of the acidity of the contaminated water may be necessary. This regulation is mainly applicable in case the organic contaminants occur in the form of salts, whereby an adjustment of the pH makes the organic contaminant more absorbable in the thermoplastic elastomer. Depending on the type of contamination, the acidity control may involve an increase or decrease in pH to 13 units, preferably up to 10 units.

For example, for the case of contaminated water containing mercaptan salts, the acidity can be lowered to obtain a better purifying capacity of the thermoplastic elastomer.

The present invention also relates to a method for removing organic contaminants from mud in which a thermoplastic elastomer is brought into contact with the mud and an ultrasonic force field is applied.

By mud is meant in the present invention a mixture of soil, water and contaminants, the term "soil" meaning gravel, clay, loam, loess, silt, peat, sand and combinations of these, such as sand, and wherein the soil concentration is 900 g / l or lower, preferably 800 g / l or lower, preferably 700 g / l or lower, preferably 600 g / l or lower, preferably 500 g / l or lower, preferably 400 g / l or lower, preferably 300 g / l or lower, preferably 200 g / l or lower, preferably 100 g / l or lower, preferably 50 g / l or lower, and wherein the concentration of organic impurities 50 g / l or lower, preferably 10 g / l or lower, preferably 1 g / l or lower, preferably 500 mg / l or lower, preferably 100 mg / l or lower, preferably 1 mg / l or lower, preferably 500 µg / l or lower, preferably 100 µg / l or lower, preferably 1 µg / l or lower, preferably 500 ng / l or lower, preferably 100 ng / l or lower, preferably 10 ng / l or lower or even 1ng / lo f lower.

Preferably the concentration of organic impurity is at least 1 pg / l, preferably at least 10 pg / l, preferably at least 100 pg / l, preferably at least 1 ng / l, preferably at least 10 ng / l, preferably at least 100 ng / l, preferably at least 1 μg / l, preferably at least 10 μg / l, preferably at least 100 μg / l, preferably at least 1 mg / l, at preferably at least 10 mg / l, preferably at least 100 mg / l, preferably at least 1 g / 10, preferably at least 10 g / l.

The sludge purification can be done according to a stationary or nBE2 stationary embodiment, analogous to that used for purifying contaminated water, whereby purified sludge is obtained with a concentration of residual organic contamination of 10 g / l or lower, preferably from 1 g / l or lower, preferably from 500 mg / l or lower, preferably from 100 mg / l or lower, preferably from 1 mg / l or lower, preferably from 500 μg / l or lower, preferably from 100 μg / l or lower, preferably from 1 μg / l or lower, preferably from 500 ng / l or lower, preferably from 100 ng / l or lower, preferably from 10 ng / l or lower, preferably from 1ng / l or lower, preferably from 500 pg / l or lower, preferably from 100 pg / l or lower, preferably from 10 pg / l or lower, preferably from 1 pg / l or lower.

The thermoplastic elastomer, which contains the impurities of the sludge, is regenerated by means of a soxhlet type extraction, by a steam treatment or by a warm air treatment and is reused after drying.

Examples The examples below are intended to illustrate the invention and by no means limit the invention.

Example 1: Synthesis of a thermoplastic elastomer based on styrene and butadiene.

A styrene-butadiene / styrene-styrene triblock copolymer was prepared by a process as described in WO 1997/40079.

A 50 liter reactor was charged with 22.8 liters of dry cyclohexane and 1638 grams of dry styrene and brought to 40 ° C with polymerization initiated by the addition of 87.3 mmol of sec-butyllithium (12 weight percent in dry cyclohexane) and 2.36 mmol of potassium tert. - amylate (5% by weight in dry cyclohexane). The reaction mixture was stirred for 30 minutes while maintaining a temperature of 68 ° C.

The reaction mixture was then cooled to 50 ° C and 1126 grams of butadiene and 1250 grams of styrene were added simultaneously. The temperature rose to 74 ° C. After a polymerization time of 13 minutes, the resulting reaction mixture was cooled to 55 ° C and a second amount consisting of 1126 grams of butadiene and 1250 grams of styrene was added. The temperature rose to 76 ° C. After a polymerization time of 13 minutes, the mixture was cooled to 55 ° C and a third amount consisting of 1126 grams of butadiene and 1250 grams of styrene was added with the temperature rising to 75 ° C. After 17 minutes, 1638 grams of styrene were added at a temperature of 70 ° C with the temperature rising to 80 ° C.

40 minutes after the styrene addition, the polymerization was terminated by the addition of 200 mmol of isopropanol, acidified by the addition of carbon dioxide and water and stabilized by the addition of 35 grams of Irganox® 3052 and 80 grams of Weston® TNPP. The polymer was then stripped of solvent and transformed into granulate form via an extruder.

The thermoplastic elastomer was characterized by a number average molecular weight of 140000 g / mol and 2 glass transition temperatures, the first glass transition temperature being between -25 and -55 ° C and the second glass transition temperature being between 60 and 100 ° C.

The thermoplastic elastomer contains 31.5 weight percent of polystyrene block.

Example 2: Synthesis of a thermoplastic elastomer based on styrene and isoprene.

A styrene-isoprene / styrene-styrene triblock copolymer was prepared in the same mode as the styrene-isoprene / styrene-styrene triblock copolymer of Example 1, with the difference that 1420 grams of isoprene and 1250 grams of styrene in three consecutive steps.

Reaction temperatures and reaction times are those of Example 1. The remaining reagents and solvents as well as their respective amount are those of Example 1 added. The thermoplastic elastomer was characterized by a number average molecular weight of 135000 g / mol and 2 glass transition temperatures, the first glass transition temperature being situated between -30 and - 60 ° C and wherein the second glass transition temperature was situated between 60 and 100 ° C.

The thermoplastic elastomer contains 29 weight percent of polystyrene block.

Example 3: Purification of an industrial waste water sample containing mineral oil and other hydrocarbons.

An industrial water sample was collected at the outlet and analyzed for C10 - C40 alkanes and aromatic hydrocarbons.

50 g of the thermoplastic elastomer of Example 1 was added to a container of 500 g of contaminated water at room temperature, the whole being subjected for 30 minutes to an ultrasonic force field produced by an ultrasonic laboratory probe UP50H (Hielscher Ultrasonics GmbH), in contact with the water surface. The mixture of "contaminated water - thermoplastic elastomer" was stirred during the ultrasonic treatment using a magnetic stirrer.

The thermoplastic elastomer was then filtered off and the purified water w BE2 analyzed.

Table 1 shows the concentration of C10 - C40 alkanes and aromatic hydrocarbons, in nanograms per milliliter, before and after purification.

Table 1 Table 1 shows that the use of thermoplastic elastomer in combination with an ultrasonic force field reduces the concentration of chemical impurities, which consist of mineral oil and other hydrocarbons, to a value included between 30 and less than 10% of the original value.

Example 4: Purification of an industrial waste water sample containing abiraterone.

An industrial water sample was collected at the outlet and analyzed for ^) - 17- (pyridin-3-yl) androsta-5,16-dien-3-ol (= abiraterone) 10 g of the thermoplastic elastomer of Example 1, was added to a container with 40 g of contaminated water at room temperature, the assembly being subjected to an ultrasonic force field produced by an ultrasonic laboratory probe UP50H (Hielscher Ultrasonics GmbH) for 0, 10 and 30 minutes respectively, in contact with the water surface. The mixture of "contaminated water-thermoplastic elastomer" was stirred during the ultrasonic treatment using a magnetic stirrer. The thermoplastic elastomer was then filtered off and the purified water was analyzed.

Table 2 shows the concentration, in nanograms per milliliter, of abiraterone, before and after purification.

Table 2

Table 2 clearly shows the effect of the ultrasonic force field (samples 3 and 4 versus sample 2) on the purifying power of the thermoplastic elastomer. The use of only thermoplastic elastomer reduces the abiraterone concentration to 25% or less of its original value; by applying ultrasonic waves, the abiraterone concentration decreases to 5% or less of its original value.

Example 5: Purification of an industrial waste water sample containing 17α-estradiol, 17β-estradiol, estrone and ethinyl estradiol.

An industrial water steel (steel 1) was collected at the outlet and analyzed for 17α-estradiol, 17β-estradiol, estrone and ethinyl estradiol. 100 g of the thermoplastic elastomer of example 2 was added to a container with 200 g of contaminated water, the whole being kept at 40 ° C for 6 hours. The thermoplastic elastomer was then filtered off and the purified water (sample 2) was analyzed.

In addition, 100 g of the thermoplastic elastomer of Example 1 was added to a container with 200 g of contaminated water at room temperature, the assembly being subjected to an ultrasonic force field produced by an UP50H ultrasonic laboratory probe (Hielscher Ultrasonics GmbH) for 30 minutes ), in contact with the water surface (sample 3).

Table 3 shows the concentrations, in nanograms per milliliter, of 17α-estradiol, 17β-estradiol, estrone and ethinyl estradiol for the different water samples (samples 1, 2 and 3).

Table 3 Table 3 shows the effect of the thermoplastic elastomer on the reduction of impurities (sample 2); a decrease of up to 20% and less of the initial values is achieved. Applying an ultrasonic force field results in a further decrease to less than 2% of the initial value.

Claims (22)

Conclusions A method for removing organic contaminants from water, comprising: - contacting water comprising organic contaminants with thermoplastic elastomer and applying a force field and / or a mechanical force to the thermoplastic elastomer while in contact is with the water; - separating the water, with a reduced concentration of organic impurities, from the thermoplastic elastomer. The method of claim 1 wherein the organic contaminants comprise a hydrocarbon or a mixture of hydrocarbons, said hydrocarbon or hydrocarbons belonging to the group comprising C1 - C60, n-alkanes, cycloalkanes and aromatic alkanes. , preferably belonging to the group comprising C 4 -C 50 n-alkanes, cycloalkanes and aromatic alkanes, more preferably belonging to the group comprising C 6 -C 40 n-alkanes, cycloalkanes and aromatic alkanes. The method of claim 1 or 2, wherein the organic contaminants comprise mineral oil. The method according to any of claims 1 to 3, wherein the organic contaminants comprise an organometallic compound selected from the group consisting of organoaluminum, organogermanium, organo mercury, organolithium, organo-lead, organomagnesium, organopalladium, organotin and organozinc. The method according to any of claims 1 to 4, wherein the organic impurities are a 2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17- hexadecahydro-1 H-cyclopenta [a] phenanthrene backbone or a backbone derived therefrom which may: - comprise one or more unsaturated double bonds, - one or more methyl, hydroxyl, aldehyde, amine, amide (-NH-) CO-R), or may include oxygen substituents and - in position 17, comprises substituents selected from the group consisting of hydrogen, hydroxyl, oxygen, a hydrocarbon substituent and an aromatic substituent, wherein: the hydrocarbon substituent: - between 1 and 10 comprises carbon atoms, - one or more unsaturated double and / or triple BE: can comprise bonds, - can comprise one or more heteroatoms, and - can form a bond with position 16; the aromatic substituent: - comprises between 1 and 10 carbon atoms, - may comprise one or more substituents and - may comprise one or more heteroatoms. The method of any one of claims 1 to 5 wherein the organic contaminants comprise a natural or synthetic hormone or hormone analogue. The method of any one of claims 1 to 6 wherein the organic contaminants comprise a endocrine disruptor endocrine disruptor. The method of any one of claims 1 to 7, wherein the thermoplastic elastomer comprises a block copolymer comprising hard sequences obtained by polymerization of monovinylarenes and soft sequences obtained by polymerization of alkylenes or by copolymerization of monovinylarenes and alkylenes. The method of any one of claims 1 to 8, wherein the thermoplastic elastomer comprises a block copolymer selected from the group consisting of styrene-butadiene-styrene, styrene-isoprene-styrene, styrene-isobutylene-styrene, styrene-ethylene- butylene-styrene, styrene-ethylene-propylene-styrene, styrene-ethylene-ethylene-propylene-styrene. The method of any one of the preceding claims, wherein said force field is an ultrasonic force field obtained by contacting the water with ultrasonic waves while the water is in contact with the elastomer. The method of claim 10, wherein the ultrasonic waves are characterized by a frequency comprised between 10 kHz and 1 MHz, preferably between 15 kHz and 500 kHz and more preferably between 20 kHz and 200 kHz. The method of any one of the preceding claims, wherein said mechanical force is applied to the elastomer by contacting particles of the elastomer with one or more moving surfaces. The method of claim 12 wherein the particles are together with the contaminated water in a cylindrical container (10), and wherein a rotating roller (11) is located in the container, eccentrically arranged in the container, through which a passage (13 ) arises between the outer wall of the roller and the inner wall of the container, and wherein the mechanical force is exerted because particles flow with the water through the passage (13). The method according to any of claims 1 to 13, wherein the contaminated water is stationary in a container (1.10), together with particles of the elastomer. The method according to any of claims 1 to 13, wherein the water is pumped through one or more containers which are completely or partially filled with thermoplastic elastomer, wherein if there are several containers, these are arranged in series and / or in parallel. The method of claim 12 wherein contaminated water is sucked into the cylinder (21), from one or more piston pump (s) (20), the cylinder comprising elastomer particles and wherein a mechanical force is exerted on these particles by pressing of piston (22) for removing the water from the cylinder. The method of any one of claims 1 to 16 wherein the contaminated water comprises components selected from the group consisting of gravel, clay, loam, loess, silt, peat, sand and combinations thereof. The method of any one of claims 1 to 17 wherein salt or acid or base or a combination of salt and base or salt and acid is added to the contaminated water. The method of any one of claims 1 to 18, wherein the concentration of organic impurity decreases by 50% or more, preferably 60% or more, preferably 70% or more, preferably 80% or more, preferably 90% or more, preferably 95% or more, preferably 97% or more, preferably 99% or more, preferably 99.5% or more, preferably 99.9% or more relative to the initial concentration. The method according to any of claims 1 to 19, comprising an additional step in which the contaminant-containing thermoplastic elastomer is isolated and regenerated, preferably via an extraction process, via steam treatment or treatment with hot or cold air. The use of the method according to any of claims 1 to 20 for purifying domestic water, industrial waste water, surface water, drinking water and effluents and / or influents of water purification stations. Device for removing organic contaminants from water according to the method according to any one of claims 1 to 11, comprising one or more containers, each provided with at least one opening for filling and / or emptying the container, the one or more a plurality of containers of thermoplastic elastomer and wherein the one or more containers comprise one or more ultrasonic probes and / or transducers positioned such that the thermoplastic elastomer, in contact with water, is subjected to an ultrasonic force field with the one or more ultrasonic probes and / or transducers are connected to one or more ultrasonic generators which can be switched on and off separately.