Resumen
Procedure for the separation of microplastics from aqueous matrices. The present invention refers to a process for the separation of microplastics from aqueous matrices based on the interaction of said microplastics with magnetic minerals that contain iron, such as magnetite, which results in the formation of an aggregate of microplastics with the mineral Magnetic iron easily separable from water by application of a magnetic field. (Machine-translation by Google Translate, not legally binding)
Reivindicaciones
1. A process for separating microplastics from an aqueous matrix comprising microplastics, the process comprising: a) providing an aqueous matrix comprising microplastics, b) adding magnetic iron mineral particles the average diameter of which is comprised between 0.1 and 500 µm to the aqueous matrix provided in step a) to form microplastic/magnetic iron mineral particle aggregates, and c) separating the microplastic/magnetic iron mineral particle aggregates from the mixture obtained in step b) by applying a magnetic field. 2. The process according to claim 1, wherein the magnetic iron mineral comprises an iron species selected from the group consisting of Fe(II), Fe(III), metallic Fe, and a mixture thereof. 3. The process according to any of claims 1 or 2, wherein the magnetic iron mineral is magnetite. 4. The process according to any of claims 1 to 3, wherein the average diameter of the magnetic iron mineral particles is comprised between 0.1 and 100 µm. 5. The process according to claim 4, wherein the average diameter of the magnetic iron mineral particles is comprised between 0.1 and 50 µm. 6. The process according to any of claims 1 to 5, wherein the weight of the magnetic iron mineral particles which is added to the aqueous matrix in step b) is 0.1 to 20 the weight of the microplastics present in the aqueous matrix provided in step a). 7. The process according to claim 6, wherein the weight of the magnetic iron mineral particles which is added to the aqueous matrix in step b) is 0.5 to 10 the weight of the microplastics present in the aqueous matrix provided in step a). 8. The process according to any of claims 1 to 7, wherein the average diameter of the microplastics is in the range of 0.1 µm to 5 mm. 9. The process according to claim 8, wherein the average diameter of the microplastics is in the range of 50 µm to 100 µm. 10. The process according to any of claims 1 to 9, wherein the microplastics are selected from the group consisting of polyethylene terephthalate, high-density polyethylene, polyvinyl chloride, low-density polyethylene, polypropylene, polystyrene, polycarbonate, polyurethane, polyester, and mixtures thereof. 11. The process according to any of claims 1 to 10, wherein the addition of the magnetic iron mineral particles to the aqueous matrix comprising microplastics of step b) is performed discontinuously or continuously. 12. The process according to any of claims 1 to 11, wherein the mixture obtained in step b) is subjected to stirring before performing step c). 13. The process according to claim 12, wherein the stirring is of the mechanical, magnetic, or electrostatic type. 14. The process according to claim 13, wherein stirring is of the mechanical type. 15. The process according to any of claims 1 to 14, wherein the pH and/or the temperature of the aqueous matrix comprising microplastics of step a) is conditioned before performing step b) such that: - the pH is in the range of 1 to 13, and/or - the temperature is in the range of 5 to 95°C. 16. The process according to claim 15, wherein the pH and/or the temperature of the aqueous matrix comprising microplastics of step a) is conditioned before performing step b) such that: - the pH is in the range of 3 to 10, and/or - the temperature is in the range of 15 to 35°C. 17. The process according to any of claims 1 to 16, wherein the separation of the microplastic/magnetic iron mineral particle aggregates of the aqueous matrix of step c) is performed using magnets or electromagnets. 18. The process according to any of claims 1 to 17, wherein the magnetic iron mineral particles of the microplastic/magnetic iron mineral particle aggregates separated in step c) are recovered so as to be reused. 19. The process according to claim 18, wherein the recovery is performed by means of a heat treatment. 20. The process according to claim 19, wherein the heat treatment comprises heating the microplastic/magnetic iron mineral particle aggregates separated in step c) in air atmosphere to a temperature comprised between 250°C and 600°C at a rate comprised between 0.5 and 20°C min<-1>. 21. Use of the process defined in any of claims 1 to 20 for water treatment. 22. Use of the process defined in any of claims 1 to 20 for the quantification of microplastics in aqueous matrices.
