Resumen
[0000] The present invention relates to a process for separating nanoplastics from aqueous matrices based on the interaction of said nanoplastics with carbon black particles, which gives rise to the formation of nanoplastic/carbon black particle aggregates that can be readily separated from the water by means of sedimentation, centrifugation, or application of a magnetic field in the case where the carbon black has been previously magnetized or where a magnetic iron material is added for interaction thereof with the nanoplastic/carbon black aggregates.
Reivindicaciones
1. A process for separating nanoplastics from aqueous matrices comprising nanoplastics, the process comprising: a) providing an aqueous matrix comprising nanoplastics, b) adding carbon black or magnetized carbon black particles to the aqueous matrix provided in step a) to form nanoplastic/carbon black or magnetized carbon black particle aggregates, and c) separating the nanoplastic/carbon black or magnetized carbon black particle aggregates from the mixture obtained in step b). 2. The process according to claim 1, wherein the size of the carbon black or magnetized carbon black particles is comprised between 10 and 80 nm. 3. The process according to any of claims 1 or 2, wherein the specific surface value of the carbon black or magnetized carbon black is comprised between 70 and 500 m<2> g<-1>. 4. The process according to any of claims 1 to 3, wherein the point of zero charge value of the carbon black or magnetized carbon black is comprised between 4.0 and 12. 5. The process according to any of claims 1 to 4, wherein the weight of the carbon black or magnetized carbon black particles which is added to the aqueous matrix in step b) is 2 to 100 the weight of nanoplastics present in the aqueous matrix provided in step a). 6. The process according to any of claims 1 to 5, wherein the mean diameter of the nanoplastics is in the range of 100 nm to 900 nm. 7. The process according to any of claims 1 to 6, wherein the nanoplastics are polystyrene nanoplastics. 8. The process according to any of claims 1 to 7, wherein the addition of carbon black or magnetized carbon black particles to the aqueous matrix comprising nanoplastics of step b) is performed discontinuously or continuously. 9. The process according to any of claims 1 to 8, wherein the mixture obtained in step b) is subjected to stirring before performing step c), preferably wherein the stirring is of a mechanical, magnetic, or electrostatic type, more preferably of a mechanical type. 10. The process according to any of claims 1 to 9, wherein carbon black is used and wherein separation of the nanoplastic/carbon black particle aggregates from the aqueous matrix of step c) is performed by means of sedimentation or centrifugation. 11. The process according to any of claims 1 to 9, wherein magnetized carbon black is used and wherein separation of the nanoplastic/magnetized carbon black particle aggregates from the aqueous matrix of step c) is performed by means of applying a magnetic field. 12. The process according to any of claims 1 to 9, wherein carbon black is used and wherein separation of the nanoplastic/carbon black particle aggregates from the aqueous matrix of step c) further comprises the addition of a magnetic iron material to the aqueous matrix comprising the nanoplastic/carbon black particle aggregates and separation is performed by means of applying a magnetic field. 13. The process according to any of claims 1 to 12, wherein the carbon black or magnetized carbon black particles of the nanoplastic/carbon black or magnetized carbon black particle aggregates separated in step c) are recovered to be reused. 14. The process according to claim 13, wherein recovery is performed by means of treating the aggregates with an organic solvent, preferably acetone, more preferably wherein the organic solvent used is acetone, using a nanoplastic/carbon black aggregate concentration or a nanoplastic/magnetized carbon black aggregate concentration of less than or equal to 25 g L<-1> and a contact time of at least 5 minutes. 15. The process according to claim 13, wherein recovery is performed by means of a heat treatment, preferably wherein the heat treatment comprises heating the nanoplastic/carbon black or magnetized carbon black particle aggregates separated in step c) in an air atmosphere to a temperature comprised between 300°C and 500°C at a speed comprised between 1 and 10°C min<-1>.
