**5. Concluding Remarks and Future Trends in the Field**

Over the course of this paper, we have reviewed the milestones of the research community focused on the strategies and approaches to face the fouling phenomenon on membranes, which in fact, is the primary drawback of pressure-driven membrane processes. Several approaches to preventing the adhesion of matter, translated to biofouling on membranes deals with the shift of their physico-chemical properties. In general, the preparation of highly hydrophilic membranes is sought using different approaches, including the preparation of nanocomposite membranes, membrane modification, and polymer blending. However, diverse options have also come out to be more effective in the removal of organic matter, e.g., combination of different techniques, resulting in efficient strategies for fouling mitigation. Nowadays, it is likely that the concept of nanocomposite membranes is the most explored approach, which comprises the embedding of nanomaterials (including clays, zeolites, metal oxides, graphene-based materials, carbon nanotubes, metal-organic frameworks, to mention just a few) into the polymer matrix. To obtain high performing membranes (in terms of permeation and rejection) with better antifouling resistance, herein, it is crucial the right selection of the nanomaterials according to their intrinsic properties, such as type of material, surface charge, composition, surface area, size, material loading, hydrophilic/hydrophobic nature, among others. However, the type of polymer and its compatibility will also play an important factor not only in the performance but also in the fabrication of the membranes. Even though there are already great advances in the field, there is still a strong need to work on the enhancement of the intrinsic properties of the membrane surface, including hydrophilicity and electrical surface charge, to improve the antifouling/biofouling and antimicrobial properties of membranes. Moreover, it is recommended to new researchers in the field the analysis of the separation performance and biofouling properties of the novel membranes using real complex solutions (such as industrial by-products and wastewaters). In this sense, the developed membranes can provide more realistic insights, which may give a clear overview of the potentiality of those membranes in water treatment applications.

**Author Contributions:** D.P.-R., Z.P.G.-A. and A.Z.-R. wrote the original draft paper. R.C.-M. conceived, designed, reviewed and edited the manuscript. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Acknowledgments:** R. Castro-Muñoz acknowledges the School of Engineering and Science and the FEMSA-Biotechnology Center at Tecnológico de Monterrey for their support through the Bioprocess (0020209I13) Focus Group.

**Conflicts of Interest:** The authors declare no conflicts of interest.
