This short review focuses on fouling by proteins and macromolecules in microfiltration/ultrafiltration. First, an experimental system that enables investigation of how the extent of the adsorption of proteins and macromolecules on membrane surfaces contributes to a decrease in filtrate flux in microfiltration/ultrafiltration is described. Using this system, a causal relationship - not a correlation - indicating that adsorption results in a decrease in filtrate flux could be clearly demonstrated in some cases. Second, a hydration structure at the membrane surface that can suppress adsorption is discussed, inspired by biomaterial research. In their hydrated states, polymers with low-fouling properties have water molecules with a particular structure. Finally, some successful examples of the development of low-fouling membranes via surface modification using low-fouling polymers are discussed.

Abstract
1. Introduction
2. Fouling by Proteins and Macromoleculesin Microfiltration/Ultrafiltration
    2.1. A simple experimental system for quantitativelydetermining the effect of adsorption on the declinein filtrate flux in microfiltration/ultrafiltration
    2.2. Characteristics of membrane surfaces havinglow-fouling properties from the viewpoint ofthe hydration structures
    2.3. Surface modification using polyCMB and poly-MEA to prevent adsorption
3. Conclusion
Reference

• Kazuki Akamatsu(Department of Environmental Chemistry and Chemical Engineering, School of Advanced Engineering, Kogakuin University) Corresponding author
• Ryo Nagumo(Department of Engineering, Nagoya Institute of Technology)
• Shin-ichi Nakao(Department of Environmental Chemistry and Chemical Engineering, School of Advanced Engineering, Kogakuin University/Research Institute for Science and Technology, Kogakuin University)