Which type of filtration uses a membrane to separate particles from water?

Microfiltration is a type of filtration that utilizes a membrane to effectively separate particles from water. This process involves passing water through a semipermeable membrane that has pores with a diameter typically ranging from 0.1 to 10 micrometers. These membrane pores allow water to flow through while blocking larger particles, bacteria, and some viruses, making microfiltration a crucial step in various water treatment processes.

This method is particularly advantageous as it can remove a wide range of contaminants without the use of chemicals, providing a physical barrier to pathogens and particulates. It is often used in both municipal water treatment and in various industrial applications where high quality water is necessary.

In contrast, the other types of filtration listed do not specifically rely on membrane technology. Sand filtration typically uses layers of sand to trap larger particles but doesn't use a membrane. Gravity filtration relies on the force of gravity to help move water through a filter medium, while carbon filtration involves the use of activated carbon to adsorb organic compounds and some contaminants but does not utilize a membrane structure.