This document summarizes membrane separation materials and modules. It discusses types of membranes including dense and microporous, as well as separation operations like reverse osmosis, ultrafiltration, and gas permeation. Common membrane materials are synthetic polymers like cellulose and rubber. Asymmetric polymer membranes have a thin selective layer supported by a porous layer. Membrane modules include flat sheet, tubular, spiral-wound and hollow fiber configurations to provide a large surface area. Characteristics like packing density, fouling resistance and cost vary between module types.