Study of Hydrophilic Membranes for Oil-Water Separation

摘要

A program was conducted to determine the feasibility of the concept of using hydrophilic membranes for oil-water separations and to evaluate conceptually its practical applicability for shipboard use. Twenty candidate membranes were screened with respect to oil rejection capabilities and product water flux. The most promising membrane, a surface-hydrolyzed cellulose acetate, showed essentially complete oil rejection and was further studied to evaluate its performance under various operating conditions. The effects of input feed temperature flow rate, salt concentrations, applied pressure, and type and concentration of oil contaminants were determined. Several simple cleaning procedures were investigated in an effort to restore product water flux after fouling of the membrane surface with oil. Preliminary designs for low-pressure systems to produce 100 and 1000 gpm of oil-free product were developed, based on a spiral-wound modular system. A summary of limitations and constraints of a proposed 100-gpm system for shipboard application is presented, along with spatial, weight, and energy requirements and economic factors for such a system. (Author)