Filtration of Fluid Media Containing very Fine Heavy Metals

The development of filter materials that can capture fine ferromagnetic and paramagnetic particles, as well as radioactive contaminants, with high efficiency is of great industrial significance in pollution control processes such as water purification and waste-water treatment. The main problem facing the development of an effective filter is the ability to efficiently filter fine particles below one micron. This project will address this problem by developing composite, nano-structured, lightweight filter materials that can effectively remove micron and sub-micron-sized particle contaminants, especially heavy metal species. The technique to grow the nano-structured filter media will have low energy consumption. In Phase I, composite nano-structured lightweight filters were developed from high performance polymers and other ingredients. Filters were designed, fabricated, and tested with a fluid media containing very fine silicon or iron oxide particles. The particle capture efficiency was far superior to the conventional filter media, with practically the same thickness, weight, and pressure drops. Phase II will optimize and scale-up the nano-structured composite filter media developed in Phase I. A continuous growing process and device will be designed and constructed as a first step toward mass production. A series of filtration tests and SEM analyses will be performed to assist the optimization. Commercial Applications and other Benefits as described by the awardee: The lightweight composite filter media should have application in a variety of recovery and pollution-control processes: treatment of radioactive water, waste water and metalworking fluids; purification of drinking water; separation of metal contaminates from engine oil; and recovery of precious metals.