Concentration of Dilute Industrial Wastes by Direct Osmosis

The purpose of this research was to study the feasibility of using direct osmosis with sea water to concentrate dilute industrial wastes. several continuous flow laboratory size osmosis units were designed, constructed, and operated successfully. Dilute waste solutions were concentrated by direct osmosis using simulated sea water on the other side of the membrane. With the reverse osmosis membranes currently available, permeation rates were much lower than expected based upon their reported reverse osmosis rates. Another problem was that the diffusion rate of sodium chloride from the sea water to the waste solution and of the metallic ions from the waste solution to the sea water. were greater than could be tolerated in most applications. This method of concentrating waste solutions does not appear to be practical until more selective high flux membranes than are cu r rently available are developed. This method would be feasible if a suitable membrane were available. Membrane development was not within the scope of thi s i nvestigation.