Cyanide removal from wastewater using gas membranes: pilot-scale study.

Results are presented for the removal of cyanide from four different wastewaters using hollow-fiber gas membranes. The pilot-scale membrane facility had a maximum treatment capacity of 1000 L using 10 hollow-fiber modules with a total membrane surface area of 180 m2. The results are in general agreement with previous laboratory-scale studies. However, different wastewaters contain different dissolved solutes. These dissolved solutes reduce the predicted efficiency of the cyanide removal process and the purity of the recovered cyanide. Other volatile species present in the wastewater could be removed with the cyanide into the strip solution. Further osmotic pressure differences between the wastewater and strip solution could lead to water vapor passing through the gas-filled pores of the microporous hollow-fiber membranes.