The second part of this review considers electrochemical methods for the treatment of organic and inorganic species, the treatment of flue gases and waste gases, and membrane-based electrochemical techniques. These methods include both direct and indirect oxidation and reduction methods for toxic organics and cyanides.Membrane-based methods include electrodialysis, electro-osmosis and electrophoresis. Other aspects considered are electrosorption, electrochemical ion-exchange, electroflotation, and electrochemically-enhanced ultra$ltation.