Potential of freezing in wastewater treatment: Soluble pollutant applications

When wastewater containing only soluble pollutants is frozen gradually, ice crystals grow from the pure water only, while pollutants are rejected into the liquid phase thus increasing their concentration. In this way, pure wa ter can be removed from various wastewaters. Two kinds of wastewater were s tudied: synthetic wastewater containing water and one or more soluble pollu tants, and industrial wastewaters turban wastewater and cutting oil wastewa ter). In most cases, separation efficiency close to 100% was achieved. A la rge range of pollutant concentrations was studied in order to determine the limits of freezing separation. (C) 2000 Elsevier Science Ltd. All rights r eserved.