ABSTRACT: Ion flotation is the term used to describe a process in which there is an initally homogeneous solution which becomes heterogeneous after the addition of an oppositely charged surfactant due to the reaction between the surfactant and specific ion(s); thus, insoluble complexes are formed. These insoluble complexes will then attached to the bubbles passing through the solution and thus leave in the foam phase. The performance of the continuous ion flotation process for the removal of haft lignin from water was investigated intensively using liquid flow rates, gas flow rates, feed locations and solution height as operational variables. The interrelationships among these physical parameters were studied and discussed. A dimensionless operational chart was established for process control. Results demonstrate that ion flotation is an effective process for removing lignin from water, provided that a quaternary ammonium salt, such as cetyldimethylbenzyl‐ammonium chloride or the like, is used as a collector. At optimum operational conditions, higher than 0.95 fractional removal of lignin can be achieved.
Outlined here is research into a process by which raw water and contaminated waters can be effectively treated by using a foam separation reactor in which cationic quaternary ammonium compound is used as both collector and disinfectant.
