2.2. Chemical precipitation
As a first step, chemical precipitation was applied to
remove the dissolved and colloidal materials that
accumulated during the brining steps and thus to relieve
the load on the following purification step, microfiltration.
Chemical precipitation was carried out in a 250-
l precipitation tank as well as a 1-l jar. It consisted of
the injection of 2 M NaOH solution into the brining wastewater,
3 min of fast mixing, 27 min of slow mixing
and 1-h sedimentation steps. Changes in TOC, suspended
solid (SS), turbidity, retention of soluble magnesium
and sediment volume were analyzed after each
experiment.