Chromium removal from ion-exchange waste brines with calcium polysulfide.

Chromium removal from ion-exchange (IX) brines presents a serious challenge to the water industry. Although chromium removal with calcium polysulfide (CaS(5)) from drinking waters has been investigated somewhat, its removal from ion-exchange brines has not been evaluated to date. In this study, a Central Composite Design as well as experimental coagulation tests were performed to investigate the influence of pH, CaS(5)/Cr(VI) molar ratio, alkalinity, and ionic strength in the removal of chromium from IX brines.

Surface complexation modeling of the removal of arsenic from ion-exchange waste brines with ferric chloride.

Brine disposal is a serious challenge of arsenic (V) removal from drinking water using ion-exchange (IX). Although arsenic removal with ferric chloride (FeCl(3)) from drinking waters is well documented, the application of FeCl(3) to remove arsenic (V) from brines has not been thoroughly investigated. In contrast to drinking water, IX brines contain high ionic strength, high alkalinity, and high arsenic concentrations; these factors are known to influence arsenic removal by FeCl(3).