Coupling ion exchange with ultrafiltration for boron removal from geothermal water-investigation of process parameters and recycle tests

Abstract

A hybrid process was established in a stirred vessel coupling ion exchange with ultrafiltration (UF). Boron selective chelating ion-exchange resins Dowex XUS-43594.00 with an average particle diameter of 20μm were used for boron separation from geothermal water and a submerged hollow fiber type UF membrane module (ZW-1, GE) was used for the filtration of the resin suspension and collecting permeate. Process variables such as the concentration of ion exchange resin in the suspension, replacement rates of fresh and saturated resins in the stirred vessel, and flow rate of permeate were evaluated in order to determine the efficiency of the hybrid process for boron removal from geothermal water. The recycle performance of the hybrid system was monitored following ten sorption–washing–elution–washing–regeneration–washing cycles.