Barium was concerned as one metal contained in industrial wastewater. A new process for removing metal contamination from wastewater has been developed. This work applied carbonate salts as a precipitant for homogeneously producing metal carbonate crystal without seed materials from synthetic wastewater using a fluidized bed homogeneous crystallizer. This work demonstrated the removal of barium from aqueous solution using fluidized-bed homogeneous crystallization (FBHC, without seeds). Synthetic barium wastewater with concentration 1000 ppm was treated. The result thus obtained indicated that effluent pH was essential parameter in determining the efficiency of this FBHC process. The barium removal efficiency at optimum condition could achieve total removal 99.6% and crystallization ratio 97.5%. Optimum pH was 10.5 to 11. This FBHC method is suitable to deal with cross section loading equal or under 1.286 kg∙m-2∙h-1, initial molar ratio of [CO3]/[Ba] 1.5, upflow velocity 30-35 m/h. The XRD analysis indicated that the barium salt crystallization product was witherite (BaCO3, barium carbonate). The surface morphology analysis revealed that barium carbonates particles (around 1 mm) were formed by the aggregation of fine crystals.

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