Development of Performance Models for Boiler Feed Water Treatment Ion Exchange Facility

Abstract

The treatment s of raw water using resins embedded with cation and anion w ere investigated in this study via a developed mathematical model. The developed mathematical model was used to predict the amount of sodium ( Na + ), calcium ( Ca 2+ ), magnesium ( Mg 2+ ) and ammonium (NH 4 ＋ ) ions removed by the resin embedded with hydrogen ion ( H + ) in the cation bed. The model was also used to investigate the amount of chloride ( Cl － ) and sulphate (SO 4 2－ ) ions treated by the resin embedded with hydroxyl ion ( OH － ) in the anion bed. The effect of flow rate and superficial velocity were also investigated. The simulation results showed that there was significant reduction of Na + , Ca 2+ , Mg 2+ , , Cl － and SO 4 2－ from their initial concentrations in raw water. This showed that the mathematical model was able to predict the concentrations of cations and anions investigated in this study. The result revealed that the flow rate of water has effect on the treatment of cations and anions in raw water using ion-exchange resins . Thus, operating the resin beds at very high flow rate reduced its performance while at very low flow rate the residence time of wastewater on the bed increased with resultant increase in performance. Similarly, high superficial velocity reduced the amount of ion concentration removed by the resin in both beds. The total final concentrations of cations in the cation bed by the model were 0.0003156, 0.0003452 and 0.0036 mol/m 3 at 4.0, 4.5 and 6.5 m/min respectively while that from the anion bed were 0.0002597, 0.0002769 and 0.00205 mol/m 3 at 4.0, 4.5 and 6.5 m/min respectively. The predicted model results, when compared with the maximum allowable limit of total concentration of both cations and anions of a functional industrial company (Notore chemical), showed a maximum percentage deviation ranging from 2.00% to 3.53% . This showed that the developed model has achieved its set objectives.