Magnesium Salt Recovery from Concentrate and Use in Treatment of Saline Water

Al-Balqa Applied University, Water and Environmental Engineering Department, Al-Huson, 21510, Jordan

^* Corresponding author: bammary@bau.edu.jo

Abstract

Magnesium salt was recovered from artificial concentrate and used in the removal of contaminants (PO₄, Turbidity and NO₃) from saline water that has high initial magnesium concentration (artificial brackish and sea water) at pH 11. Solar panels were used to enhance and expedite the precipitation process. PO₄ removal efficiency increased as Recovered Magnesium Salt (RMS) increased, with the highest removal reaching 99.7% at a dose of 200 mg/l (RMS), initial PO₄–P concentration of 20 mg/l, and water salinity of 40,000 mg/l. Removal efficiency of PO₄ increased as the salinity of water increased. However, beyond 10,000 mg/l salinity, the improvement was practically non-existent. Removal efficiency for turbidity and NO₃ also improved as the dose of RMS increased. There was no correlation between TDS concentration and turbidity or NO₃ removal efficiency. Turbidity removal efficiencies reached a value of 90% at a dose of 200 mg/l RMS for initial turbidity value of 50 NTU, and water salinity of 40,000 mg/l. NO₃ removal efficiency ranged from 38.4% to 99.2%. The study also evaluated the effect of anti-scalant use on the removal efficiency of PO4, turbidity, and NO₃ using RMS. Results have shown, using 2 anti-scalants (Phosphonic acid and a proprietary anti-scalant (AS-4100)), that the negative effect disappears after two hours of anti-scalant addition.