Research Article

Chloride Ion Removal from the Wet Flue Gas Desulfurization and Denitrification Wastewater Using Friedel’s Salt Precipitation Method

Table 2

Results of Cl and SO42− removal.

NumberAverageStandard deviation
123

Average removal efficiencies of Cl (%)85.4987.5686.2686.440.138
Average removal efficiencies of SO42− (%)99.0699.1098.6098.920.278

Two-stage Freund’s salt precipitation method. (1) The first stage mainly removed SO42− (4000 mg/L), the molar ratio of Ca(OH)2 to NaAlO2 to SO42− was constant at 4 : 1 : 1; the solution’s temperature was 25°C, reaction time was 30 min, and the stirring speed was 400 r/min. (2) The second stage mainly removed Cl (2000 mg/L), the molar ratio of Ca(OH)2 to NaAlO2 to Cl was constant at 6 : 3 : 1, respectively, and other operating conditions were the same as the first stage.