Evaluation of the performance of titanium and zirconium salts as coagulants in industrial wastewater treatment: pollutant removal, sludge production, and sludge characteristics

Abstract In this study, titanium tetrachloride (TiCl 4 ), zirconium (ZrCl and oxychloride (ZrOCl 2 ·8H O) were evaluated using jar test experiments as coagulants compared with traditional aluminum sulfate (Al (SO ) 3 ·18H ferric chloride (FeCl for industrial wastewater treatment. The effects of the initial pH 4–10 coagulant doses 10–100 mg/L on chemical oxygen demand (COD) total suspended solids (TSS) removal investigated. performances five also assessed in terms settled sludge volume, volume index (SVI), efficiencies metals, color, phosphorus (TP) under optimum conditions. addition, contents residual produced all tested conditions determined. results showed that maximum efficiency COD (69.33%) was achieved 100 TiCl at 8. TSS (98.32%) 50 Al O both 8 10. SVI generated by lower than other four coagulants. ZrCl , ZrOCl O, FeCl resulted 128.13, 92.39, 72.26, 69.66 mL/g SVI, while 48.84 mL/g. Ti- Zr-based better TP, Zn, Cu Al(SO O. from Ti Zr had a very high TP content. indicated could be used alternatives to