[Exploration of newly-formed ferric as the coagulant].

A new coagulant was synthesized by oxidizing Fe(II) with H2O2 instantaneously. Key parameters in the preparation of the coagulant including aging time, acid volume, and n(H2O2 )/n(Fe) were investigated through jar tests. The optimized coagulant was then compared with Fe2 (SO4)3 and PFS (poly-ferric sulphate) in residual turbidity, UV254, Zeta potential to evaluate its coagulation efficiency and infer the reaction mechanism. Aging time has a little effect on coagulation efficiency. The optimized acid concentration was 0.1 mol x L(-1). Coagulation efficiency increased with n(H2O2)/n (Fe). 0.55 is the most economical and efficient molar ratio. The removal efficiency of turbidity of the newly-formed ferric is similar to Fe2 (SO4)3 or PFS. The removal efficiency of UV254 by newly-formed ferric is higher than that by Fe2 (SO4)3 by 20%-44%. The Zeta potential of supernatant after being treated by newly-formed ferric gradually increased to 0 mV with the increasing coagulant dosage, indicating a strong effect of charge neutralization. The newly-formed ferric is a promising new coagulant with an extremely short aging time, a simple synthesis process, a lower cost than Fe2 (SO4)3 or PFS by more than 50%, and a high removal efficiency of UV254 absorbance.