Practical application of ferrate(VI) for water and wastewater treatment: site study’s approach

This paper presents the work aiming to validate the practical feasibility of ferrate(VI) used as an alternative to the existing coagulant (e.g., ferric chloride/sulphate) for both drinking water and domestic sewage treatment via series of pilot plant trials. For drinking water treatment, a ferrate(VI) dose of 0.1¿mg/L can achieve 93% and 97% particle removal (in terms of particle counting) after the filtration for raw water and for the ozonized water, respectively, which is satisfied to the treated water quality requirement for the particles’ removal. Moreover, ferrate(VI) can remove 10% metformin, benzotriazole and acesulfam from raw water but FeCl3 with ozonation can’t. When treating domestic sewage at pilot scale trials, ferrate(VI) demonstrated encouraging performance as well, at a very lower dose range, 0.1–0.2¿mg Fe/L, ferrate(VI) achieved better performance in comparison with high dosed ferric sulphate. This will reduce chemical demand and sludge production and therefore results in a low operating cost and generates substantial cost saving in treating sewage.