Intensified water denitrification by means of a spinning disk reactor and stirred tank in series: Kinetic modelling and computational fluid dynamics. (April 2020)

• Record Type: Journal Article
• Authors: Vilardi, Giorgio; De Caprariis, Benedetta; Stoller, Marco; Di Palma, Luca; Verdone, Nicola
• Is Part Of: Journal of water process engineering. Volume 34(2020)
• Publication Date: 2020-04
• Subjects: Nitrate -- Process intensification -- nZVI -- CFD -- SDR; Water-supply engineering -- Periodicals; Saline water conversion -- Periodicals; Seawater -- Distillation -- Periodicals; Sanitary engineering -- Periodicals; Sewage -- Purification -- Periodicals; 627
• DOI: 10.1016/j.jwpe.2020.101147
• Languages: English
• ISSNs: 2214-7144

Abstract

Graphical abstract: Highlights: nZVI particles have been successfully used to reduce nitrates in water. Coupling SDR and STR allowed to intensify mixing and nitrate reduction. Maximum nitrate removal efficiency of about 90 % in less than 30 min was reached. The CFD model built in Ansys Fluent well interpreted experimental results. Abstract: The aim of this work was to investigate the performances of a spinning disk reactor for the removal of nitrate from aqueous solutions, by using iron nanoparticles as reducing agent. The influence of three operating parameters, i.e. rotational velocity, feed injection point position and recirculation flow-rate was investigated through evaluating the nitrate reduction efficiency and kinetics. Increasing the rotational velocity led to a better nitrate reduction efficiency and faster kinetics. The optimal rotational velocity was 147 rad/s, whereas the optimal feed injection point distance from disk centre and recirculation flow-rate were 3 cm and 250 ml/min, respectively. The data were compared with those reported in literature and obtained by classical batch reactor and clearly demonstrated the better performances obtained by this intensified equipment. Finally, a mass transfer based kinetic model was proposed, and a computational fluid dynamic model was implemented to simulate the fluid dynamics of the rotating liquid film.